Best gear for 1/4 mile

Chevydrivin,in the past when Iv had a tranny slip or a converter fade away I can usualy tell by my 60ft time falling off like say a 1.49 insted of 1.35 this is a slight slip and befor some body says you SPUN off the line NO it hooked hard pulled front wheels did every thing it should do.Also if you have a real bad slip at high RPM'S say at the 1/8 mile point ETC,IV had the car go up on the REV-LIMITER.I trashed that converter,you can tell if the tiers are spining off the line by putting shoe polish on the rears and whatch the car leave the line you can tell if thats whats slipping not the tranny or converter.also if you spin off the line you will pick up alot more MPH at the traps.put some runs on the car and start comparing time slips thats the best place to start.get a summit / jeg's log book or even a note book to keep records.

I have a way of calculating the correct rear gear for your application given the tire size and maximum engine rpm. BUT take into consideration THIS.....the formula I use only takes into consideration maximum engine rpm with a one to one transmission output and tire size. That considered, you need to look at it this way, with a one horse power engine capable of 4,000 rpm and the tire size of 30" and a gear ratio of 4-50, you will eventually reach a maximum speed of 100 mph. It may take all day, but you will get there, relatively with a 1,000 horse power engine capable of the same maximum rpm of 4,000 you'll reach the same 100 mph with the same gear ratio of 4-50 but you'll get there before you hit the end of the driveway
So all these things being understood it is up to you to consider you're power to weight ratio, maximum horsepower and torque and how far into the upper rpm ranges you want to push your engine.
All that being said, I need your tire size and maximum engine rpm and I will assume that you are running an engine with 375 to 400 horsepower, the higher horsepower and torque, the higher you can run your gear. I will also assume at this point you are running a 26" X 9" tire and if it is a small block you're probably capable of running 7,000 rpm. Which would give you an appropiate ratio of 4-30 which should run you through the quarter at approx. 125 mph and also give you a halfway decent streetable.
Shaggy

Hi Guys
Richmond Gears has a calculator on there web site for guys like us trying to figure out what gears would suit our needs the best. You just have to punch in your HP, Tire Size and RPM you want to go threw the lights with and it spits out the gears you would need, or dam close to it anyways.

www.richmondgear.com

I used there web site to buy the gears i needed and it worked out great for me.

OPPS..oh ya...you need to know the weight of the car also. But dont forget, thats rear wheel HP on there web site. So you will have to figure out what your rear wheel HP is and not your engine HP.

Thought this post was dead. It was a converter problem. Got a new converter, and ran it, blew up a turbo, got a spare turbo, then spun the rod bearings as stated in the spun bearings post.

$.56 to 5.13 i,d say for an average bracket car. I ran a 391 with 26 in. tall slicks ant car ran consistent 12s Changed to 4.57s and ran out of motor in last 200 feet and had to pedal. no better time . channged to 30 in. slicks and put car in high 11s Sometimes gear changes work better with a specific tire size . If you use 2 much gear you can compensate with taller tires if you have enough convertor to stay in your power in the 60 ft.

Im running the 4:57 gears with 33" tires. When i cross the line im turning at 6300 RPM. When i drop back down to my 32" tires, I was crossing the line at 6700 RPM. The only time i use the 32" tires is if i know the track is really going to hook up hard, the smaller tire gives me a better hole shot. ( 2 speed powerglide) My engine will still pull at that RPM, But i just prefer to keep the RPM's down to help save engine.

i make power all the way to 7200 and i am going through the lights at 62-6500 which is why i am going to my 5:13's with the 29 tall tire. right now its 4:88's :D

When you run a tiny little motor, you need really big gears . . . :LOL:

Quote:

---

Originally Posted by Henry Rifle

When you run a tiny little motor, you need really big gears . . . :LOL:

---

Like my little 283?LOL, guess it depends on if you want to go on the hwy too. my 4 speed with 3.70 gear winds all the way out in 3rd gear 26.4 tire and for the hwy I still got 4th gear. If I kept it off the hwy I could go 4.56 and wind 4th out in the quarter.

:rolleyes: