Transmission gear ratios.
 

When i went through my Doug Nash 4+1 i documented my gear ratios. After talking with one of my PR friends he told me my ratios needed to be changed. The transmission ratios that are in it right now are 1st-2.40 2nd-2.22 3rd-2.07 4th-1.33 5th-1.00. What he recommended is 1st-3.05 2nd-2.07 3rd-1.65 4th-1.33 5th-1.00. I am running a 28" tire with a 4.89 gear. Does this sound right before i order $800 worth of gears or will it not make a lot of difference? Thanks for any input.

Allen

Any advise guys?

i dont think too many people change their gearing because it is so expensive

Yeah, i guess this is kinda a weird question that very few would have an opinion on. The stock ratios on a 3rd gen have a lot taller first gear with a large jump between first and second. 1st-3.48 2nd-2.015. I think that large a jump would be undesirable for a full drag car. Does first need to be that low to get a good launch/60ft in a light car? Or would the 2.40 actually help spool the turbo by lugging the motor a little?

Allen

I would leave the gears you have in, less gap means less rpm loss and keeps you in the power band better

Thanks for the advise. I am really worried about getting the car off the line. It is a light car but i am worried about the 2.40 first with my 11 lb chromolly flywheel and my Tilton 7.25 clutch. I'm think it would really hurt my 60' times. I am also concerned that the other gear setup will hurt my ET. I don't have enough experience with rotaries to know witch way to go.

Thanks Again
Allen

I think it would be best so sacrifice a little on the 60ft, for the gain you will get with the closer gears. Excpecially with that monster turbo. Also, there are guys running power glides, C4's, and TH350's with rotarys, they do get the torque multiplication, which helps since there first gear is similar to yours, but you will be able to launch at a much higher rpm, so i think it will be a fair trade off.

Found a site that does transmission comparisons. With the gear set that is in it now it will go over 60 MPH in first gear. Is it just me or is that way too high?

http://www.fatboyraceworks.com/gears...raph&Compare=1

Hmm..... i bet they would run similar 1/4 times, just with differnt 60ft's and trap speeds.

Run what you have in the Trans now
 

I would recommend running what you have in the Trans now. Once you get to the track and start playing with tuning and boost you'll be surprised at what turning up the boost will do.

Well i finally decided i am going to swap the gears. I started thinking about it and in the first 3 gears there is only a speed difference of 9.62 MPH. I figure even if it didn't bog off the line there was no way i could shift it that fast.


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