Wondering if a 31 spline, 373 rear gears are better for my street & strip foxbody or would the 308 or 327 gears be better for a vortech supercharged 302 with an AOD manual valve body trans with 525 hp at the crank and 486 rwhp...which gear ratio world give my foxbody the best performance on the street and on the track??
Gear selection with performance in mind is going to depend on your power band and tire sizing. If gearing it strictly for the track, you will want your 1:1 gear to be a little over your max hp rpm, say 500 rpm more. So if you make max power at say 5500rpm, you want the gear ratio that will put you through the traps at 6000rpm.
I am going to guess that with your mods and a 26" tall tire that a 3.73 will be your top performer, but a 3.55 may be better for mixed driving. The converter selection with the auto will be key because getting off the line may be tricky with a higher gear set and not enough convertor.
Don't fear the gear. Especially with an aod. I'm still a fan of 4.10s with that trans. 6500 at the stripe would be around 120mph which is where a hci vortech car should be (assuming it has an hci, at that power I would think it would and should have no problem going closer to 7000).
Don't fear the gear. Especially with an aod. I'm still a fan of 4.10s with that trans. 6500 at the stripe would be around 120mph which is where a hci vortech car should be (assuming it has an hci, at that power I would think it would and should have no problem going closer to 7000).
depends on the cam.... Why spin it out to 7k if your done by 5800??
I had a custom cam made for my current build blower cam 114 lsa idles great makes power everywhere but noses over at 6k so i shift at 5800. stock limiter. 3.08 gear t5
depends on the cam.... Why spin it out to 7k if your done by 5800??
I had a custom cam made for my current build blower cam 114 lsa idles great makes power everywhere but noses over at 6k so i shift at 5800. stock limiter. 3.08 gear t5
Exactly what I was trying to get at with his peak power rpm. No point in putting a gear in it that spins him to 7k on the big end of he is all done by 5500. And vice versa, he needs a gear that will get him into the power band.
A lot of a people are confused by gears. The rear gear only gets you into the power band more quickly. Getting off the line is the most critical point of drag racing. Every mph you add at the beginning of the track is one you get to carry through its entire length. Going to numerically higher, aka "shorter," gears will always help you come out of the hole, as long as you have the traction to make use of them. The optimum rear gear ratio will be the one that takes you through the traps at, or slightly above, the shift point in your final gear, assuming you can keep it in that final gear. This will give you the highest power "under the curve" throughout the run.
The only way a shorter gear will cost you, all other things equal, is if you end up being forced to shift into a gear that takes you out of the powerband, or you're forced into a gear you can't take full advantage of, like when you would cross the traps in the 1/8 at the top of 3rd, but now with a shorter gear you have to shift to 4th with like 200 ft to go.