Engine/Transmission (1998.5 - 2002) numerically lower gear ratio faster in 1/4 mile?

[jkidd]

standard options are 4. 10 and 3. 54



I found that 3. 54 is much faster, (no numbers) , maybe just because I have a 6spd.



Does anyone know where the cut off is for speed at 400-500HP? for example is a 3. 07 significantly faster, or those with a GV gear vendor or US Gear?



Thanks for helping me with my curiosity.

 

[TCluff]

How many times did you have to shift with the 4. 10's as apposed to the 3. 55's? With an automatic you would want the (numerically) highest gear ratio possible to run without running out of RPM at the end of the track!

 

[Bob4x4]

Horsepower dictates mph in the 1/4. The et will vary with driver ability,gears launch etc.

 

[JDiepstra]

Well, the lower gearing (higher number) would theoretically get you going faster but if there is an extra shift it may slow you down a bit.

 

[jkidd]

it seems diesel does not rev as quickly as gas. I could hardly peel the tires with 4. 10 at 400hp, with 3. 54 it is much easier.



with 4. 10 I would have to shift to 5th by 55mph at 3300rpm

with 3. 54 I can do 60 in 4th. lost about . 5 seconds too (less shifting)



I have not been to the track, and don't want to do more than 80 on the street.

 

[MA2LA]

I noticed this along time ago. when you have a motor that has great torque but doesn't rev very fast its better to go with taller earing to a point. it allows you to stay in the meat of the power band longer and use what ya got. I used the same principal when racing ATVs it was nothing to go 1 or 2 tooth on the front sprocket when you started adding power.

 

[jkidd]

I had a grand prix with 2. 97.

the newer 3. 27 and aftermarket 3. 6 were faster ET times, but the 2. 97 had a higher speed at the end of the 1/4 mile,



example 2. 97 13. 1s 110mph

3. 29 13. 0s 107. 5mph



does anyone have times/experience with different gear ratios for et and mph?

 

[coreyallan]

I 2nd MA2LA, with lower gears horsepower will help you because your effectively making torque, but with a diesel you already have torque and you want wheel speed so higher gears are the way to go to a certain extent both to keeper cummin and not run into a gear/wheel speed limmited situation, we all know she goes flat up on the top..... Not a reeeevvvver... . But... You can also play w gearing effictively by changing your tire size, if your runnin 3. 54's and 35's than you might effectively have somewhere in the neighborhood of 3. 10's +- or if your runnin 4. 10's and 35's than mabey your somewhere around effectively 3. 73's +-. Its something to consider, im sure my numbers are off but you understand what im sayin... .

 

[ASharp]

Thank you for this post!!!! I have the exact same issue and have actually thought about selling my truck for an automatic. As you can see by my sig I have quite a bit of power, approx 425-450hp and 800-900 tq, but it seems that I have to shift so fast with the 410's the turbo never has a chance to pull through the RPM's.

I would like to keep my truck as it is VERY VERY clean. I pull 10-20% of the time. The rest of the time I bought this truck to show the people in my town what a REAL muscle car is, not some japanese rice burner!

I have been thinking about going to a 354 or even higher. Can anyone comment?

 

[coreyallan]

Well, do you have a short throw shift kit and do you have a leveling kit? your truck should clear 35's w-out a lift anyway. If you are running a 285 or 295 try stepping up to a 315, I'm sure you know somone who has two old ones you can use for an expariment. Give it a try and if 35's or 36's put you in the correct power band then figure out the correction in gear ratio by using the 285/295 vs the 315 as part of the equation... But... If you make passes in 4wD than this might not work because you need to clear the same rubber in the front as in the back..... Also, i'm not sure if you use your speedometer as a reference but I cant remember in a Dodge but I think it will be off w the larger tires?

 

[jkidd]

larger tires, 285/75 315/75

check into a gear vendor/US gear. Not sure how much power they can hold.

I had looked into a spicer aux transmission to give me an 18spd. , But I am not able to fab.

 

[Timbeaux38]

You can pick up MPH in the 1/4 going to a 3. 55 from a 4. 10. I know of a few high HP trucks that run out of revs at about 1000-1100 feet