Seeing how a lot of guys around here have had a lot of success getting these cars down the track in a short amount of time, I was hoping someone could offer a little insight on why I am having such a hard time doing it myself. I seem to have narrowed my issues down to 2 areas, but am unsure what is causing the one and not sure how to correct the second.
My car has made the power on the dyno and ran the mph at the track to support much lower ET's that I have been able to manage. I'm running a Vortech S-Trim at 8lbs, 4.10's, 2600 stall converter, and the other supporting mods that go along with them. The tune is dead on as far as air/fuel, and the car runs great. It is a conservative tune, so timing is pretty mild, and it shifts by 6400rpm.
The car made 392rwhp on a DynoJet, and has run a handful of passes at 110-112 mph. My ET's have all been right around 13.0 - 13.1 at two different tracks, both ~1000 ft above sea level. I really feel the car should be running a 12.5-12.6 with it's current power and gearing. Here is the slip from my quickest ET run:
60' 2.047
330 5.586
1/8 8.428
mph 87.13
1000 10.916
1/4 12.970
mph 110.72
It seems the first issue is my 60' times. I have never been able to pull a sub 2.0 short time! The track was hooking very well on Sunday and it didn't seem to spin at all off the line. I tried launching from 1000rpm to flash the converter, and launching at 1800-2000 rpm with it stall up against it. It really didn't seem to make much of a difference. All my other short times for the day were 2.1's. What I did notice was it felt like the car bogged pretty bad off the launch. It would fall on its face for a half second, and then take off like it should. The best way to describe it would be like launching a manual trans car on sticky tires at too low of a rpm. Any idea what to look for as to the cause of this. Do you think it is in the tune, or something mechanical?
Second issue is the 1-2 shift. It is blowing the tires off really bad on the 1-2 every time down the track. It is bad enough you can feel the car stop accelerating for half a second until it grabs traction again. I think I went too aggressive on the JMOD. Any ideas for fixing this short of getting another valve body and going to a milder setting with the JMOD?
If I could get my short times down to a 1.8-1.9, and hook up the 1-2 shift, I'm confident that I could drop .4 - .5 off of my ET. Any suggestions or thoughts?
Thomas
My car has made the power on the dyno and ran the mph at the track to support much lower ET's that I have been able to manage. I'm running a Vortech S-Trim at 8lbs, 4.10's, 2600 stall converter, and the other supporting mods that go along with them. The tune is dead on as far as air/fuel, and the car runs great. It is a conservative tune, so timing is pretty mild, and it shifts by 6400rpm.
The car made 392rwhp on a DynoJet, and has run a handful of passes at 110-112 mph. My ET's have all been right around 13.0 - 13.1 at two different tracks, both ~1000 ft above sea level. I really feel the car should be running a 12.5-12.6 with it's current power and gearing. Here is the slip from my quickest ET run:
60' 2.047
330 5.586
1/8 8.428
mph 87.13
1000 10.916
1/4 12.970
mph 110.72
It seems the first issue is my 60' times. I have never been able to pull a sub 2.0 short time! The track was hooking very well on Sunday and it didn't seem to spin at all off the line. I tried launching from 1000rpm to flash the converter, and launching at 1800-2000 rpm with it stall up against it. It really didn't seem to make much of a difference. All my other short times for the day were 2.1's. What I did notice was it felt like the car bogged pretty bad off the launch. It would fall on its face for a half second, and then take off like it should. The best way to describe it would be like launching a manual trans car on sticky tires at too low of a rpm. Any idea what to look for as to the cause of this. Do you think it is in the tune, or something mechanical?
Second issue is the 1-2 shift. It is blowing the tires off really bad on the 1-2 every time down the track. It is bad enough you can feel the car stop accelerating for half a second until it grabs traction again. I think I went too aggressive on the JMOD. Any ideas for fixing this short of getting another valve body and going to a milder setting with the JMOD?
If I could get my short times down to a 1.8-1.9, and hook up the 1-2 shift, I'm confident that I could drop .4 - .5 off of my ET. Any suggestions or thoughts?
Thomas