Speedy's Ride.......2005 Pontiac Grand Prix GTP Comp G

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speedy_2

speedy_2

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speedy_2
Well I'm not on here much, but I think the last time I was regularly on here I had a '98 Seville STS. Which has been gone for like 4 years. After that I had a '98 Z28, but didn't keep it long once I met my wife. Sold that, shared her car for awhile. This past April, we've bought a car that's worth sharing lol. I'll also get to mod it a little, which should turn it into a pretty peppy family sedan. lol Since these pics I've had it tinted and I have a Cold Air Intake sitting in the garage that I'll be installed soon.


2005 Pontiac Grand Prix GTP Comp G

48K Miles
Sunroof
HUD
But, cloth interior. Actually perfect since it is going to be a family car. :lol:
100% Stock.

Plans:

3.4 pulley
Tune
Headers
CAI


compg1.jpg


compg11.jpg


compg2.jpg


compg3.jpg


compg10.jpg


compg4.jpg


compg8.jpg



compg5.jpg


compg6.jpg


compg7.jpg


clean1.jpg


Bought a buffer. Pic after the buff job..
clean2.jpg
 
I remember your STS. Too bad it's gone. The GTP is a nice car. Pretty quick too from what I've read. The color is great too. 👍
 
All things considered, they are pretty quick cars given their age and relative barbarism in comparison to the current crop of Epsilon II cars. I thought the GTP/CG was an interesting car, but it's a shame it never really compared to the concept cars Pontiac kept rolling out at the time. I'd swap the wheels out if I were you, probably going for something similar to what they had on the G-Force concept:

G-force1.jpg
 
I clicked this thread expecting some kind of mech.
 
Nice dude, have you taken it to the 1/4 mile strip yet? I have a 97 GTP that got a 14.6 with a intake. Your car is exactly where I want mine.
 
YSSMAN
All things considered, they are pretty quick cars given their age and relative barbarism in comparison to the current crop of Epsilon II cars. I thought the GTP/CG was an interesting car, but it's a shame it never really compared to the concept cars Pontiac kept rolling out at the time. I'd swap the wheels out if I were you, probably going for something similar to what they had on the G-Force concept:

G-force1.jpg
Click to expand...


I agree. I mean, yeah, no DOHC...no variable valve timing...etc. But who cares. I can work on it myself. Parts are cheap. It looks great. Rides great. Modifying is easy and cheap as well. And, since it's in such great condition and low miles, I see myself getting a lot of life out of it.

By the way, a set of stainless steel headers and piping all the way to the cat is only $205 shipped. A Tuned PCM another $200 or so. The smaller pulley I'm getting for $20 used. All the other things are small...cooler plugs, wires, fluid changes, etc. Cars modded like I have planned are seeing ~13.9 in the 1/4 mile.
 
Modded 3800SCs certainly are quick...

I prefer the 97-03 body in a coupe (interior as well), but even so, very nice car. Good to see it's got a leather wrapped wheel too, GM's "base" wheel is just bleh.
 
speedy_2
Cars modded like I have planned are seeing ~13.9 in the 1/4 mile.
Click to expand...

Theres a guy on the Grand Prix forum running 13.6 with headers, intake, tune plugs, Tstat and fat tires on the front. I think you should expect better then 13.9 with that 3.4 you got on there.
 
Nice car. I got a '97 GTP myself.

As stated above be careful of the trans. I've heard they were maxed out from the factory.
 
Nice ride 👍

I know a few people that have these Pontiac's and they all swear good by them.

Good luck with yours.
 
Definately not. They are poor performers on the top end unless you have a nice cam or swap the supercharger for a turbo setup.

Mine pulls like crazy until about ~70-80mph, then it falls flat. Still pulls, just not strong.
 
Mine has a pretty average 3.4" pulley setup. TOG headers, Borla exhaust, Wizair intake, SLP 1.8 roller rockers.

Even with that it still doesn't like to go over 70-80mph. Not that I do that regularly.

Rockers do help a bit, cheaper and easier than a cam if money is an object.
 
Cool. I'm thinking about a 3.4" setup. Nothing insane, but I want to make sure I don't have any KR. Headers, rockers, tune, and maybe an intercooler.
 
Part of the reason is the supercharger, part because the stock flow parts are like breathing through straws as seems typical of older GM engines, and part because the automatic is geared for intergalactic travel. So, besides having an engine that doesn't breath well at high rpm, you're also stuck there forever because 3rd gear spans a whole 45 miles per hour, which is stupendous.

I'd suspect the basic intake/header/exhaust combo would shop a serious chunk off that same acceleration run, but it's still going to take forever with the stock 4-speed's gearing. Get a final drive that's about triple the stock one and maybe 4th gear will actually matter. Actually, that might be the most effective thing of all! Do some math and get a drive that cuts 3rd gear's top end from 125 to...100 or so. That's still taller than most manual transmissions. Highway economy in 4th shouldn't suffer too awful much because you'll still be cruising at about 800rpm instead of 350 and kick-downs to pass would be less common because of the increased torque. That would make it much more drivable I think.
 
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speedy_2
Cool. I'm thinking about a 3.4" setup. Nothing insane, but I want to make sure I don't have any KR. Headers, rockers, tune, and maybe an intercooler.
Click to expand...

I forgot to add I got a DHP PCM also.

As far as the gearing, you should be good with the Comp G, which I believe came with a 3:29 final. My '97 only has a 2:93 gear in it.

I never felt the need for a gear swap. The engine produces enough torque that I can pass cars and go up hills without having to downshift.

If I do need more power, I just tap the performance shift button and punch the accelerator and I get a 3-1 downshift. Which is alot of fun until the day my trans goes kablooey. :)
 
Cool. I do have the 3:29 final gear. I would love for the trans to skip a gear when down shifting. So annoying for it to go to 2nd for a split-second and then to 3rd.
 
You would need a PCM upgrade to do that. Either a DHP or Intense. Or tune the stock pcm if you know how. I didn't want to mess with it and got the DHP.

In addition to the 3-1 downshift, it boosts line pressure so shifts are faster and firmer.

Not sure if newer gp's had a performance shift button or not, but mine turns off the DHP functions when I don't want them.
 

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