gear question

[Norton22]

I am looking at running a 1/3 mile dirt track Does anyone run that small of a track I am looking for a good starting point for my gear ratio 2300 mustang

[boportt]

6.99 w.71" rollout tire

[steveshawjr]

3.27 rear gear with the stock 7.5
3.08 works aswell with a bit smaller tire about 500rpm less

some run a 3.08 with a 5speed as well with about a 75 inch tire

[Dirtman29]

I run a T5 in 2nd/308 gear, tires are 77 1/2" rollout, on a 1/3 mile I hit 6800 RPMs (thats all it will turn) just before corner entry. Most are turning 7K-7300 RPM with same gearing & tire size. I have to run OEM exh. manifold to not float valves at the flagstand! I would estimate a 300-500 RPM jump with a header.

[wil8115]

depends on what RPM you'll need to turn. anything from 6.25-7 might work.
we use 68-72" 'ish rollouts.(GY short track special 22" or 23" x8x13's)
various setups turn 6500-9000

[return to dirt]

I am looking at running a 1/3 mile dirt track Does anyone run that small of a track I am looking for a good starting point for my gear ratio 2300 mustang

can't help you on what gear to run but i got a chuckle out of your definition of a small track. to me a 1/3 mile track is huge.

olin

[dannyracer6]

I run a T5 in 2nd/308 gear, tires are 77 1/2" rollout, on a 1/3 mile I hit 6800 RPMs (thats all it will turn) just before corner entry. Most are turning 7K-7300 RPM with same gearing & tire size. I have to run OEM exh. manifold to not float valves at the flagstand! I would estimate a 300-500 RPM jump with a header.

which t5 do you have, the 237 or the 234 second gear? You did not say what you can do with the engine. If you are floating the valves, put on bigger valve springs. The lifters should handle up to at least 7500, I have seen some go to 8 with hyd .
If you have the 237 second and use the 3.08 you have a f inal drive of 7.30 then figure in your tire roll out. If it is a 2.34 you have a 721. there is no reason you cant get at least 73ish with that 730 gear final on a 1/3. I used 15" tires and a 214 second gear with a 3.80 rear for an 813 final and got to 78 to 8000 on a 1/3. Just do the numbers, and try them out...Good Luck

Dan

[car62]

actually Dan,there are several more 2nd gear ratios for the T5

1.93
1.94
1.99
2.14
2.32
2.37

[Dan32]

I run a T5 in 2nd/308 gear, tires are 77 1/2" rollout, on a 1/3 mile I hit 6800 RPMs (thats all it will turn) just before corner entry. Most are turning 7K-7300 RPM with same gearing & tire size. I have to run OEM exh. manifold to not float valves at the flagstand! I would estimate a 300-500 RPM jump with a header.

you need better spring pressure!