Raced the Pontiac Grand Prix

[DAVe3283]

Firebird had their midnight drags last night, and I wanted to shake it up a bit, so instead of my truck, I brought my 1998 Pontiac Grand Prix GTP daily driver.

The car has a L32 in place of the stock L67 (because I seized the stock one) with the Gen V supercharger. It's got 60# injectors, a ZZP XP cam, LS6 valve springs, a 1" intercooler, a 3.1" supercharger pulley, and a mild build trans. All run off the original 1998 controls for now.

Once they finally prepped the track, I managed to run a 14.315 @99.80 MPH. I am actually really pleased with this considering the car barely ran 90 MPH stock. I ran the car in street trim (full interior, subwoofer, full tire pressure). If I cared, I bet I could break 100 MPH by cheesing it a bit, or coming back on a cooler day.

I also brought my Suburban out of curiosity, and convinced a friend who'd never raced before to bring his VW Golf GTI. The Pontiac was the quickest of that group, though the Suburban and the GTI were pretty competitive with each other. Overall had a great night, even if I didn't go near as fast as my truck does.

 

[zakkb787]

That’s impressive! Wild seeing those older cars like that run with good numbers.

 

[Chevy1925]

Man if you could make that thing hook, she’d be mid/low 13s

 

[DAVe3283]

My brother was driving it to the track (I was driving the Suburban) and he ended up at a stop light next to a Ford Focus RS. He got the jump, then the RS went after it (all I could hear was the RS exhaust). I kept expecting the RS to start to pull on the GTP, but it never did. They both shut down around 70 MPH, and the look on the RS drivers face was priceless, I'm told.

I'm going to dyno it later this summer when the operator recovers from back surgery. Stock it did 205 HP, so that dyno might be a bit generous. Wouldn't surprise me to see ~300 on that dyno now. From the track times and handing the RS its butt, I'm guessing it's in the 260-280 WHP range in reality. A stock RS makes 282 at the tires, and they weigh about the same.

It's a blast as a daily driver. The supercharger means there's no lag at all, so it'll surprise cars much faster than it has any business taking on, at least up to 50 MPH or so. So in town... yeah, it's a riot.

 

[PureHybrid]

Nice run, but can't help notice how well the left lane back halved :rofl:

 

[DAVe3283]

Nice run, but can't help notice how well the left lane back halved :rofl:

Yeah, I ended up next to a properly fast turbo car. I'll try and get the dash cam video of the race, he flys by me shortly after the launch.

 

[SmokeShow]

Nice run, but can't help notice how well the left lane back halved :rofl:

I was gonna say the same thing... whatever it is, it has the MPH to be a lot quicker than 11.50 in the quarter

 

[Burn Down]

Nice Dave:thumb:

There are a couple cars that are flirting with the roll bar rules... They roll out slow then hammer it or stab the brakes at the end, the later is pretty sketchy.

 

[DAVe3283]

[YOUTUBE]Yw501dcl-aI[/YOUTUBE]
Here's the dash cam video from the car. I am not sure if the other guy was trying to skirt the rules, or just didn't have time to get on the turbo at the line. He didn't stay on the first stage very long at all, but I kind of bumped to 2nd stage pretty quick, so maybe he was feeling rushed? (Sorry random dude!)

It kind of amuses me that I only shift once in the 1/4. 1-2 happens at 58 MPH and 2-3 happens at 100 MPH, right after I cross the line. That car is geared stupid tall. Thought about changing sprockets when I was having the trans built, but I was worried about hurting the already mediocre fuel economy.

For the curious, the Suburban ran a 15.631 @ 92.43 MPH on [THREAD=42711]my 425 HP tune[/THREAD]. It didn't really want to build boost on the line in the heat, so I just left really soft. The converter is a bit too tight for racing, but is great for how I use it normally. My friend's GTI ran a best of 15.211 @ 93.64 MPH. I was surprised how well the Suburban hung with the GTI considering it's a 7500 lb 8-passenger pig.

 

[TheBac]

That didnt move out too darn bad, Dave. I can definitely imagine its fun on the street.

(Ill be the one to say it in the spirit of the site) -- work on the 60ft, and a 13 could be within reach.


What did you have done to the trans to get it to hold power?

 

[DAVe3283]

That didnt move out too darn bad, Dave. I can definitely imagine its fun on the street.

(Ill be the one to say it in the spirit of the site) -- work on the 60ft, and a 13 could be within reach.


What did you have done to the trans to get it to hold power?

The transmission is a stock rebuild with a billet Sonnax 3rd clutch piston and an upgraded low-stall torque concerter. The supercharged cars came with a 4T65E HD, which was pretty strong to begin with. I smoked the stock torque converter clutch, so I bought a 2nd car with a fresh stock rebuild transmission, for $1,000 less than the invoice on the transmission! It was built by the same shop that does my truck, so i know it was done right. Stripped the car of everything I wanted, then scrapped it. (Nice to have spares of almost everything when you drive a 21 year old car.) Took the transmission back to the shop and had them put a different torque converter in it, and they had a billet piston assembly a customer had stiffed them on, so they let me have it at cost. All in all a very cheap transmission, depending on how you do the math on the value of the spare car I got with it. I have less into this car in total than I have into my Allison in my truck.

I think the only way to improve the 60' on this thing is better tires, and pray I don't explode my cheap Chinese CVs. When this set of tires is done, I may put something a bit nicer on, but I think slicks would be playing with fire , so I probably won't go that route.