Thread: 2002 Grand Prix GTP 3800 series II sedan

Hello Everyone,
I have just a quick one what is there if any? I am wondering what there is to enhance my engine or what not,
so that I could be running at 1500 r.p.m at highway speeds. Any ideas???

Thanks...

If I understand your question right, you want to know if it's possible to be running 1500rpm's at highway speed (60mph)? If so, the only way to do this is to swap gearsets in the transmission with something lower than the stock 2.93's.

Changing to wider gears isn't going to improve mpg at all. Doing so would make the engine work harder and use more gas at the lower rpm. Stick with the stock gears. But for more mpgs, is suggest making your own intake, and getting rid of the u bend.

yes in fact more mpg's thanks

air intake system or intake heads? Also you seem to know some things about this will true dual exhaust drop or gain or even change my mpg???

I think he means an air intake (in place of the stock airbox). True duals will not really do much as the stock system flows pretty good already. CAI, Headers, U-Bend delete and a tune will net you the most. I'm not even sure how you would get true duals on this motor seeing as how the front manifold is well, facing the front, lol.. I guess you could technically bring it down in front and then run it to the back but clearance down there is minimal at best and you'd have to fit 2.5" pipe through there.

Other things you can do would be to clean the MAF, make sure the plugs/wires are new (and NOT use Platinum plugs), take care of any vacuum leaks, keep your tires properly inflated, and remove any unnecessary junk from the car (subs, stuff in trunk, etc). Oh, and always run 91+ (93 if you can get it) octane gas in it. This is a MUST for the S/C cars.

My 00 GP GT can squeak out about 410 miles to a full tank if I run it all the way down to empty (which isn't good on the pump). And the GT has 3.29 gears in it. Not sure what my 95 Bonneville has for gears in it but I get about 15 more miles to a full tank in it. At 60 it cruises at about 1600 rpm or so.

The front manifold, downpipe and u bend are the restrictions. Changing the mufflers won't do anything except change the sound. But what he said. The cold air intake, headers, and a tune.

What I meant by make your own intake is don't get a Cai off a vendor. Buy a cone filter at local parts store and a few tube pieces and assemble it yourself.