qpe

Hi all H-T members

I've tunned my h22a ( with crome pro) some time ago and I think mine turbo its going into surge ( 99% sure about it

its fine at about 5psi but its really bad at higher boost and rpms, 5000-6000



so the question is can bad tune result in turbo surge
I have hks sequential bov its hooked up with eagle vacuum manifold
tial 44mm wastegate with the same source of vacuum
the turbo is Garrett T3/TO4E 60 trim w/ .63 a/r



thanks

TheShodan

iTrader: (14)

Define what you believe is "turbo surge". That might help us, help you a little better.

qpe

Is that fluttering sound and its definitely coming out of the turbo as its opposite side to bov so you can say, like I said I can hear bov working properly at low boost and then the different sound coming of the turbo at higher boost

just found that on youtube mine sounds exactly the same

thanks for fast reply

http://www.youtube.com/watch?v=nCj6Spwl1CU

qpe

bump
please for more input

TheShodan

iTrader: (14)

Gotta give folks a minute.

1) No. a "tune" doesn't cause compressor surge, its is something mechanical that is occurring in your case.

2) Have the wastegate as a separate source to the vacuum manifold and make sure it isn't "tee-d" off with the Blow off valve. Seems as though that the screw on the back of the BOV is a little too tight. Loosen that up a bit.

3) make sure your vacuum hoses aren't collapsing under pressure. cheap vacuum lines tend to do that if they are weak and collapsing under load.

Try those three things first, then get back to us.

qpe

Sorry I'm kinda desperate

1) ok so its not 'tune'

2) I will make separated vacuum sources today,
actually my hks doesn't have that screw on the back, unless its inside, can it be there??

3)I do use honda stock vacuum hose for bov vacuum source, Ill get something with ticker "walls"

thanks TheShodan

TheShodan

iTrader: (14)

The newer ones do not have the screw in the back. (Forgotten). Try the first method first and separate those lines first, and make sure they are quality vacuum hoses. Not that colorful B.S.

qpe

I can't really get why turbos go into surge while throttle is still open ,I always thought that was coz of bad/not tunned fuel map i.e engine can't take the pressure turbo is pushing into it

like on the video , the bov doesn't have anything to do with it

can anyone explain it

Im looking for some vacuum hosing , will samco be good

Divers

There are two kinds of compressor surge. I doubt you have the one in the skyline video. The most common is a bov not working properly. The other (like in the video) is when the turbo is operating in the surge zone of the compressor map. The surge line is found on a compressor map and all characteristics left of the line will cause the compressor to surge. Usually caused by the turbo being improperly sized. A ported housing moves the surge line left and allows for a bigger turbo on a smaller engine.
Are you sure air is coming out of the inlet of the turbo while under load? Or is the BOV leaking under load? Or is the BOV not opening or not opening enough after closing the throttle?

qpe

thanks for the input guys

Yes I'm pretty sure is coming out of the turbo under load so the throttle is open, I would say if the bov was liking.

I might not opening enough while the throttle closed after higher boost, when boosting up to only 5psi all is fine, I can hear the bov is working properly and the turbo doesn't go into surge

when accelerating slowly once it get to 5k rmps turbo goes mad, exactly the same as in the video

Would the turbo porting make any significant difference or its only makes sense for high performance cars ??

TheShodan

iTrader: (14)

No. Porting a turbo has nothing to do with your issue, nor would an anti-surge housing help.. Check also to see if there is any boost cut or limiters from your engine management or boost controller. that may be part of it as well.

qpe

So what do you mean by boost cuts? Sorry but english is not my first language so I wanna make sure I got right
There is manual boost controller but is set open so the boost level is imposed by the wastegate's spring

I'm not sure if the tuner set any kind of limits on my ECU