Thread: 1999 grand prix gt question

Hello all, I'm new here but I have a couple questions about this car.
I do car audio for part of my yearly income, and I have a good ammount of weaight in the trunk. I therefore have a little bit of sag in the back. It's noticeable looking at Tue car. If anyone has any experience with heavy loads in the trunk and upgrading shocks or whateber , please let me know a great choice in what I should do to raise the rear back up n still maintain stability etc.

second. I'm wanting to get started on slightly upgrading performance. Would a exhaust upgrade, cold air intake, and chip tuning suffice? If so any ggestions on what to use? If not, what should I do for basic upgrades. I don't have thousands to spend lol. I can have everything put on dirt cheap. It's jus tI would like some suggestions. I've been looking at a lot of stuff and there's so many option
Thanks in advance MP3

wow my phone typing is alil off lol Sry for the spelling n such

Welcome! Since you're new here I'll offer some advice before you get grilled, lol...

The sagging back end is likely due to the old springs and struts. Replace them and the rear should level out unless you have so much audio back there that you would have to go with something else.

Before upgrading anything, IMO I would take care of ANY regular maint. things that need to be replaced before trying to upgrade anything. GT's aren't fast and usually a top swap or a turbo setup is the only real way to make one fast. Can it be improved, sure. But "fast" really isn't what a GT is for. For exhaust I'd get a set of headers. Search the forums for the best kind. Can be found for $200 or so. You could do a U-bend delete as well. Leave the rest of the stock catback alone. Nothing will help unless you are above the 400HP area. I

Installing a CAI can help, but really won't boost HP, just helps it breath better. Can be homemade for way less than can be bought from a vendor. Lowe's or Home Depot and some time and there you go.

There is no "chip" for these cars that is worth it. If you really want to make the best of it get a real tuner (HP Tuners or the like) and a laptop and have at it.

Do a search for the "Safely modding your 3800" thread and read it well. Lots of good info in there.

Being a 99 I'd be checking the front sway bar where the endlinks go through as they like to crack, then replace the entire lower control arms with Moog from Rock Auto, then replace the LIM gaskets with the updated aluminum ones. Those seem to be the most common things to start with maint. wise.

Are those E3 plugs platinum? If so they will give you issues sooner or later. These ignition system only run properly on either the factory irridium or plain old copper plugs, just an FYI.

Hello all. I have a 99 GT as well and planned on doing a top swap in the near future. But first I want to make sure everything else is good on the car before I get into that. Suspension(my rear sags as well) I have 2 12s and 3 amps. Also I need an alignment because its eating tires like crazy. Now I know the GT is not considered fast but its quicker than most 3800 n/a powered cars because its the only car that comes with the 3.29 gear ratio. It's also about 100lbs lighter than the Buick Regal (top competitor in its class). Although its a grocery getter, I've surprisingly beaten a lot of cars in my GT. Cars I've raced are (Buick Regal LS-foud taurus 24v-ford Lincoln town car signature sries- ford 500-impala ls-dodge magnum 2.7-98 Bonneville SLE-ford Crown Victoria police edition-94 Cadillac deville 24v 4.9) there's more just can't think right now. I also raced a 2012 Maxima 3.5 but I lost bad lol. These were all dig races and my GT came on top every time. I'm not saying its fast, but its faster than most grocery getters in its class.