20SS06

Hey guys,

So I installed a larger cam that was profiled by Pat G. He said to set the shift point at 6500 rpm. My max blower speed as rated by Whipple is 18000 rpm. I did some calculations with my 10% overdriven crank:

3.000 supercharger pulley shifting at 6500 = 17983.33 rpm

2.875 supercharger pulley shifting at 6500 = 18765.21 rpm

I have both pulleys on hand as well as a 2.750 pulley. My question is which pulley would you go with and what rpm would you shift at? Would a smaller pulley shifting at say 6200 rpm net more power than a bigger pulley shifting at 6500 rpm?

Opinions are much appreciated!

Vortec350ss

iTrader: (20)

I have heard the 2.3 whipple can be overspun... as far as which I would go with I think that is a question you will have to answer with trials.

the smaller pulley will definitely feel faster on the street, but the larger pulley and higher shift points may actually be faster at the track. being a 6 speed your trans keeps the engine in the meat of its power really well, so I wouldnt think that an extra 300 RPM would net as big of a difference as the 4 speeds do.

20SS06

Thanks Vortec. Over spinning it is! I'll let you know how it goes.

JohnDaMan

iTrader: (7)

I had a 2.3 Whipple on my 04 Lightning for quite awhile. Yes, you can overspin the blower, I overspun mine a lot! The problem I always ran into was the heat it created from pushing the little blower outside it's efficiency range. I would notice my IATs would skyrocket after anything past a 2nd gear pull. The truck had a Meziere coolant pump, 10gallon intercooler tank in the bed and a Trick Performance custom intercooler. It had about every cooling option you could get basically. Overspin it and see how it does but watch those IATs real carefully. I would bet on a good, long WOT pull in 3rd gear you'll see those IATs go higher than you think.

20SS06

Thanks for your input JohnDaMan. Wow you got a lot of cooling going on and still noticed high IATs. I would say it depends on how much it's being over spun. With my current setup and shifting at 6600 (cuz I have a pretty big cam installed now), my blower will be roughly spinning at 19054 rpm. However, I also do have a big intercooler and a pre-blower dual nozzle methanol setup which to my thinking will definitely cool the air in the blower. Note: I am injecting a hefty dose of meth. Anyways I will be tuning it next weekend and will let you guys know how it runs. I will post a video as well.
Fingers crossed

MonkeyRench

Is your blower still under warranty? Might want to go with the bigger pulley if it is. I'm with Vortec350ss on this one, spinning the blower might not actually be an advantage with the few hundred rpm difference. Keeping the blower spinning in the right zone and going with Pat G's advice on the spinning the motor at 6500 for the cam will pay off. I overspun a vortec for a while and it just blew hot air after a certain point. I did add meth to keep the intake temps down but I think I shortened the life of the poor blower.