How To Fix Compressor Surge?

[bazr33]

Turbo was hiflowed through turbo australia.

plain bearing, steel wheel, 270 thrust bearing.

power fc, z32 afm, 550inj, fuel reg, walbro fuel pump, FMIC, AVCR.

set on 18psi

i noticed compressor surge on about 5 psi on the highway.

have tried changing from my turbosmart bov to a standard one, no difference.

have an adjustable actuator, what can i do to fix this annoying surge.

who should i speak to?

[paulr33]

ideally try and monitor pressure at both ends to try and isolate it

compress surge occurs when pressure past the compressor wheel exceeds what the compressor can actually supply, ie say hiting 27psi and the compressor can only yield 15psi etc. it surges violently. perhaps the bov is leaking or not closing properly? checked for obvious leaks ?

[bazr33]

what boost can the r33 hiflow handle?

is 18psi too much for it?

The standard bov does leak to start with doesnt it?

would it be worth removing the bov altogether and see what it does?

[paulr33]

sorry i am a goose

the bov is opening as part of the pressure spiking

what happens is the compressor is ramping up boost

the pressure spikes significantly and the bov is opening to dump the pressure

but its probably spiking really high and quickly so it makes the wheel surge too

i dont think the bov is at cause here, i think its the compressor wheel

surging while ramping boost is common with highflows, well more so than a off the shelf spec turbocharger

speak to the people who hiflowed it

[skylinecouple]

I run 18psi and no boost leaks.Standard GTST R33 bov.Thats with GCG hiflow.

[bazr33]

so best option is to speak with where i got it rebalanced and cleaned

and i might be up to buy another compressor wheel?

might of been a poorly hiflow

[paulr33]

ask them, they should be able to tell you

[Slide]

Do you have a pic of the front and back of the turbo so we can see what wheels are in it?

It will explain a lot.

Diffusal wall machining is a critical part in avoiding compressor surge also.

[R31Nismoid]

If the comp wheel is too big then its going to get surge thats for sure.

Could be a bad wheel match.

What are the specs?

[bazr33]

i will get the specs as soon as i get the car back from my tuner.

thanks

[bazr33]

The only other thing is when i installed the turbo

i still had stock injectors and afm, turbo was sitting on 12psi

with my standard airbox.

i didn't witness compressor surge at all,

then when i installed pod, 550inj, fuel reg, and z32 afm and put it to 18psi, thats the only time it started doing it.

I even dropped boost back to 12psi and still does it.

Anyway, i have sent a email regarding whats goin on to the turbo mob and i'll see what they say.

[bazr33]

I have my car back from my tuner

everything else is awesome on my car and thanks heaps to my tuner

a/f ratios are at 12, the rb20 adjustable actuator i put on my car, cause i thought it might of caused the problem didn't help. My tuner ended up fabricating a replacement adjustable rod, as the original was rusted out and couldn't be turned.

from looking at it, we think its the bov, either lost tension and is bouncing, forcing air into my intake pipe, inturn dumpin fuel into my engine, bringing the a/f to 10.

The bov as been wound right to hard, to stop the bouncing and has seemed to hold up, as i have the car back and hasn't done it.

Turbosmart also believe running another tee into the other intake runner could possibly dampen the pulsation, suckin excess air from the bov.

Anyway i thank my tuner heaps, has looked after my car, and has contacted me whenever news arised about the tune, or anything to do with the car.

Will not hesitate to take the car back to him, if anything happens, or for future mods.

[bazr33]

i also have notice that i had my bov connected too two sources

one: is my boost controller

two: the vaccum line off the plenum

i have been speaking to turbosmart, and they have said that this could be the problem.

so im going to change my setup i have and just have the bov connected to the vaccum line only.

then the boost controller solenoid to the vaccum line in between the FPR and Plenum.

The hesitation im getting could possibly be the interference of two sources connected to the bov

will let ya know how it goes.

[RB20/30Det_VL]

mate u will find that its a miss matched compressor/compressor wheel, i had the same thing with a gcg hiflow of an rb20 turbo which uses the same internals as the rb25/vg30 gcg highflow, i used to get to 5psi then off/on throttle then it would go to 10psi etc, bov would vent too even when turned hard as it could

i should of know better then to hiflow an rb20 turbo, oh well lesson learnt!

[bazr33]

rb20/30det vl

Have you put a new turbo on from that rb20 hiflow

if so

has it stopped the surging??

[RB20/30Det_VL]

nar not yet i should see if the bloke that i sold it to has witnessed it yet

i can give u a dyno sheet that shows how poor the boost is held

scott from insight in sydney who tuned my car said it is because of mismatched housings/wheel selection

[CEF11E]

this often happens with hiflows. if you are going to get one get one that has been researched and built for a specific application like a Slide hiflow or a GCG.

now it will prob cost twice as much to geo sorted

[Dale FZ1]

Check here

http://www.turbobygarrett.com/turbobygarre...bo_tech103.html

for the Garrett tutorial on what causes surge

So the question is

1. how did you decide on the specs for the high flow?

2. do you know what size/spec impellers have been used? (if so, post them up please)

Edited February 20, 2007 by Dale FZ1

[bazr33]

Thats the turbo,

im not sure of teh specs of the wheels used, i bought the turbo off a mate

i will ask to see if he would know what size the wheels were

turbo australia did clean the wheels and rebalanced them

so hopefully they remember me and could tell

but i was thinking they would of seen then if it was a missmatch of wheel size for the r33 turbo etc.

Only problem i have is, it never did it at 12psi with my standard airbox still on.

i probably did say that earlier in the post but yeah not sure.

Yet when it wasnt doin it, i still had standard injectors,

time it did start doing this, was when i upgraded to metal induction pipe, z32afm, 555inj's and fuel reg.

and set on 18psi.

[paulr33]

read the garrett page it will explain why

then you can see if the compressor actually can support that pressure ratio & level (it probably cant, which is why its surging)