Quick Boost Question

[racinjason89]

I'm not sure where to post this, so here it is. I have a 96 mystic with a kenne bell on it. I've adapted a 2.2L Blowzilla, but it's putting out more boost than I want. Unfortuately, I can't go bigger on the blower pulley because of the belt routing (it will rub itself). My question is: If I get an underdrive crank pulley that is 25% smaller than stock, will this take away 25% of the boost? Or is there some equation I need? Someone please help! :dunno:

[Dave B.]

how much boost is it making?

[racinjason89]

20-22 PSI :eek:

[blk04cobra1]

that's definitely not the stock pulley...

[racinjason89]

It's the 12 psi pulley that comes with a 2.2L blower (or so KB says). There is no actual 2.2L kit for my car. I custom fabricated a bypass for it! I think the underdrive crank will do the trick, but I just wanted someone elses input!

[Dave B.]

I must admit that I am not qualified to answer your question on that kind of problem

[NO 5 OH]

Jason... you are correct in your thoughts in that the smaller the crank pulley is the less boost you will see. To give you an idea... all the "lower" kits for the 03/04 Cobras make their boost by increasing the size of the lower crank pulley. I can't say as to how much boost you'll drop with a 25% underdriven crank pulley but it will be less than the current 21-22 psi you're seeing now.

You could always run race gas and get it tuned for that boost... it would be really fun :D:D:D

Hope this helps,

Shannon

[Ram77mus]

I WOULD START WITH THE UNDER DRIVE PULLEY- THAT A LOT OF BOOST ,AND IF IT'S A STOCK SHORT BLOCK- OOOOO'BOY:eek:

[racinjason89]

I ordered the pulley today. The problem with all that boost, my car hates any timing! Therefore, HP numbers aren't what they should be! So my thought was to lower the boost a few psi and add timing. I should know in about a week. I appreciate all the help. I'll try to repost about the results. And by the way, not a stock short block! I'm not quite that crazy!! :D