Progress Thread Might as well start a progress thread on my 92 GT Hatch.

good to know a guy

So I stepped down a pulley size or 2, got a green belt trying to mitigate any possible slip....it did not work, slipping at 6 psi, should go to 10. I attempted to retightenen the belt and tried swapping in my old belt but it was too big. I think I was just overconfident with the griptech pulley and just a 6 rib. I found a 8 rib on marketplace that I am hopefully going to pick up next weekend but that means yet another pulley and belt combo to buy. I don't want to trash the charger bearings but I used the socket head holes in the tensioner to crank it down this time. Before I was just pushing down hard while tightening.

On the positive side, I love what this pulley does down low. The boost comes in much earlier and it feels way better. Old pulley would go from no boost to 7.5psi between 3500 and 6000. Now I'm already feeling it before I hit 3k. Not doing any more pulls till I can get rid of this slip. Any other tips and tricks to get the belt more sticky?

Bullitt347 said:

8 rib is probably your best bet.
I run 8 rib on my racecar and it sees 20 psi from the hit.
I am still running the stock tensioner from 1989, just with a wider pulley for the 8 rib belt.
I get a little bit of belt dust on the S/C pulley and bracket area, probably from the belt slipping on the 1-2 shift.
The sudden rpm drop from shift causes the S/C belt to slip because the S/C cannot drop rpm like the engine does.
With the pulley ratio it would be asking the S/C to drop 6K rpm instantly.
Mine is a Twin Screw, so there is a lot more mass spinning a ton of rpm.

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Yup, that makes a lot of sense. In my test and tune I was just running up gradually in 3rd gear to watch AFR with no tip in enrichment as well as boost. AFR was looking good at 11.0 and once I saw 6psi, boost started to bounce erratically. I may try again with my belt tension adjustments and now that I have given more heat cycles to the belt. I'm sure it needs to settle in a bit and get broken in before I see peak performance from it.

Did you say 20lbs? I have to assume you are not talking about a 302 anymore at those kind of cylinder pressures.

Noobz347 said:

I was going to ask about your belt-wrap but it looks like you got plenty.

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Yes sir, that's with the belt tightened to a low E, maybe a D. I have the space to get a slightly longer belt and wrap even more but there does not seem to be another intermediate size available to get me there before it's too long.

Scored a 8in/8rib crank pulley locally. Got my new charger pulley on the FedEx truck now. Should help with the slippage on 2 fronts. Went with a 3.1 charger pulley. Coincidental, got 2 griptec 6 rib pulleys for sale, less that 300 miles.

Hopefully I'll be done with the pulley/belt madness. Should have a peak blower speed right around what I was getting with the 2.7 and 6.87 pulley. I really liked that boost came in earlier in the rpm range. Street car should not see a lot of full 6k pulls so technically overspinning a smidge but it won't see that often.

The new pulley has drilled and tapped holes in the rim, came from a combo with an old school "race" line vortech (I saw it in the guys shop). Is that for some kind of bolt on belt retainer lip?