Ive got a 65mm pully on my charger and was wondering what boost I should be getting? I think ive seen it at 0.7 Bar near redline. Should it be more though? Im running twin v belts so could it be slipping at high RPM?
John
the belts are most likely slipping. You should be getting more like 0.9 - 1.1 bar depending on the spec of the engine, a longer duration cam, gt inlet or ported/big valve head will decrease the boost pressure you see in the inlet manifold slightly.
depending on yr charger too... ported ones push out more air
my charger has had the Jabba R1 rebuild not too long ago
Well you are definetly loosing power then, a toothed pulley system would solve this issue however i am not sure where you can get one from anymore. No doubt Pete will have some ideas.
Belt dressing would help to reduce the slip for the mean time though.
what is belt dressing? Im thinking about selling my G soon anyway but it would be nice to get the power up a bit before it goes
An R1 charger with 65mm pulley should make 0.7 bar by about 3000rpm, peaking at around 1 bar. The belt slip is only an issue at high rpm. Do you have an induction kit? An unmodified stock airbox is very restrictive and will limit boost to 0.7/0.8 bar (as I found out when I first put a smaller pulley on).
yeh ive got the jabba sport induction kit with heat sheild. On boost I cant hear any escaping air at all. Could it be the butterfly valve that closes to direct boost into the throttle?
I'd still suspect the belts slipping before anything else. How old are they?
Yeh, Ive just looked through my huge folder of history and the only documentation I can find about the V belts being changed was from 2002....7 years ago. So its most probably the belts then.