I have a 2800lb. foxbody with a Lq4/l92. The cam is a 232/234 114lsa with .571 .578 lift. It has the vic jr. with an 870cfm apd carb. The trans is a th350 with an ati 8" 4500 stall(it was intended for a bigger cubed ls) and art carr transbrake. Rear end has strange spool and 33 spline axles with 3.73 ratio. I'm running 26x11.5x17 et streets, they hook with no spinning. I also have lakewood drag shocks all around and an anti-roll bar.

I'm leaving on the brake with the two step at 3800rpm and it consistently runs 1.55 60ft. I think it should be in the mid 1.4 or lower.
It runs the 1/8 in 6.9@100 and the 1/4 at 10.85@124.

Is the converter too much for my power level? Would I be better off with a lower rpm, tighter converter built for my power level?

 

What RPM does the car hold just on the brake, w/o the 2 step?

 

right around 3900

 

If you are NA only, that stall is too small. 3900 on the brake is a small stall for NA. Send it back and have them loosen it to about 52-5400 and you should go 1.3s.

 

I am not convinced the stall is too small at that weight!

I would suggest one of two things. Change to 4.11 gears or leave at a higher RPM off the brake!

Do you have a 2-step? What RPM are you shifting at? What power level is the car NA at the wheels?

N2

 

Turn the 2 step off. Push the button on the brake, put the throttle to the floor and leave at whatever it will rev. I agree it needs more gear and probably a looser converter. If its going to be na then 5000+. If you are going to spray it leave that converter in there and regear it.

 

I have the two set at 3800, I shift at 6600 and cross the traps around 6300. I'm getting it dynoed tomorrow. I would guess around 390rwhp.

I will eventually run about a 125-150 shot, so I'll probably need the 3.73.

I'll try next time leaving without the two step.

 

How tall of a tire? If you are going to spray it, then I would leave that converter in there. Its hard to have a nitrous motor run really well on motor. The combination is not ideal. I had an s10 that went 10.90's on motor. It had 4.57 gears and a real tight 3800 converter. I sprayed it with 250 of the brake and it went 8.90's. On motor it would not leave for the life of me. It was a pig. I think the 60 ft was in the 1.5's on motor and it went a 1.29 on the bottle.

 

I bet some more compression would do your 60' wonders.

 

Its a 26" tire on a 17x9 bullit wheel. I do have some 28x10.5x15 hoosiers on some welds I can try, but I was thinking they were too tall for my gear and I was trying to make it look like a street car. I will try and find some 26 for the 15's and see if they will help out.

You are probably right, it's about 9.6 with the l92 heads.


I'm about to head out to the dyno, maybe i'll get some insight as to where to shift and see where the the torque peak is at.

 

6600 shift and 6300 crossing the line, indicates you need more gear! If you're going to spray it just step up to the 28" tire.

 

So if I spray 150 that would put me around 134-138. With 4.11 and 28's that would put me around @7400 crossing the traps. Is that's too much for a stock 6.0 bottom end?

 

i trap 133 on 4.10's and 28's and i'm at 6500 rpms.

 

I think I calculated that wrong. It would be 6750

 

That sounds closer to it, you have an auto so there will be a little bit of slippage from the converter.

 

I have a 4L60E but 4.10s, 28" and 134mph I am at 7200...

ss4000 stall

 

Went to the track tonight. I dropped the two step to 3300. It ran a 1.51 60. I only had one run, so next week I'll experiment with a lower launch rpm

 

My car always 60'd best off idle.
Definatley investigate leaving at different rpms, with and without 2 step etc. before changing any parts.
Leaving off idle will allow the converter to flash higher so I would defiantely try that and see how she likes it. Try not using the 2 step for a few passes as well.

 

Most milder bolt on combo's and NA cars leave best with a lot of flash left in the converter or even of idle like tektrans said. Especially since you dropped 4 tenths off your 60' leaving at a lower rpm. I would try 2800-3000 off the trans brake or footbrake since you can probably hold 2800-3000 with your service brakes. It will really flash off on the footbrake at 3000 going to 4500. Most stalls will flash higher than what they are rated for anyways.