So my father is looking to start modifying his 2000 Grand Prix GTP 4 dr. Nothing too crazy, just looking for a little more power.
The car has 87,000 miles. Great shape. When he first got it it had a little problem that we sorted out with the MAF.
So far it has just the resonator deleted (was when he got it), A K&N drop in filter, and we modded the air box. (Took the baffle out, and routed out the holes in the side of the air box. Read a write up somewhere, called the "Whine Box mod".
He already has a ZZP Front Power Log ready and waiting, but also wants other items as well. He'd like to do everything all at once. He's looking at the ZZP Rear Power Log, Ceramic Coated Crossover, 3" Downpipe with Cat, PCM 1.0, Colder Plugs, Lower temp T-Stat, and 3.4 modular pulley kit.
Problem we're having is ZZP doesn't seem to have any of the Ceramic Coated Crossovers in stock. I'm on th email list, but that's been at least a month. Emailed them and they said they don't know when they will be in stock, that they are waiting on cores to be sent out to be coated.
So my question is, are they just stock crossovers that have been coated? Do they do any port work to them? And if no port work is done, is it a vital piece then.
I've read that the rear power log and the crossover aren't that important, but would like some input.
He also wants to modify the exhaust from the cat back, he wants to put a glasspack where the resonator is, then delete the mufflers, and just run pipe to some resonated tips. I'm not sure if this is the optimum way to get good sound, but he seems to think so.
My friend who spends a lot of time with us has an 03 Audi A4 3.0 Quattro 6 speed that he had the mid muffler/resonator deleted and replaced with an x pipe, and the mufflers replaced with straight pipe, and resonated tips put on it. It sounds great. Very exotic sounding and loud. Has a mix between a VR6 and a 350Z tone to it. So I think that's why he wants to put it on his GTP. But I haven't heard many setups that I think sound good on the GTP. I've heard one on a dyno on youtube, but it was turbocharged and it sounded very reminiscent of a Toyota JZ Inline 6 Engine. Most of the other GTP's I've heard sound raspy, and not very "tuned" sounding.
So what's your guys suggestions? I'm trying to convince him to forget the rear power log and crossover and just order the rest of the stuff he wanted, and try to figure out a different exhaust setup. But I'm not a 3800 series expert, so I don't really know what works best.
Oh, and what could he expect power wise from the K&N drop in, air box mod, Front P-Log, 3" downpipe w/ Cat, 3.4 pulley, PCM 1.0, Colder plugs, and Lower temp T-stat?