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rear gear affects on 1/4 mile

1K views 14 replies 11 participants last post by  tomthecomic 
#1 ·
In the process of building a new motor for my 63 Nova , it currently has 3.90 gears in the rear end with a 26 inch tire . The motor is going to be super charged with close to 600 hp +/- . I already know its going to run out of gears with the 3.9s and about perfect would be 3.55s . How much affect on the 1/4 mile time would going to a little taller gear to make it a little more freeway freindly be , like going to a 3.00 ? I am estimating low 10s in the 130s mph
 
#3 ·
Current trans is a th350 with a shift kit and 3000 stall convertor , I was thinking it would be alot less money for rear gears than a trans .
car is a weekender only so its not driven alot . After I get done paying for this motor I want to do a new paint job , so there goes another years worth of Fun money , I was also thinking about bolt on overdrive Like the V02 but its like $1500 , can almost do the 700r4 for that .
 
#12 ·
I am pretty sure they have mods to run full manual on the 4l80e...as long as shiftin all the time doesnt bother you.

They also have controllers priced anywhere from 1000 to 1900 dollars.

Anyway you you try it the 4l80e route is a pricey one.
Either spend it on gas or spend it on an OD transmission. I cant say it will take a long time for the transmission to pay itself off in gas the way gas keeps rising.
Things to ponder for your project.
 
#13 ·
Depends on the engine rpms. my car trapped 135 mph with a 3.90 gear, 26 inch tall tires, around 6800 rpm at the end of the track. This is with a final trans ratio of 1:1.

First you need to figure out what will be your engine's max rpm? Then pick a gear and tire diameter so that it hits the max rpm at the target trap speed.
 
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