[orion_uv]

ok, how much punishment can a T-5 tranny take? A stock 5 speed on my 1990 IROC. I'm looking at a vortech supercharger and it'll give me about 340HP and 415 ft. lbs of torque. will I have to do anything to the tranny or will it be fine? I might strap on NOS but again i'll be careful. Can u suggest anything I would do to the tranny if it isnt gonna be tough enough?

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1990 Camaro IROC-Z 305 TPI.

www.geocities.com/camaromandan/home.html

[Joshua Leslie]

Hey..
I dont know from personal xperience, but I heard that the t-5 is junk, and should not be heavly abused unless built up.
Just what I heard
Josh

[gheatly]

The T-5 will not last, even if you baby it. It's not just hard launches that hurt; it is the full throttle runs throught the gears. The tranny's internals just don't have the torque capacity.

I had a 91 Mustang with a T-5 and had the tranny replaced twice under warranty, both before 30,000 miles - and this car was not abused. The only mods I had done was to add aftermarket headers, exhaust, pulleys, and K&N air filter.

[Huck]

Are you going dragging with slicks???? If so, you probably want to consider a different trannie. If it's pretty much a street car, look at it this way - the stock V-8 camaro will spin the tires, right?? That's your limiting factor. No matter how much power you put into it, unless you use stickier tires to hook MUCH better, you can only transmit so much torque through the trannie to the ground in the lower gears, which are the weak point. In higher gears, where you can transmit the engines full torque, the gears are stronger (cause the gears are closer to equal size - you don't have one that's way big, and one that's way small). So if you're not planning on putting slicks on, or just REALLY abusing it on the street on a consistent basis, you'll probably be o.k. If you ARE planning on really pounding on it all the time, or dragging it with slicks frequently, you probably ought to look at another trannie.

If it's just a street car, you might as well see how far it'll go, and spend the extra money when, and if, it dies.

Lots of drag racing Mustangs out there with T-5's. They may be a LITTLE stronger, but I don't buy the argument that there that much more stout. 25lb-ft. of extra strength doesn't mean dick. And that's about what the difference is, according to most of what I've seen. Plus, the T-5 is light (80-90 lbs.) and shifts nice (especially with a tight, short throw shifter - my B&M Ripper works well - a friend who used to own a Mustang loved it). And you've already got it. For the cost of one of the heavier-duty trannies, you can go through your existing trannie and two more, AT LEAST. I'd only swap it if it's a largely a drag car, or one that'll be on the strip regularly.

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Huck
355 SBC powered '87 Chrysler Conquest TSi - 10.3:1, Vortec heads, XE 268H cam, HEI, eq. length shorties, Performer RPM intake, 750 Edelbrock (1407), T-5 and 3.54:1 posi indep. rear

[gheatly]

Huck,

Your reasoning is wrong. If an engine makes 415 hp at, say 3,500 RPMs, and you are driving down the highway at 60 MPH and nail the throttle at 3,500 RPMs, you will transmit 415 ft-lbs of torque thru the tranny.

The T-5 will not absorb this punishment on a consistent basis. I almost never performed hard launches in my Mustang, and it could smoke the tires all day. Most of the punishment came from full throttle runs up the entrances of freeways. Both trannies ate up the second gear syncro. This was the weak spot in the Mustang T-5. As you correctly pointed out, GM's version of the T-5 was not as strong as the Mustang version.

Orion, you may not blow out the tranny, but you will eat up the syncros. This will make the tranny difficult to shift and it will grind when you shift gears.

[Racer#00]

I had and 87 Mustang GT. Had fun with it and didn't beat it to hard. Second gear went on it too.

If you are spending the money on the engine, why not make sure the rest of the drivetrain is up to par?

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Racer#00

Plain Jane 67
76 Trans Am Stock Car
74 Z28 (Basket case)

[Eric68]

I had an 84 Z28 with the T5 and used it with a 350 - 400 HP 355. Maybe I got lucky but I never had any trouble with it other than a pressure plate that popped all the springs. It was running fine when I sold the car with 130,000 miles.

There are two versions out there, I think that in about 86 they went to heavier materials in the syncros and upped the torque capacity from 300 to 325 ft/lbs.

[Huck]

Gheatly -

O.k., you got me - it's only really first gear that you won't transmit full torque on street tires. Actually at some point you will in ALL gears, but it's the SHOCK that causes the problems - the momentary load peak when you dump the clutch that is much higher than the actual continuous torque of the engine due to the rotating inertia of the engine, and the inertia of the car. But, due to slippage (on street tires), that shock is minimized in first gear - which is the weakest, and is what the load rating is based on. In second gear, you're not trying to get a car moving from a dead stand still - you've got some momentum in the right direction, and the gears are stronger. The higher gears are MUCH stronger - it's pretty much going up exponentially.

And killing your synchros has nothing to do with the strength of the trannie. It has more to do with how you shift and how completely the clutch is disengaged as you shift. Could be aggravated by a bad synchro design, but there seem to be plenty of cars surviving (and many racing). They did change from brass synchros to paper synchros in the mid-80's ('88, or maybe mid-'87, for the Camaros).

It may not be a good trannie for a drag car, but I think its bad rep for street cars is overblown. And Orion can use his current trannie, and buy two more for the cost of the cheapest alternative. Just my opinion. I may be proved wrong - I'm running one behind a 375-400 hp and 400+lb-ft engine, which I don't abuse, generally, but it gets hammered periodically. We'll see.

I've also talked to several others who're running them behind engines similar to mine with satisfactory results. You've obviously got some first hand experience with this trannie, as has Racer#00, but the majority screaming about it are usually just spouting the "conventional wisdom", without any personal experience.

[Huck]

Gheatly -

I just saw your signature on another post and noticed you're running a TKO. I guess we both have our reasons for arguing in favor of, or against, the T-5! I thought about using the TKO in my engine swap, but decided that for the cost of 2 rebuilt T-5's to get a TKO, I'd see how far I could get on the T-5. And, like I said, if I'm not drag racing it regularly, I don't see that I'm stressing the trannie that much more on the street than a stock engine, with the exception of the occasional full-on blast. So I don't expect it to last 150,000 miles in one piece. But I don't expect it to die in 30,000 either. Time will tell, I guess.

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Huck
355 SBC powered '87 Chrysler Conquest TSi - 10.3:1, Vortec heads, XE 268H cam, HEI, eq. length shorties, Performer RPM intake, 750 Edelbrock (1407), T-5 and 3.54:1 posi indep. rear