GrnDragon

iTrader: (4)

I have finally been test driving my TA around, but I am only seeing about 3-4 psi at 3800-4000 rpm. I sized/designed everything for about 12 psi (estimated HP at that level). With a redline of 6300 do you think I will hit it or do I need a smaller SC pulley?
7.65 Crank pulley and 4.5 SC pulley on a F1A...more engine spec and some vids in the below thread...

Should I buy a 4.25" SC pulley???


https://ls1tech.com/forums/lt1-lt4-m...in-rubber.html

gccasper04

iTrader: (4)

See what it shows at redline and go from there. My 7.65/4.0 Made 15# at 5500

Id imagine youd be a littler higher then 4 at 4000 though.

Bob@BruteSpeed

iTrader: (16)

What is your elevation? Nevermind, I looked it up and you're close to sea level. As has been posted, you need to take it up higher to see what it will produce. The graph below was with an F-1A at 12.4 psi at redline. Bob

GrnDragon

iTrader: (4)

Good Problem to have update!!!!

I changed the 4.5" pulley to a 4.25" and did a couple pulls up to 5700 RPM (redline is about 6500) in second gear got 6 psi boost (again thought there was a boost problem). I thought I was getting into it, since it was pulling so hard. Came home and checked the data log it was only about 1/2 throttle! I sent the log to my tuner anyways, and he sent me an update.

I loaded the new tune and did a couple more pulls, this time REALLY pushing the fine line of doing a 1/8 mile burnout. 2nd Gear, 6400 RPM, hit the rev limiter, going 85 mph, and hit 13 psi!!!!! I thought I was going WOT, again came home and checked the data log and was ONLY 65% throttle. This thing is INSANE! Based on the base engine HP (485 FWHP), Boost level, and drive train loss it was making about 775 RWHP.

I will admit that Bob was correct, I just changed back to the 4.5" blower pulley.

I never would have thought I would say I am making too much HP!

Bob@BruteSpeed

iTrader: (16)

Good to see it's making boost! Bob