I guess i'll take my build questions elsewhere. :roll:

Seriously, i'm providing the most information i can, i don't know the diameter of his pulley, he hasn't replied to my questions about it.

Yes, i have it all figured out, you're trying to tell a guy what he can't do with an engine you know nothing about. :roll:

Like i said, it's for the learning experience. I spent too much money on the exhaust anyway to have to hack it up for a turbo.

I'm not looking for big power, just the experience.

Edit: It's a 2.5 liter.

ok, so you only want to change the crank pully to get more boost at the SC.... why not just drop a pullie size on the SC instread

No, i'm not intentionally changing the size, the issue lies in getting ahold of a supercharger pulley for these cars, there's one company out of Germany that offers them, but basically people said "Good luck getting ahold of one". The one pictured is a drilled Escort pulley which is actually a harmonic balancer. I rather not run a harmonic balancer, i went to the junkyard and pulled one of those, didn't seem like a good idea to put it on my car. The Durango one was my best option i found as i looked around, fitment was great, but the size has me concerned.

I'm not changing anything for more boost, my car came factory with V-belts, i need to convert to the ribbed type.

Any ideas for a larger supercharger pulley...? :?

Really though willwren, don't let me lose my appreciation to the Pontiac guys, the local GTP guys have been more than helpful to me at no charge for small parts and just help in general. Seemed the guys here were the same until you started posting.

Get the sizes of your two pullies and I'll convert it to a pulley size as it would be on a Bonneville so these guys can get a better idea.

Look, Will is just trying to help you keep from sending some top engine parts through the hood. I've seen it happen. If you could give us more information that would help us believe that 12psi with 9.2:1 compression won't make a big bomb, we can seriously help you here.

How much have you opened the intake? How much have you opened the exhaust? How far have you upped the rocker ratio so that beast can breathe? Hypereutectic pistons? Have your calculations handy? I would love to see those, and could really help you double-check your math.

No matter the make or model, non-supercharged/turbo'd versions have higher compression than the supercharged/turbo'd engines for a very good reason. We're not here to second-guess the engineers. And the BMW engineers didn't use magical indestructible heads and pistons. In fact, you'll very likely see the same pattern in those makes as well.

If you choose to just slap it on and start 'er up, please make sure no one else is nearby.

Excuse me, I'm confused, but I'll ask anyways....the picture you posted is not the actual motor you're working on? But you are working on a motor, but don't know the sizes of the pulleys you have? Can you measure them?

I can measure my crank pulley tomorrow and my supercharger pulley (it's a stock one).

9.2, not 9.5

When you say the supercharger pulley is a "stock one" what do you mean? I thought you had some kind of pulley from a Durango. Or did you just decide not to use that one? I think I'm beginning to understand now. :lol:

To us, the word 'stock' regarding a SC pulley is either 2.5" or 2.8" for an M62.

Notice where he drew the circle. He's changing the crank pulley. The SC pulley is stock and the crank pulley has been added to the car (which has a v belt setup). He's going to the durange pulley if it won't be bad for boost.