[RileyF100]

I am very new to the racing world, so bare with me. I was wondering why people would go to a higher rear end ratio if it makes you slower (at said RPM) and what would be better, going up the in ratio or down?

[3valve46]

well friend,higher ratios (example 4.10s instead of 3.31s) keep you in the powerband,and really help for drag racing.3.31s are longer gears,and arent really good for drag racing ,although on the highway,3.31s are great due to the fact that at higher speeds the car will be in its powerband,s197s especially.and were talking speeds of over 100 mph.But with 4.10s past 100,itll be in a higher gear which means lower rpm's,which meas not being in powerband.

[RileyF100]

So, with a 3.18, if i went to say 3.55, it would slow the car but keep the car in the power band longer?

[limp1969]

3.18 70mph 2000 rpm
3.55 70mph 2300 rpm 5th gear

there is a formula but I do not know it. Above is an example
I have a 94 gt DD with 4.10 5 speed 18" wheels w/245 at 2600 rpm is around 70mph


Think of it like riding a ten speed bike. When you shift the rear gears from big( lots of teeth) to small (fewer teeth) the smaller the gear the harder it is to pedal but the a higher top speed can be obtained if you have the power to do it. The bigger the gear the easier it is to pedal so the quicker you can move the weight. So if getting to 100 mph as quick as you can is what you want a higher gear will be needed lets say a 4.30 but if you are looking for gas milage or higher speeds a 3.07 would be better
But if you are looking for the best of both worlds put a 3.73 in.
Hope this helps a little

[3valve46]

Originally Posted by RileyF100

So, with a 3.18, if i went to say 3.55, it would slow the car but keep the car in the power band longer?

3.55s would be better for drag racing.ok heres an example.
my gt has 3.31s.i shift at into second gear at 40 mph,into third at 72 mph,into fourth at 110 mph,and idk about fifth because im still in fourth all the way up 150.hence why it will pull real good on the highway,because im in fourth instead of having to shift and into fifth and losing the power band by dropping rpm's like i would with 3.55 gears.the top speed of my gt is alittle higher than another gt just like mine,but with 3.55s.
and 3.55s shift points are 40 mph,66 mph,100 mph,and 135 mph.hope this helps.

[MU3ST5ANG1]

in the basic form, gear ratio is = to driven gear (the one that helps drive your axles otherwise known as a ring gear) / drive gear (the one thats attached to your drive shaft otherwise known as a pinion gear)
so the higher the ratio, the more the torque or bottom end power you get.
a higher number such as 410 or 4.10:1 represents the pinion gear spinning 4.10 times to every 1 revolution of the ring gear which produces better low end torque.
when discussing gearing, IF 373 is a good compromise for street and strip, 410 is more strip and 355 is more street.....hope that makes sense

[RileyF100]

Ya, thanks, that helps a lot, now i am just wondering if i can fit an automatic w/overdrive into my little mustang. It would really help compared to the auto that is in it now, says the RPM calculator. But it's that or a manual, 4 or 5 spd, and my dad doesn't want me goin either auto w/over or 5 speed because i can go a bit faster.

[MU3ST5ANG1]

tell him that most drag cars are 2 or 3 speed powerglides... hahahaha (well a lot of them that i know of)

[sethxs06]

I have a 95 v6 auto with overdrive and it's not a whole lot faster than a regular auto. I would try to drop a 5 speed in it

[RileyF100]

Ok, thanks for that, I was thinking T-5, but i have heard they can't take the RPMs and HP very well. Is this true?

[sethxs06]

Originally Posted by RileyF100

Ok, thanks for that, I was thinking T-5, but i have heard they can't take the RPMs and HP very well. Is this true?

I've never heard that but you should look into it more.

[RileyF100]

A quick question, how much torque could you get out of a 78 302 with the only mod is a 4 bbl carb? (estimate)

[RileyF100]

I am also wondering if anyone knows if this T5 will bolt up to a 78 302 without costly modification? T5 Tremec