Just bought a 2000 Grand Prix GT with 135k
Ive wanted one for a long long time and finally pulled the trigger and got one for a steal
Thinking i want to buy a used supercharger in the near future. What would I look for when buying one?
What would the average cost of one be?
We get that question a few times, "Can I bolt a supercharger to the top of my N/A car." The short answer is no, but the long answer is yes, if you're interested in swapping the whole top end out.
At the very least you'll need:
Supercharger and L67 lower intake manifold
L67 throttle body (if you're lucky a SC will come with one)
L67 fuel rails and injectors
L67 heads
L67 valve covers
L67 MAP sensor
L67 brake booster vacuum line
Fuel and vacuum lines
All the various minor crap (head bolts, rocker bolts, head gasket, LIM gasket, valve cover gasket, S/C gasket, TB gasket, etc.)
Another oil and coolant change that you'll need after doing this job
Also be prepared to splice some wires to get the fuel injectors, MAP sensor, etc. to work right.
And once it's finished, make sure you have a supercharged tune ready to throw on the car. If not, you may be able to drive it straight to the tuner, but it'll run like crap.
All that's off the top of my head. The only top swap I witnessed personally, they bypassed the A/C pulley since it was broken anyway, and used a 1" offset pulley that's normally used in a ZZP SSM90 kit, permitting the use of an 855 belt to drive the whole thing if I recall correctly. We didn't get an L67 ignition bracket, but you would need one of those too if you intended on keeping the A/C.
Expect to budget $600 for the job, and don't be surprised if it climbs to $800 or more. Not to dissuade you - blower whine is a glorious sound on a GP GT - but it's quite a bit of work. Moreover, the N/A cars have a higher compression bottom end, 9.5:1 vs. 8.5:1, meaning about 5-10% more power made on a top swapped GT vs. a GTP.
