Compressor Surge or Turbo Stutter/Shudder at part THROTTLE!!

[Axl]

I just installed Pte Stk loc IC, 70mm TB, Precision Plenum & PP, 50lb inj and a Red 93 chip burned for my car. (While driving and under half throttle) When my booost comes up to 10lbs. I get really bad turbo shudder like I just pulled my foot off the throttle but Im keeping it at same throttle position. I noticed that the needle on my boost gauge flutters when this happens.

I noticed that I have MAL code 44

Any suggestions as to cause??????? New to Scanmaster and such

Mods in sig.

 

[suicide six]

What type o2 sensor?how old?

 

[suicide six]

Could be boost creep or starting of wiped out cam lobe.

 

[suicide six]

But by your setup Id say its TB,plenum or IC and ducting.This area 9 to sat 13lbs is this problems sweet spot.,

 

[TurboBob]

its part throttle surge. Try taking the RJC boost controller off, and running the hose straight from the turbo to the wastegate, then run the gate so its not really tight and see if that helps.

The idea is to turn the boost down to see if it eliminates the problem.

Try it and post back.

Bob

 

[Axl]

I installed the IC, TB, PLENUM on friday. Drove the car and I cant remeber if it was doing this but for the firdt few miles of driving the turbo was making a distinct whine like an SC, but stopped.

On saturday I installed the 50lbers, new chip and scanmaster. I was going to replace PCV valve while I was at it but parts store only caried FRAM. I definitely noticed the stutter on Saturday but I cant remember if it did it on friday.

 

[VadersV6]

Mine has always done the same thing, and Ive changed just about everything and tried everything, including going to tuner style on the wastegate. Cam isnt going flat. No idea what it is, but the car still hauls ass, so who cares.

 

[turbobuickman]

Its not all that uncommon, especially with large front mounts.

 

[GNVYUS 1]

Got it here also.

It's very common when you free up that much backpressure in the inlet system to get surge at mid boost.

No biggie if you asked me, you will learn how to feather around it. I usually slowly keep building psi so it does not happen. Or build and slowly come out and then back in. You will have to see how your set up treats your right foot.

 

[Fuelie600]

I use a Greddy Profec, and I eliminated this surge by raising the boost start point to 13 psi. Smooth as silk now! :biggrin:

 

[TurboBuRick]

Mine has always done the same thing, and Ive changed just about everything and tried everything, including going to tuner style on the wastegate. Cam isnt going flat. No idea what it is, but the car still hauls ass, so who cares.

This worked great for me.

Relocate ls1 maf into up pipe. These sensors work to good in our cars. They sens the waisted air and trigger fuel. Moving mine improved the all around driveability.
Alcohol needs to get its power from bat. or alt.
This eliminates any interfeirence with your translator and ls1 maf.
Smooth as glass. :biggrin:

 

[Axl]

I took her for a spin again today and noticed that it only surges around 10psi but if i give it a little more gas its smoother.

 

[VadersV6]

I always felt it could be caused by an imbalance between the compressor side and the turbine side...like the efficiency balance is all ****ed up. My intake end of things is pretty free flowing, but my whole exhaust (with the exception of an extrude honed exhaust elbow) is bone stock. It will build boost just as fast at half throttle as it will at WOT...which is very fast. I'll only get maybe 4 more psi at WOT vs. half. Seems like the turbine spools it up really fast, but the compressor cant get enough air moving into the motor. I think theres alot of air trying to move in, but the throttle position isnt letting it. Ive always wondered how the turbo can spool so fast at part throttle, and not really much faster at WOT.