Well the fact that it didnt do it before on standard pipe and map, and now it does?
What exactly is compressor surge? Is it the blades of the compressor stalling, due to not enough flow on the exhaust side or something?

The mapper has reduced boost request in that rpm range and a few other things that he expected would help. I Would have to ask him to see exactly what though.

As much info as you have is all appreciated. Thanks guys.

 

because the boost has been increased.

I don't know who mapped it but did they not explain what it was? were they unsure?
did they say it wasn't compressor surge?
if someone mapping a newage sti doesn't know what or recoinise compressor surge then I would be very worried as it is more common they do it than don't do it with exhaust mods and a remap.

It is in basic terms the inlet side of the turbo spinning up so quick the flow of air passing through/over the blades of the turbo impeller is disturbed/distorted.

Simon

 

He did think it was the compressor wheel causing air turbulence.
After a few tweaks it was reduced, but still there.
So after some deliberation to rule out damage to the turbo, and be sure it was compressor surge, we put the ori exhaust back on and the ori map.

The noise is reduced, but still there.
My thoughts were that it may be a thrust bearing or something, but then I'd imagine it would make noise the whole time its producing boost.

The tuner has done a few scoobs but not a huge amount, but is regarded very highly amongst other drivers.
Highly recommended by VAG drivers, diesel and petrol and has done quite a bit of work with some porche racing team in the uk, and tuning for 1 off modded cars, audi S3's and the like with FMIC's hybrid turbo's, straight through exhausts etc.

Is a subaru that different to these?? I would have thought the theory is the exact same.

 

I wasnt meant to sound like I was having a go at him, more trying to establish if they knew if it was surge or not.
But yes knowledge of the car you are mapping is of upmost importance.
Without hearing it we are struggling to know whether it is surge or not

 

I didnt intend you to think i thought that, more just trying to establish whether you think he would know his stuff or not.
He actually has a B4 legacy as a daily himself come to think of it

I could try recording it from inside the car, but i don't know if it will be audible.
I can give it ago and up load onto good old youtube!
Or if you know of a sound clip online that is surge, i could say yes its the same or no its not.
Hmm, id be relieved if thats all it is, as i had visions of striping out the turbo an having to get a new one.

 

I have the same car my friend, and last year i did the 3" de cat and ported and wrapped the headers, colder grade plugs k&n filter and still only made 332/343 mind you it is some difference over standard, and that was done by Bob R who is probably on of the best. Im thinking of a new turbo (321h) injectors and caik. that should be around the 400 mark i would think......