91_bowtie

iTrader: (5)

Last february, I blew up the stock 5.3. I was running the 3.5" pulley on the whipple, and it made 10 psi. When I bought this pulley, whipple told me it was the smallest one they made for the 2300ax blower. In the last few months, I've built a 370 to handle the power a little better. I'm using diamond 15cc dished pistons, which should put me at 8.8 CR. The new cam was designed to build boost quick, and it does. It jumps to 4psi very easily. We put it on the dyno for some tuning and found that it wouldn't make over 5.5 psi consistantly. It spiked at 6 psi during one pull. In order to build more boost, I either need to get a custom pulley made or use an overdrive crank pulley. Has anyone used the overdrive crank pulley? What diameter would I need to make 3 more psi?

I'm a little confused why it builds 4psi at half throttle and only makes 1.5 more at wot. I'm wondering if I hooked up the whipple bypass incorrectly when I put it all back together.

Any ideas?

nightrunner

iTrader: (4)

if everything is working right, id be looking at a bigger blower. either swaping to a KB or a 3.3L Whipple or even a Magnuson TVS when they are available

you are intercooled, right?

91_bowtie

iTrader: (5)

Right now my only cooling method is the snow perf meth kit, but I was planning on building a front mount setup this fall. If I yank the blower, I'm going turbo. I could build a nice turbo setup for alot less than the cost of the bigger blower.

This is the same kit that whipple sells for the 6.0, so I'm a little confused why their smallest pulley only makes 5.5 psi.

nightrunner

iTrader: (4)

a cam will drop your boost level too.

did you put ported heads on it

91_bowtie

iTrader: (5)

I know. The cam I had before bled some off. This one was designed to hold the charge.

nope, but the 317's do flow a little better.

I know boost is just a measure of the restriction. My rwhp was way lower than I thought it should be, but torque was pretty strong. I guess I just maxed out the whipple. I thought it had more in it.

nightrunner

iTrader: (4)

i personally would have had an intercooler all along. if you add one now that will only lower your boost level but you could probably run more timing and/or less meth.

sounds like the only solution is to get a bigger compressor, whether it be a bigger blower or a turbo sized for the motor.

i dont think you will find a crank pulley that will fix the 3psi low boost problem

03sierraslt

iTrader: (22)

They only make a 3.5 pulley? WTF? Your whipple isnt much different then my KB and I am runing a 3 3/8's pulley. KB makes them down to 2.5" for mine.

1slow01Z71

iTrader: (36)

I dont know what your numbers were but ranwalk made like 530rwhp and 5XX tq if I remember right. If you are bored search for it in the dyno section.

91_bowtie

iTrader: (5)

The motor needs more boost, not a cooler charge. This motor was built to handle 15 psi. easily. It is much more efficient than the old setup. It's asking alot of the 2300 to fill 6.2 litres as opposed to the 5.3 that it was filling before. I still question what pulleys whipple sells to the people who buy this kit for their 6.0. It already has alot of timing, and absolutely zero KR, while running pump gas.

There are several people that make the overdrive pulleys. I was just wondering if anyone on here was running one. I can relocate the tensioner if clearance becomes an issue. I didn't see any dust on the pulley, so I don't think I have a problem with belt slip, and I'm running a brand new gatorback belt.

2.5" pulley damn... that'd be nice. My IAT's would be around 280 with that though.

nightrunner

iTrader: (4)

i was just saying that i didnt think you would be able to find a overdrive crank pulley big enough to make an additional 3psi