gear ratios

I am going to make a gear change after breaking my 4.86 gears last year and just wanted some opinions.

I know there are a lot on here that think the higher gears are better because of big torque #'s. I have ran 4.86 and 4.30's in the 1/8 and have found the 4.86 to be quicker in the 1/8 mile. I have also ran out to 1000 ' with 4.86 and et 6.665 @ 7600 rpm so this has me leaning towards changing to 5.13 gears.

I think I can cover the 1/8 mile with them , and I don't expect big mph #'s with the p-51's , I mean 135-138mph I think is good for a door car in the 1/8 mile . If you get up into the 140-145 mph range its going to take upwards of 1100 hp to do it.

What do you guys think ?

A little squirt of giggle gas goes a long way.......

Steeper gear will help a converter thats on the loose side, but that said one will run harder with a tighter converter and a higher numerical gear in the 1/8th anyway.

Just have to try every possibility.

dfree383 wrote:A little squirt of giggle gas goes a long way.......

Hush your mouth! No No No!

I really don't think it would pick up more rpm with 5:13 gears than it would going out to 1000 ' with 4.86's. I have seen consistent gains of 2 numbers of et for 1 number of 60' .

Squirt away Freeloader that is the easy way out lol .

Ms mustang is gonna have to come to the realization that Ky either needs a squirt of nos or a big big new engine

MsKYMustang wrote:

dfree383 wrote:A little squirt of giggle gas goes a long way.......

Hush your mouth! No No No!

Don't be sceer'd.....

I love the easy way out!

KY JELLY wrote: Ms mustang is gonna have to come to the realization that Ky either needs a squirt of nos or a big big new engine

I vote for big engine!

richter69 wrote:Steeper gear will help a converter thats on the loose side, but that said one will run harder with a tighter converter and a higher numerical gear in the 1/8th anyway.

Just have to try every possibility.

This is the direction I have went with mine and so far it works.

MsKYMustang wrote:

KY JELLY wrote: Ms mustang is gonna have to come to the realization that Ky either needs a squirt of nos or a big big new engine

I vote for big engine!

Their you go Randy.... Momma say's bigger is better !!!! and you now have permission !!!!

dfree383 wrote:

MsKYMustang wrote:

KY JELLY wrote: Ms mustang is gonna have to come to the realization that Ky either needs a squirt of nos or a big big new engine

I vote for big engine!

Their you go Randy.... Momma say's bigger is better !!!! and you now have permission !!!!

yes that is good news , but I am not done with this p-51 engine yet

just doing the math my car is 11% quicker et wise from the 1/8 to the 1000' timers than from the 330 timers to the 1/8 with 4.86 gears. A 2-3 % improvement to the 1/8 would be great.

A legal nhra pro stock car is about 14.5% quicker , but that is geared for 1/4 and 10,000rpm+ exotic parts got to keep that in mind.

If your 4.86's are the big pinion gears, do you have the parts on hand to make the swap over to the small pinion 5.13's? If you have all the parts already you might as well give the steeper 5.13 gear a try just for shits & grins.

A 5.13/5.14 gear might ET better than the 4.86 in the 1/8 mile NA, but with more torque (some nitrous added or a bigger motor), I'm thinking the 4.86 (or smaller) might ET better.

How close is the current converter choice to being "dead nuts" perfect? Or is it a little on the loose/tight side for this engine combo?

A small block gear in that package? I'd guess I'm missing something.