Originally Posted by Boost3dxEvO

I just put on a turbo kit, along with full bolt ons... here is my mod list:

Precision 57 trim Dual BB Turbo
ETS Tubular Manifold
ETS 3" Downpipe
ETS 3.5" Downpipe Back Exhaust
ETS Short Route LICP
ETS UICP
ETS 3" O2 Housing
ETS Intake
K+N Long Filter
Tial 50mm BOV
MAF Gen 1 Translator
3" GM MAF
Tial 38mm Wastegate (Recirculated)
Walbro 255 Fuel Pump
Precision 780cc Injectors
Hallman Pro MBC
Cosworth M2 Cams
ARP Headstuds


Okay.. onto the problem.... If I am in a high gear with low rpm and do WOT .. as the boost rises to the top (20psi) ... it hits 20psi and AGGRESSIVELY go back and forth between 15psi and 20psi and in between.. and my car stutters like H3LL!!

I used to have the stock MAF with a Forge RS bov and my car would stutter if I was barely on the gas and let off really quick... but this new stuttering is at WOT and is really aggressive.

In the lower gears it is okay, but still ... when I reach full boost (20psi) my boost gauge just hits 20psi and the needle shakes like crazy and goes between 19psi and 20psi.. I really need help!!! PLEASEEEE!!!!!

I really would like to pinpoint the issue.. this is scary to me.

Please help!!!!

Originally Posted by kaonashi

def a leak you shouldnt hit fool spool from a roll until around 3500-4k


ETS sends that turbo out with the .63 a/r so its a good size like I said he shouldnt be spooling that soon even with the BB

This is the Spec's on the ETS 57 trim and his should be like this. Unless he said different.


Part Number: SC3431R
Max Rated HP: 545
Inlet/Outlet Size: 3"/2"
Bearing System: Ball Bearing
A/R Ratio: .48, .63 or .82
Garrett Compressor Wheel Trim: 57
Garrett Turbine Wheel Trim: 76

Garrett Compressor Wheel Specs:
Wheel Trim: 57
Wheel Inducer: 2.230" (56mm)
Wheel Exducer: 2.950" (75mm)

Garrett Turbine Wheel Specs:
Wheel Trim: 76
Wheel Style: T31
Wheel Inducer: 2.559" (65mm)
Wheel Exducer: 2.228" (57mm)

Originally Posted by 04AWDTURBOEVO

I am going to guess here and say that the MAF Gen 1 Translator and 3" GM MAF may be the cause of the problem.
This Mod can be causing the issue.

Get it look at by the person who set it up for you. Could need more fine tuning.

Originally Posted by evilbada

I think its the spring on the Tial BOV,

It's not holding boost therefore opening a bit under WOT causing the loss of boost pressure. But strong enough to hold more than 15psi.

Swap your Bov to your previous forge rs then test again.

Originally Posted by Boost3dxEvO

ETS's turbos are Precision.. but yes, it is a .63 AR

Originally Posted by dxbevo9

i had the same exact problem..on my stock turbo...tried out everything...and at the end i found out that i have set the gain too high on my EBC(greddy profec B-spec II) as well as setting the "limit boost" to my target 1.5bar while the gain was trying to exceed this limit...the limiter was trying to stop it causing it to stutter and bounce back between 1.5bar & 1.2bar causing the car to jerk back an forth and drive like ****..

just as you mentioned, this situation was exajorated when boosting in higher gears from low rpm than it did in lower gears...nonetheless...still did it untill i turned my gain down and turned off the boost limit..

i know you have an MBC...but i just thought i should share.