The RCME ’98 Pontiac Grand Prix GTP Sedan
Above professional photo by Xtreme Photography Santa Maria, CA was scanned as delivered.
Front wheel drive cars aren’t very exciting to watch leave the line so there aren’t any real exciting pictures here. If there’s something I really miss about a rear wheel drive it’s the fun of getting daylight under the front tires. The picture below was taken at the 2000 NHRA Division 6 ET Finals in Woodburn, OR. I was meaning to alert the photographer at the right time so I could get a nice burnout shot which is about as interesting as it gets for FWD but I kept forgetting to tell him that I wanted a burnout shot. I was told the NHRA photographer got a shot of my first round elimination burnout but I have not seen it and it did not appear in National Dragster since I tossed my chances all away with a red light in the first round.
In the 80 degree heat of the day when this photo below was taken the car ran a 13.73 ET without hooking well at the start line (if you look at the photo closely you can tell the front tires are spinning). It ran a best ET of 13.68 in the first round of eliminations on Sunday morning (the ET Finals are a 3-4 day event depending on how long you want to make it) after some stormy weather moved through and we had a headwind coming straight up the track so everyone was adjusting their dial-ins slower to compensate. I dialed what I considered to be a somewhat soft 13.83 due to that headwind coming down the track. Unfortunately I suffered a break in my concentration and fouled on the start by a rather hefty margin (.266 light on a .500 tree, YIKES! long, story) so I ran the car out all the way (since breakout was no longer of concern) and it ran the 13.68 even with the stiff headwind. The car I ran against was over .3 tenths slower than their dial-in with a slower, less aerodynamic car yet they ran it hard all the way through the finish traps also, a common tactic to get a handle on your dial for the next round when your opponent fouls. Hard to say how much the headwind might have slowed that run for me since my day was done and I’d get no more chances to see how quick it might run that day.
The picture below is at Seattle International Raceway earlier in the year (August) while still running a stock pulley setup on a warm summer night. Dial on the window on this pass was a 14.44 in case you can’t quite make it out on the window. It had run best of 14.01 ET with the stock pulley in place in cooler weather as well as the stock exhaust that it has to this day. In the other lane a 2000 GTP can be seen that I’m trying to chase down that is also raced regularly at SIR by Cobina Olin, her dial on her completely stock GTP is typically around the 15.00 zone.
RCME 1998 Pontiac Grand Prix GTP at Seattle International Raceway. Photo by Nitro Model Kent, WA
Listing of all current performance modifications
Air intake varies between RCME prototype CAI and a RCME custom cone install . The RCME prototype CAI is still under development and due to the success of this simple cone install is on hold until I get a reason to work on it more.
Reprogrammed PCM (GP Store)
RCME Pro Series Strut Tower Braces front and rear
Nitto 555R Drag Radials (245/50-16, 225/50-16 were used with stock pulley)
Koni Adjustable Strut Inserts (rears are set to full firm for drag use to minimize squat and the resulting weight transfer off the front end that compromises traction)
160 degree thermostat (the only reason for this is to help keep it cooler from one run to the next)
Interchangeable Pulley Supercharger Snout (I can’t really call it a Magnuson any more, the only thing Magnuson about it now is the shaft after I was done with it). Pulley sizes vary from the 3.8″ stock size (thanks to a one off 3.8 from Pulley Boys, Thanks Brian) down to 3.0″ in diameter. The 3.2″ seems to be about the limit on a stock fuel system, I have made only two runs with the 3.0 and both met with problems that I have not yet investigated but first suspect is fuel delivery with the stock FPR.
Complete unaltered stock exhaust system still intact (yes this means U-bend and all, it’s still as delivered from the factory), this is still completely stock to this day.
Best dragstrip times so far with these modifications
60′ 1.863
330′ 5.527
1/8 ET 8.682
1/8 MPH 80.89
1000′ 11.385
1/4 ET 13.683
1/4 MPH 101.14
1/4 mile dragstrip time milestones
14.89 @ 91.99 First track outing with 2700 miles on odometer, sunny ~72° F, 2.17 60′
14.60 @ 94.83 Best completely showroom stock time, evening ~68° F, 2.16 60′
14.25 @ 97.91 The only modification at this point was my first version custom intake, sunny ~70° F, 2.18 60′ spinning badly on stock Goodyear RS-As. So here you can see a solid 3/10ths+ improvement (not based on just one run) from a simple mod like a free flowing intake consisting of a piece of ABS drain pipe that was modified internally (and externally for appearance) and a K&N 9″ cone filter. With a good short time (60′) and good air density a ’99+ GTP can lay down a 1/4 mile time in this zone.
14.16 @ 97.21 Same as above but with modified PCM, the launch (short time) had a lot to do with this run being better than the above run though, partly sunny ~71° F, 2.02 60′ on stock Goodyear RS-As. No benefits from the PCM can be documented at this point with only the two mods so far. The first run with the modified PCM put in at the track at a previous outing (actually the day of the above run) after a day of dialing into eliminations at 14.3 was a 14.43. A subsequent run without any cool down time was a 14.6 so heat played a large factor there.
13.9? @ ~97 Stock pulley, same mods as above but with 225/50 Nitto 555R DRs. This is a speculative time, although I only put this here because I’m confident in it’s accuracy, because the timing system at SIR failed as it tended to do all too often and I got no time slip or recorded finish line time. I was wanting to get this car in the 13′s without doing any real mods like changing the sc pulley. Fortunately the tower did have interval times and showed 11.672 for the 1000′ mark. Using timing history that extrapolates to approx a 13.97 E.T. Again, this was with the stock pulley still. 60′ was 2.08 since the Nittos did not hook well either. Evening ~70° F As far as I’m concerned I’m the only one to have gotten a GTP into the 13 second zone without a pulley and so few mods.
13.71 @ 101.14 It’s very first recorded 13 second run. This is with nothing more than my custom intake, reprogrammed PCM, 3.2″ Pulley on Magnuson snout, 245/50/16 Nitto 555R drag radials. Overcast ~66° F, 1.96 60′. The run before this was with a 3.6″ pulley on and it ran a 14.001 at 99.17, short time was a 2.04. A 3.0″ pulley was put on later in the day after I was out of elims but it appears to be too much with a stock FPR and it slowed significantly to a 14.36 @ 89 mph. The 3.0 has been tried 2 times subsequent to this and the results have been the same so I conclude at this point it needs some fuel help with the 3.0 or possibly the stock exhaust is creating a problem, the fuel supply issue is more likely.
13.68 @ 99.17 Best ET thus far. This run took place shortly after a storm and with a very strong headwind. Overcast 63° F, 1.88 60′.
13.89 @ 99.90 Best ET thus far with the 17″ AE 174 wheels and RE730 street tires, sunny ~75° F, 1.96 60′
Here’s an updated picture with the new wheels and tires. The tires are 255/50-17 Bridgestone RE730s and the wheels are American Eagle 174 in the only size they come in which is 17 x 7.5. This wheel has the proper 5 x 115mm bolt circle and not the incorrect 4.5″/114.3mm. This shot was taken in the parking lot of TRW in my home town of Portland, MI while visiting, I now live in Washington state near Seattle.
1998 Pontiac Grand Prix GTP with 55/50-17 Bridgestone RE730s and American Eagle 174 wheels
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