VTA ...

[Dash08]

Originally Posted by djuosnteisn No, you definitely need the vac line hooked up. Some of the pics above were just taken before everything was put back together. You need to hook that line up, or you'll get bad compressor surge.

Thanks for clarifying. That was throwing me off. Didn't look right so i thought I'd ask.

[djuosnteisn]

NP amigo. I'm glad when people just ask, cause if you were a lil confused, that means several other people probably were too... which means there's a good chance someone is going to try it, hahaha.


Fuck fridays are so slow at work.... ugh.

[EdgeAutosport.com]

ewg vta without the dump tube

[PapaSmurf]

I have the ultimate VTA gates... but i has no picture at work lol

[EdgeAutosport.com]

@PapaSmurf

[SLOWHATCH]

I want to VTA my DNP ewg manifold and my turbosmart kompact bpv.
So the GA is mandatory to run bpv vta?

[4G63]

Video of sweet ass TIAL Q (VTA Im running speed density) compressor surge on the Evo uploaded soon. Gonna go take a video on the GoPro LOL

[djuosnteisn]

You're getting surge? With a bov that big?

I'll be running a tial q on my ms3 once i got top mount

[Lex]

This thread got filled up fast!

Let me quickly explain what's going on with this VTA business.

The OEM, Forge, Greddy, etc. push type of valves have 3 forces acting on them:

1. Spring pressure always acting to close the valve
2. Vacuum/boost at the top of the valve. When under vacuum from the manifold (idle, closing the throttle), the valve is pulled open. When under boost at the manifold, the valve is pushed closed from this point.
3. Boost pressure against the bottom of the piston itself from the charge piping. This pushes the valve open under boost and provides no force when not under boost at the charge pipes. Remember charge pipes never see vacuum.

So under boost, both charge pipes and manifold see boost. Under vacuum (idle, low load), charge pipes see no pressure, manifold sees vacuum. This is explained below

Under boost, you have the spring and manifold boost source at the top trying to close the valve, and boost in the charge pipe on the bottom trying to open the valve. The spring and boost pressure forces from the top are hopefully stronger than the boost from the bottom so the valve stays closed. This is shown below.



When you let go of the throttle, there is a spike in boost pressure from the bottom, and a pull from the vacuum in the manifold from the top (since the manifold is under vacuum when you let go of the gas). This means only the spring is trying to keep the valve closed and that's not enough acting against those other forces so it will open and let excess boost out.



At idle, you have no boost pressure at the bottom in the charge pipes. You just have the spring pressure keeping the valve closed and vacuum from the top trying to open it. Depending on how soft the spring is, vacuum will start pulling the valve open. The OEM one starts to pull open at 15 inches of mercury. At sea level we idle at 21-22 for a healthy motor. So the valve will stay open and allow air to pass causing a leak. This will happen at idle and low loads and the car will run rich and like crap.



As you apply more throttle, the vacuum at the top starts to be less strong, allowing the
valve to close and then you enter boost which I described above.

In order to stop the leak at idle (and when coasting and under light loads) you need a very stiff spring. This is all good and dandy until you realize that such a stiff spring will cause compressor surge since the valve won't open quickly enough or will close too soon when you let go of the throttle in boost since the stiff spring is keeping it shut.

Now where does the GA fit in here? Well, *most* push type valves such as the OEM one, even ones meant to VTA like the greddy have a hard time tuning the spring so that they don't leak at idle while also not causing compressor surge. @Daddy Chinkus complained about this and it sparked the idea of using the Guardian Angel to control the valve not just as a failsafe, but also to control it so that it stays shut under the idle and low throttle conditions. It also shuts if off quicker when letting off the throttle causing less backfiring etc. That way you can have your cake and eat it too. You can have a push type BPV such as the OEM one and run it VTA. You can even run the OEM one VTA which you won't be able to otherwise.

[Dash08]

Fuck, hate being a noob to certain things, but what are you guys using to cap off the recirc inlet on the TIP?

I'm thinking a silicone or rubber hose cap with a clamp. Ace hardware, Lowe's?

[Lex]

Originally Posted by Dash08 Fuck, hate being a noob to certain things, but what are you guys using to cap off the recirc inlet on the TIP? I'm thinking a silicone or rubber hose cap with a clamp. Ace hardware, Lowe's?

Use one of these if using an inlet pipe and clamp it down. They come in all sizes.



I am just testing now and I put a small plastic container and clamped it down in my recirc hose. That will be cleaned up later though.

[EdgeAutosport.com]

Originally Posted by Dash08 Fuck, hate being a noob to certain things, but what are you guys using to cap off the recirc inlet on the TIP? I'm thinking a silicone or rubber hose cap with a clamp. Ace hardware, Lowe's?

Or get a plastic pvc plug. They sell them at home depot or lowes for a buck, thats what I did with mine or we have these in stock if you wanna be all pretty

[rfinkle2]

Originally Posted by Dano First off let me say I am not an advocate of rice...ur I mean VTA...my Forge sounds just fine and I can hear plenty of woosh out of my SRI....but riddle me this. Would it make sense to do some work with the shift control tables to reduce the rich condition/backfire on clutch in/out. I have not really messed with the tables much and don't know how bad the rich condition gets and how much backfiring goes on... I have changed a few things to reduce my own backfiring due to all the meth left over on throttle lift. It helps but not all the time...lol I don't know how far they can compensate but it might be worth trying. You could alter both the IGN comp to reduce ign retard and reduce the addition of fuel with clutch in...IDK these tables may not be able to compensate that fast or that much...lol Care should be taken when altering the max ign retard and you might always want it negative..I am running the cobb suggested -3 which does make the car respond faster post shift and has reduced my backfires. Haven't altered the load comp tables enough to get any conclusive results. just thinking out loud here but you might tweak those load based fuel comp tables to add less fuel since you will already get plenty of fuel by VTAing. Not sure WTF you would do with the Load/RPM table since you may shift at different RPMs but the load only table would be a good place to start. anyway I may be totally off base since I have no VTA experience and very little with these new tables. now the bigger question....brown or white? edit: well I guess nevermind if you are actually running a BOV there might not be any rich condition issues.

There are actually some differences in the 2d and 3d tables that I matched on one persons map to help with a rich condition.

I think you are onto something for sure with one of the tables adding some fuel that may be taken out.

[4G63]

Originally Posted by djuosnteisn You're getting surge? With a bov that big? I'll be running a tial q on my ms3 once i got top mount

I got the spring for the vacuum pressure I'll have after I install my GSC S2 cams. Therefore it's currently the wrong spring by a little bit. I think I got the 10psi spring in there now

Edit: I have the Precision billet surge protector on the turbo. Not a huge deal for a bit I'll swap out springs soon

[ms3rick]

So a crushed 1g dsm should be good? I wanna rice to scare walking foes

[Dano]

@Lex

is this change going to happen in a FW or software update for the GA and how do existing users get it loaded?

maybe a premature question...lol

I too have put in my red spring to keep my Forge closed but is causes waaay too much surge. back on the famous "blue 2 shims" setup

[Lex]

Originally Posted by Dano @Lex is this change going to happen in a FW or software update for the GA and how do existing users get it loaded? maybe a premature question...lol I too have put in my red spring to keep my Forge closed but is causes waaay too much surge. back on the famous "blue 2 shims" setup

This is a software/FW change for now. I am going to build it in as a feature users can turn on or off as they choose. I need to do more testing. I actually need some different BPVs to test on.

Anyone willing to let me borrow a Forge, a Greddy, and anything else they are using?

[helmetface]

Originally Posted by Lex This is a software/FW change for now. I am going to build it in as a feature users can turn on or off as they choose. I need to do more testing. I actually need some different BPVs to test on. Anyone willing to let me borrow a Forge, a Greddy, and anything else they are using?

Borrow logs or borrow them physically?


I know this is a dumb question and you mean physically but I know they aren't a ton of people running mine so I figured I'd ask...lol

[djuosnteisn]

Originally Posted by Lex

Looks like @PapaSmurf's condom collection.

[Lex]

Originally Posted by helmetfail Borrow logs or borrow them physically? I know this is a dumb question and you mean physically but I know they aren't a ton of people running mine so I figured I'd ask...lol

Borrow physically. I'll pay shipping both ways and a little extra for the trouble.

[Dano]

Originally Posted by Lex This is a software/FW change for now. I am going to build it in as a feature users can turn on or off as they choose. I need to do more testing. I actually need some different BPVs to test on. Anyone willing to let me borrow a Forge, a Greddy, and anything else they are using?

cool...BTW I have been inadvertently testing my GA while ratcheting up my boost with the new MAP. I am confident enough that I no longer use my Boost limit tables....not that the throttle close ever did anything but the FC did and I prefer the "softer" cut the GA provides.

Its cool to see that the product may already be expanding its functionality with the BPV leak control.

Originally Posted by Lex Borrow physically. I'll pay shipping both ways and a little reach around for the trouble.

fixed

[PapaSmurf]

Originally Posted by djuosnteisn Looks like @PapaSmurf's condom collection.

I DONT USE CONDOMS

[helmetface]

Originally Posted by Lex Borrow physically. I'll pay shipping both ways and a little extra for the trouble.

PM'ing

[TiGraySpeed6]

you're creative bastard @Lex
This is great fun to watch, and to see somebody play who has the skills to play, it's really just fun to watch.

I love having forced induction.

[Lex]

Originally Posted by Dano cool...BTW I have been inadvertently testing my GA while ratcheting up my boost with the new MAP. I am confident enough that I no longer use my Boost limit tables....not that the throttle close ever did anything but the FC did and I prefer the "softer" cut the GA provides. Its cool to see that the product may already be expanding its functionality with the BPV leak control.

Awesome to hear Dan! The FC tables do work but soooo slowly if shit really hits the fan. BTW, the throttle close works, you just need to have 80s or lower in your DBW tables. That's even slower though, it's more for fine control.

I hope this feature will be pretty cool and functional. You will also ALWAYS know the GA is working properly since it's always activated. If I can see a difference in spool that will be even better. We'll see.

[4G63]

@djuosnteisn

Fast forward to 0:30 seconds. Runs for 2 mins middle part of video you can hear it. Don't know how to edit videos on the GoPro yet I'm a noob

@Lex is this how BOV's are supposed to work?

Evo VIII Compressor Surge TIAL Q - YouTube

[TRSpeed]

Mother of god. That hurts to here.

And yes sounds like definitely comp surge.
Sent from my DROID4 using Tapatalk 2

[Lex]

Originally Posted by 4G63 @djuosnteisn Fast forward to 0:30 seconds. Runs for 2 mins middle part of video you can hear it. Don't know how to edit videos on the GoPro yet I'm a noob @Lex is this how BOV's are supposed to work? Evo VIII Compressor Surge TIAL Q - YouTube

You needs softer spring or perhaps the plumbing is not correct.

[dMuze]

i know i would get a lot of afterfire between shifts when running my hybrid in 50/50. car would shift a lot less smooth than it does now in full recirc.

[anavrinIV]

Originally Posted by dMuze i know i would get a lot of afterfire between shifts when running my hybrid in 50/50. car would shift a lot less smooth than it does now in full recirc.

I'm finding that running vta on my ssqv3 yields smoother shifts (under part throttle conditions) than running it in recirc did. definitely a few afterfires now (subtle, which is why I wasn't hearing them before) but the car runs fine. Of course, I have a valve meant to run vta so with the exception of complete throttle liftoff it holds fine.

[m4tic]

Originally Posted by Lex This thread got filled up fast! Let me quickly explain what's going on with this VTA business.

@Lex on the first point with boost pressure acting on both sides of the valve... i should point out that with pressure on both sides this is essentially a net pressure differential of 0; so its up to the spring to hold the valve closed.

[IMASA]

Originally Posted by Lex This is a software/FW change for now. I am going to build it in as a feature users can turn on or off as they choose. I need to do more testing. I actually need some different BPVs to test on. Anyone willing to let me borrow a Forge, a Greddy, and anything else they are using?

Hey Lex,

My Forge V1 is available if you need it.

[djuosnteisn]

Originally Posted by 4G63 ... is this how BOV's are supposed to work? ...

Definitely surgey sounding. Softer spring is indeed required.

Hopefully it doesn't open under vac with the softer spring, cause that's the norm on our platform. People have to shim them to get them just right, and it's a bitch.


Here's how a clean blow off should sound (kinda hard to hear, crank volume):

VTA on the top mount s300sx perm dragon.MP4 - YouTube

VTA on the top mount s300sx perm dragon.MP4 - YouTube

Note, my car blows off this clean even at 0 psi most the time. But if you can get your's to the point where it blows off clean at ~5psi of boost, i'd call it decently good. Surge below that point probably won't be enough to damage the turbo as long as it's a decently built turbo.

[Lex]

Originally Posted by djuosnteisn Definitely surgey sounding. Softer spring is indeed required. Hopefully it doesn't open under vac with the softer spring, cause that's the norm on our platform. People have to shim them to get them just right, and it's a bitch. Here's how a clean blow off should sound (kinda hard to hear, crank volume): VTA on the top mount s300sx perm dragon.MP4 - YouTube Note, my car blows off this clean even at 0 psi most the time. But if you can get your's to the point where it blows off clean at ~5psi of boost, i'd call it decently good. Surge below that point probably won't be enough to damage the turbo as long as it's a decently built turbo.

I am playing around with timing transitions just right ... we will see how this differs on different BPV/BOVs but I found that if I wait for the valve to crack open at 80 Kpa (still not boost, boost starts at 100 Kpa) there will be part throttle surge. There's definitely a happy place to blow off at part throttle and it's interesting to see how narrow the window is (hence the difficulty to get just right with shims).

Originally Posted by IMASA Hey Lex, My Forge V1 is available if you need it.

Yes sir, I will need it thank you and it will work out great since you're local.

[86AmishMs3]

Originally Posted by djuosnteisn Definitely surgey sounding. Softer spring is indeed required. Hopefully it doesn't open under vac with the softer spring, cause that's the norm on our platform. People have to shim them to get them just right, and it's a bitch. Here's how a clean blow off should sound (kinda hard to hear, crank volume): Note, my car blows off this clean even at 0 psi most the time. But if you can get your's to the point where it blows off clean at ~5psi of boost, i'd call it decently good. Surge below that point probably won't be enough to damage the turbo as long as it's a decently built turbo.

Also another good thing to point out about surge, is that surge is not as bad a thing for ball bearing turbos then it is for journal bearing turbos. Journal bearing turbos you're overloading the thrust bearing and causing metal, metal contact since you're pushing away that oil film.

Ball bearings the thrust force is distributed pretty well across the ball bearings.

For me I just tuned my bpv/bov to the point where I'm not slamming my face into the windshield when I let off the throttle at partial boost. Otherwise NCE about the turkey living under my hood. Only really get surge from 0-3ish psi.

[kritz]

VTA! MCY!

[4G63]

Originally Posted by djuosnteisn Definitely surgey sounding. Softer spring is indeed required. Hopefully it doesn't open under vac with the softer spring, cause that's the norm on our platform. People have to shim them to get them just right, and it's a bitch.

Yea I know it needs the softer spring like I was saying the one in their currently was for the vacuum I'd have at idle with the 274 cams in there. Wasn't going to install it til the cams but had to hear it lol. With a softer spring it should be fine I haven't seen anyone use any shimming to get it to work it's just the right spring that matters as you know.

My pipe setup like @Lex said isnt plumbed wrong but it is terrible now I'm gonna have to spend another $400 on some upper piping setup The pipe I got for cheap is hitting my Optima RedTop battery (it's a little wider than stock)

(piping wasn't all clamped for pic, speed density sensor is also resting on my valve cover because of the pipe being pushed over by the battery. Had to wrap it with krampton tape rated to 3000 degrees lol)

I'm done didn't mean to hijack I'm sorry Lex!!!

[Dash08]

Well, this is bullshit.

Nobody sells those vinyl plastic end caps to cap off the recirc inlet. I wanted to use something soft so I can throw a hose clamp on it for a good seal.

I see the hard PVC plastic plugs and caps, but how do you keep the fucker on there? Can't put a hose clamp on PVC, that won't do shit.

Any other suggestions?

[anavrinIV]

Originally Posted by Dash08 Well, this is bullshit. Nobody sells those vinyl plastic end caps to cap off the recirc inlet. I wanted to use something soft so I can throw a hose clamp on it for a good seal. I see the hard PVC plastic plugs and caps, but how do you keep the fucker on there? Can't put a hose clamp on PVC, that won't do shit. Any other suggestions?

home depot has copper pipe caps, 1", for under $3. cut a short length of recirc hose, cram the cap in one end, and put the other end of the hose on the TIP. clamp both sides. done. that's how I have mine and no leaks, and as tight as the cap is in the hose it won't come out, especially with a clamp on it.

[JBR]

^^^This is a great idea.

I used a rubber plug from Ace Hardware and wrapped the exposed portion with a little electrical tape.