[whokilledkaji]

I'm looking at the Alta 15% reduction supercharger pulley, but I have some questions...


I wonder... Do I need the pulley remover tool?

Also, about installation... Is it difficult? Can anybody do it or should it be a mechanic? Any how-tos out there? (I did a search, but didn't find anything...)

Finally, what benifits do you get from a pulley? (I'm new to engine mods and I'm still trying to study up...)


Thanks!!!

[whokilledkaji]

Can somebody at least tell me if I need the pulley remover?

Do I need a new belt too?

[St00ge]

ok, this is what the pulley does, from what i understand. Since it's smaller, it spins faster than the standard pulley for the same crank revolution, thus the supercharger generates more boost for every RPM, meaning you get less lag at lower RPM, and more torque throughout the rev range.

You don't have to get the reduced size belt for the 15% pulley, but you should if you're going for the 17% or the 19%. You do need a pulley remover tool. You should get someone else to do it unless you know the MCS engine well, cos as i understand it, you have to lift the engine out of the bay or something like that....Installing the actuall pulley is the easy bit, but the delicate part is lifting the engine out....look around Randy Webb's site for a how-to, there should be something there if you're confident about doing it urself...

I personally would recommend getting the 17% pulley, as i've been assured by ppl from BMW that it is within the supercharger capabilities, but they said that to me, and i had an 05 MCS. If you don't, i'd go and do some more research, or talk to some ppl that have the 17% pulley. 15% is basically a JCW pulley, and is the safe option, and the 19% is pure performance, and is just out of the supercharger's capabilities, so if you do a lot of high-rev driving, i'd recommend against the 19%....17% is fine for high-rev driving, and is a good comprimise between the two.

To sum up, the smaller the pulley, the quicker the boost arrives, and the more boost you get. But bear in mind that you're spinning the supercharger faster than it should be spun after the 15% pulley....I'm probably getting the 17% and the smaller belt to go with it. And from alta, cos they make the best one....

If you want more info, you'd be better off doing a search, there are oodles of threads about the alta pulleys...that's how i got the above info. and PM ppl that have different pulleys...

Elie

[boothy]

http://store.webbmotorsports.com/for...topic.php?t=17

I think most people do use a smaller belt 2 reduce slipage even on the 15% i Know i have and a few others

[minigolf]

Quote: Originally Posted by etalj

...15% is basically a JCW pulley, and is the safe option...

IIRC JCW pulley is more like a 13% reduction.

[RickB]

I've watched Randy Webb do two pulley installs, including mine, and to watch him do it, you'd think anyone who'd ever turned a wrench could do it in an hour. But, the guy is an absolute maestro, driving two floor jacks simultaneously to both lift and tip the engine so that it's just clear of the chassis, for access to the pulley and tensioner. Even though I probably paid a bit more than I might have if I'd had the work done locally, I considered the price difference to be cheap insurance.
I have about 15,000 miles on the car since the installation, using the stock belt but colder plugs, and couldn't be happier. The car runs and sounds great, and I've taken no hit whatsoever in fuel economy, even though I reckon I've picked up 20hp with the pulley and cold-air intake.

[St00ge]

Quote: Originally Posted by minigolf

IIRC JCW pulley is more like a 13% reduction.

I thought the JCW had a 14.3% pulley...

[XTREEM]

I think you thought right Elie....

[St00ge]

Quote: Originally Posted by XTREEM

I think you thought right Elie....

for once

By the way RickB, wat pulley and intake are you running?

Elie

[whokilledkaji]

Wow guys! Thanks for the great info!!!

[St00ge]

keep us posted...

Elie