Quote:
Originally Posted by swarfman64
Hmmmm, Im getting some serious compressor surge, I think. I'm just checking the preload on the wast gate first but I'm getting pulsing/flutter under moderate throttle. Sounds like comp surge to me. It boosts about 7psi on 100kmh cruise at 1200 deg EGT and a rich 13:1AFR. I'm actually thinking this turbo is a little on the small side. No mapping until I sort the pulsing  |
Andrew, one word about AFR, 13.1:1 for a turbo normally should be a little bit to lean, since the optimal rich AFR for a naturally aspirated engine is a 13.23:1 value.
For a turbo at least you'll be better in the range of 11.5 - 11.8:1 AFR, but when you're changing it then go stepwise like 0.3 to keep it a little bit in the 'soft' range.
Good luck
