305IrocZ28

This is an issue I dont see frequently discussed on this site- everyone talks about modifying their beasts, but they fail to mention one thing- what can the transmission handle? I see Summit selling TCI Streetfighter 700R4s that can apparently handle up to 450 ft-lbs of torque...now, if that is aftermarket, the stock 700R4 must not be able to handle that...all of these people who modify their 'rocs seem to do it without worrying about the tranny. What is the limit?

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305IrocZ28- Al
1990 Iroc-z 305 TPI auto, Flowmaster exhaust, 2 Rockford 10'' Punch woofers w/ 160a2 amp, 2.73 rear (1650 rpms @ 60mph)

Omega

iTrader: (1)

I wouldn't go with a TCI trans, someone here did and they are regretting it. Goto the trans board. There two guys there that are experts: Pro Built Automatics and transfixleo. They would be able to help you. I am pretty sure that a 700 can be built up to 600 HP.

ATOMonkey

Good question. All transmissions are torque rated. This trans might be old enough that GM released the specs on it somewhere. If I had to guess....I'd say....550 ft-lbs.

Brian K

Stock I am told up to 400HP depending on the year. Built as far as your $$ allows..

88blkiroc

well 4L60E's are running behind some very fast cars these days so im assuming that since the 700R-4 (4L60) is an ancestor of the 4L60E that i could theoretically handle just about the same amount of power.

Greg90iroc

the 700 R4 is not as strong as the 4l60E because it does not apply as hard but that can be solved with a billet servo. The 700 R4 can handle my engine but i am scared to see what would happen if i add any more power. the 89 and up 700 R4 is stronger because it has a 10 vane pump instead of the 7 vane pump used before 89. this allows it to apply harder and last longer.

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90 IROC l98
last season best corected 13.62 @102
mods
full exhaust, AFPR, pulley, jet stage 1 chip, billet servo, 52mm throttle body, slp runners and some 1.6 RR's and a few other little things.
243 RWHP and 342 RWTQ with hot engine and 90 octain fuel

FlashGTA

I have a TCI streetfighter 700R4 and I love it, great transmission. I would however recommend going with ProBuiltAutomatics if you aren't in a hurry for a new tranny. But as far as stock capability, I'd guess about 400 ft-lb.

MartyMcFly

The 700-R4 is the stronger tranny. My friend works at a dealership and is always complaining about how the 4L60-E is a piece of crap, always goinig out and such.


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Ludicrous Speed GO!!!
Does anyone know what movie this is from?

Guido

I have a Darrel Young built 700R4. It has been in my car for 3 1/2 seasons now and it has held up to im sure 500+ runs. Its living behind my blown 406 right now but I wonder how long that will last.

Ive got a Th400 in the garage I am going to have rebuilt with a transbrake this winter.

For now, I am happy with my 700R4 except for the 1-2 gear shift ratio. That thing is an RPM killer!

Shift @ 6500, goes back down to 5100..

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-86 IROC
11.31 @ 120.2 mph
-=ICON Motorsports=-