ok what gives, for the last race of the season I switched from 3.42's to 3.73's and in hopes of gaining a little mph and 60' time but I only got the mph and about a tenth. car is running a 383 with low compression mild 236/244 hyd roller cam and 700R4 w 3000 10" stall 255/60/16 et street radials and figured it should pull better 60' times with a little lower gear but no luck I foot break it to about 2000 before launch. Any suggestions or ideas would be great.

 

not really much of a gear change, although is it spinning off the line? Air could be different, etc although you picked up mph, could be suspension related.

 

how much rpm did you see at the stripe?? i'm guessing around 500rpm increase and overall not a huge gain gear wise since the jump is soo small.

what were your 60's before and after the gear swap?

 

Unless you did a gear change on the same day, you're never going to get an equal comparison. The air could be different and the engine made less HP with the deeper gears.

As mentioned above, that's not much of a gear change. I used 4.56 and 4.86 gears with my bigger tires and didn't see any improvement in 60' times.

 

what converter do you have in there now? what does it flash to? try braking it to about 1500 and flashing it from there....
if your converter is small, you might want to look at an edge converter


i know that a 3400 stall and motive 373 gears are in my future with my crappy 60' times 1.97 with mickey thompson ET's and a 383 hsr

 

I went from a 3.89 to a 4.56 and didnt see much change in 60ft. but from a 4.56 to a 5.14 was all the difference in the world.

 

As much as I'd like to, I'm not ready to try 5.14's yet. It may be too much for my combination. I currently shift around 6800 and go through the traps around 7200. Maybe if I had a tighter converter.

 

My car never see's the 1/4. 5.14 a little much for the car with my 28" tires, but it helps 3240lbs. to react on a pro tree. I shift and turn your same rpms in the 1/8th, lol

 

Stall in there is 3000 and flashes to about 2800 I do need to play with launch rpm some but was trying to be consistant this night. trap RPM is about 5500 up from 5000. 60's are between 1.94 and 1.98. with a trap speed of 103.6 I should be running much quicker than 13.4

 

ditch the radials and run slicks and I bet your 60' will drop back to where you want it, FYI my 305 was running 13.0 at 102 consistently with 1.6X 60' times.

 

are you still running tpi or do u have a hsr or sr or something else?