Does anyone know what size charger pulley would be a good replacement? My car is bone stock ( for now ) only had it 2 weeks, but reading your threads has sparked my interest for mods. Will i notice any increase with just a pulley change or does it work in conjunction with other mods. I do not race my cars frequently " other is a Corvette" but too uncomfortable for cruising. But like the power to embarrass the local imports when needed. On a side note i am only getting 20 mpg is this average considering i drive 100 miles a day with 75 percent being hwy 65-70 mph.

Going to assume you mean 2000 or 2000+.

You would want to open up the intake by either changing your airbox to a FWI or at minimum a K&N or other high flow filter. A normally safe pulley size is the 3.5". That size typically keeps KR at a minimum (if any).

Please note that changing the pulley requires a specific puller designed for the M90 SC pulley to remove. Any other pullers can damage the charger snout or pulley.

Your mileage probably isn't too off for driving 25% city. If you drive 100 miles a day, that means 25 miles are city miles, and that'* a lot of stop-and-go. If you haven't given it a tune-up recently that will help. But opening up your intake can help mileage as well, which you should do anyway since you want to get a smaller pulley. It would be good to get a scantool or an Aeroforce scan gauge so you can monitor KR, even though the 3.5 is the safer route than a 3.4.

Not to seem uninformed but what is KR? What is the stock pulley size?

Stock size is 3.8"

KR is knock retard. The PCM will pull timing when the knock sensors hear 'knock' or predetonation in at attempt to avoid engine damage. After a 3.5 pulley for example, you may see 1–2 degrees of KR. That means your PCM is pulling that amount of timing. Each degree IIRC is an equivalent to a loss of 2 hp. So 5 degrees of KR would be a loss of 10hp.

You want to pay attention to KR when you mod. If you decrease the pulley size, you'll want to open up the intake too, as stated, and you may also consider opening up the exhaust. You let more air in, you have to let more out.

In addition to what has already been said, I own a 2000 SSEi and I have added NGK TR55 plugs, a tranny cooler, a K&N air filter and gutted the baffels out of my air bow and simply drilled some 3/4 in holes in the box, 180 thermostat, deleted the screen out of the */C, adjusted the */C to max boost at low RPM, Solid tranny mount up front, and added flowmaster 40'*. My average MPG on the interstate while driving from NC to WA state was about 24-27 and around town an average of about 20-22 roughly. My trip was in the summer and it ran at about 180 degrees consistantly. Also remember tire pressure can play a big part also in your MPG and the condition of your catalytic converter. My next thing i plan on doing is a high flow converter. I still have the stock pulley on it and want to do that also next. The PCM upgradeis a good investment also thru intense last I remembered (yet another upgrade I am planning on doing).

Cliff