Well,I installed the smaller pulley on my Whipple this past friday night.Can you tell a difference going from 6 pounds boost to 8??Definatley...Truck felt better/stronger at part throttle and WOT.But I was getting audible detonation,even though I showed zero KR.So to be safe until I can get another tune or water injection I put the 6pounder back on.
I'm thinking about ordering the SMC water/alky injection kit tommorow.
Damn boost is addictive

Randy

 

how much timing are you seeing? i doubt you will see any gains with 8psi and a more conservative tune(too much hot air) but i would really like to see how the water injection works. that audiable knock with no KR is BAD!! you need to figure that one out or you will break something, that should be your first concern, get that figured out then toss on the 8psi pully.

 

I have been running 7 psi pretty much since I put the blower on but recently I put on a 9lb pulley. At the same time I did a little porting on the intake. I was disappointed when I went for a drive and only had 7.5 or so psi. I gave up, figuring the port work I did caused improved flow thus less boost (all boost is is resistance to flow). A couple days ago I was staring at the motor trying to think of something else to do and I noticed shredded rubber dust around the top pulley (belt slippage). My kit came with a 3 5/8 pulley and now I am down to a 2 3/4 and was still running the belt that came with it. So I went to the parts store and got a shorter belt and now I have 9 psi and audible detonation! I took it out last night and added some fuel and pulled some timing and I think I got rid of the pinging but as Parish said I think it is slower now with more boost/less timing. I was running 14,5 with 7 psi and now I have it pulled back to 11.5. According to my Vericom it lost 2 mph in the 1/4.

 

I backed up my WOT timing with my Predator but never did get rid of the detonation.Also after backing up the timing the truck didnt feel as fast as it does with the 6 pound pulley and full timing.But....man it felt good with full timing and the 8 pounder,even with the detonation.Even if the detonation was gone at WOT,i have no way to tune for part throttle and was getting detonation at part throttle also.I hope Whipple is really coming out with an intercooler this time.I still think i'm going to try water injection until then.