~Boost Lag...

[JRockinVR4]

I have a '93 VR4 and I've been trying to get my bost to stop lagging at launch. The engine needs to have a steady 2k+RPM rev to take off or else the engine will bog down. I'm not sure if it's boost or not. Also, when ever I get about 4kRPM or higher at full throttle, it feels like the boost dump irregularly, which in turn really takes away from performance. You can't floor the car at all or this will happen...what should I do about this? (sorry if I didn't explin right) Is there some sort of sensor or something I can adjust besides the waste gates??

Also, I had a couple more questions. How much boost can the stock 3000GT VR4 engine handle? I know it has to be more than the stock 7psi each that the turbos put out...

[xXxRocker5150]

when was the last time you changed or cleaned your air filter??? What octane gas were you running??? Also, is your cat converter okay, or what??? I'm sure there's other problems, but those are just some that I could think of off the top of my head. Also when was the last time you did a tune up. The VR-4 stock can put out 14.5 PSI of boost w/ a manual boost controller b4 the turbos start blowing nothin but hot air... if I were you, I'd take it up to maybe 10, or get a Down pipe and gut your cats, and take it to 12 for sure (just to be on the safe side).

[JRockinVR4]

This is going to sound weird, but when I adjusted the waste gates today, I found something interesting: the wastegate tube was disassembled. As you can imagine, this adds a boost leak, which, in turn, reduces performance. I was surprised to find out that the owner before me sent the car to the shop to have the turbos rebuilt or something and the jackass mechanic never put the wastegate line back on. Problem solved, the car won't quit now... BTW, just did a tune up last weekend...oil change, couple fuse replacements and a wax (i know that's not tuning, but what's a car without the shiny?). K&N Filtering System does me right, though, with that 1,000,000 warranty.

[Hotshot8792]

Originally Posted by JRockinVR4

This is going to sound weird, but when I adjusted the waste gates today, I found something interesting: the wastegate tube was disassembled. As you can imagine, this adds a boost leak, which, in turn, reduces performance. I was surprised to find out that the owner before me sent the car to the shop to have the turbos rebuilt or something and the jackass mechanic never put the wastegate line back on. Problem solved, the car won't quit now... BTW, just did a tune up last weekend...oil change, couple fuse replacements and a wax (i know that's not tuning, but what's a car without the shiny?). K&N Filtering System does me right, though, with that 1,000,000 warranty.

ouch, with that, not only does it cause a boost leak, it causes your turbos to max themselves out, which with the boost leak will make you run like 7 psi lol i've done it on accident before a couple years ago

[94yellowtt]

Originally Posted by JRockinVR4

I have a '93 VR4 and I've been trying to get my bost to stop lagging at launch. The engine needs to have a steady 2k+RPM rev to take off or else the engine will bog down. I'm not sure if it's boost or not. Also, when ever I get about 4kRPM or higher at full throttle, it feels like the boost dump irregularly, which in turn really takes away from performance. You can't floor the car at all or this will happen...what should I do about this? (sorry if I didn't explin right) Is there some sort of sensor or something I can adjust besides the waste gates??

Also, I had a couple more questions. How much boost can the stock 3000GT VR4 engine handle? I know it has to be more than the stock 7psi each that the turbos put out...

get hooked up with a boost controller.I had the same problem with boost lag.It would only boost 6.5 lbs even at full throttle.The problem was the wastegate solenoid.If it is not working then the solenoid is closed not venting any boost and you pressure goes directly to the wastegates and keeps them open at 7 lbs.The exhaust also makes a strange noise.To correct this i just joined the 2 vacuum lines from the solenoid.I have put up to 18 lbs of boost with no problems for the past 3 years.

[Igovert500]

Originally Posted by 94yellowtt

I have put up to 18 lbs of boost ith no problems for the past 3 years.

For the love of your car, I hope you aren't doing that on your stock fuel system. On the stock fuel pump and injectors, you can't boost safely past 14.5psi. 18psi is just begging for knock.

[Stealth-Twinturbo]

I have run dynoed at 15 psi and 17 psi and it makes .5 more hp at 17psi because the turbos are blowing so much hot air. I also have 550cc Supra fuel pump and a tuned AFC II and still 18psi on stock fuel is crazy. I just recently went to AEM and a Custom turbo set up 400AWHP.

[94yellowtt]

Originally Posted by Igovert500

For the love of your car, I hope you aren't doing that on your stock fuel system. On the stock fuel pump and injectors, you can't boost safely past 14.5psi. 18psi is just begging for knock.

My car is anything but stock.I have a garage full of stock parts.Fuel management has been changed as has the intrcooling pipes and intercoolers themselves.Mostly HKS.
Turbos are 13gs.
As far as plugs im running Bosch platinum 4s.Why go through the trouble of changing gap.I had a problem with spark blowout with original plugs.
I also have a knock sensor led installed which never came on yet.
This is i think very important.My street racing days are gone and now building a show car out of it.Where i come from if you get caught street racing your car is confiscated due to 2 deaths.
This year i put on my 99 vr4 front end and have lots of plans for the future.I've gone 38 000 into it so i guess im married to it now.
My boost is set at 15 now and is just a cruiser on sunday nights.