Mildly hot rodded 454 (about :hail:450 hp) and T56 six speed tranny, custom made by myself exhaust ( ooops i forgot the cats and muffler on my dual exhaust! ) on a late eighties iroc-z. Anyone have a good estimated time?

 

I don't know how fast it will go, but without cats and mufflers you are likely to chase away or kill any birds/wildlife in the area

 

run mufflers but no cats. you will warp your exhaust valves in a hurry. you will need drag radials or slicks, a nice torque arm and several suspension goodies to put that power to the ground, but low 12's or 11's could be possible. if you really do have 450 horsepower, it will come down to traction.

 

umm,
it would be pretty fast, but Im sure you could get the kind of power you are looking for out of a small block (400), and have much less of a pain in the @ss! You would also save weight which is the same in my book as gaining power. Its my opinion also that a T56 would not only explode with that kind of torque, but hinder you at the track. You'd be better off with a th400 and a stall.

-Doug

 

A t56 can officially withstand 450 ft/lbs of tourque. And yes one could get the same power with a SBC but for one the SB 400s arent of the same quality, its easier to get the power from a BBC, they have a much better torque curve at the high power levels, and heaviest BBC to lightest SBC there is about 150 lbs(but since im going to get aluminum high performance rectangular closed port heads i think i'll shave a bit of that off). Thanks for your ideas though, i guess everyone's got their opinions, and the previous ones are just mine.

 

Watch out for the T56's...

The big boy LS1's (422ci) eat these things like candy. I've seen people replace them time and time again even with stock displacement motors.

Youve been warned!

 

What would be a better choice? I would rather have a stick, i was looking at G-force trannies but their $$$$$ (in a dream worldi would get one of those). Im not just going to be drag racing (mainly its gonna be a sleeper that wakes up for rich kids and their 20,000$+ cars), i would like to enter into road racing, in which case i would feel hindered by an auto. If the t56's are so bad how, is the same tranny used on a viper. This is really puzzling me.

 

muncie!

You dont have to take my word on the t56

Here, go check out www.ls1tech.com and go to the drivetrain forum. Look at all the posts about broken/braking T56's.

Doug

 

Thanx doug i'll check that out. Do muncies have six speeds? man the thought of flying up through 6 gearsis great!

 

How so??, then I guess all the people at the track that run open headers or street rods that have open headers burn there valves..

 

Hes right syaing to run mufflers. Racers rebuild their engines constantly.

 

ive been running my 79 dodge truck now for a little over a year and have no warped exhaust valves. Put over 30 000 km on it, and surprisingly the cops havent hasseled me about the straight pipes. just my .02 cents
oh ya, its the original motor and has never been rebuilt.

Digger

 

You should throw a 4 speed trans behind that motor. A Borg Warner super T-10 would be nice. If you can't find one of them Pick up a Richmond gear four speed.

 

Why not try a Tremec TKO. I think they can take around 500+ lbft.

 

you can also drive without 1/2 of your oil but it doesnt make it right

i am just saying, big block head work would be mega expensive. at least get car chemistry inserts. also, drag racers run straight pipe but most trailor their cars and dont run the motors more than a 1/4 mile a night

 

Yeah, and a built one can take more. (A built T56 can take more than the "official rating" or 450 as well and I would want the second overdrive if I were driving the car on the highway on a regular basis) Anyway, I like the TKO in my Cobra. Ask about them on www.corral.net, probably in the windsor section.