I'm considering upgrading my supercharger pully. If I measured right, I have a 4" pully, I assume this is stock. I'm coinsidering adding one of these from intense-racing.com.

MKP-320 - 3.20" Magnuson MP112 Supercharger Pulley
MKP-310 - 3.10" Magnuson MP112 Supercharger Pulley
MKP-300 - 3.00" Magnuson MP112 Supercharger Pulley
MKP-290 - 2.90" Magnuson MP112 Supercharger Pulley

I'm wondering if these will work on my 1997 SSEI, if I will need any special tools (dose not look like it) and approx. how much HP will I be looking to add? Also, will I need to change my stock belt to a shorter belt or change a idler pully to conpensate for the smaller diameter?

Any other information would be great. Thanks to all.

Well, unless you have an MP112 (and not the stock Gen 3 Eaton M90), those pulleys won't work.

Your stock pulley is 3.8" diameter. You really don't want to go below 3.4 (or 3.3) without supporting mods, but I'll let others with more experience in this give you an idea of what is necessary. You want to check out the Intense Modular Pulley System.

Welcome to the pulley club (or soon to change a pulley)

Having a 97 SSEi like you, I searched around before doing it and found that first you need to open up the air intake system by gutting the airbox and dropping in a K&N or changing to a "rice pipe", or going with a fenderwell intake system.

Once you have more air in..then you can swap the pulley w/o too many issues.

I chose to gut the airbox (can go into further if you'd like) and then happen across a pulley and pulley puller on ebay. The puller is a specialized puller required to change the pulley on an M90 (the supercharger on our 97 SSEi'*).

Pulleys can be found from many vendors. There are also standard looking pullies like you currently have on your car and what is referred to as MPS or Multiple Pulley Systems. The valve of an MPS is when you change from one pulley size to another if you plan on adding more mods and things to your car and wish to change the pulley with out renting the special puller again.

Intense, Pulleyboys and ZZP are three of the Bonneville Club approved vendors. Ebay may also be another good source as some of the vendors may auction a MPS at a reduced cost from time to time.

I originally won an auction for a 3.4" pulley and have run it well with some Knock Retardation. The 3.5" is probably a better solution to start wtih and I may be changing up to that size myself.

You want to go with a 3.5" pulley if you plan on leaving your car mostly stock. If you're gonna do some mods to it other than the pulley than you might want to go with a 3.4" pulley, but definately no smaller than that.

Your stock pulley is 3.8". When you measured it you measured the side of it and measured from top to bottom, but really the belt actually sits on the pulley lower than the area you measured and its 3.8" where the belt sits.

You also don't want one of the MP112 pulleys, because you don't have an MP112. Your blower is an M90. There should be M90 pulleys on their site, and I know that pretty much every other 3800 vendor sells them as well.

This is already done. I made my own CAI.

See, this is why I ask questions. I found the correct pulley now. $60 aint that bad. I'll have to see what I can do about the puller. If anyone is in the area with a puller, speak up, I'll be happy to drive over and bring beer.

Well, I'm leaning towards the 3.5 right now. I plan a few mods, perhaps headers at some point, but that'* going to cost me.

Dan..another possibility on the puller is to check the GP clubs in the area. It'* a popular swap with them as well. Possibly more of them local than bonne'*.