T-56 vs TKO

[RPM427]

I am looking into getting new axles, diff, and slicks to run at the drag strip. I doubt my t-5 is going to take that abuse for long. I am debating which tranny to buy, the TKO or the T-56.

What are the pro's and con's of each? How much tweaking does the T-56 require to fit? How much more does it weigh, etc?

[429mustang]

I'd go eith a tko or tko II. They run under $2000. The T-56 runs more around $3000, plus I'd think the Tko II would be stronger.

[lx5091]

you can get the t-56 for much less than $3000, I've seen it for $2195. I personally like the Viper T-56 because it has a .50 6th gear. You could run 4:56.1 gears and still get 24mpg driving 75 on the highway!! Check this site out...

Prices are high here, but a wealth of info regarding T-56 and fox body mustangs... click on D&D Drivetrain

www.ddperformance.com/index2.htm

[jim_howard_pdx]

The problem is your torque. The T56 and the Tremec are both rated at less than 450 foot lbs of torque. Neither is designed for the quarter mile. They are track based transmissions.

The viper T56 has much beefier gears. I understand a unit configured to run in a high torque Mustang goes for about 3900.00. Get a scatter shield, I have had friends survive exploded clutches for their 275.00 investment, while those that gambled have lost toes, feet, or an entire LEG! Some unfortunates have lost their lives.

I think this is money VERY WELL SPENT! But for launching a car at the quarter mile, I would go a Lentco AOD. These are good to 750 HP and will reduce parts breakage.

Now if you are a street highway driver, and not a ham handed quarter mile burn artist like me, then the World Class T-5 will probably work out great for you. Most of the wear is in the syncros, and a replacement kit for these is under a 150 bucks. You can rebuild this unit yourself.

The TREMEC is the unit I am considering. I have friends running these behind 426 Hemis and 440 wedge Magnums without any breakage. They should be good for my small block.

What clutch are you running now, and if you quarter mile it, what RPM do you launch at?

[RPM427]

The prices i have seen for a regular t-56 are around $1995, compared to a TKO at $1799.

The viper tranny looks like what I was looking for, an extra gear for highway driving. I am probably going to do that. It can handle 550+ ftlbs, It will only see that when I take it to the track on slicks, It will never see that much torque on street tires.

Does anyone know how much more the T-56 weighs over the TKO?

[jim_howard_pdx]

I should be within 75 lbs with a scatter shield. I would recommend running the 1350 spicer tranny yoke, and replace your rear end yoke for the 1350 joint as well. USE A STEEL DRIVESHAFT. Have your shop fill your steel driveshaft with foam, and balance it on the car if they have the ability. That way you are balancing the rear end differential, axles, lrims, nuts and lugs, tires, everything. This will be something you can FEEL everytime you race.

You might be able to get a rebuilt Viper tranny. A new one will be about 3900.00. A rebuilt unit will be fine on a mustang, but they have to use the right input shaft, or you will need to spend time modifying your flywheel and run a dodge clutch and pressure plate.

[jim_howard_pdx]

By the way, what are your times at the track? What is your gear ratio? Your set-up looks really sweet.

I ported my trick flow heads to the felpro 1262S gasket set. Man what a difference that makes. I was expecting to lose some low end torque but that did not happen. The torque stayed, and the upper end rpm horsepower is dynamically increased. Feels like a turbocharger above 5,000 rpm. I am expecting mid 12's at the track with my 3.25 gears, and I am hoping to hit mid 11's with slicks and 4.30 gears. With Nitrous, I might be able to hit high 10's, but the early mustangs just are not as solid a launch platform as your excellent fox chassis.

[drtbiker]

i got my tremec 3550 to my door with bell housing and everything for like $1400

later

[RPM427]

I am very happy with my setup, It turned out better then I had hoped. My cam is accually a custom cam very similiar to the trickflow stage II. I also have 3.73's.

My best time was 12.85 @109 on Nitto 555's. I have recently installed a Zex kit and can't believe how fast it is now. I have yet to run it at the track with the juice. I am hoping for mid to 11's on slicks.

Some time next year I am sending my heads to bennett racing to be upgraded to stage II or III and installed on a sportsman 408! I am also going to get a "big shot" kit from NOS to use with the edelbrock victor intake. It should really move once I get it to hook up.

I am going to uprade the entire drivetrain some time before that, including the tranny.

Do you feel an aliuminuim drivshaft would be too weak?

[jim_howard_pdx]

I absolutely do.

We run aluminum on all our road racing engines (graphite shafts are lighter and have even less vibration but they break too easily) and we run foam filled steel on our drag engines. I think spicer 1330 style U joints are acceptable, but on any car running 10 seconds or faster, you should consider switching to the 1350 spicer joints. I have never broken one, even on 1100 HP engines running 7.23 index times.

Run the big NOS fogger system. If you have the money run a progressive NOS which means you will have two tanks, two warming blankets, and even more hose lines. It is well worth it. I like to run a 200 hp shot through second gear and a 375 hot through my 3rd gear on an automatic car.

Also, if you run high horsepower nitrous, you should coat the piston tops and the combustion chambers. Coating is relatively cheap, but the stuff REAKS (really smelly BAD). So don't bake them at home.