Indiana Z06

I have an 02 Z06 with an East Coast Superchargers ATI D1SC. The car has no restrictor plate and is running a 4.25" pulley. Here is my problem: my builder is tuning for the new pulley, which should make 8 lbs of boost. In 1st and 2nd gear, the car makes a solid 8 lbs of boost. When it's shifted into 3rd and 4th gear, the car only makes 5 lbs. The belt (shredded), tensioner bearing (bearing went bad) and BOV were all replaced with new parts and there is no indication of belt slip. All pipes have been checked for leakage. What do you guys think could cause the boost loss in 3rd and 4th? He took the car to the track tonight and it ran 123 mph with the full 8 lbs of boost in 1st and 2nd and only the 5 lbs in 3rd and 4th gear. Thanks.

LustrousWS6

iTrader: (1)

Stock displacement? If so, belt slip would be my only guess once you're getting the tires to hook up (after 2nd gear).

Hopefully some that are more experienced with the Procharger kits will chime in. Are you running the 6 or 8 rib belt?

EPP

iTrader: (22)

A dirty air filter may be the problem.
Also, the spark could be getting blown out if the wrong gap is used.
What intake manifold are you using? Bob

Indiana Z06

Hey Bob. It's barely got any miles on the kit so I don't think it's the filter. The motor is stock LS6 and it's not missing so I don't think it's blowing the spark out. The boost gauge is showing 8 lbs in first and second and only 5 in 3rd and 4th.

EPP

iTrader: (22)

You won't necessarily feel a miss when the boost is blowing out the flame. We use NGK TR6 pn# 4177 plugs gapped at .035 for starters.
Normally at 8 psi .035 is perfect.

You also want to check for any black powder on the blower housing, which is an indication of belt slippage. Bob

white01ss

iTrader: (37)

I had my bypass valve hooked up wrong before and only ran 115-118 in the quarter with 6 lbs, but after it was fixed it ran consistent 123 mph on 4 back to back runs with 8 lbs.

I would say the problem is with the boost gauge possibly leaking boost and giving a false reading. Plug the in car gauge's reference line and connect a good shop style gauge to a different spot and run it again for comparison.

Indiana Z06

Thanks for the help guys. I appreciate it.

white01ss

iTrader: (37)

You can perform a quick test of the BPV by plugging the vacuum line that feeds it (keeping the BPV closed) and take it for a quick spin. If you get 8 lbs in 3rd/4th then there's a problem with the BPV or the vacuum line going to it.

NOTE: You don't want to leave it like that for long or it can cause accelerated wear to your $3000 blower.

This is how I found my BPV problem. Believe it or not, I still got 5 lbs of boost with an open BPV and ran a best of 12.1 @ 116!

What are the rest of the stats on the 123 mph run? 60', 1/8 et/mph, 1000', etc. I'll compare them to mine.

white01ss

iTrader: (37)

Curious if you figured this out yet...

bluehawk2

iTrader: (74)

I am curious as well I have had my car on the dyno twice, one time it was with the 4.25 pulley which would go to 5.5 lbs at 5000 and then flat line. Don't think it is a belt slip prob because I an not getting dust on the housing and the belt is tighter than dicks hat band.

I put the 4.00 pulley on expecting some good numbers and it will only make 6 pounds at 5100 same thing rises great until 5100 and then it goes flat If this is a belt slip prob with the 8 rib then I am going to call it a day with the procharger. I don't think that is it

I am about to do a pressure test on all of the pipes, but for right now i am thinking it could be a problem with the procharger bypass valve