BRIAN67SHELBY

I just wanted to get a thread started for those Mach1 owners that decided to go with the T56. If you want, please inform us on your overall satisfaction of the T56 and if you have had any problems with it at all. Please elaborate on your choice of rear gears for your specific T56 gearing (viper spec, cobra, etc) and what seems to work best for road race, drag racing, or daily driver etc. Also, please include if the car is a daily driver, weekend drag, all out race.

I purchased my T56 from DD performance with gear ratios( 2.97, 2.07, 1.43, 1.00, .80, .62. I've had the trans now going on a year without any flaw whatsoever. It came as a kit with crossmember, Alum DS etc. I really wanted a alum flywheel, so I purchased one with a good clutch setup prior to install. As for the shifter, I didn't really have a preference on those. I did choose Pro 5.0 and I'm very pleased with the centering springs and the ease of going into third and it feels solid. My car is a daily driver approx. 50 miles to and from work. I'm still using stock 3.55 gearing( which I heard is a really good gear for SCCA road racing) and I'm thinking about going with 4.10 gearing and still using a 275/35/18 tire which would be very close to a diameter of my other wheel/tire setup 275/40/17 simply because that I like to take my car to the strip every now and then. I've heard that the 4.30's are the best for drag racing if the rearend is built correctly with good control arms and slicks or DR's. But some of the guys that I've talked to didn't refer to the transmissions gearing in relation to the rear gear choice. I guess that is the real reason for this thread. Sorry if this info has already been covered/posted elsewhere.

darkmach1

No T-56 here but I've heard you need at least 4.10s to take advantage of the longer gears of the T-56.

rygi23

No T56 either but for n/a 1/4 mi. the 4.30s/4.56s with std. 3650 tranny gearing suffice w/o control arms or suspension work so long as their's atleast DRs w/ a descent burnout, though I'm sure every little bit helps. I have 4.10s and 3650, the 3.38 1st gear is nice but only turning 5.5K through the traps, it sucks. With T56 2.97 1st gear wouldn't go any less than 4.30s. My wish list is 4.56s and v-spec w/ it's .50 6th gear. IMO 4.10 is optimal for road racing and 4.56 is optimal for n/a 1/4 mi. f/i is a whole nother story.

USMCrebel

i thought i remembered the t-56 having the same gearing as the 3650 except for the .60 or something 6th gear.

darkmach1

Negative...3650=

1st: 3.380:1
2nd: 2.000:1
3rd: 1.320:1
4th: 1.000:1
5th: 0.670:1 (used on 01-04 with 3.27:1 final drive)
5th: 0.620:1 (used in 03-04 with 3.55:1 final drive, Mach1)
Rev: 3.380:1

USMCrebel

whats the t-56 gearing?

jmac72187

Depends on the spec you get. The Cobra, Viper, etc all have different gearing.

darkmach1

The OP posted the ratios on the first post.

Jazzer The Cat

I don't have a Mach, but have done a T-56 swap in my Saleen. This link is about how to do a swap, but has TONS of information on the different gearing and some links to help gather info.

I have the same gearing as Brian, but don't have the same HP/T numbers. The gearing is not a whole lot different from that of most 5 speeds until you get to the 5th~6th gears. Depending on the model, you really just add a higher gear to your average T-3650/T-5/T-45 or have a .08 inbetween the what is the 4th~5th of those transmissions. Somewhat taller 1st, so this should be considered for one who wants to go the the 1/4 mile regularly.

I don't 1/4 my ride, but have a theory as to the advantage of Brians and my own gearing. The T-3650/T-5/T-45 all have a somewhat lower 1st gear in relation to 2nd~4th of our gear boxes. One guy I know, is REALLY into the 1/4 and likes this extra-low 1st gear. He says it helps him get off the line better, to which I have no argument, as I don't race, but..... My theory is an equal "step" between gears should be BETTER than the relatively large step between 1st~2nd of his T-45. I think that using a lower final gear in the rear axle will affod an even gap between the gears and keep the shifting smooth along the 1/4 mile pass.

I had a T-5 in my '85 GT and then a T-3650 in my current Saleen when I purchased it. It was somewhat difficult to get a nice smooth shift going 1st~2nd due to this larger gap between these gears. I immediately noticed a much smoother shift going with my T-56 after my swap. Seems to me, a 4:10< set of gears would compensate for the taller 1st gear of the T-3650/T-5/T-45 and put the ALL the gears evenly spaced for good RPM range through the gears up the 1/4.

One will not see 5th gear in the 1/4, but is VERY nice for those 50~60 MPH zones with my 3:55's.

Jazzer

BRIAN67SHELBY

You can contact DD performance and they can build a T56 with the gear ratios to suit your driving style. I do like the fact that the RPMs are a little over 2000 in 6th gear at 70 MPH and that I can still pass cars on the interstate without having to downshift to 5th. I would imagine that would be extremely easy with the 4.10 gears installed. I have experienced a right rear axle seal that apparently dried out or cracked( all that high speed interstate traffic) and this caused my gear oil to seap out causing my gears to start to whine. I replenished the gear oil that was missing, but the damage was already done I believe. I found a total rearend rebuild kit with axles, diff and all at latemodelrestorationsupply.com that includes 4.10's. I am in the process of building a house now and I'm really hoping I can convince the wife that this would be a "need" instead of a want. As for the gearing questions about the T56s heres a little info just in case you would like a certain gear ratio setup:

2003/04 Terminator: 2.66, 1.78, 1.30, 1.00, .80, .63 w/ 3.55 final drive
2000 Cobra R race : 2.97, 2.07, 1.43, 1.00, .80, .62 w/ 3.55 final drive
2008 Shelby GT500 : 2.97, 1.78, 1.30, 1.00, .80, .63 w/ 3.31 final drive
2010 Shelby GT500 : 2.97, 1.78, 1.30, 1.00, .74, .50 w/ 3.55 final drive

Here is a link to a good gear calculator that shows your RPM according to your wheel/ tire combo: http://xse.com/leres/bin/gearratio?t...le=40&wheel=17