Help with 1/4 mile times!!
 

I just got back from the track tonight and I'm a little disappointed with my times. The following run is with all mods in sig except for underdrives. I am also running the stock fuel system but I have an adjustable FPR set to 42 psi, and timing was at 18* BTDC. (I actually picked up 1 tenth with upping the timing from 16* to 18*)

R/T....674
60'....2.146
330...5.788
1/8....8.816
MPH...81.11
1000..11.428
1/4.....13.632
MPH....102.24

My 60' still sucked, but wheel spin was not that bad. I think my AOD is contributing to my poor 60' times, or I'm not launching it hard enough.

Should I be running a higher fuel pressure? I ran some #'s though an analyzer and it says with the stock fuel system I should be running 51 psi, does that sound right? I'm heading back next week to race again, and I'm hoping after a little more tweaking I can pull a low 13 sec time. Any help here would be much appreciated!!

-Craig

You could un a 13.2-13.3 on slicks which sounds about right to me. Consideringyou are only trapping 102 mph.

You will need to get some more HP out of your combo and increase your trap speed to the tune of 105 or so MPH before you will hit 12's.

I wouldnt be too upset.

1/4 mile times
 

Yeah, your 60ft. time is killing you. Are you heating your drag radials up some? You should be able to get a lower 60ft. time with some practice. Do you have a trans brake or anything? What RPMs are you able to launch at? Your fuel pressure is fine...if not a tad high. But 51psi. would be WAY too much! 18 degrees of timing is up there too...but if you're not pinging and you say it took a tenth off your 1320' time, then keep it there.

Yeah, pretty much everything Simi and Dark said. You are running 13.6 on a 2.15 60-ft. Get yourself some traction and a good launch and you should be pulling low 1.9s to possible 1.8s ESPECIALLY launching at 3k!! I pulled 1.9 60fts with a 13.6 1/4 mile (8.7 1/8th mile) launching at 1200 rpm in my '79 with Nitto DR (23-28 psi) with a C4 so I don't think your tires are so much the problem. How do you think your driving technique is (getting out of the hole???) I don't see 13.3 being impossible at all for you. Also, have you considered an aluminum driveshaft?

Yes, I have an aluminum driveshaft. I don't think traction is a problem, I think it's more of my style that needs improving. I ran on Nitto drag radials with 15 psi in the tires. I was stalling my converter at 2000 rpm, then launching 3/4 pedal for a split second, then full pedal. I had very little wheel spin before the D/R's grabbed. Oh and I have my front sway bar removed.

I just adjusted my timing back down to 15*, and set my fuel pressure to 51 psi, and the car seems to pull a lot harder thoughout the whole rpm band.

I really wish I had gotten more then two runs in, so I could have played around with a few more things. I'm heading back next wednesday to give it a shot again. This time I'm putting my underdrives back on, going to run a short belt, and I have some donut spares for the front.

My Nittos always worked best at 25-28 psi. Back then I pulled 2.0 60ft's in a basicly stock 5 speed 88GT vert with lowering springs and front sway bar still in.

If I would drop the pressure below 23 psi my 60ft would be in the 2.1's and 2's.

Two runs isnt enough to get the most out of you car. I am sure it has more in it.

You have to really roast the nitto's to get good traction.

Good luck,

I always bring a timing light and fuel pressure guage to the track for test and tune, make adjustments little by little and you'll get there. If your getting great traction, launch harder, you want to ultimately find the point of traction that is right before spinning the tires over, then you know your launch point, play with the different air pressures in the tire too.

with your mods, I'd think the MPH would be closer to 107-108..
what RPM are you shifting at?

I was manualy shifting my AOD for a slightly higher shift point. I would shift at 5300-5400 rpms, and with the AOD lag it ended up being 5700-5800 rpms I believe.

shift kit
 

since you are shifting urs manually......i was curious if u had a shift kit in ur AOD?

I use to do that with my car, but the shift kit I have now shifts great....
Ryan