register gallery
 

Go Back   Mazdaspeed Forums >
MAZDASPEED SECTION
>
Mazdaspeed 3/6 MZR Gen1 Forums (2006-2009)
> MazdaSpeed 3/6 - Suspension & Brakes

MazdaSpeed 3/6 - Suspension & Brakes Discussion for suspension items like coilovers, springs, sway bars, mounts,chassis bracing and brakes.


Welcome to Mazdaspeed Forums .

You are currently viewing our boards as a guest which gives you limited access to view most discussions and access our other features. By joining our free community you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is fast, simple and absolutely free so please, join our community today!

If you have any problems with the registration process or your account login, please contact contact us.

*When you join MSF as a registered user, there will be No Ads.

*Registered Members get access to the Off Topic Area of the Forum

*Registered Members have an opportunity to upgrade their accounts to VIP, which brings a host of goddies for supporting MSF such as Raffles, Additional Forum Access, More PM Storage, The ability to upload more Images and many other enhancements.

*Registered members also get access to the live chat box!
Like Tree294Likes
Reply
 
Bookmark and Share LinkBack Thread Tools Search this Thread Display Modes
 Old 10-23-2014, 12:48 PM   #161
Eth Fiend
 
phate's Avatar
 
Join Date: May 2010
Location: Auburn Hills, MI
Posts: 6,879   (View Stats)
iTrader: (10)
Rep Power: 11164
phate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the world
Thanks: 14,813
Thanked 21,641 Times in 5,840 Posts
Groans: 7
Groaned at 17 Times in 14 Posts
(Thread Starter)
Not Ranked  0 score     
Default

Originally Posted by KevinK2 View Post
If the competition is on R-Comp tires, I think that gives them an edge on you. I only have experience on the bigger road-race tracks, and they were super sticky ... after a run, I could dig out a chunk of the soft rubber with my thumb nail. Worth several seconds there. You would need ones that don't require lots of heat up.
Ha, yeah, just a small advantage. Compared to a sticky street tire of the same size, they're worth upwards of 2 seconds on a 60 second course with proper alignment. The A6 compound is for autocross in that it heats up very quickly but still works well at moderate temps. It might sound silly, but I want to maximize the car with street tires first. My goal is to run as quickly as they do (hopefully faster), but on street tires that fit without cutting fenders.



Originally Posted by KevinK2 View Post
I do believe you are right about FSB being interchangeable. Racing Beat impies this:

Racingbeat Mazda-6/MS6/Sway-Bars

Wekk before race day, it looks like you could uncouple just one end of the FSB endlink, and tie it off, to check what no FSB is about. You will find a lot of lean, perhaps making the bump-toe change worse.

If you can find a CS 25mm rear bar, and add a "stiff" hole position to it, that would give you a 1mm stiffer bar (~17% stiffer), vs the whiteline. Prothane makes a low profile bushing kit for that size, in case axle boot clearance is an issue.

.
I think I've convinced myself that FSB removal will be a quick and easy test to know where I should be heading. If it picks up grip despite the extra roll/camber loss and potential bump steer issues, then I need either way more rear, or even less front, roll resistance. If it's detrimental, then it gives me bounds on just how much front:rear roll stiffness is required. [Edit: I suppose if it's detrimental, it could just be the camber/toe changes doing it through the increased roll.]

Measuring rear bar stiffness will be a priority winter project. That will allow me to equate front and rear bar changes and give give me an accurate total roll resistance/roll angle.




I asked @Mazdazilla6; if he could grab some pics of the end link orientation with the CS rear bar. It looks like there will be plenty of room to add holes to make the bar stiffer, so it is an option.









I talked to Whiteline and they are not willing to make a thicker rear bar for the MS6. I didn't think they would, but it never hurts to ask, right?
__________________
-06 MS6
-Corn fed 07 MS3 - Sold



www.mazdamotorsports.com <<--Mazda racer support program that is free to join and will save you a ton of money.

Last edited by phate; 10-23-2014 at 01:13 PM.
phate is offline   Reply With Quote
The Following User Says Thank You to phate For This Useful Post:
Funkster777 (10-24-2014)
 Old 10-23-2014, 12:53 PM   #162
 
TiGraySpeed6's Avatar
 
Join Date: Jun 2009
Location: Tally, FL
Posts: 3,981   (View Stats)
iTrader: (1)
Rep Power: 3035
TiGraySpeed6 is the leader of the worldTiGraySpeed6 is the leader of the worldTiGraySpeed6 is the leader of the worldTiGraySpeed6 is the leader of the worldTiGraySpeed6 is the leader of the worldTiGraySpeed6 is the leader of the worldTiGraySpeed6 is the leader of the worldTiGraySpeed6 is the leader of the worldTiGraySpeed6 is the leader of the worldTiGraySpeed6 is the leader of the worldTiGraySpeed6 is the leader of the world
Thanks: 4,683
Thanked 5,748 Times in 2,277 Posts
Groans: 2
Groaned at 3 Times in 3 Posts
Not Ranked  0 score     
Default

Hmmmmm, interesting- looks like that has the same clearance issues as the WL on the stiff setting
__________________
Was a Mazdaspeed6 GT #3476 TiGray slicktop
Now in a BMW 135i - double the turbos, double the fun!
E82.N54 2009 / BSM / A/T / Drop-in / PR CP / Berk Street / MHD / xHP
340hp / 371tq
TiGraySpeed6 is offline   Reply With Quote
The Following User Says Thank You to TiGraySpeed6 For This Useful Post:
phate (10-23-2014)
 Old 10-23-2014, 03:49 PM   #163
 
KevinK2's Avatar
 
Join Date: Nov 2013
Location: Delaware
Posts: 885   (View Stats)
iTrader: (0)
Rep Power: 0
KevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the world
Thanks: 216
Thanked 725 Times in 375 Posts
Groans: 0
Groaned at 79 Times in 52 Posts
Not Ranked  0 score     
Default

Originally Posted by phate View Post
I think I've convinced myself that FSB removal will be a quick and easy test to know where I should be heading. If it picks up grip despite the extra roll/camber loss and potential bump steer issues, then I need either way more rear, or even less front, roll resistance. If it's detrimental, then it gives me bounds on just how much front:rear roll stiffness is required. [Edit: I suppose if it's detrimental, it could just be the camber/toe changes doing it through the increased roll.]

Measuring rear bar stiffness will be a priority winter project. That will allow me to equate front and rear bar changes and give give me an accurate total roll resistance/roll angle.
There are some "free try" compact FEA programs for beams only. With correct dimensions from an existing bar, I could determine the bar's rate.

I talked to Whiteline and they are not willing to make a thicker rear bar for the MS6. I didn't think they would, but it never hurts to ask, right?
Yup. I contacted CorkSport to see if they would make a batch of bars. They said they tossed 2-3 bad bars for every good one they made. I wonder if they would turn over their bending program to another supplier?

It seams you could go with stiffer springs, if you modified the rear end like CanyonRider did with his M6, allowing a variety of standard 2-1/2" Race Springs:

CanyonRider Modified Rear Suspension

.
__________________
From Delaware
Current Fleet: 04 Mazda6, 93 Rx7 TT, 76 Triumph 750 Trident

Tracked Cars: 68 Triumph GT6 (~full race prep'd), 81 Porsche 924 Turbo, 93 Rx7 twin turbo
KevinK2 is offline   Reply With Quote
 Old 10-23-2014, 08:12 PM   #164
Eth Fiend
 
phate's Avatar
 
Join Date: May 2010
Location: Auburn Hills, MI
Posts: 6,879   (View Stats)
iTrader: (10)
Rep Power: 11164
phate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the world
Thanks: 14,813
Thanked 21,641 Times in 5,840 Posts
Groans: 7
Groaned at 17 Times in 14 Posts
(Thread Starter)
Not Ranked  0 score     
Default

No cutting like that is allowed, unfortunately. I originally wanted to run a 2.5" ID spring in the rear, but scrapped that idea because it would require removal of the bump stop cup in the subframe.

I'll see what I can do about the bar's dimensions.
__________________
-06 MS6
-Corn fed 07 MS3 - Sold



www.mazdamotorsports.com <<--Mazda racer support program that is free to join and will save you a ton of money.
phate is offline   Reply With Quote
 Old 10-24-2014, 06:19 PM   #165
 
KevinK2's Avatar
 
Join Date: Nov 2013
Location: Delaware
Posts: 885   (View Stats)
iTrader: (0)
Rep Power: 0
KevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the world
Thanks: 216
Thanked 725 Times in 375 Posts
Groans: 0
Groaned at 79 Times in 52 Posts
Not Ranked  0 score     
Default

Originally Posted by phate View Post
No cutting like that is allowed, unfortunately. I originally wanted to run a 2.5" ID spring in the rear, but scrapped that idea because it would require removal of the bump stop cup in the subframe.

I'll see what I can do about the bar's dimensions.
Considering the dual-use concept, and knowing Porsche uses linear springs with very active bump-cushions(springs) on their great handling new cars, a custom bump cushion may allow higher effective rear spring rates.

http://fatcatmotorsports.com/igaller...SpringRate.GIF

.
__________________
From Delaware
Current Fleet: 04 Mazda6, 93 Rx7 TT, 76 Triumph 750 Trident

Tracked Cars: 68 Triumph GT6 (~full race prep'd), 81 Porsche 924 Turbo, 93 Rx7 twin turbo
KevinK2 is offline   Reply With Quote
The Following User Says Thank You to KevinK2 For This Useful Post:
phate (10-28-2014)
 Old 10-25-2014, 07:52 AM   #166
Eth Fiend
 
phate's Avatar
 
Join Date: May 2010
Location: Auburn Hills, MI
Posts: 6,879   (View Stats)
iTrader: (10)
Rep Power: 11164
phate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the world
Thanks: 14,813
Thanked 21,641 Times in 5,840 Posts
Groans: 7
Groaned at 17 Times in 14 Posts
(Thread Starter)
Not Ranked  0 score     
Default

I'm still thinking I need to tweak the balance with bars and springs as much as I can, first. I mentioned in post 115 that I wasn't too keen on the idea of waiting for bump cushion engagement after turn in. I picked up quite a bit of turn in grip and overall front grip shifting bias to the rear with the stiffer springs/bars. That's my main reasoning for wanting to tweak with bars and springs before bump cushions. It seems to me the shift in immediate load transfer was helpful, and I should continue down that path.
__________________
-06 MS6
-Corn fed 07 MS3 - Sold



www.mazdamotorsports.com <<--Mazda racer support program that is free to join and will save you a ton of money.
phate is offline   Reply With Quote
 Old 10-25-2014, 08:33 AM   #167
 
KevinK2's Avatar
 
Join Date: Nov 2013
Location: Delaware
Posts: 885   (View Stats)
iTrader: (0)
Rep Power: 0
KevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the world
Thanks: 216
Thanked 725 Times in 375 Posts
Groans: 0
Groaned at 79 Times in 52 Posts
Not Ranked  0 score     
Default

Originally Posted by phate View Post
I'm still thinking I need to tweak the balance with bars and springs as much as I can, first. I mentioned in post 115 that I wasn't too keen on the idea of waiting for bump cushion engagement after turn in. I picked up quite a bit of turn in grip and overall front grip shifting bias to the rear with the stiffer springs/bars. That's my main reasoning for wanting to tweak with bars and springs before bump cushions. It seems to me the shift in immediate load transfer was helpful, and I should continue down that path.
I agree completely, assuming conventional use of bump cushions. But I was thinking out of the box, suggesting that you would already be loading custom, long bump cushions with the car parked, and before turn-in. Effectively stiffening these limiting rear springs to allow stiffer race springs up front. These bump cushions, in theory, would be designed for most of the shock travel, with minimal entry into the very stiff condition. They would likely unload at full droop.

I suggested this since you are limited in sway bars, by the rear bar, to just a few mm's more than stock, and currently the oem up front. You also seem to be limited in spring rate based on the oem shaped rear race spring used. You are planning to go from the current 600# springs to the 700# max available spring. If you still need stiffer rear springs, for balance or less body roll, the special rear bump cushions would get above 700 lb/in.

This comment is just exploring a concept, hopefully within the rules, to get to much stiffer "rear" springs. BUT, I hope the 700 lb rear springs do it for you.

.
__________________
From Delaware
Current Fleet: 04 Mazda6, 93 Rx7 TT, 76 Triumph 750 Trident

Tracked Cars: 68 Triumph GT6 (~full race prep'd), 81 Porsche 924 Turbo, 93 Rx7 twin turbo

Last edited by KevinK2; 10-26-2014 at 09:35 AM. Reason: editing
KevinK2 is offline   Reply With Quote
The Following 2 Users Say Thank You to KevinK2 For This Useful Post:
Nliiitend1 (10-25-2014), phate (10-28-2014)
 Old 10-26-2014, 02:14 PM   #168
 
KevinK2's Avatar
 
Join Date: Nov 2013
Location: Delaware
Posts: 885   (View Stats)
iTrader: (0)
Rep Power: 0
KevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the world
Thanks: 216
Thanked 725 Times in 375 Posts
Groans: 0
Groaned at 79 Times in 52 Posts
Not Ranked  0 score     
Default Springs & Bars Suspension Balance Test

I've used this simple method to determine whether the suspension has front or rear bias, or close to neutral.

On a flat concrete floor, shimmed if needed, park the car. Then place 12" by 3/4" thk squares of wood in front of two, diagonally located tires. Open trunk, & find a place along the bottom of the opening to put a level, and shim it to get bubble on the middle. Drive the car onto the wood squares, park, and check the level.

Based on the new level reading, you can tell which end of the car has more roll stiffness, or if it is the same F & R.

notes:

-> helps to inflate tires to the max.
-> for very stiff suspensions, my need to use 1/2" thk wood or less.
-> assumes high chassis stiffness ( not for convertibles )

.
__________________
From Delaware
Current Fleet: 04 Mazda6, 93 Rx7 TT, 76 Triumph 750 Trident

Tracked Cars: 68 Triumph GT6 (~full race prep'd), 81 Porsche 924 Turbo, 93 Rx7 twin turbo
KevinK2 is offline   Reply With Quote
The Following User Says Thank You to KevinK2 For This Useful Post:
phate (10-28-2014)
 Old 10-26-2014, 08:48 PM   #169
 
zenit's Avatar
 
Join Date: Apr 2013
Location: Evanston, IL
Posts: 1,354   (View Stats)
iTrader: (1)
Rep Power: 1307
zenit is the leader of the worldzenit is the leader of the worldzenit is the leader of the worldzenit is the leader of the worldzenit is the leader of the worldzenit is the leader of the worldzenit is the leader of the worldzenit is the leader of the worldzenit is the leader of the worldzenit is the leader of the worldzenit is the leader of the world
Thanks: 938
Thanked 2,083 Times in 729 Posts
Groans: 56
Groaned at 7 Times in 6 Posts
Not Ranked  0 score     
Default



Raw Data

Alright, some Nator IL folks loaned me a garage to measure the rear toe here. Thanks @xfeejayx @WetzMS3!

In short, toe goes in as wheel goes up (in bump). At the furthest of the furthest droop ~4-5 inches measured from fender to tire tread indicator (that little triangle). The smallest ride height measured was when the indicator triangle was 2/32nds from the fender, so pretty well tucked and probably never gets to this level in an autox/track context. This also means toe goes OUT as wheel goes down. Toe was measured as difference between the front of rim and rear of rim to vehicle center line, basic string alignment, so the extension/retraction of the wheel is controlled for. Regardless, I collected that data and I can control for it, if necessary.

In general, delta toe for 1/2" in bump is ~0.05 degrees in. This is for one wheel!

Eyeballing your chart @phate, it looks like the mid range of chart is roughly the same slope. Overall though, it looks like MS3 has a much more linear toe slope.

zenit is offline   Reply With Quote
The Following 9 Users Say Thank You to zenit For This Useful Post:
Code Monkey (10-27-2014), Crarrs (10-28-2014), Micha (11-01-2014), Nliiitend1 (10-28-2014), phate (10-26-2014), Tomas (10-28-2014), WetzMS3 (10-27-2014), wolly6973 (10-27-2014), xfeejayx (10-27-2014)
 Old 10-26-2014, 09:09 PM   #170
Eth Fiend
 
phate's Avatar
 
Join Date: May 2010
Location: Auburn Hills, MI
Posts: 6,879   (View Stats)
iTrader: (10)
Rep Power: 11164
phate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the world
Thanks: 14,813
Thanked 21,641 Times in 5,840 Posts
Groans: 7
Groaned at 17 Times in 14 Posts
(Thread Starter)
Not Ranked  0 score     
Default

Originally Posted by zenit View Post
http://i1318.photobucket.com/albums/t646/zenit125/MS3RearToe_zps67d7fb76.png

Raw Data

Alright, some Nator IL folks loaned me a garage to measure the rear toe here. Thanks xfeejayx WetzMS3

In short, toe goes in as wheel goes up (in bump). At the furthest of the furthest droop ~4-5 inches measured from fender to tire tread indicator (that little triangle). The smallest ride height measured was when the indicator triangle was 2/32nds from the fender, so pretty well tucked and probably never gets to this level in an autox/track context. This also means toe goes OUT as wheel goes down. Toe was measured as difference between the front of rim and rear of rim to vehicle center line, basic string alignment, so the extension/retraction of the wheel is controlled for. Regardless, I collected that data and I can control for it, if necessary.

In general, delta toe for 1/2" in bump is ~0.05 degrees in. This is for one wheel!

Eyeballing your chart phate, it looks like the mid range of chart is roughly the same slope. Overall though, it looks like MS3 has a much more linear toe slope.
Very cool. I'll have to look at it more tomorrow and plot them and the rate of change next to each other tomorrow. The 3 has a LOT of bump steer back there! Looks to be over twice as much per 1" wheel travel in the used/usable range.
__________________
-06 MS6
-Corn fed 07 MS3 - Sold



www.mazdamotorsports.com <<--Mazda racer support program that is free to join and will save you a ton of money.
phate is offline   Reply With Quote
 Old 10-27-2014, 11:38 AM   #171
Eth Fiend
 
phate's Avatar
 
Join Date: May 2010
Location: Auburn Hills, MI
Posts: 6,879   (View Stats)
iTrader: (10)
Rep Power: 11164
phate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the world
Thanks: 14,813
Thanked 21,641 Times in 5,840 Posts
Groans: 7
Groaned at 17 Times in 14 Posts
(Thread Starter)
Not Ranked  0 score     
Default

@zenit;, did you pull the shock for these measurements? Just wondering where your full bump measure actually is (bump stop/frame stop or not). I think the tread indicator 2/32" below fender is a realistic roll angle for an MS3 on sticky tires with stock suspension.
__________________
-06 MS6
-Corn fed 07 MS3 - Sold



www.mazdamotorsports.com <<--Mazda racer support program that is free to join and will save you a ton of money.
phate is offline   Reply With Quote
 Old 10-27-2014, 03:55 PM   #172
 
zenit's Avatar
 
Join Date: Apr 2013
Location: Evanston, IL
Posts: 1,354   (View Stats)
iTrader: (1)
Rep Power: 1307
zenit is the leader of the worldzenit is the leader of the worldzenit is the leader of the worldzenit is the leader of the worldzenit is the leader of the worldzenit is the leader of the worldzenit is the leader of the worldzenit is the leader of the worldzenit is the leader of the worldzenit is the leader of the worldzenit is the leader of the world
Thanks: 938
Thanked 2,083 Times in 729 Posts
Groans: 56
Groaned at 7 Times in 6 Posts
Not Ranked  0 score     
Default

Originally Posted by phate View Post
@zenit;, did you pull the shock for these measurements? Just wondering where your full bump measure actually is (bump stop/frame stop or not). I think the tread indicator 2/32" below fender is a realistic roll angle for an MS3 on sticky tires with stock suspension.
Nope, I left the shock on. Mostly I stopped at that angle because I could tell that the measurements were very linear just from writing them down, and jacking the control arm up further got to be kind of sketchy.

Let me borrow a garage, some butcher paper and some fancy FSAE software and I'll get you a full model with my little height gauge and laser.
zenit is offline   Reply With Quote
The Following 2 Users Say Thank You to zenit For This Useful Post:
phate (10-28-2014), WetzMS3 (10-29-2014)
 Old 10-28-2014, 06:47 AM   #173
Bob Ross Fanclub
 
Tomas's Avatar
 
Join Date: Jan 2009
Location: SEFL
Posts: 3,732   (View Stats)
iTrader: (8)
Rep Power: 4251
Tomas is the leader of the worldTomas is the leader of the worldTomas is the leader of the worldTomas is the leader of the worldTomas is the leader of the worldTomas is the leader of the worldTomas is the leader of the worldTomas is the leader of the worldTomas is the leader of the worldTomas is the leader of the worldTomas is the leader of the world
Thanks: 4,486
Thanked 8,100 Times in 2,308 Posts
Groans: 0
Groaned at 33 Times in 19 Posts
Not Ranked  0 score     
Default

If you used a string up to measure toe then the results are definitely accurate.
I suppose may be some of the old logic regarding rear toe to bump/droop action can be, or has been discredited now a days.
Or may be the changes are so minute that when you have static toe in of -1mm in the rear as OEM specs call for, once toe starts going out when the rear lifts it just never gets to the point where it creates a dangerous snap oversteer situation.
__________________

MAKE LOVE TO THE CANVAS
Tomas is offline   Reply With Quote
The Following User Says Thank You to Tomas For This Useful Post:
phate (10-28-2014)
 Old 10-28-2014, 06:42 PM   #174
 
zenit's Avatar
 
Join Date: Apr 2013
Location: Evanston, IL
Posts: 1,354   (View Stats)
iTrader: (1)
Rep Power: 1307
zenit is the leader of the worldzenit is the leader of the worldzenit is the leader of the worldzenit is the leader of the worldzenit is the leader of the worldzenit is the leader of the worldzenit is the leader of the worldzenit is the leader of the worldzenit is the leader of the worldzenit is the leader of the worldzenit is the leader of the world
Thanks: 938
Thanked 2,083 Times in 729 Posts
Groans: 56
Groaned at 7 Times in 6 Posts
Not Ranked  0 score     
Default

Originally Posted by Tomas View Post
...once toe starts going out when the rear lifts it just never gets to the point where it creates a dangerous snap oversteer situation.
I think this is it. At the time I measured my ride height at 3.5", so at full lift @ 5"- Dukes of Hazard style, <0.1 degrees toes out. For reference, I've run 1/16th of rear toe OUT on the street (with good tires!) with no worrisome rotation issues.

With my old RE11's at the end of their life (rock hard and slippery), 1/16th would easily rotate the car @ AutoX. Never ran those tires with toe out on the street.
zenit is offline   Reply With Quote
The Following User Says Thank You to zenit For This Useful Post:
phate (10-28-2014)
 Old 10-28-2014, 07:22 PM   #175
Eth Fiend
 
phate's Avatar
 
Join Date: May 2010
Location: Auburn Hills, MI
Posts: 6,879   (View Stats)
iTrader: (10)
Rep Power: 11164
phate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the world
Thanks: 14,813
Thanked 21,641 Times in 5,840 Posts
Groans: 7
Groaned at 17 Times in 14 Posts
(Thread Starter)
Not Ranked  0 score     
Default

Yeah, I agree. A tenth or two change of slip angle isn't going to be a drastic change, even on a very peaky race tire. In the situation you're describing, the rear of the car is getting unloaded anyway, reducing grip back there. It just adds to that effect if toe is moving out at the same time.

I still autocross MS3's every once in a while [and remember I owned an MS3 for 3 years and autocrossed it near as much as I do my MS6, now], and the lift off over steer is MUCH easier to effect compared to trying to get the MS6 to rotate by lifting. This might be part of the reason.
__________________
-06 MS6
-Corn fed 07 MS3 - Sold



www.mazdamotorsports.com <<--Mazda racer support program that is free to join and will save you a ton of money.
phate is offline   Reply With Quote
The Following User Says Thank You to phate For This Useful Post:
zenit (10-31-2014)
 Old 10-28-2014, 08:21 PM   #176
Eth Fiend
 
phate's Avatar
 
Join Date: May 2010
Location: Auburn Hills, MI
Posts: 6,879   (View Stats)
iTrader: (10)
Rep Power: 11164
phate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the world
Thanks: 14,813
Thanked 21,641 Times in 5,840 Posts
Groans: 7
Groaned at 17 Times in 14 Posts
(Thread Starter)
Not Ranked  0 score     
Default

Originally Posted by KevinK2 View Post
I agree completely, assuming conventional use of bump cushions. But I was thinking out of the box, suggesting that you would already be loading custom, long bump cushions with the car parked, and before turn-in. Effectively stiffening these limiting rear springs to allow stiffer race springs up front. These bump cushions, in theory, would be designed for most of the shock travel, with minimal entry into the very stiff condition. They would likely unload at full droop.

I suggested this since you are limited in sway bars, by the rear bar, to just a few mm's more than stock, and currently the oem up front. You also seem to be limited in spring rate based on the oem shaped rear race spring used. You are planning to go from the current 600# springs to the 700# max available spring. If you still need stiffer rear springs, for balance or less body roll, the special rear bump cushions would get above 700 lb/in.

This comment is just exploring a concept, hopefully within the rules, to get to much stiffer "rear" springs. BUT, I hope the 700 lb rear springs do it for you.

.
I've already moved to the 700# springs in the rear and have autocrossed 2 days with them. Notes are in post 147. In short, I'm happy with where things are headed and I want to continue shifting bias rearward to see where things end up. The car seems to have picked up front grip with each increase in rear bias



I had considered this idea with bumpstops, but discarded it because I thought they would wear out very quickly being used nearly all the time. I've also considered that I might be worrying about that for no good reason. But, thinking about it again, I might have an idea of how to implement this with a height adjustable engagement plate. I have definitely thrown out the idea of cutting the LCA's spring seat out, which leaves me with using some sort of "bolt on" device.

If I use a ~2.5" adjustable height spring pedestal in the lower control arm (similar to the 3.5" adjusters I have up top), discarded the spring seat collars and used a closed end, threaded (on the ID) cylinder inside of the spring, I could adjust the engagement point to wherever I needed. I'm not set on this option, but it's the best I've come up with so far. I'll double check the LCA spring seat measurements (it has that big cylinder-ish pedestal in the middle) and start calling around about these.

Fat Cat has a number of bump stop options with varying lengths and rates:

46/54mm

58mm

76mm


@Code Monkey; are you using FCM bump stops in the rear?
__________________
-06 MS6
-Corn fed 07 MS3 - Sold



www.mazdamotorsports.com <<--Mazda racer support program that is free to join and will save you a ton of money.
phate is offline   Reply With Quote
 Old 10-28-2014, 08:37 PM   #177
 
Code Monkey's Avatar
 
Join Date: Feb 2012
Location: Bryan, TX
Posts: 7,644   (View Stats)
iTrader: (28)
Rep Power: 5034
Code Monkey is the leader of the worldCode Monkey is the leader of the worldCode Monkey is the leader of the worldCode Monkey is the leader of the worldCode Monkey is the leader of the worldCode Monkey is the leader of the worldCode Monkey is the leader of the worldCode Monkey is the leader of the worldCode Monkey is the leader of the worldCode Monkey is the leader of the worldCode Monkey is the leader of the world
Thanks: 11,642
Thanked 9,765 Times in 3,844 Posts
Groans: 17
Groaned at 32 Times in 22 Posts
Not Ranked  0 score     
Default

Originally Posted by phate View Post
are you using FCM bump stops in the rear?
Stock, but they look like someone cut off a piece.
Attached Images
File Type: jpg SAM_5393.JPG (433.6 KB, 10 views)
__________________
2006 Mazdaspeed6
EFR 7163|FMIC|South Bend|FCM coilovers|Powerbrake BBK|RPF1 18x10.5|Nitto NT01
stripped|caged|freektuned

2017 Subaru BRZ
MCS TT1 coilovers|Brembo BBK|6UL 17x9|Trofeo R|ACE 350|flex fuel|Delicious tuned
Code Monkey is offline   Reply With Quote
The Following User Says Thank You to Code Monkey For This Useful Post:
phate (10-28-2014)
 Old 10-28-2014, 08:40 PM   #178
Eth Fiend
 
phate's Avatar
 
Join Date: May 2010
Location: Auburn Hills, MI
Posts: 6,879   (View Stats)
iTrader: (10)
Rep Power: 11164
phate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the world
Thanks: 14,813
Thanked 21,641 Times in 5,840 Posts
Groans: 7
Groaned at 17 Times in 14 Posts
(Thread Starter)
Not Ranked  0 score     
Default

Originally Posted by Code Monkey View Post
Stock, but they look like someone cut off a piece.
Gotcha. I need to measure the ID of the bump stop cup. Might have to make some sort of adapter.
__________________
-06 MS6
-Corn fed 07 MS3 - Sold



www.mazdamotorsports.com <<--Mazda racer support program that is free to join and will save you a ton of money.
phate is offline   Reply With Quote
 Old 10-29-2014, 07:21 AM   #179
Eth Fiend
 
phate's Avatar
 
Join Date: May 2010
Location: Auburn Hills, MI
Posts: 6,879   (View Stats)
iTrader: (10)
Rep Power: 11164
phate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the world
Thanks: 14,813
Thanked 21,641 Times in 5,840 Posts
Groans: 7
Groaned at 17 Times in 14 Posts
(Thread Starter)
Not Ranked  0 score     
Default

I was going through some pictures this morning trying to see if this was a realistic option, or not. This picture is a little blurry, but I think it shows there could be enough room to do what I'm talking about. One issue might be the little tab that prevents the spring from rotating:



It looks like the OD of that center cylinder is right at 2":



So I might have to slot the perch base for that tab. I'll draw one up in Solid Works to see if that will present any strength issues.
__________________
-06 MS6
-Corn fed 07 MS3 - Sold



www.mazdamotorsports.com <<--Mazda racer support program that is free to join and will save you a ton of money.
phate is offline   Reply With Quote
 Old 10-29-2014, 08:29 AM   #180
 
WetzMS3's Avatar
 
Join Date: Jul 2013
Location: Westchester, IL
Posts: 5,772   (View Stats)
iTrader: (0)
Rep Power: 4904
WetzMS3 is the leader of the worldWetzMS3 is the leader of the worldWetzMS3 is the leader of the worldWetzMS3 is the leader of the worldWetzMS3 is the leader of the worldWetzMS3 is the leader of the worldWetzMS3 is the leader of the worldWetzMS3 is the leader of the worldWetzMS3 is the leader of the worldWetzMS3 is the leader of the worldWetzMS3 is the leader of the world
Thanks: 14,635
Thanked 9,203 Times in 3,608 Posts
Groans: 430
Groaned at 247 Times in 83 Posts
Not Ranked  0 score     
Default

Originally Posted by zenit View Post
Nope, I left the shock on. Mostly I stopped at that angle because I could tell that the measurements were very linear just from writing them down, and jacking the control arm up further got to be kind of sketchy.

Let me borrow a garage, some butcher paper and some fancy FSAE software and I'll get you a full model with my little height gauge and laser.
Grab some butcher paper and come on by when you want to get this fancy measuring done.
__________________
2013 MS3 Black Mica
SLUGGISH RUGGISH BONE

SLUNTWORKS SPEEDSHOP
WetzMS3 is offline   Reply With Quote
The Following User Says Thank You to WetzMS3 For This Useful Post:
zenit (10-31-2014)
 Old 10-29-2014, 11:57 AM   #181
 
KevinK2's Avatar
 
Join Date: Nov 2013
Location: Delaware
Posts: 885   (View Stats)
iTrader: (0)
Rep Power: 0
KevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the world
Thanks: 216
Thanked 725 Times in 375 Posts
Groans: 0
Groaned at 79 Times in 52 Posts
Not Ranked  0 score     
Default

Originally Posted by phate View Post
.... In short, I'm happy with where things are headed and I want to continue shifting bias rearward to see where things end up. The car seems to have picked up front grip with each increase in rear bias

I had considered this idea with bumpstops, but discarded it because I thought they would wear out very quickly being used nearly all the time. I've also considered that I might be worrying about that for no good reason. But, thinking about it again, I might have an idea of how to implement this with a height adjustable engagement plate. I have definitely thrown out the idea of cutting the LCA's spring seat out, which leaves me with using some sort of "bolt on" device......
Unlike the FCM bump stops linked, I had in mind what may "look" like 2 in series, preloaded at a low rate, and not getting into a super stiff zone until near full stroke. Easier said than done. Good idea on the adjustable seat, as it relies more on the typical type bump stop/cushion.

In older cars, there were no "bump cushions", but with more compact suspensions, you see them take an active part in helping the spring. In my M6, parked, there is only ~ 1-1/4 gap before the cushion makes contact in compression.

Another way to stiffen the rear spring is hard rubber inserts, Nascar style. They reduce the # active coils, and rate increase as active coils are removed. Not sure what class you run, but for ST:

"Coil springs may incorporate spring rubbers. Suspension bump
stops may be altered or removed"

EDTI: I found this link about spring inserts from a familiar source:
FCM on Spring Rubbers

These are quite soft. Others are stiff and designed to eliminate the gap change between a pait of coils.




Note: It seems like most call the multi lobed urethane inserts, like the oem ones in the rear, "Bump Stops". But by dropping the Cushion term, one misses their non-linear spring action that most always works actively with oem springs. On the M6 rear, true bump stops are hard rubber pieces attached to the frame, where the a-arm would hit if all else failed and/or was overloaded.

.
__________________
From Delaware
Current Fleet: 04 Mazda6, 93 Rx7 TT, 76 Triumph 750 Trident

Tracked Cars: 68 Triumph GT6 (~full race prep'd), 81 Porsche 924 Turbo, 93 Rx7 twin turbo

Last edited by KevinK2; 10-29-2014 at 01:42 PM.
KevinK2 is offline   Reply With Quote
The Following User Says Thank You to KevinK2 For This Useful Post:
phate (10-29-2014)
 Old 10-31-2014, 10:21 AM   #182
 
KevinK2's Avatar
 
Join Date: Nov 2013
Location: Delaware
Posts: 885   (View Stats)
iTrader: (0)
Rep Power: 0
KevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the world
Thanks: 216
Thanked 725 Times in 375 Posts
Groans: 0
Groaned at 79 Times in 52 Posts
Not Ranked  0 score     
Default

Does anyone know what formula FCM uses in their spread sheet to calculate sway bar stiffness?

If it is based on Puhn's equation (variables a,b,c), the roll stiffness is underestimated without the correction factor of 2 for cornering. This is very frequently overlooked.

.
__________________
From Delaware
Current Fleet: 04 Mazda6, 93 Rx7 TT, 76 Triumph 750 Trident

Tracked Cars: 68 Triumph GT6 (~full race prep'd), 81 Porsche 924 Turbo, 93 Rx7 twin turbo
KevinK2 is offline   Reply With Quote
 Old 10-31-2014, 10:43 AM   #183
Eth Fiend
 
phate's Avatar
 
Join Date: May 2010
Location: Auburn Hills, MI
Posts: 6,879   (View Stats)
iTrader: (10)
Rep Power: 11164
phate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the world
Thanks: 14,813
Thanked 21,641 Times in 5,840 Posts
Groans: 7
Groaned at 17 Times in 14 Posts
(Thread Starter)
Not Ranked  0 score     
Default

Call him up. Seems like you have a lot to tell him about suspension design.
__________________
-06 MS6
-Corn fed 07 MS3 - Sold



www.mazdamotorsports.com <<--Mazda racer support program that is free to join and will save you a ton of money.
phate is offline   Reply With Quote
The Following 2 Users Say Thank You to phate For This Useful Post:
Deldran (10-31-2014), wolly6973 (10-31-2014)
 Old 10-31-2014, 11:24 AM   #184
 
KevinK2's Avatar
 
Join Date: Nov 2013
Location: Delaware
Posts: 885   (View Stats)
iTrader: (0)
Rep Power: 0
KevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the world
Thanks: 216
Thanked 725 Times in 375 Posts
Groans: 0
Groaned at 79 Times in 52 Posts
Not Ranked  0 score     
Default

No I don't, just a potential typo that makes a big difference. About 1/2 of the articles/calculators I checked had it wrong, treating sway bars like springs to get the wheel rate. He is one sharp guy on tuning shocks, and he uses spring inserts, like I had suggested here.

.
__________________
From Delaware
Current Fleet: 04 Mazda6, 93 Rx7 TT, 76 Triumph 750 Trident

Tracked Cars: 68 Triumph GT6 (~full race prep'd), 81 Porsche 924 Turbo, 93 Rx7 twin turbo
KevinK2 is offline   Reply With Quote
 Old 10-31-2014, 11:32 AM   #185
Eth Fiend
 
phate's Avatar
 
Join Date: May 2010
Location: Auburn Hills, MI
Posts: 6,879   (View Stats)
iTrader: (10)
Rep Power: 11164
phate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the world
Thanks: 14,813
Thanked 21,641 Times in 5,840 Posts
Groans: 7
Groaned at 17 Times in 14 Posts
(Thread Starter)
Not Ranked  0 score     
Default

Gotcha. I don't know, never asked him.

I did add the rear bar motion ratio to the op this morning. .33 mr from the control arm measurements (if the end links are perpendicular to the control arm).
__________________
-06 MS6
-Corn fed 07 MS3 - Sold



www.mazdamotorsports.com <<--Mazda racer support program that is free to join and will save you a ton of money.
phate is offline   Reply With Quote
The Following User Says Thank You to phate For This Useful Post:
KevinK2 (10-31-2014)
 Old 10-31-2014, 05:19 PM   #186
Eth Fiend
 
phate's Avatar
 
Join Date: May 2010
Location: Auburn Hills, MI
Posts: 6,879   (View Stats)
iTrader: (10)
Rep Power: 11164
phate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the world
Thanks: 14,813
Thanked 21,641 Times in 5,840 Posts
Groans: 7
Groaned at 17 Times in 14 Posts
(Thread Starter)
Not Ranked  0 score     
Default

Had a few minutes tonight to press the other arms' bushings out. I'll measure them next week and start calling around for replacements. That trailing arm bushing is FLIMSY!!









I have the LCA bushings pressed out already, too, but don't have pics of it. It looks about the same as the others, though. Hopefully there are some good and inexpensive options!
__________________
-06 MS6
-Corn fed 07 MS3 - Sold



www.mazdamotorsports.com <<--Mazda racer support program that is free to join and will save you a ton of money.
phate is offline   Reply With Quote
The Following 4 Users Say Thank You to phate For This Useful Post:
Code Monkey (10-31-2014), Funkster777 (11-02-2014), jbbuie (10-31-2014), wolly6973 (10-31-2014)
 Old 11-01-2014, 08:39 AM   #187
Eth Fiend
 
phate's Avatar
 
Join Date: May 2010
Location: Auburn Hills, MI
Posts: 6,879   (View Stats)
iTrader: (10)
Rep Power: 11164
phate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the world
Thanks: 14,813
Thanked 21,641 Times in 5,840 Posts
Groans: 7
Groaned at 17 Times in 14 Posts
(Thread Starter)
Not Ranked  0 score     
Default

I thought I had posted this here, but I guess not. This pic shows how much bind is built into the rear suspension bushings. I know some of the 3/MS3/Focus bushings are solid poly and supposedly work fine, but I've seen others that have space on two sides to allow deflection in that plane.



Prothane, PowerFlex, and Whiteline all offer rear suspension bushings for the 3's and Focus', so they'll be my first stops. I know HardRace makes some different bushings for the 6, but they're fairly expensive and some folks seem to think they're too stiff.
__________________
-06 MS6
-Corn fed 07 MS3 - Sold



www.mazdamotorsports.com <<--Mazda racer support program that is free to join and will save you a ton of money.
phate is offline   Reply With Quote
The Following 5 Users Say Thank You to phate For This Useful Post:
Code Monkey (11-01-2014), Funkster777 (11-02-2014), Nliiitend1 (11-01-2014), TiGraySpeed6 (11-01-2014), WetzMS3 (11-07-2014)
 Old 11-01-2014, 08:59 AM   #188
 
zenit's Avatar
 
Join Date: Apr 2013
Location: Evanston, IL
Posts: 1,354   (View Stats)
iTrader: (1)
Rep Power: 1307
zenit is the leader of the worldzenit is the leader of the worldzenit is the leader of the worldzenit is the leader of the worldzenit is the leader of the worldzenit is the leader of the worldzenit is the leader of the worldzenit is the leader of the worldzenit is the leader of the worldzenit is the leader of the worldzenit is the leader of the world
Thanks: 938
Thanked 2,083 Times in 729 Posts
Groans: 56
Groaned at 7 Times in 6 Posts
Not Ranked  0 score     
Default

Spherical bro!

There are ton of horror stories and success stories about poly, and unfortunately they didn't work for me.

I'm curious to see what you mean by the space for deflection.
zenit is offline   Reply With Quote
The Following 2 Users Say Thank You to zenit For This Useful Post:
Nliiitend1 (11-01-2014), phate (11-01-2014)
 Old 11-01-2014, 09:11 AM   #189
 
Deldran's Avatar
 
Join Date: Jan 2012
Location: Central IL
Posts: 3,138   (View Stats)
iTrader: (2)
Rep Power: 0
Deldran is the leader of the worldDeldran is the leader of the worldDeldran is the leader of the worldDeldran is the leader of the worldDeldran is the leader of the worldDeldran is the leader of the worldDeldran is the leader of the worldDeldran is the leader of the worldDeldran is the leader of the worldDeldran is the leader of the worldDeldran is the leader of the world
Thanks: 19,219
Thanked 3,292 Times in 1,322 Posts
Groans: 118
Groaned at 44 Times in 34 Posts
Not Ranked  0 score     
Default

Originally Posted by zenit View Post
Spherical bro!

There are ton of horror stories and success stories about poly, and unfortunately they didn't work for me.

I'm curious to see what you mean by the space for deflection.
If I remember correctly I don't believe spherical is legal in SP classes

Sent from my gs5
__________________
Damond Built Speed 6

Deldran is offline   Reply With Quote
The Following User Says Thank You to Deldran For This Useful Post:
phate (11-01-2014)
 Old 11-01-2014, 01:09 PM   #190
 
KevinK2's Avatar
 
Join Date: Nov 2013
Location: Delaware
Posts: 885   (View Stats)
iTrader: (0)
Rep Power: 0
KevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the world
Thanks: 216
Thanked 725 Times in 375 Posts
Groans: 0
Groaned at 79 Times in 52 Posts
Not Ranked  0 score     
Default

That's a lot of twisting, was the oem all elastomer? If there is no standard part, you could have a stiff bush made from this common industrial bushing Nylatron/Moly material:
Nylatron Properties

Rather than full width contact, you could have about a 3/8" wide mid section of close clearance to the clamped collar.

.
__________________
From Delaware
Current Fleet: 04 Mazda6, 93 Rx7 TT, 76 Triumph 750 Trident

Tracked Cars: 68 Triumph GT6 (~full race prep'd), 81 Porsche 924 Turbo, 93 Rx7 twin turbo
KevinK2 is offline   Reply With Quote
The Following User Says Thank You to KevinK2 For This Useful Post:
phate (11-01-2014)
 Old 11-01-2014, 01:16 PM   #191
 
KevinK2's Avatar
 
Join Date: Nov 2013
Location: Delaware
Posts: 885   (View Stats)
iTrader: (0)
Rep Power: 0
KevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the world
Thanks: 216
Thanked 725 Times in 375 Posts
Groans: 0
Groaned at 79 Times in 52 Posts
Not Ranked  0 score     
Default

Originally Posted by KevinK2 View Post
Does anyone know what formula FCM uses in their spread sheet to calculate sway bar stiffness? ....
I checked it based on examples from the Rx8 spreadsheet, and my spreadsheet, and looks like he CORRECTLY used twice the Puhn rate as his "raw rate" at the bar ends.

.
__________________
From Delaware
Current Fleet: 04 Mazda6, 93 Rx7 TT, 76 Triumph 750 Trident

Tracked Cars: 68 Triumph GT6 (~full race prep'd), 81 Porsche 924 Turbo, 93 Rx7 twin turbo
KevinK2 is offline   Reply With Quote
The Following User Says Thank You to KevinK2 For This Useful Post:
phate (11-01-2014)
 Old 11-02-2014, 05:38 PM   #192
 
KevinK2's Avatar
 
Join Date: Nov 2013
Location: Delaware
Posts: 885   (View Stats)
iTrader: (0)
Rep Power: 0
KevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the world
Thanks: 216
Thanked 725 Times in 375 Posts
Groans: 0
Groaned at 79 Times in 52 Posts
Not Ranked  0 score     
Default

From op: Bilsteins
BE5-A256/24-102568 and BE5-A257/24-102575 are the part #'s for the fronts

I looked these up and FCM starts with the B6 (HD) shock, vs the B8 Sport shock, geometrically designed for use with lowering springs. I'm not questioning FCM, but just curious as to why the B6's?

.
__________________
From Delaware
Current Fleet: 04 Mazda6, 93 Rx7 TT, 76 Triumph 750 Trident

Tracked Cars: 68 Triumph GT6 (~full race prep'd), 81 Porsche 924 Turbo, 93 Rx7 twin turbo
KevinK2 is offline   Reply With Quote
 Old 11-02-2014, 05:48 PM   #193
Eth Fiend
 
phate's Avatar
 
Join Date: May 2010
Location: Auburn Hills, MI
Posts: 6,879   (View Stats)
iTrader: (10)
Rep Power: 11164
phate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the world
Thanks: 14,813
Thanked 21,641 Times in 5,840 Posts
Groans: 7
Groaned at 17 Times in 14 Posts
(Thread Starter)
Not Ranked  0 score     
Default

Originally Posted by KevinK2 View Post
From op: Bilsteins
BE5-A256/24-102568 and BE5-A257/24-102575 are the part #'s for the fronts

I looked these up and FCM starts with the B6 (HD) shock, vs the B8 Sport shock, geometrically designed for use with lowering springs. I'm not questioning FCM, but just curious as to why the B6's?

.
Those are what I had on the car. Memory may be incorrect, but B8's aren't available or they weren't available state side. As far as I know, the only difference between the two is shaft length, where the B8's are a little bit shorter.
__________________
-06 MS6
-Corn fed 07 MS3 - Sold



www.mazdamotorsports.com <<--Mazda racer support program that is free to join and will save you a ton of money.
phate is offline   Reply With Quote
 Old 11-04-2014, 09:34 AM   #194
 
KevinK2's Avatar
 
Join Date: Nov 2013
Location: Delaware
Posts: 885   (View Stats)
iTrader: (0)
Rep Power: 0
KevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the world
Thanks: 216
Thanked 725 Times in 375 Posts
Groans: 0
Groaned at 79 Times in 52 Posts
Not Ranked  0 score     
Default

Now that you mentioned it, I recall looking at the Bilstein application guide and B8's were special order.

Originally Posted by phate
... I know HardRace makes some different bushings for the 6, but they're fairly expensive and some folks seem to think they're too stiff.
And a monoball is against the SCCA rules. Beside the "center contact" Nylatron I had mentioned, I had used a 3 disc bushing in a similar application. In this case, there would be a central disc, about 1/3 width, of the close clearance Nylatron. Then on both sides would be ~soft urethane discs for centering, that would allow the misalignment shown.

.
__________________
From Delaware
Current Fleet: 04 Mazda6, 93 Rx7 TT, 76 Triumph 750 Trident

Tracked Cars: 68 Triumph GT6 (~full race prep'd), 81 Porsche 924 Turbo, 93 Rx7 twin turbo
KevinK2 is offline   Reply With Quote
 Old 11-04-2014, 11:05 AM   #195
 
KevinK2's Avatar
 
Join Date: Nov 2013
Location: Delaware
Posts: 885   (View Stats)
iTrader: (0)
Rep Power: 0
KevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the world
Thanks: 216
Thanked 725 Times in 375 Posts
Groans: 0
Groaned at 79 Times in 52 Posts
Not Ranked  0 score     
Default

Except for the RSB, you have posted enough info to plug in my suspension spread sheet. I could run a case with the max possible stiffness of the rear bar, assuming the bar has no vertical loop, or loops under the axles.

You have posted the corner wts, spring rates, and MR's. What I need (either values or post number):

> F&R roll center distance from ground

> F&R track

> Tire Size

> F&R sprung mass heights

> CG height, if you have it

Thats all, except for what I forgot. It would be interesting to see the max total front WT bias, vs the weight bias. Can also run it on an online calculator.

.
__________________
From Delaware
Current Fleet: 04 Mazda6, 93 Rx7 TT, 76 Triumph 750 Trident

Tracked Cars: 68 Triumph GT6 (~full race prep'd), 81 Porsche 924 Turbo, 93 Rx7 twin turbo
KevinK2 is offline   Reply With Quote
 Old 11-04-2014, 11:14 AM   #196
Eth Fiend
 
phate's Avatar
 
Join Date: May 2010
Location: Auburn Hills, MI
Posts: 6,879   (View Stats)
iTrader: (10)
Rep Power: 11164
phate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the world
Thanks: 14,813
Thanked 21,641 Times in 5,840 Posts
Groans: 7
Groaned at 17 Times in 14 Posts
(Thread Starter)
Not Ranked  0 score     
Default

I can post them up tonight or tomorrow. I'll just screenshot my current worksheet with those figures, so long as we can do a comparison between our results.
__________________
-06 MS6
-Corn fed 07 MS3 - Sold



www.mazdamotorsports.com <<--Mazda racer support program that is free to join and will save you a ton of money.
phate is offline   Reply With Quote
 Old 11-04-2014, 11:40 AM   #197
 
KevinK2's Avatar
 
Join Date: Nov 2013
Location: Delaware
Posts: 885   (View Stats)
iTrader: (0)
Rep Power: 0
KevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the world
Thanks: 216
Thanked 725 Times in 375 Posts
Groans: 0
Groaned at 79 Times in 52 Posts
Not Ranked  0 score     
Default

Right, I'll post the results. Should just take a few minutes.

.
__________________
From Delaware
Current Fleet: 04 Mazda6, 93 Rx7 TT, 76 Triumph 750 Trident

Tracked Cars: 68 Triumph GT6 (~full race prep'd), 81 Porsche 924 Turbo, 93 Rx7 twin turbo
KevinK2 is offline   Reply With Quote
 Old 11-07-2014, 10:28 AM   #198
 
KevinK2's Avatar
 
Join Date: Nov 2013
Location: Delaware
Posts: 885   (View Stats)
iTrader: (0)
Rep Power: 0
KevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the world
Thanks: 216
Thanked 725 Times in 375 Posts
Groans: 0
Groaned at 79 Times in 52 Posts
Not Ranked  0 score     
Default

Originally Posted by KevinK2 View Post
requested variables, REVISED 11-7-14

> F&R roll center distance from ground

> F&R track

> Tire Size

> F&R sprung weight cg heights ------ OR
>
> CG height and location between axles

.
__________________
From Delaware
Current Fleet: 04 Mazda6, 93 Rx7 TT, 76 Triumph 750 Trident

Tracked Cars: 68 Triumph GT6 (~full race prep'd), 81 Porsche 924 Turbo, 93 Rx7 twin turbo
KevinK2 is offline   Reply With Quote
 Old 11-07-2014, 10:40 AM   #199
Eth Fiend
 
phate's Avatar
 
Join Date: May 2010
Location: Auburn Hills, MI
Posts: 6,879   (View Stats)
iTrader: (10)
Rep Power: 11164
phate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the worldphate is the leader of the world
Thanks: 14,813
Thanked 21,641 Times in 5,840 Posts
Groans: 7
Groaned at 17 Times in 14 Posts
(Thread Starter)
Not Ranked  0 score     
Default

Busy week, traveling today then getting the car ready tonight for the weekend. I haven't forgotten.
__________________
-06 MS6
-Corn fed 07 MS3 - Sold



www.mazdamotorsports.com <<--Mazda racer support program that is free to join and will save you a ton of money.
phate is offline   Reply With Quote
 Old 11-07-2014, 11:34 AM   #200
 
KevinK2's Avatar
 
Join Date: Nov 2013
Location: Delaware
Posts: 885   (View Stats)
iTrader: (0)
Rep Power: 0
KevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the worldKevinK2 is the leader of the world
Thanks: 216
Thanked 725 Times in 375 Posts
Groans: 0
Groaned at 79 Times in 52 Posts
Not Ranked  0 score     
Default

No problem. I've "cleaned-up" my messy working SS. Now comparing results with this online calculator from what seems like a good source:


farnorthracing autocross secrets


.
__________________
From Delaware
Current Fleet: 04 Mazda6, 93 Rx7 TT, 76 Triumph 750 Trident

Tracked Cars: 68 Triumph GT6 (~full race prep'd), 81 Porsche 924 Turbo, 93 Rx7 twin turbo
KevinK2 is offline   Reply With Quote
The Following User Says Thank You to KevinK2 For This Useful Post:
phate (11-07-2014)
Reply


LinkBacks (?)
LinkBack to this Thread: http://www.mazdaspeedforums.org/forum/f12/mazdaspeed-6-suspension-data-diy-bilstein-coilovers-161806/
Posted By For Type Date
Shocks for a daily driven Mazdaspeed 6 This thread Refback 12-05-2015 09:07 PM
Whats New/General Speed 6 Discussion - Page 296 This thread Refback 11-29-2015 05:42 PM
fe1rx Ohlins Installation - Page 7 This thread Refback 08-23-2015 04:39 AM
fe1rx Ohlins Installation - Page 6 This thread Refback 04-25-2015 01:24 PM
Prepping as dedicated track car - Page 56 - Mazda 6 Forums : Mazda 6 Forum / Mazda Atenza Forum This thread Refback 02-21-2015 12:36 PM
BC coilovers VS. H&R coilovers - Page 15 - Mazda 6 Forums : Mazda 6 Forum / Mazda Atenza Forum This thread Refback 08-26-2014 07:50 AM
Whats New/General Speed 6 Discussion - Page 297 This thread Refback 07-28-2014 08:03 PM
racing aspirations » Suspension Geometry Calculator This thread Refback 06-21-2014 02:57 AM
Prepping as dedicated track car - Page 50 - Mazda 6 Forums : Mazda 6 Forum / Mazda Atenza Forum Post #48 Pingback 03-14-2014 12:36 PM
Prepping as dedicated track car - Page 46 - Mazda 6 Forums : Mazda 6 Forum / Mazda Atenza Forum This thread Refback 01-20-2014 11:02 AM

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Suspension/combo or coilovers?? gurusev 2010 MS3 - Suspension & Brakes 35 07-31-2013 10:06 AM
BC Coilovers or Bilstein Dampers/H&R Springs Bleupit80 MazdaSpeed 3/6 - Suspension & Brakes 6 02-12-2013 06:35 AM
BC BR Extreme Low Coilovers vs KSport Kontrol Pro Coilovers Doberman MazdaSpeed 3/6 - Suspension & Brakes 9 07-28-2012 07:35 AM
Suspension Techniques Coilovers? asiandude74 MazdaSpeed 3/6 - Suspension & Brakes 6 02-05-2011 11:15 PM
MSD Dashhawk Data Logger Data Base JimmyMac MazdaSpeed 3/6 - ECU Computer Tuning 2 06-30-2008 09:43 AM


All times are GMT -7. The time now is 04:22 PM.
Powered by vBulletin® Version 3.8.6
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.
SEO by vBSEO ©2011, Crawlability, Inc.
vB.Sponsors
Template-Modifications by TMS
©Copyright 2008 ; 2018 Cymru Internet Services LLC | FYHN™ Autosports HQ
Ad Management plugin by RedTyger
Page generated in 0.53915 seconds with 28 queries