Stock SN/89 Pulley Wanted

[dls322]

Hi,
I need a pulley for a SN/89. I recently had the shop install my unit and the pulley that it came with is too small, and boosting too much.....haha, i know thats a good thing, but i want this unit to last.

Thanks!
Dave

[dls322]

It has to be an 8 rib pulley too. Thanks!

[speedytang]

Hard to find a 4" or larger pulley in a 8-rib. EBay is probably your best bet used.

[dls322]

Thanks for the reply.

I just had the charger installed and the bottom crank pulley is an 8 rib setup and the supercharger pulley is a 6 rib. The belt is now shredding at the tensioner becasue it's at a slight angle. I either need to get a 8 rib supercharger pulley or get a 6 rib crank pulley....gotta love ebay used supercharger kits that give you mixed parts!!

Any suggestions? Paradise recommended going back to a 6 rib crank and they could get me one for $100. BUT, my supercharger pulley is the smaller one and it's boosting too much, i would have to change that then too. It seems just easier to get the 8 rib supercharger pulley, that is the route my shop said to go.

I am measuring everything tonight so i can speak more educated on the subject. Thanks!!!

[speedytang]

What size is the 6-rib on the 'SN' and what psi are you seeing and what psi do you want. I am trying to calculate what size you need to find.
Thanks

[dls322]

I have to measure the pulleys when i get home. I will post the sizes tonight. I just got the car back from the shop yesterday. The place is a really good shop and actually a paxton authorized installer. They tuned the car and computer with a SCT chip they installed as well.

The guy warned me that there was a smaller pulley on it. He had it on the dyno and it made 350 hp at 5000 rpms, but after that the belt would slip. It also shot up to a max of 9 psi of boost. He recommended just taking it easy and not overreving it until i got a new pulley. He would install the new pulley for free when i get it.

9psi is tooo much in my opinion, i want to have fun with the car and would be happy with stock boost of 6psi, since i don't want to be replacing the supercharger anytime soon.

This whole project went double over budget allready! I just want to get this issue ironed out so i can enjoy my debt :teeth:

[speedytang]

Sounds Good

[dls322]

Ok, I measured the pulleys. The supercharger one is a 3.75" and the crank pulley is 7". The supercharger pulley is 6 rib and the crank is 8 rib.

Weird that it hits 9 psi on the dyno. The guy that i got it back from said that it had been rebuilt, but i have no way to confirm that.

Is this setup safe or should i a go bigger to the 4" or 4.25"?

One more question is that should the tensioner pulley have back and forward play in it? I can slide it back and forth (i have to really push it because the belt is on) but it will more towards the engine and then back towards the radiator. Is that normal for the tensioner? The tensioner has no ribs on it and is plastic.

To recap i have a 6 rib belt on the setup and it's gettign shredded by the tensioner, i think due to the angle the belt is going due to the crank being an 8 rib setup. And the belt is slipping around 5k.

Should i get a 8 rib pulley on the supercharger or a 6 rib crank pulley? I think i twill be cheaper to get the 8 rib supercharger pulley.

I really appreciate the help, i was heartbroken after just getting her back after waiting almost 3 years to save up for the job and having issues :cry:

Thanks!!!! :teeth:

[dls322]

Ok, I called Paradise today and gave them the measurements. He said my 7" crank pually was not stock and really overspinning the charger. He said i could run the 4.25 8 rib, but after he did the math he said i would have to limit my engine rpms to 5k. He checked and he actually had an 8 rib 4.5 supercharger pulley on the shelf. He's sending that out to me. Sounds to be perfect.

I can't wait :teeth:

Thanks for your help everyone!!!!

Anyone have anby guesses to a belt size now for a 4.5 and 7" pullies, 8 rib?

[speedytang]

That would be perfect if he has one.