I had ASP make a 9.5" crank pulley for my race car.
I had a 2.87" blower pulley on at one time.
If you do the math, the 2.8L Kenne Bell was spinning 26,480 rpm at 8K engine rpm.
It did not make more boost. It just added heat to the air it compressed.
I was stuck at 20 psi regardless of how fast I spun the S/C.
I slowed it back down to 21K rpm and made the same 20 psi.
You could also change everything over to 8 rib.
Pretty straight forward.
I had a 2.87" blower pulley on at one time.
If you do the math, the 2.8L Kenne Bell was spinning 26,480 rpm at 8K engine rpm.
It did not make more boost. It just added heat to the air it compressed.
I was stuck at 20 psi regardless of how fast I spun the S/C.
I slowed it back down to 21K rpm and made the same 20 psi.
You could also change everything over to 8 rib.
Pretty straight forward.
On this project, I'm not really after more boost. I want to swap my current pulley (small) for a larger one and maintain approx the same boost level I have now so that I have a little more 'grip' on the blower pulley.
How large of a S/C pulley do you want to go?
I have a pretty good assortment, although they are all 8 rib, but it would still work.
Well... Initially, I thought the OEM crank pulley was 4.375. 85GT informed me that it's 5.791. Then, Toolow told me about the F150 5.8 crank pulley and that it is 6.5 inches.
So, 5.691 / 6.5 (just ballparking at the moment) gives me 0.890. Let's just round that off to 20%.
My idea is to increase the blower pully size by 20%-ish percent and under drive the WP and Alt by about the same or close, if poss.
At one point, long ago, I recall doing the math for my My 2.2L and if I recall correctly, the current setup put at or near the top of the blower at 6250. So, I'm not really looking to increase boost but there may be a hair of wiggle room up there. I'm pretty sure I based by calculations on a 6250 cutoff. It's not even necessary to rev this combo that high (although fun as fk).
The smallest I got is 2.87" I think. A bit more than the 10% you want.
Rule of thumb with KB's is that with every 1/8" of S/C pulley change you get a 1 psi boost change.
2.87 of 2.625 = 0.914 so, that's right at 10%.
I have a few other pulleys for the SC. I gotta go around and find them all, along with my pulley tool.
Just our of curiosity, what does a complete 8-rib setup go for? Does it apply to the PS pump, and A/C too?
You would need all the pulley's and I imagine the A/C one would be a bugger to get., although, with the correct dimensions sent ASP should be able to make that one as well.
I bought some of my S/C pulley's from Billet Specialties, and some were made by ASP.
All the crank pulley's were made by ASP as well as idler and tensioner and Alt.
I don't have P/S, A/C.
Prices are based per item, and depending on size/dimensions it could change a bit.
I paid just over $200 for the 9.5" crank pulley. I wanted a 10" one, but their biggest block of Billet Aluminum was 10" and they could only mill out a 9.5" out of that, and I am sure prices for billet aluminum have changed a bit since I had my pulley's made.