Re: compression reduction, B234F + Turbo
Postat: mån sep 19, 2016 6:14 pm
A small update.
The car has been dynoed on a rolling road to 561bhp/6073rpm, and 685Nm/5403rpm @295kpa manifold pressure. Ordinary Shell Vpower.
Fastest 201:
1,77sek 60feet
7,91sek 201m
Fastest 402 last year.
1/4 in 12,32sek @ 196km/t
It puzzles me that the engine falls "flat" on its face around 6500rpm loosing almost 100bhp at 6800rpm.
I am keeping the boost constant around 295kpa with the boost controller, so its not a drop in measured boost.
Is this simply the range of the stock cams on a turbocharged B234? Very little heat in the exhaust, so this seems not to be the bottleneck. The boostcontroller does not call for more turbopressure, even at 7000rpm so the compressor seems to be ok. Charge air temp is steady around 36degrees.
I am a bit suspicious on the hydraulic lifters but they are hard to check for. Im running KL racing valvesprings 34kg. The engine maintains around 5bars of oilpressure at 2500rpm and above.
Any good suggestions to get a B234 turbo to rev further up?
The car has been dynoed on a rolling road to 561bhp/6073rpm, and 685Nm/5403rpm @295kpa manifold pressure. Ordinary Shell Vpower.
Fastest 201:
1,77sek 60feet
7,91sek 201m
Fastest 402 last year.
1/4 in 12,32sek @ 196km/t
It puzzles me that the engine falls "flat" on its face around 6500rpm loosing almost 100bhp at 6800rpm.
I am keeping the boost constant around 295kpa with the boost controller, so its not a drop in measured boost.
Is this simply the range of the stock cams on a turbocharged B234? Very little heat in the exhaust, so this seems not to be the bottleneck. The boostcontroller does not call for more turbopressure, even at 7000rpm so the compressor seems to be ok. Charge air temp is steady around 36degrees.
I am a bit suspicious on the hydraulic lifters but they are hard to check for. Im running KL racing valvesprings 34kg. The engine maintains around 5bars of oilpressure at 2500rpm and above.
Any good suggestions to get a B234 turbo to rev further up?