Competition What rpm to shift at when drag racing

[DBraunig]

hey guys,



12 valve automatic at the drag strip... . what rpm do i want to shift at to get my best times? should i have the trans shift out early, or hold it into the higher rpms? I was thinking of tuning it to match the torque curve on the dyno, but that has me shifting at 24-2600 and i am thinking that a higher shift point would help. any thoughts are appreciated.



Dave

 

[JGheen]

hey guys,



I was thinking of tuning it to match the torque curve on the dyno, but that has me shifting at 24-2600 and i am thinking that a higher shift point would help.



Dave

That is probably your best bet, as I would get your dyno numbers, examine the curve and go from there. Where ever your horsepower falls off is a good place to shift because beyond that your obviously not making anymore power and the truck is not being pushed any harder... . time to shift to the next gear and go through the curve again.



Joe

 

[crawler]

If you haven't added a GSK to your truck then you're best times will probably come by letting the truck do the shifting.



Holding your gears any longer and it probably won't get any faster.



Now if we're talking 1/8th mile then you might want to lock out overdrive and hold 3rd. It all just depends on what your MPH is at the big end of the track.





Later,

Wes

 

[DBraunig]

i run the 3k gsk. 77 mph in the 1/8 and 96 at end of the 1/4, with a 1. 87 60ft, high 13's now, i am looking to get into the 12's on #2 only. truck weighs 7300 with me and a rider in it. i am considering the 4k gsk, but not if i won't need those rpm as shift points.



thanks again,



Dave

 

[crawler]

If you go to the 4K GSK then you would want to hold your gears a bit longer.



With the 3K holding the gears probably won't yeild much better times.



But, it all boiles down to trying it out and seeing what works best for you.







Later,

Wes