Compressor Surge at low RPM......
Posted: Wed Feb 11, 2009 11:52 am
Morning all!!
Got some compressor surge at low RPM, specially in 4th and 5th gears, not at all that i can detect in 1st/2nd/3rd gears. I had a little bit before but it wasn't too bad. Now i have the slightly larger and smooth type RCM Turbo inlet hose it's definately got worse. I know what causes the surge and why so apart from getting a bigger and better designed Turbo with anti-surge design on the cold side inlet or restricting the inlet with something (defeats the object of buying the RCM inlet in the first place), or getting a bottom end with larger displacement, what other options do i have apart from mapping?
I'm in the process of lowering boost at lower rpms via boost and wastegate maps as we speak. I'm undecided weather or not lowering AVCS will help across the affected rpm range. I think it might because a bit less duration on the inlet valves would mean a bit less air entering the cylinder but i haven't read this anywhere so not sure if it will work. I'll look into that when i've done some logging on the new maps but if you have any thoughts i would appreciate your comments.
Does anyone know of anything on the market that might also help with that. I'm not running any aftermarket bovs or anything like that and i'm told rescaling the MAF has no affect. This isn't surge on lift off but on acceleration at low rpms.
Cheers
Got some compressor surge at low RPM, specially in 4th and 5th gears, not at all that i can detect in 1st/2nd/3rd gears. I had a little bit before but it wasn't too bad. Now i have the slightly larger and smooth type RCM Turbo inlet hose it's definately got worse. I know what causes the surge and why so apart from getting a bigger and better designed Turbo with anti-surge design on the cold side inlet or restricting the inlet with something (defeats the object of buying the RCM inlet in the first place), or getting a bottom end with larger displacement, what other options do i have apart from mapping?
I'm in the process of lowering boost at lower rpms via boost and wastegate maps as we speak. I'm undecided weather or not lowering AVCS will help across the affected rpm range. I think it might because a bit less duration on the inlet valves would mean a bit less air entering the cylinder but i haven't read this anywhere so not sure if it will work. I'll look into that when i've done some logging on the new maps but if you have any thoughts i would appreciate your comments.
Does anyone know of anything on the market that might also help with that. I'm not running any aftermarket bovs or anything like that and i'm told rescaling the MAF has no affect. This isn't surge on lift off but on acceleration at low rpms.
Cheers
:thumb: