TH350 vs TH400 Strength
Discussion
How much wider are th400s than the th350 ? Where are they actually bigger ? And how much power could a th350 take. Im running a th350 with my 750hp blown big block. Not sure what has been done to it appart from shift kit etc and just wondering if im waiting for a bomb to explode ! What sort of upgrades would i need for either gearbox to hold this sort of power in a 2400lbs jeep ?? (If you dont ask questions you never find out the answers) So sorry for all the questions. Anyone got a box for sale thats suitable for the above figures. Thanks.
Adam, I would suggest you speak to Mr Frost as trans are his forte.
http://www.pistonheads.com/gassing/profile.asp?mem...
http://www.pistonheads.com/gassing/profile.asp?mem...
v8 jago said:
How much wider are th400s than the th350 ? Where are they actually bigger ? And how much power could a th350 take. Im running a th350 with my 750hp blown big block. Not sure what has been done to it appart from shift kit etc and just wondering if im waiting for a bomb to explode ! What sort of upgrades would i need for either gearbox to hold this sort of power in a 2400lbs jeep ?? (If you dont ask questions you never find out the answers) So sorry for all the questions. Anyone got a box for sale thats suitable for the above figures. Thanks.
You need a TH400 for that power level.TH400 is longer than a 350.I can build you a box..
How much longer are they. Ive got a feeling you might say that i need the 1 1/2" taking back of the prop that ive just had added :O The problem ive got is that im going to have to sell my th350 to get another box. I have some cash to go towards another box but doubt i can afford the price of a new one, With the been made unemployed last week been a problem. Im all ears if you have got something or better still a 2nd hand one.
v8 jago said:
How much longer are they. Ive got a feeling you might say that i need the 1 1/2" taking back of the prop that ive just had added :O The problem ive got is that im going to have to sell my th350 to get another box. I have some cash to go towards another box but doubt i can afford the price of a new one, With the been made unemployed last week been a problem. Im all ears if you have got something or better still a 2nd hand one.
your feeling is correct If you have no money then i guess you're stuck with the 350 for now but expect it to go south when you give it some power.I have nothing second hand.Maybe try ED classifieds to pick something up. Unfortunately for me to rebuild transmissions at less then it costs to buy the parts would be a disaster business wise..
just my luck. Ive been looking on ed but at the moment there is nothing. Ill keep looking for now and see what comes up and see if its ok for my needs. Thunderbelmont Expecting to be Shot Down in Flames said:
Why use a TH400 for that "little" power? Why not use a GM-Muncie M22 Rock Crusher manual?
Less loss through the transmission, and capable of handling well over 1000bhp of turbocharged big-block
You drag racers with your rev'n'go gearboxes....Less loss through the transmission, and capable of handling well over 1000bhp of turbocharged big-block
thunderbelmont said:
Thunderbelmont Expecting to be Shot Down in Flames said:
Why use a TH400 for that "little" power? Why not use a GM-Muncie M22 Rock Crusher manual?
Less loss through the transmission, and capable of handling well over 1000bhp of turbocharged big-block
You drag racers with your rev'n'go gearboxes....Less loss through the transmission, and capable of handling well over 1000bhp of turbocharged big-block
They might stand the power but they will never stand drag race shifting.Even the pure drag race manual transmissions break on a regular basis.I know,i had one for a long time..
thunderbelmont said:
Thunderbelmont Expecting to be Shot Down in Flames said:
Why use a TH400 for that "little" power? Why not use a GM-Muncie M22 Rock Crusher manual?
Less loss through the transmission, and capable of handling well over 1000bhp of turbocharged big-block
You drag racers with your rev'n'go gearboxes....Less loss through the transmission, and capable of handling well over 1000bhp of turbocharged big-block
I wuz only askin'!!
Now I know. It's something that's plagued me for some time - why use auto boxes when we (I say we - roundy roundy circuit racers) don't use them because they sap sooooo much power and are so much slower over a lap.
OK, it's fit'n'forget. I can go with that.
It's obvious with nitro motors, or anything over 800lbft torque, due to the slamming of the gear shift, so a sloppy slushbox is much more "gentle" at handling the change.
I guess ultimately, it "should" be better to run a manuel, but due to shift reliability, a slushbox has to be the safer bet.
Perhaps I'll find out some more on a thrash-wot-u-nick day when I do some straightline testing of "Harry".
Now I know. It's something that's plagued me for some time - why use auto boxes when we (I say we - roundy roundy circuit racers) don't use them because they sap sooooo much power and are so much slower over a lap.
OK, it's fit'n'forget. I can go with that.
It's obvious with nitro motors, or anything over 800lbft torque, due to the slamming of the gear shift, so a sloppy slushbox is much more "gentle" at handling the change.
I guess ultimately, it "should" be better to run a manuel, but due to shift reliability, a slushbox has to be the safer bet.
Perhaps I'll find out some more on a thrash-wot-u-nick day when I do some straightline testing of "Harry".
Mike,
I've only come across a couple of cars running traditional fluid type auto's in my 19 years active in the sport. And they were all driven by disabled drivers, and both were American muscle in FIA Historics.
Neither very successful as they were (a) heavy, and (b) under braked - where the regs wouldn't allow you to compensate for the auto box with hooooge brakes. They could be quick over a lap or two, but sustained faster lappery takes it's toll in the anchors department.
I'm sure that a well setup car, with a good box would work quite well in sprinting.
I've only come across a couple of cars running traditional fluid type auto's in my 19 years active in the sport. And they were all driven by disabled drivers, and both were American muscle in FIA Historics.
Neither very successful as they were (a) heavy, and (b) under braked - where the regs wouldn't allow you to compensate for the auto box with hooooge brakes. They could be quick over a lap or two, but sustained faster lappery takes it's toll in the anchors department.
I'm sure that a well setup car, with a good box would work quite well in sprinting.
thunderbelmont said:
I wuz only askin'!!
It's obvious with nitro motors, or anything over 800lbft torque, due to the slamming of the gear shift, so a sloppy slushbox is much more "gentle" at handling the change.
And when you get to 8000 lbft torque, you throw the whole gearbox away It's obvious with nitro motors, or anything over 800lbft torque, due to the slamming of the gear shift, so a sloppy slushbox is much more "gentle" at handling the change.
Just a agricultural clutch pack to gently (ha!) feed the power in....
Well, that's the theory at least....
Edited by mr_twig on Monday 29th June 12:46
Gassing Station | Drag Racing | Top of Page | What's New | My Stuff