poor mans od trans out of a th400

[kad5118]

wasup evey one I have been really thinking about my drive train setup for my 1980 montecarlo.and what i am looking for is topend speed over 140 as well as mpgs.

I have a 4.8 turbo vortec thats will be put together in the next 60 to 90 days.it will have somewhere between 670 to 720 hp to the rear wheel not the crank.I have a th 200r4 thats was built for 500hp but turboing my 4.8 i will past that number super easy without trying.I was looking at a th400 because they can handle about 900 -1200hp for a good price.

I was thinking about going that route because i have stock 2.29 gears in my rearend and my mechanic is going to bullet proof my rear end and drive shaft.so it can handle my hp range as mentioned above.hopeful i can get the topend speed and drivability out of that setup.I am looking for like 150-160 trap speeds with this combo.I will have more than enough torque to push that tall gear with authority with my cam and turbo setup what do you guys think.

 

[jdietschweiler]

Is your rear a 7.5? If so, dont waste the money "bullet proofing"

 

[DRIVEN]

what do you guys think.

Is that your question?
I think that a 150-160mph trap speed is pretty ambitious. Seems like you'd need to be in the 9's to do that. That's possible with a cam swap and a turbo on a little 4.8? Looks to me like you want to be fast, quick, reliable and fuel efficient. If you figure out how to do all of those at once, please let us know the magic combination.

If you were asking questions about drivetrain opinions, I would run your "500hp" 200-4R first to see how it holds up. If it fails you could spend the money to upgrade it. Or you could put a healthy TH400 and a Gear Vendors overdrive behind it. The 200-4R has quite a bit less parasitic loss though. Not sure there's any amount of good parts to make a 7.5" live behind 700+hp. You should really consider a 12 bolt or 9" instead.

 

[DRIVEN]

...and start setting aside some cash for safety gear. Quicker than 11.50 requires more than just a factory seat belt at most tracks 😀 .

 

[307 Regal]

Even with a higher spline count posi and a girdle cover, I really don't think a 7.5 rear is going to take ~700hp very long. Especially with 2.29 gears. Since you mentioned driveability, instead of going with the TH400 I would contact ckperformance to see what they can do with your 200-4R. http://www.ckperformance.com/resources/ ... SIONS.html Their pro street/strip 200-4R is advertised to handle 800hp/800ft lbs. The OD gear might help your top end too. I know it's nearly 3k, but a boosted LS 4.8L is nothing to take lightly.
Here's the very similar 5.3 LS:
http://www.youtube.com/watch?v=Qk9uU_3VHT0
Very quick, but judging from the video your trap speed goal may be a little high.

 

[online170]

.......it will have somewhere between 670 to 720 hp to the rear wheel not the crank.......I am looking for like 150-160 trap speeds with this combo.

Lol. Id like to know how you got your GBody to 2000 lbs.

A 4L80E will do everything a TH400 will do with a GV overdrive, but it will also have lock up, and be less than 1/2 the price.

My $0.02.

 

[jdietschweiler]

We dont mean to piss in your wheaties but your goals are not realistic.
My malibu weighs 3500# with a half tank and my 260#*ss in it
Dont overlook a powerglide
7.5 rear wont last

And play with these

http://www.wallaceracing.com/Calculators.htm

Good luck

 

[pontiacgp]

I don't know much about a 4.8 turbo vortec so I googled it and came across this thread you posted about a year ago....
http://www.theturboforums.com/threads/3 ... ear-wheels

 

[jdietschweiler]

Its 4.8 vortec....come on man...get with the times..

 

[pontiacgp]

Its 4.8 vortec....come on man...get with the times..

opps, I didn't hit the 8 key hard enough and only half of it showed up....