[drostedrummer89]

I posted this in the local Michigan thread, but I need all the input I can get.

I need some help. I am working with Trevor (focusontheD) with his topspeed turbo'd svt zx5. He purchased the car as it sits, from a member on here with the turbonetics t3 super 60, and fully built motor.

I was driving it for the first time and I noticed that it doesn't achieve full boost until 5k rpm at wot, from any rpm. Even if I was doing 40 in second gear (~4000 rpm) it still lagged until 5-5500 rpm, then it pulls strong no matter how many gears you run it through. I don't have much experience with turbo cars, but I do no that a turbo that size should not be lagging that much.

I spoke with Brad (Mlbbaseball) and he said that it was probably a boost leak, and we tested the cold side piping and there weren't any leaks.

As a side note, he did have an incident when he was running on his high boost setting (20 psi) where his oil dipstick tube and valve cover breather blew off, blowing oil everywhere. Could both problems point to something like the wastegate? If its stuck open, it won't build enough boost, and if its stuck closed, it could spike the boost and create cylinder blowby?

Any advice is appreciated!


Matt
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[FocusZx3Oh]

Hmmm that sounds like the same prob John 03orangesvt had when I was with him and his ring landings went out. I cant remember if there was any issues with the boost. I do know there was oil everywhere. Good luck. Hope you can figure it out

 

[bmylez]

That sounds like a gigantic boost leak...but having the dipstick and VC breather blow off means the crank case was pressurized a ton and that sounds bad.

 

[ZXthrizzle05]

Ohh my. Idk what that is but I hope I don't run into the same problem with my build

 

[cedwards89]

Boost leak test all of the piping not just the cold side. Put your tester on the intake side of the turbo and test away.

And 5000-5500 for full boost at 20 psi isnt really that bad since a lot can factor when the turbo will spool. Built motor so lower compression? Lower the c/r will mean more lag.

Intake mani also changes rpm range a lot. Still have stock SVT?


Maybe more info on the motor specs.

 

[drostedrummer89]

Sorry, I know it was a very general help question. He has the entire spec sheet, he got the car from ccurry89. Here is a video that the original owner made. Notice how long it takes to boost, at WOT by 3k rpm he still didn't have any boost. I'm pretty sure it lags worse than that now.

http://www.youtube.com/watch?v=p4Rejc0_AHU&feature=youtube_gdata_player

The lag was just as bad for me at 13 psi as it was at 20, it was terrible. I know that turbo cars would not even be popular if they all lagged like this. I didn't enjoy getting smoked off the line, and waiting for boost that didn't come until the races were already over.

He does still have the stock svt intake manifold, and did have a code for "dsi motor stuck open" or something along those lines. However, we started it up and the dsi cycled open and closed. So not sure if that's another part of the problem?

Progress:
Today we checked the compression, they are JE 9:1 rods with wiseco pistons (I think) and they were all between 105-120, within 10% of each other. We inspected the bov, and found nothing. We then checked the Tial 38 mm wastegate, and when I took it off the manifold, the valve face actually fell off the stem and into my hand.


Pics:
Valve face

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[1turbofocus]

Very typical for tial to do and why I wont use them, If you look at the turbonetics evo you will see there valve is actually like a valve in a Cyl head and a much better design

Tom

 

[drostedrummer89]

Very typical for tial to do and why I wont use them, If you look at the turbonetics evo you will see there valve is actually like a valve in a Cyl head and a much better design

Tom

So do you think that's the main reason for his lag/boost leak? Also, his imrc is throwing a code, if its stuck open wouldn't that also kill virtually all low end torque before the boost hits?

Matt


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[oknvragain]

Thats is for sure the reason for the lag. A leak that bad would be just like running a larger exhaust depending on how you have it dumped. I could see that affecting other areas but i can't say for sure. I'd go ahead and replace the wastegate since you know it's toast anyway. Then reset the computer and see if the CE light comes back.

 

[drostedrummer89]

Welll see the valve still sits up against the valve seat, we turned the wastegate away from the dump tube and it wasn't leaking at idke, but in no way does that mean that at 3k rpm in 2nd gear that its not pissing air out. We contacted Tial, and their headquarters are an hour from us, and are fixing/replacing under warranty, dropping it off tomorrow.

We tested the imrc,, and it seemed to cycled open upon idle, and when we revved to 5k it did close, but then it seemed like it stopped working. Going to do some more testing and replacing what's broken.

Matt
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[1turbofocus]

shoot me a datalog as well I might can see something there

Tom

 

[drostedrummer89]

We will certainly do that. Thanks.

Matt
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[drostedrummer89]

Tom, how much will the imrc problem affect low end? We know the lever and cable are attached, and you can switch the lever manually. It seems like that module could be the culprit.

We can datalog early next week. How do you want the datalog, email? Aim?

Matt
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[03OrangeSVT]

If you are on short runners it will DECIMATE your low end.

 

[drostedrummer89]

Yea they are definately stuck on short, and the low end is certainly decimated.

Matt
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[drostedrummer89]

The wg leak definately helped boost quicker, but off the line is still SO slow. Does anyone know if the predator is capable of creating a 2 step rev limiter? It may not have the direct one touch setting, but can a tuner set a circumstance where if the vehicle speed is zero, car is in first gear, that the redline can be set to a user specified setting?

Matt
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[starfuryt550]

Like I had told you when we talked, I don't know about the predator at all.

But the eBoost2 controller can do boost by rpm, gears, etc. That should help a ton if tuned properly and help get more power where it actually needs to be and be usable.

I don't think that is your problem, though. That turbo, which that manifold and the engine as it sits, should hit full boost by 4k no matter what.

 

[1turbofocus]

Where is the IMRC at , if it is in the key off position that is the long runners and yes will hurt bottom end some

Before you worry about 2 step I would make sure this engine is working properly and that the tune is safe

Tom

 

[drostedrummer89]

When the car is off the cable has no tension, when you start the car it does pull the runner switch taught. We did a compression test and it was good and within 10% on all 4. We can send a datalog to you but the predator is proving hard to learn how to navigate. But things seem to be running better.

Andrei, it is damn close to hitting full boost by 4k now. Much much faster. But if he were to have full boost from a dig, such as this STi in the video below, his launches would be a whole different animal.

http://www.youtube.com/watch?v=y_XErSGxpTY&feature=youtube_gdata_player

Matt
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[Roushturboedzx3]

what turbo does he have? i hope he has a 3076 or a 35r if he has boost by 4k