Surging turbo

[Abo Bob]

I have an AVC-R and standard turbo. Recently I got a chipped standard ECU which brings my power on nice and smoothly so i decided to have a little play at higher boost.

I have had it tuned to 0.85 bar which is fine but I put it up to 1 bar and it surges. Everything else seems to go well but I can hear the turbo going "wheee ooooh wheeee ooohh"

Why is this? I haven't adjusted the boost duty cos I have no idea what it is or how to. Perhaps someone could explain this too.

Basically I was thinking of having a high boost setting that can be used for say a quick 1st gear, 2nd gear run then back off. I have the standard intercooler at the moment though so maybe I should hold off on that.

I have been using Roil recently which makes my turbo a fair bit quieter I presume due to better lubrication. Would this keep it cooler (ie safer) or is it the compressing of air that creates the turbo killing heat?

Thanks guys.

[EnricoPalazzo]

The sound u are hearing could be the rubber intake off the airfilter collapsing and hence stopping airflow and making that sound.

[Abo Bob]

I am keeping my foot flat when this happens so not letting the pressure off. I wouldn't think that it would collapse then come good again several times without letting the boost off.

[EnricoPalazzo]

yeh but ive never heard of a stock turbo surging. interesting.

[ed]

how many km's have you done? maybe the turbo is on it's way out?

[blind_elk]

Compressor surge - at 1bar, you have pushed the induction system outside it's optimum operating parameters.

The compression of the intake air is what adds heat that will eventually kill an engine. A decent front-mount might help solve the problem, but you really need to get the whole system re-programmed. The "chip" is probably not programmed to efficiently feed the engine at 1bar of boost.

Zoom did an article about a year ago - see if you can get hold of a back copy.

[Abo Bob]

I get this surging at 0.8 bar even. I can feel the power surging. Funny thing is that when it was on the dyno I didn't really notice it and you can't tell from the graph but I put that down to the dyno run being in 3rd gear(auto) and the surge happens more in second gear. 1st gear is so quick it doesn't have time to surge.

I am thinking it might be something to do with the wastegate actuator not being strong enough or something at higher boost.

[Abo Bob]

BTW I've done 85000 kms which I believe to be genuine.

[Driver]

yeah same

my dyno runs lookd to be strong

but its a diff story on the road

[Abo Bob]

Difference is that I have plenty of power right through this. It's not really a problem I guess. I'm just curious.