Possible track spring spring setup for use with Koni yellows

ualeks

Any thoughts on using off-the-shelf struts and shocks from larger/heavier vehicles that share the same platform? I am thinking along the lines of Mazda5, Volvo S40, etc. I am not sure if the dampers are ohysically the same size on these vehicles vs. Mazda3, but by looking at Koni part numbers (nearly the same) , I am going to assume that they are pretty close. I would think that they would have "stiffer" dampening to control the stiffer springs required for a heavier vehicle?

stretch

Hey guys. No new news yet, but several phone calls made and another potential damper company involved in the project. Still no ETA on the springs, but I just put in a phone call to see what the hold-up is.

No, I wouldn't try to use another OE damper. I wouldn't trust the quality, plus odds are the valving and damper lengths would be way off of what we're looking for.

ualeks

I think you misunderstood. I wasn't thinking of another OE damper for the same reasons you stated.

I was thinking along the lines of using something like a Koni sport made for something like a Mazda5 or Volvo S40. I sent Koni an email asking for specs. Based on what they sent me back, the Koni sport for a Mazda5 are 35% stiffer (rebound) in the front and 20% stiffer (rebound) in the rear than their Mazda3 application. Compressions forces are identical for both. Based on the specs they provided, physical dimensions apper to be identical (min and max length). This sounds like what you would need to control a higher rate spring.

Now the question is who has got the means to get their hands on a set and take measurements to see if they are infact the same dimensions....body length & diameter, stroke length, shaft diameter (would need to fit into the existing mounts), etc.

FreeFlyFreak

Originally Posted by stretch

Hey guys. No new news yet, but several phone calls made and another potential damper company involved in the project. Still no ETA on the springs, but I just put in a phone call to see what the hold-up is.

What is the other damper company who is involved?
Any news in the springs?
Why not get some Hypercoils in the sizes spring rates you think will work.

stretch

Sure, here's an update:

I've felt a few different setups now. I'm still waiting on the manufacturer (don't get me started!) on our spec'd springs, but in the meantime I have another company's springs installed on standard Koni Yellows. This setup feels OK, but there's lots of room for improvement I think. I'll know more when I get to competitively drive on the setup, and of course I'm much more concerned over how our actual prototype springs feel. Certainly even this makeshift setup is better than low-end coilovers, but it's just our starting point.

One thing I really wanted to share, though, is my experience taking apart struts on a car that I believe had about 15k miles on it. This was a different vehicle than CP-E's shop car which has had nothing but dyno time and no real driving. Here's what I found:

- BOTH rear struts blown. One was badly leaking oil and clunking, but the other had lost a considerable amount of gas pressure and valving.

- BOTH front bump stops were obliterated. The top progression on one fell out into three parts when I removed the dust boot, while the other bump stop was cracked on all sides. This means both were rendered pretty useless.

I took pictures of both with CP-E's shop camera, so maybe they'll get put online soon. There's not much to see except busted parts. However, the points are these:

- The stock dampers suck. I had thought otherwise after seeing a dyno of new parts, but that dyno was worthless. Why? The dampers wear out amazingly fast. Even if the oil is not obviously leaking oil and/or clunking, the seals wear quickly and the car loses its valving. This is obvious to me now after having exposure to several cars. It's disappointing to see Mazda used a typical lowest-price damper on this car.

- I really don't like the way lowering springs feel on stock dampers. This option is out; I won't let CP-E's name go on a product marketed for the stock dampers. I also wouldn't recommend this to anyone.

- A stock car clearly hits its bump stops hard and often. The destruction of bump stops is common on lowered cars, but I was surprised to see it even with the stock springs. Lowering springs make this many, many times worse by removing that inch of space between ride height and when the bump stop engages. We are going to explore a new bump stop solution, although we may not need it with the added travel afforded by the Koni's. Still, I think those on the stock suspension who think the car is abruptly bottoming out (you shouldn't feel this happen if the bump stops are properly cushioning the bump) will appreciate the option.

Originally Posted by ualeks

I think you misunderstood. I wasn't thinking of another OE damper for the same reasons you stated.

I was thinking along the lines of using something like a Koni sport made for something like a Mazda5 or Volvo S40. I sent Koni an email asking for specs. Based on what they sent me back, the Koni sport for a Mazda5 are 35% stiffer (rebound) in the front and 20% stiffer (rebound) in the rear than their Mazda3 application. Compressions forces are identical for both. Based on the specs they provided, physical dimensions apper to be identical (min and max length). This sounds like what you would need to control a higher rate spring.

Now the question is who has got the means to get their hands on a set and take measurements to see if they are infact the same dimensions....body length & diameter, stroke length, shaft diameter (would need to fit into the existing mounts), etc.

I did indeed misunderstand, and I really like that idea. I will follow up on it and get more details. Koni and I have been playing phone tag a bit as of late! Thank you for the suggestion.

AutoXRacer

MazdaSteve3

The stock dampers suck. I had thought otherwise after seeing a dyno of new parts, but that dyno was worthless. Why? The dampers wear out amazingly fast. Even if the oil is not obviously leaking oil and/or clunking, the seals wear quickly and the car loses its valving. This is obvious to me now after having exposure to several cars. It's disappointing to see Mazda used a typical lowest-price damper on this car.

Yes they do. Mine are just over 25k and I'm bouncing all over the place. I didn't know they were so bad as to tear up the bump stops. Wow. I had wanted to donate mine for dynoing, but the result is clear - junk.

- I really don't like the way lowering springs feel on stock dampers. This option is out; I won't let CP-E's name go on a product marketed for the stock dampers. I also wouldn't recommend this to anyone.

Yep, been there done that didn't like it.

- A stock car clearly hits its bump stops hard and often. The destruction of bump stops is common on lowered cars, but I was surprised to see it even with the stock springs. Lowering springs make this many, many times worse by removing that inch of space between ride height and when the bump stop engages. We are going to explore a new bump stop solution, although we may not need it with the added travel afforded by the Koni's. Still, I think those on the stock suspension who think the car is abruptly bottoming out (you shouldn't feel this happen if the bump stops are properly cushioning the bump) will appreciate the option.

Oddly, the instructions for the Mazdaspeed lowering springs tell you to remove the front bumpstops (permanently). Ridiculous, but true. Guess what becomes the new bumpstop? The tires.

Keep working! We all need a good solution. Are you still planning on using standard Koni yellows, or is the shock decision still to be made? I can't stand the suspension as is. I still have the MS springs and yellows in the garage, maybe I'll have to put those on until the CP-E option is ready.

MazdaSteve3

Originally Posted by ualeks

I think you misunderstood. I wasn't thinking of another OE damper for the same reasons you stated.

I was thinking along the lines of using something like a Koni sport made for something like a Mazda5 or Volvo S40. I sent Koni an email asking for specs. Based on what they sent me back, the Koni sport for a Mazda5 are 35% stiffer (rebound) in the front and 20% stiffer (rebound) in the rear than their Mazda3 application. Compressions forces are identical for both. Based on the specs they provided, physical dimensions apper to be identical (min and max length). This sounds like what you would need to control a higher rate spring.

Now the question is who has got the means to get their hands on a set and take measurements to see if they are infact the same dimensions....body length & diameter, stroke length, shaft diameter (would need to fit into the existing mounts), etc.

Good chance that the S40 parts would fit. Bilstein lists the S40 front struts for the MS3, standard 3 stuff for the rear.

Frequentflyer · 04:03 PM

Only downsides with the Bilsteins are that they are significantly more expensive than Koni Sports and they are non-adjustable. I've run Bilsteins on my '99 Miata (sport suspension package) back in the day and I did very well in A-stock with them, but if it's going to cost upwards of $1200-1400 for a set of Bilsteins w/springs, we're pushing coilover territory there. Edit: Ok, they may not end up being THAT much. I had seen them upwards of $375 each for the fronts, but looks like that's retail. Better prices I've found are $240 each for the fronts and $120 each for the rear. So $720 vs. $600 for the Konis. Not too bad if we determine the Bilsteins are a higher quality shock (which I'd be willing to bet they are).

gtlaw

Originally Posted by stretch

Sure, here's an update:

I've felt a few different setups now. I'm still waiting on the manufacturer (don't get me started!) on our spec'd springs, but in the meantime I have another company's springs installed on standard Koni Yellows. This setup feels OK, but there's lots of room for improvement I think. I'll know more when I get to competitively drive on the setup, and of course I'm much more concerned over how our actual prototype springs feel. Certainly even this makeshift setup is better than low-end coilovers, but it's just our starting point.

One thing I really wanted to share, though, is my experience taking apart struts on a car that I believe had about 15k miles on it. This was a different vehicle than CP-E's shop car which has had nothing but dyno time and no real driving. Here's what I found:

- BOTH rear struts blown. One was badly leaking oil and clunking, but the other had lost a considerable amount of gas pressure and valving.

- BOTH front bump stops were obliterated. The top progression on one fell out into three parts when I removed the dust boot, while the other bump stop was cracked on all sides. This means both were rendered pretty useless.

I took pictures of both with CP-E's shop camera, so maybe they'll get put online soon. There's not much to see except busted parts. However, the points are these:

- The stock dampers suck. I had thought otherwise after seeing a dyno of new parts, but that dyno was worthless. Why? The dampers wear out amazingly fast. Even if the oil is not obviously leaking oil and/or clunking, the seals wear quickly and the car loses its valving. This is obvious to me now after having exposure to several cars. It's disappointing to see Mazda used a typical lowest-price damper on this car.

- I really don't like the way lowering springs feel on stock dampers. This option is out; I won't let CP-E's name go on a product marketed for the stock dampers. I also wouldn't recommend this to anyone.

- A stock car clearly hits its bump stops hard and often. The destruction of bump stops is common on lowered cars, but I was surprised to see it even with the stock springs. Lowering springs make this many, many times worse by removing that inch of space between ride height and when the bump stop engages. We are going to explore a new bump stop solution, although we may not need it with the added travel afforded by the Koni's. Still, I think those on the stock suspension who think the car is abruptly bottoming out (you shouldn't feel this happen if the bump stops are properly cushioning the bump) will appreciate the option.

I did indeed misunderstand, and I really like that idea. I will follow up on it and get more details. Koni and I have been playing phone tag a bit as of late! Thank you for the suggestion.

keep up the good work. I'm excited to get a good suspension setup next spring when I take my car out of storage

how about using the foam koni bumpstops?

MazdaSteve3

Originally Posted by MazdaSteve3

Good chance that the S40 parts would fit. Bilstein lists the S40 front struts for the MS3, standard 3 stuff for the rear.

But they list the S40 parts for the front of the regular 3 as well, so there isn't any difference in the valving they use from a 3i to an S40 (Bilstein). The valving is apparently the same between the HD and Sport options also, the only difference being the ride height.