Rb26 2860 -5's Compressor Surge

[Mark-32]

My RB25 did exactly this same thing when it had the twin turbo setup. It was due to the turbos forcing more air than the engine could take at low rpm so the air choofed back thru the filters. At top end this problem was gone and made good power. (399rwkw @ 17psi)

I changed from the twins to a T51r and the problem was gone. I was told it will damage the turbos as the exhaust wheel turning one way and the extra air trying to turn inlet wheel the opposite....

So is this true that it can damage the turbos mate?

Can anyone verify this?

I might have to fix it by going back to the plumback setup if it is.

[R31Nismoid]

Ah ok i was going to say the power sounds about right for 1bar give/take, and given a built motor crank it upto 20psi and see 380rwkw

Comp surge especially whilst building boost is bad, you are fighting two forces at once.

Backing off throttle isn't such a worry though (the other type)

[WHITER33GTS-T]

So is this true that it can damage the turbos mate?

Can anyone verify this?

I might have to fix it by going back to the plumback setup if it is.

I was told by a few places that it puts added stress on the turbo shaft as the wheels try going different ways as the pressure comes back thru the compressor cover.

I also tried the same twin turbo setup on a 25/30 and had the same result just with the choofing noises at lower revs

Maybe a question for the tuners....

Would it make much of a difference changing the cam timing to clear up the surge...?

[WHITER33GTS-T]

Is it this bad...?

Have a read here.

http://www.skylinesaustralia.com/forums/Co...ompressor+surge

[Mark-32]

So how exactly does the plumb back setup solve the problem?

Wouldnt the extra air that is escaping through the compressor cover still escape, only instead of escaping all the way back through to the air filters its just get resirculated back into the intake?

Im just trying to understand how the plum back would solve the issue of too much air geting forced into the engine at low revs. As surely the same amount of air is geting fed into the engine plum back fitted or not........?

[R31Nismoid]

I told you in the first reply

[si]

Have a read of this thread - http://www.skylinesaustralia.com/forums/Gt...-F-t160901.html

It can be tuned out. It's also possible your wastegates aren't set the same causing one turbo to try and run more boost.

I run the trust/greddy piping too with hks 2530s but i have the standard bovs. Only rarely got the shuffling going up a hill in 5th.

[Mark-32]

Have a read of this thread - http://www.skylinesaustralia.com/forums/Gt...-F-t160901.html

It can be tuned out. It's also possible your wastegates aren't set the same causing one turbo to try and run more boost.

I run the trust/greddy piping too with hks 2530s but i have the standard bovs. Only rarely got the shuffling going up a hill in 5th.

Thanks heaps for that man. Thats exactly what I was after!