T-5 Torque Rating
 

As we all know, the T-5 is one of the most popular mods for vintage mustangs. I myself am looking into doing this upgrade, but I have a feeling that when all is said and done, my engine will produce a high amount of torque. The World Class T-5z which is what Ford used on the '93 cobra has a max rating of 330 ft*lb of torque, which is the highest rating on any of the T-5's.

This is where my question comes into play. I know a built engine can pump out oodles of torque, but in a 65 stang it would take extra effort to put in a tremec 3550 or something like that. I'd rather pay more IF I can to increase the torque limit on the T-5 because of the availibilty of conversion kits and just all around ease. So, is it possible to increase the torque rating on a T-5, and does anyone know of a company that sells/builds these transmissions. Thnx for your help!

There is probably a better chance of getting information about upgrading T5s in the windsor forum.

The T5-Z is a Tremec built tranny. The real issue is what you'll be doing with the car. If you plan to run around town on street tires getting into it once in awhile then the T5-Z should be fine. OTOH, if you plan to race on Saturdays, put slicks on for extra traction, etc., then perhaps it isn't the right transmission for you. Remember the torque handling you need is both a combination of engine power and wheel resistance.

I've been reading up on the T-5 and on the Tremec T-3550 and Tko's. I know that what it will come to how strong I build my engine. What I'm a little vague on is what the torque rating is referring to. Is it the amount of torque the engine is putting out, or is it the resistance between the engine and the tires.

I doubt that I would take my car to the track often, perhaps once every once in a while, if anything once a year. I do want a car that can pull a 0-60 mph in less than 5 seconds, and more than likely will not have more than 375 hp, and this is on a built 289/302. Thanks for your reply.

It is the torque the tranny can stand up to when the input shaft is turned and the output shaft is stationary. Thus if the wheels break away before the tranny breaks then 330 ft-lbs is enough for any engine. Even one with 4,500hp and beaucoup torque.

Of course, the worst situation for a car is normally a WOT start with clutch dumped. Peak torque in this case skyrockets. Note that 375hp is not the deciding factor in whether the tranny breaks...torque is.

Look at this list of 289/302 production engines torque ratings: 305, 300, 310, 310, 290, 329. Of these, the early Hi-Po put out the highest maximum torque, not the Boss 302.

Look at this list of 351 engines: 350, 370, 385. Of these, the 351w puts out the most torque, not the 351c Boss or the 351c CJ.

Note that even though the hp ratings of the 289/302's varies quite a lot, the torque ratings are quite close together. This should tell you that even if you build a 375hp 302, it will only produce about 330 ft-lbs of torque. Hence the T5 will hold up to almost any 302 in almost any situation. When it won't hold up is when you drag race every Saturday (or daily on the street) with tires offering great turning resistance. And note the higher axle ratio you use the less strain is put on the tranny. So if you drag race your 302 with slicks and a 4:11 rear, its not likely you'll blow the T5.

here is some info:

ratings

and this one:

ratings2

hope this helps you.