those numbers are too high the supercharger clutch is proven to slip at around 23 psi...

and I know that the Let Pulley is larger than the renntech or asp and if this renntech was 20-21 Let Pulley would be around 23 and that would probably not work...

 

I'm interested to know where this was proven... I've heard it before but do not know the original source. I'm making a pulley that's larger than the LET pulley, but I wouldn't know how to quantifiably determine if it's actually slipping. Do you have a link somewhere

 

Vadim from Mbworld.org proved it a while back.. the thread is there, but it is a real pain in the *** to find it there...

What size are you looking to make the pulley?

 

192mm, already made and fitted. Made a 97mm water pump, but I need to get it shaved just a bit more. It fits, but it's a close call, and since the WP pulley is steel, a thin wall should be fine. My only obstacle is finding a belt that fits. I believe stock is 113.5" and I have a 116.25" belt on order, and I'm hoping that fits. Belts that large and with that many ribs are hard to come by. Even the one I did manage to find was only 7 rib.

 

Nice Job! Look forward to hearing how it all works out. Did you just machine down the stock WP Pulley? Is your Crank Pulley dampened?

Please post a few pics if you get the chance.

 

that's a large pulley, but I do not think your getting the danger zone with the clutch slipping cause the let pulley is 185mm... but you are gonna be pushing quiet a high psi... higher than anyone I know... for these engines... please let us know of your results...

 

That was one of the things that was nice about the Renntech kit, you used the OEM belt. There was no guess work, it was a nice neat package ready to just bolt on. But I know, too many $$$.

 

You are going to be pretty close if not hitting the redline of the SC with a 192mm pulley. One of the SLK32 guys was running a 192mm pulley and got very minimal gains in the higher RPM. The IAT's are probably getting high enough that the ECU is pulling timing negating much of the gain by going so large.

Make sure you log your IAT's and timing and get your car dyno'd. I am interested in seeing the results of your large pulley. Hopefully you will have great results.

 

There's a guy by the name of Larry Woodruff that lives around the corner from me, he has a machine shop and builds race engines and has for years. He is one of the top race engine builders in the tri-state area, anyone in the tri-state area that is a serious racer (1,000 + HP) has probably heard his name. He helps the owners run a 6 year old 1/8th mile track named ET Dragway that is only about 15 miles from me. I had stopped and talked with him this past Sunday about getting me another 8" pumpkin for my 64.5 Mustang that I had put 3:55 gears in a few years ago. I want to keep my 3:55 pumpkin in tact and get another with 3:25's, the car is running around 3,000 at 60 MPH (pumping water too fast through the radiator & getting hot). I stopped in to see him yesterday to see what he had come up with. While I was there I asked him where the closest 1/4 track was at, he said Indy was the closest and that's about a 2 hour drive for me. So I was asking him about the different classes at the 1/8 mile track he helps run. He said that they have a street class, (but called it something else) then the next step up was the Pro class. I showed him the results of a run with the GTECH meter and he said if the meter was right, I may not be able to run the street class. He said my 60 foot was not too good, (probably the TC kicking in on the launch) and that if I was able to hook up on the launch with a better 60 foot time I would be under 8 seconds in the 1/8th witch is their cut off point for the street class (meter was 8.263 w/ bad 60'). I didn't know weather to be happy or sad, If I was to take it there I would want to be one of the fastest in my class of course.

 

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I know how you feel. Traction control off and just mashing it results in roasting the tires on the launch.

 

I noticed in your signature you have the Renntech too. You have any secrets on getting a good launch? I only done 3 runs on this little GTECH meter, the first 2 were on pavement and the launches sucked, both were 12.9 @ 109 MPH. The third one was on concrete, but you could still feel the TC kicking in. I thought about trying starting in W mode & then going back to 1st once I got moving.