T56 with 4.10's, resulting gear ratios?

[CdnNavybob]

OK, I'm usually pretty good with math but I think I'm doing something wrong here because I can't get my number to make sense.

I'm currently running 4.10's with the stock T45 in my 2000 GT. What are my actual ratios (gear ratio x final drive ratio?) right now and what will they be if I can find a used or salvaged T56 from a Cobra? The 4th gear syncro in my T45 is going and since I've put in a Tri-Ax and the 4.10's Ford won't touch it under warranty even though they are a technology exchange partner with Steeda and the gears are FRP. Are there any other cars out there other than the Viper that have a T56 from the factory? I doubt I'd find a Viper in a salvage yard but I'd be open to other donor cars if they exist.

I autocross this car and I'm wondering how much shorter 2nd gear is going to be. I don't want to have to shift into 3rd at any point while autocrossing. I also have about 20 minutes of highway commuting everyday so I'm interested to see if my highway RPMs will be a bit lower.

Thanks to anybody who can help.

 

[CdnNavybob]

anyone?

 

[hognutz]

okay well f-bodies have had t-56's since 93. vets have had them since 91 or 92 I do belive. vipers have them. new gto's have them. there are lots of different versions%2

 

[hognutz]

here is a link to tremec's site

http://www.tremec.com/English/products/T-56.asp

 

[CdnNavybob]

OK, thanks.

Now two more questions. Which number on that list applies to the Cobra T56? And, how do I come up with the right number for how these gear ratios compare to my current T45? The numbers I get when I multpily the gear ratio by the final drive ratio don't seem to make sense to me.

 

[hognutz]

Well I listed all that in my first post but it all got erased so how. here is is again. I edited my post to add more and it froze up and all the info got erased.

t-56
2.97
2.07
1.43
1.00
0.8
0.62
3.28

t-45
3.37
1.99
1.33
1.00
0.67
N/A
3.22

tr-3650
3.38
2.00
1.32
1.00
0.62
N/A
3.38

I also posted that different models from different cars have differnet shifter locations, input shaft lenght, spline count, etc so it would be easier to use the cobra model from a ease of swap perspective.

you also have to cosider that you final drive ratio is the same with a tr-3650 as t-56 you just don't have the big ration drop from 4th to 5th. you will get a closer ratio feel from the t-56 that is nicer to drive IMO and first gear is a little taller so it won't feel so short with 4.10's. this will proably not benefit you much in a strait line though as you should not need 5th for the 1/4 if you car is setup correctly.



here is a link to a gear calculator.

http://www.f-body.org/gears/

I know it is an fbody site but it will do the math for you.

my .02 is run the t-56. when my t-45 goes tits up that is what is going in. I hate the huge gap from 4th to 5th but I an not a strait line only kind of guy. if you are save the $$$ and get the 3650. you can also look at the geforce stuff if really high torque capacity is important.