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Need this question answered!!

3K views 21 replies 13 participants last post by  vinniekq2 
#1 ·
Hey guys i have a 350 turbo transmission and 2800-3200 stall in my car with a 4:11 gear behind it. if i installl a 4 or 5 speed manual will it lower my rpms and allow me to have better top end speed? if so what trannys should i look to be getting for a decent price that will hold up to hot rodding a 400 hp small block? any feed back would be nice
 
#4 ·
Unless yours is a lock-up converter (doubtful) it slips. All the time. By various amounts. At near red-line speeds, figure about 7 to 10 percent slipage. How well the manual transmission will work will depend largely on how well you work the manual transmission.
 
#9 ·
The gear vendors is a great unit.. It will run you about 3K to buy the unit.
It will give you a 22% Overdrive.

You may be able to do a trans swap cheaper.
well im kinda wanting a maunal anyways ;) but i need good reason to convert to a manual... will a muncie m22 or m21 or whatever there called do the job? i just want to know is it my 4:11 posi trac or my 3 speed auto with a boss hog 2800-3200 stall that is liminting my top end too 100-120 mph
 
#8 ·
A T5 or a T56; the T5 is a 5 speed with an OD 5th, nice tranny but 400 horses, actually the mid range torque that goes with that power, will be on the upper limit of this tranny. The T56 has OD ratios in 5th and 6th, the tranny is a true heavy duty unit that will easily handle a 400 horse small block.

Having an overdrive generally doesn't add any top end, most engine's (contrary to "Car and Driver" and "Road and Track" calculated top speed based on the enigne's red line times the top gear ratio) cannot pull those RPMs in an overdrive ratio and often can't pull redline in 1 to 1. So in and of itself OD will reduce cruise RPMs but won't necessarily add top end road speed.

Bogie
 
#10 ·
Your 4.11 is not any help in gaining top speed..And has been said the convertor is probably showing some slippage as well.. Hard to say if changing the trans will help you much if any as you are getting into the area of aerodyamics as well..Top speed cars are a whole different deal than drag cars so figure on some $$$$$ to change it over..

Sam
 
#11 ·
Don't know your tire diameter, but a 26" tire, 6000 rpm, high gear (1.0 ratio), with 4.11 rear results in about 116 mph. 400hp ought to pull to that no problem. To go faster, you need a higher rpm, taller tire, or lower gear (less than 4.11), or some combination of those. As was mentioned earlier, go too far, and you won't really go any faster, you'll just turn a lower rpm and take longer to get there.
 
#12 ·
Don't know your tire diameter, but a 26" tire, 6000 rpm, high gear (1.0 ratio), with 4.11 rear results in about 116 mph. 400hp ought to pull to that no problem. To go faster, you need a higher rpm, taller tire, or lower gear (less than 4.11), or some combination of those. As was mentioned earlier, go too far, and you won't really go any faster, you'll just turn a lower rpm and take longer to get there.
ok my next question would a muncie m22 manual transmision give me a better street car then my turbo 350? like better pull,burnouts... anything?
 
#13 ·
which would you have?

ok so i thank everyone for answering my other post but now i would like to know what would you rather have.. if you had a 1978 camaro and a soild 400 hp small block and a 4:11 posi track....and this was just a street car....would you rather have a good manual 4 or 5 speed or a automatic??? i cant decide i love driving manuals but i already have a turbo 350 in it......
 
#14 ·
78 Camaro = fat heavy car,lose some weight. I put a T400 in my 80 Camaro because the T350 came apart twice. Put taller tires on the car and see how that works for you(borrow them for a day) A muncie,plus heavy leaf spring car plus 10 bolt diff plus burn outs === expensive. count on breaking spider gears,wheel hop is a possibility, The muncie will break on occasion if you dont upgrade the case.
The car is too heavy so most of the parts will eventually break,including the clutch.
How did you arrive at the 400 horse power figure?
 
#18 ·
78 Camaro = fat heavy car,lose some weight. I put a T400 in my 80 Camaro because the T350 came apart twice. Put taller tires on the car and see how that works for you(borrow them for a day) A muncie,plus heavy leaf spring car plus 10 bolt diff plus burn outs === expensive. count on breaking spider gears,wheel hop is a possibility, The muncie will break on occasion if you dont upgrade the case.
The car is too heavy so most of the parts will eventually break,including the clutch.
How did you arrive at the 400 horse power figure?
the 400 horse power mark is what me and my engine builder settled on when i brought him my block and my 91 corvette heads......
 
#17 ·
Several options. You could rebuild the TH350 with a manual valve body/shift kit and you'd have a trans to shift, but just no clutch. If you want to launch a little harder add a trans brake to that build.
You could also go with either 200r or 700r4 and also a manual shift kit, then you'd have the shifting and the overdrive, plus if you went with the 700r4 you'd have a granny first gear with those 4.11 gears for a real launch!
Or go with a T56 5 speed or 6 speed and get a good hard launch, and overdrive for the highway.
Yes, your Camaro is heavy, and it takes a bit to get them moving, but I'd guess my '71 with 427 is a bit heavier and I'm running a 3.42 posi without suffering acceleration, or top end. Mine's no barely legal street car, but still runs low 12's with street tires, at around 118 mph. And it's running a TH350 built to handle BBC torque.
 
#19 ·
Which would you rather have?

thank you everyone for all the answers you gave me on my other post but now i would just like to know (for a street car) would you rather have a good auto tranny or a good manual? 400 hp small block and 4:11 rear end in 1978 camaro.....let me in on what you would want to put between that motor and rear end.... name trannys and gear ratios......thanks
 
#22 ·
My corvette,I converted to a TKO 5 speed and gave a local kid the old 4 speed.I dont drag race so the standard is for fun sport driving.
For drag racing I would use a turbo 400 if the car was a regular street car and probably a powerglide if race olny.
If the car was really something to look at ,I might consider the TCI 6 speed auto.The car would have to be worth the investment.as $6,000 is a lot more than $800 for a turbo 400
 
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