Compressor Surge!!

IPT · 04-08-2002, 04:46 PM

Ok Pop Quiz time. How to get rid of Compressor surge. I have a Mini-Mutt turbo. It is my 14B turbo that has a clipped turbine wheel with a garret 1905 compressor wheel in it. I have never had this problem before, until I installed my PMS unit with the blow through MAF (VERY NICE

) I am getting compressor surge in 4th or 5th gear when I am too lazy to down shift to pass slow people. It is surging below 3500 rpms and then it will clear up.

Mods:
FMIC + piping
PMS + MAF
650cc injectors
fuel pump
3" O2 eliminator turbo back exhaust.
Some other things I for get about.

What can I do to help it not to surge?? I have a couple of ideas I just want to see what every one else thinks..

L2RTSiAWD · 04-09-2002, 03:10 PM

What BOV to you have? you need to adjust it softer.

Later,

IPT · 04-09-2002, 03:33 PM

It is a crushed 1G BOV. I am only running 18psi. It do not hear the flutter until it gets over 14 psi I do not hear it at high rpms. It just pulls like a train.

L2RTSiAWD · 04-09-2002, 04:29 PM

You will only hear it at low throttle low rpm's where the BOV cannot vent that little of air. You will not be able to stop it unless you:

1. Get a new BOV-Something adjustable(greddy type-s, TurboXS RFL)
2. Get a new 1g not crushed
3. Never run light throttle or lower boost.

Later,

IPT · 04-09-2002, 08:26 PM

I hear the flutter under WOT.

L2RTSiAWD · 04-10-2002, 10:54 AM

You said in your first post that it happens below 3500 rpms. bottom line you will need a new BOV.

Late,

IPT · 04-10-2002, 11:08 AM

I hear it under WOT under 3500 rpms. Like when you lazily go to pass some one and let the turbo spool. That is when I hear it. I have an uncrushed 1G BOV. Try that first right?? I have just been putting off getting the Greddy until after I do the motor.

I just don't understand why the BOV is the problem under 3500 rpms at WOT in the taller gears... I am missing something... HELP!!

L2RTSiAWD · 04-10-2002, 11:17 AM

Well I'm not that familiar with a PMS but I would try the uncrushed BOV first, then look at the PMS.

Later,

Tevenor · 04-10-2002, 11:59 AM

In the upper gearing, there is a much bigger load on the engine. You will build boost A hell of a lot quicker than in the lower gears. It is not uncommon for my T-25 to hit 16 psi of boost at 2300 in 4th if I am crusing around 2k. (Although my T-25 hits 16 psi by 2800 in second too

)

More load = quicker boost = lower flutter limit.

jw · 04-10-2002, 06:23 PM

What does your vacuum read?

IPT · 04-10-2002, 07:26 PM

When?? AT idle it is 18-20 inch of hg