Hey Guy. I have a stock 99 SSEI. I wanted to through a new supercharger pulley. I wantedto know How small i can go and what i need to do to get the smallest one.

you need to first get the car running in top form first, so a full tune up is in order. There is no magical forumla to tell you what pulley you can run safely.

personally i wouldnt run smaller than a 3.5" with out more mods

totallya agree, no smaller then a 3.5" Make sure the cars up to snuff first. Going to a 3.4" is risking damage if your not set up right.

well i have a computer and the enige only says i have a misfire cylinder 4. i already did new plugs and new wire. I also took apart the ICM and cleaned that. it is all running smoth. But its bringign up cylinder 4 misfire and A emisions system control code. Other than thats it runs perfect.

definately get that misfire and emission code taken care of first. personally i wouldnt even attempt a pulley drop until you get more mods, ive seen too many chiped pistons. i would get the exhaust opened up, cold air intake(i see you have one), reprogrammed computer, 180* thermostat, 1 step colder plugs, then you could safely drop to a 3.5 or 3.4 depending on how much you open up your exhaust. but above all you need a way to scan your car for kr so you dont blow the motor.

What do you mean about the exhaust opened up. And i just got new plugs and wires.

Opening up the exhaust means removing as much back pressure as possible. Headers, 3" pipe, hi-flo cat, Magnaflow or Flowmaster mufflers - is a good example of open exhaust.

Should i look into doing a hole new flow master exhaust system. Headers to tips. My had has and old 3800 seriors motor in our basment from a 98 sse. i could also instead use those headers and work from there. What do you think would be better.

No need to replace the exhaust. Stock is a 2.5". Headers, 3" down pipe, 3" free flow cat, and a good muffler for a nice tone. That'* all you will need.

For the smallest pulley to be run, you need to get a whole lot of stuff. Stage 3/4 heads, larger valves, about 130# springs, a cam, rockers if they will fit, a double roller timing chain, an intercooler, the LIM opened up to fit the intercooler, a ported supercharger, a bigger throttle body, larger fuel injectors, a more powerful fuel pump, headers, a high flow cat, 3" exhaust tapering down to no smaller than 2.5" or staying at 3", and you can retain your stock muffler if you'd like.

That takes care of the basics. You will find that if you go this route, there are many little things to buy, like different fuel rails and some fuel lines to go over/around the supercharger once the intercooler is put on, and then there'* that whole thing about the transmission being eaten in the first few weeks of you running with such a setup.