I took my car to the track for the first time last weekend. It's a supercharged 97 auto w/ 3.33 pulley, Stillen Y, and 2.5" exhaust. Car weighed in at 3250 without me, mostly due to the 19"s and big stereo.

I only got 3 runs in, and they were all pretty bad. The third one involved accidentally putting the car in neutral (I wasn't driving) so I won't worry about that run.

But the first two runs were a 15.367 @ 91.43 and a 15.360 @ 90.5 . I was running on 19"s at 42 psi so there was no traction, but I thought my trap speeds would be higher. The times I can understand due to traction, etc. But I always thought my car had more power than that. Anybody know what other supercharged auto's have run? I'd like some comparison.

 

Jeff...Typical SC auto runs in the mid 14s. Something is wrong with your car. I would check the knock sensor, spark plugs and the Y-pipe flex section. Those are the typical known problems. Those 19s and stereo shouldn't hold you back that much. My car runs Mid 15s without nitrous with 18s and a small subbox.

 

Well, after resetting the ecu, my car isn't throwing anymore codes for knock sensor or anything.

The Stillen Y pipes have flex section issues also? Hmm, I'll have to check that this weekend.

I've got some new ngk's i'm installing tomorrow with a heat range of 6. Should I just leave the factory gap in there or regap it?

And I'm also replacing the fuel filter this weekend, it's been a while. My car does feel to be a little down on power lately, I thought it was just the heat.

 

Shadow-

Go thru and check everything like your plugs, vacumn lines, check your fuel pressure, intake pipes, BOV seal, etc and replace your fuel filter for good measure. Honestly, I don't think that there is much wrong with your car. Right away I see 3 huge factors that are making your SC Max slow:

1) It was freaking hot in Atlanta. I was driving thru Atlanta on my way back to Kansas City from my vacation in Florida. The temps were so bad that my wife's Legacy GT A/C could barely keep the car cool. The track temp was probably well into the 100s plus you're having to sit in line for a while which allows the engine to bake, especially with a SC. Right there you're looking at .2-.4 and 3-4mph drop in performance. I know my car is that much slower in hot sweltering heat like that.

2) Heavy 18" rims with heavy and wide low profile tires at 42 psi is doing you no good. The SC is centerfugal (sp) which means it doesn't create much lowend power. Most of the gains are after 5000rpms. With heavy wheels/tires, an auto, and high heat, the car is an absolute dawg to 40mph. The drag and rotational mass of the wheels will also work against you the entire length of the track. I'd say you're at at least .2 and 2mph lost to the heavy wheels.

3) Stereo weight. It sounds to me like you've got a 170-200lb stereo in your car. That's an instant .2-.3 and 2mph right there. Again, the SC doesn't make the torque to get the heft off the line.


Weight (rotational and static) really hurts the performance on a small displacement V6 even if it's SC'd. I suggest you pull out as much of the stereo stuff as you can, replace the front wheels with drag radials and the smallest diameter and lightest rims you can fit, and most importantly RACE IN COLD WEATHER. From what I'm seeing, these 3 factors I listed are sucking out an honest .8-1.0 seconds and 6-8mph from your 1/4 mile. If you want to go fast and quick, YOU'VE GOT TO SET YOUR CAR UP FOR IT. It's as simple as that. From what I hear, the Atlanta track isn't known for producing very good ETs/MPHs. It really is true that some tracks are just faster than others. It can do with the way the track measuring devices are setup or the overall environmental conditions of the track (altitude, traction, grade).



Dave

 

Unfortunately, the stereo isn't removable. All 4 amps, subs, etc are basically built into the trunk. We did weigh it in around 200.

I'm going back to the track in 2 weeks, I'm getting my friend's 300ZX wheels to run with, hopefully that will help some. And it will be at night where the temps are much cooler. I think they measured the on track temp at about 135 or so.

The car was a dog off the line, after the car stopped spinning the tires, it would totally bog.

I've checked all the intake pipes, I'm replacing the plugs tonight, and the fuel filter too.

 

Well, I got back to the track again. I replaced the plugs, fuel filter, etc. and the car has really seemed to run better lately. But the numbers are still the same. I ran a 15.336 @91.15, a 15.337 @ 91.17, a 15.86@88.6, a 15.744@88.8, and a 15.714@88.8. My 60 ft. times hovered around the 2.5 range with a 2.489 as the best.

The car is so slow off the line. No matter where I launch at, it spins then bogs. 1K, 2K, 2.5K my 60 fts remain the same.

And the tranny is inconsistent. One run it shifts at redline every time, the next run it shifts early at 6300. I would manually shift it, but I have trouble keeping it from bouncing off fuel cut that way.

It doesn't help that I watch Jaimiecbr900 run a 14.6, 13.8, 14.0, and 14.2 and then Jay25 run a 13.8, 14.1, and like a 14.3. So I can't even say that the track is bad. Bosco500 was running mid 14's all night too.

At this point, I'm taking the car to a dyno to see what the numbers there say and if my car is down on power.

 

Something must still not be right with your car. A SC auto Maxima should hit at least high 14s. Too bad we don't have more SC auto owners running at the track to compare with. Only other one I could think of that consistently run at the track is SteveChicagoSC.

As far as launching goes, did you just stomp on the gas out of the hole? I would try launching it easier, in another word, don't slam on the gas. Ease it out out of the hole and when you get traction, then slam on the gas. I'm not saying to wait forever, this all should happen within a split second. That is, if you haven't try it already.

Also, I would try emailing SteveChicagoSC to ask for some tips maybe if you can find his email address.

 

On the launch, I was basically launching at 1K to 2K, I was trying different ways. My 60 fts were terrible at around 2.5 or so on all of them. It's more the trap speeds that bother me. JaimeCBR900 was running 2.5 ft 60's, and he was running 103-105 traps on nitrous. I don't get why my traps were in the 88-91 mph range. That's what lightly modded auto maximas run.

First time I went to the track, my car was running badly, misfiring due to wrong plugs, old fuel filter, all that stuff. I've since replaced the plugs, the fuel filter, and the car feels like it's running, much better but the track times remain the same. I even did a compression test to see if the engine was going, but all cylinders checked in at 180-185.

What I'm wondering about now is that I can't hear my fuel pump anymore. My fuel pump is wired to be on all the time, I used to be able to hear it right before I started the car. I can't hear it anymore. Since I unhooked my fuel pressure gauge, I don't know if my car is running lower fuel pressures or what. I'll have the gauge back on in a couple of days.

 

dude i'm not auto or supercharged..but my supercharged 4th gen friends ran mid to high 13s.....

my 60' was 2.457 with my 19s...had my tire pressure set at 30psi..but i did have a slipping clutch...ended up with 14.57@99mph

 

Well, I think I may have found out my problem. My Vortech inline fuel pump isn't working right now.

 

Is your SC 4th gen friend an auto or 5spd? If it's a 5spd, that is about right. If it's an auto...wow!

 

Well, I finally fixed the problem with my car. Basically, all summer, my Vortech fuel pump hasn't been on. The power wire to the battery was unhooked because we had pulled the battery earlier in June for like 2 weeks to redo my whole stereo and somehow that wire never got reconnected. My car never threw any new codes so I never knew it until I realized that I couldn't hear the pump. I had gotten so used to it that I didn't even realize it wasn't on for the longest time. Now that it's hooked back up, the car is fast again. And my prototype LSD goes in tomorrow, so I will ahve the car back at the track in a couple of weeks to see how it does.

 

he ran 13.7 with his 97 auto..

 

What size pulley is he running? Give me something positive to shoot for.