Hey, havent posted in awhile but I finally got my FMIC and all that on and a 3.33" pulley. The thing is with my big 32"x12"x3" intercooler Im only seeing like 6.5lbs of boost. Im just wondering what size pulley would you think net me around 10lbs? I just worry now about spinning the s/c head unit too much to make only 10 or so lbs. any help would be great.
pulley size Q's.
- Thread starter 96PonyGT
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i'm pretty sure that a V2 can be spun up to 60k + i do believe, and a 2.90 pulley at 6200 rpms is going to spin it to 52,000 impeller speed.
all you have to do is find the max impeller speed for the blower and the formula to figuring out the blower speed is easy. These are what you need to figure it out.
1. Blower pulley size (i'm running a 2.90)
2. Crank pulley size (stock is 6.75)
3. Engine Rpms (how far you are going to push it, i use 6200-6500)
4. Setup ratio (3.61 for a V2)
then it's (6.75/2.90) x 3.61 x 6200 = 52,096 (which is the impeller speed)
the break down is just (crank / blower pulley) x setup ratio x rpms
all you have to do is find the max impeller speed for the blower and the formula to figuring out the blower speed is easy. These are what you need to figure it out.
1. Blower pulley size (i'm running a 2.90)
2. Crank pulley size (stock is 6.75)
3. Engine Rpms (how far you are going to push it, i use 6200-6500)
4. Setup ratio (3.61 for a V2)
then it's (6.75/2.90) x 3.61 x 6200 = 52,096 (which is the impeller speed)
the break down is just (crank / blower pulley) x setup ratio x rpms
97stanger
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just be careful, i run a 3.12 on my 6 rib and i was told thats pretty close to the smallest you can run without getting belt slip. you may want to run 8 rib any smaller than that
I ran a 3.12 pulley, with stock manifolds, stock heads with a big 31x12x4 FMIC and made 10 lbs with no belt slip. I've got a couple friends running smaller 6rib pulleys and they definitely have belt slip up top.
yeah i've got an 8 rib setup and i'm happy with it, AFM Boost pipe and i'm happy with my procharger.. little bit more
From Vortech Website V2 S-trim
so you don't want to go over 50000 impeller speed 3.14 pulley puts you at 46,276 at 6200 rpms i'm not sure what you are pushing a stock engine to i'd assume you are not going over 6500 which is 48,516 impeller speed.
hope this helps some
From Vortech Website V2 S-trim
so you don't want to go over 50000 impeller speed 3.14 pulley puts you at 46,276 at 6200 rpms i'm not sure what you are pushing a stock engine to i'd assume you are not going over 6500 which is 48,516 impeller speed.
hope this helps some
thanks for the help. I might just go with the 3.12. And I have an AFM boost pipe, I figured it would have made up a bit more boost. Maybe I will check for a leak, although my tuner said he didnt think there was one. Whos knows...
keep in mind that boost is a measurement of restriction, so it's possible for you to make more power with less boost if cooler air is going into the engine 
also i'm not a vortech man but let me know how much of a change you see with the boost pipe.. have you installed it yet? i've got alot of parts sitting at home waiting for me to install them (i'm deployed overseas) and i want to know how bit of a pita it is to install the AFM boost pipe. Also if you haven't done any fuel upgrades the AFM Big pump kit they sell is really good i've been using it. also post some pictures of your setup i enjoy looking at other peoples setup with superchargers.
also i'm not a vortech man but let me know how much of a change you see with the boost pipe.. have you installed it yet? i've got alot of parts sitting at home waiting for me to install them (i'm deployed overseas) and i want to know how bit of a pita it is to install the AFM boost pipe. Also if you haven't done any fuel upgrades the AFM Big pump kit they sell is really good i've been using it. also post some pictures of your setup i enjoy looking at other peoples setup with superchargers.
97stanger
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that does seem extremely low amount of boost. as stated, just remember its only a measurement of restriction. I run the 3.12 pulley, SQ trim, paxton front mount, headers, and blower cams and see about 10psi
with stock 3.60 pulley i see 7psi non intercooled, just bought a 3.33, any clue what i'll be at hoping for 9-10psi.... no powerpipe, o/r x pipe and straight through mufflers, BONE STOCK motor.
i would think a powerpipe and 3.33 would be more than 6psi especially through a stock exhaust, i'd say you have/had a leak. was you running the IAC hose to the powerpipe like its supposed to be, if so there is your leak. i went through this when i installed my kit, i had to put a check valve in the IAC hose, even with a new IAC it doesnt close off at WOT allowing boost to go back to the inlet. i was barely seeing 2psi at 6000rpm, with the check valve i get 7psi on a stock vortech kit.... even though it seems like every couple days i end up with a leak somewhere now. nothing worse than going to the track and only making 2psi......
i would think a powerpipe and 3.33 would be more than 6psi especially through a stock exhaust, i'd say you have/had a leak. was you running the IAC hose to the powerpipe like its supposed to be, if so there is your leak. i went through this when i installed my kit, i had to put a check valve in the IAC hose, even with a new IAC it doesnt close off at WOT allowing boost to go back to the inlet. i was barely seeing 2psi at 6000rpm, with the check valve i get 7psi on a stock vortech kit.... even though it seems like every couple days i end up with a leak somewhere now. nothing worse than going to the track and only making 2psi......
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