Racing transmissions?

[shadow]

Are there any racing transmissions out there that can take some 400lbs of torque that aren't dog-geared or that new fancy F1 semiautotransmissions?

I'm sure there are automatics out there, but are there any manuals?

thx guys!

 

[ratkil]

/confused What constitutes a racing transmission? I have a borg-warner four speed that is pretty much bullet proof. Was on a 351 cleveland, very short throws and tight pattern.

 

[Emulex]

most tremec's are rated at about 650hp with warranty (speaking ford) the t-56 will easily handle that all day long with power shifting, drag racing.

 

[BigLance]

Turbo 400 for Automatic
Rockcrusher 4 spd. for Standard

 

[Demon-Xanth]

Depends on the app. Richmond makes good crashboxes that would probably work for most applications. Lencos are damn near indestructible but require major modifications and are heavy.

 

[Zapster]

Contact B&M Transmissions. They make racing transmissions.

 

[shadow]

well let me put it this way, I am thinking in my head of adding a turbocharger to a 2.5L 4banger, the resultant of which would destroy the factory 5speed synchro transmission. I am looking for something that will take 400lbs of torque all day long. I can switch the gears in my gearbox directly for dog gears but ultimately in my head I want this car to be streetable, hence no dog gears...

So I if I wish to do what I want to do with the car in my head I will have to replace both the clutch and the transmission, the diff's should be ok (2 of them, 4wd car). That leaves me needing a new clutch and transmission capable of handling 400lbs of torque all day long.

thankyou for all your replies thus far, I greatly appreciate it

 

[Emulex]

oh front wheel drive car You're talking some BIG bucks. I thought you meant front engine-rear drive vehicle like a stang or camaro.


Good luck dude. sounds like its going to cost some big bucks ($3-4K) to make that.

 

[shadow]

AWD, not FWD

 

[Demon-Xanth]

shadow: even worse. Kiss your bank account goodbye.

Edit: iirc a stock Audi quatro transmission replacement is an 8 kilobuck bill.

 

[shadow]

owie!!

 

[Zenmervolt]

4 wheel drive or all wheel drive? There is a difference, and it could be an expensive one. All wheel drive tends to use a lot of electro-hydraulics to transfer torque, while strict 4 wheel drive is a non-variable 25% to each wheel. If you have all wheel drive, 400 ft-lbs of torque could really mess up a stock viscous coupling. Basically you are looking at having to replace the guts of an AWD system. A 4WD system may still have problems, but mainly of snapping driveshafts and halfshafts because the stock parts cannot handle the extra torsion produced by an engine with what is most likely more than double the design torque. Assuming traditional 4WD layout (engine sends power rearward to a transfer case, which has driveshafts running to the front and rear) you should be able to find a good transmission relatively easily. Be prepred to spend a large amount of money on this though, and watch for excessive wear in peripheral parts, as that much extra power will strain pretty much everything in the drivetrain.

Zenmervolt

EDIT: Oh, AWD. You're screwed. Probably better off buying a new car that can run fast completely stock. Sorry.

 

[shadow]

damn,

having only read about dog-gears I wonder if they are really that bad for street driving, or if they are livable....

any input guys?

 

[Demon-Xanth]

Dog tooth gears have the main disadvantage of being rough and noisy as hell. I don't know about longevity though.

 

[Zenmervolt]

If by "dog-gears" you simply mean straight-cut gears (as opposed to the normal helical-cut gears in street transmissions), they are fine for street driving as far as reliability and drivability goes, though since they are almost always non-synchro you'll have to learn how to double clutch and rev-match. As for livability, well, that's subjective. I have never driven a car with straight-cut gears myself, but I have been told they whine like banshees (imagine the sound a car makes while going in reverse, only louder and omnipresent).

Zenmervolt

EDIT: Straight-cut gears actually have better durability than helical-cut gears. All else being equal, a straight-cut gear will always be stronger than a helical-cut gear, which is why straight-cut gears are still used in racing transmissions.

 

[shadow]

yikes, guess I'll have to see how well I can double-clutch and rev-match.

 

[Demon-Xanth]

I knew straight cut were stronger. I just didn't know if they were subject to more wear or not.

 

[shadow]

well if I picture a rev-mismatched shift without synchros in my head I see the dog teeth of the collar scraping alot against the slots of the gear.... So the most wear would happen to the tips of the dog teeth and the tips of the gears....

 

[Zenmervolt]

<<I knew straight cut were stronger. I just didn't know if they were subject to more wear or not.>>

You make a good point, and I'm not too sure about that either. Considering that most straight-cut gears are used in applications with high streeses (and hence, high wear), I suppose it would be hard to compare their service lives to those of helical-cut gears. I'll have to send that question to Road &amp; Track and see what they have to say about it.

Zenmervolt

EDIT: My guess, however, would be that the only appreciable wear would come from grinding the gears (non-rev-matched shifts), the only caveat being that not grinding the gears will be harder than with a synchro transmission. Of course, people managed without synchros until the 1950's so it's not like it's imposibly hard to master a non-synchro transmission.

 

[Soybomb]

<< a turbocharger to a 2.5L 4banger >>


I know of turbo 4 2.5L chrysler cars that are making HP of that level, some with autos some with manuals and they do fine. The Getrag 555 or 568 that most came with handles it okay especially with a reinforcement plate. The clutch if a much more troublesome area than tranny strength.

You might talk to others who use that tranny before you sink big $$$ into a custom one. The NV4500 is a popular tranny with 4 wheel trucks.

ZV: Fwiw in a 4wd system you're splitting the power 50-50 between the front and rear axles. How its distributed to the wheels depends on the differential in the axle, you've only got 25%x4 if you've got a locker in each axle.

 

[Zenmervolt]

<<ZV: Fwiw in a 4wd system you're splitting the power 50-50 between the front and rear axles. How its distributed to the wheels depends on the differential in the axle, you've only got 25%x4 if you've got a locker in each axle.>>

/smacks self on forehead

I really should have remembered that, it's the basic operating principle of a differential for pete's sake. Thanks for the reminder. Anyway, he has an AWD system, which will probably have a little trouble with that much power considering it is probably a VC setup and not a transfer case and differential setup. We'd need to know the car to be certain of which type of system it had though.

Zenmervolt

 

[Demon-Xanth]

In a fully locked 4x4 setup, all wheels turn at the same speed. The torque goes to whatever wheel is (attempting) to turn the slowest. If you've ever seen a '78 GMC truck's frame flex because of the 4wd system being in lock while turning you'll appreciate the strength of the components.

 

[Cable God]

I can tell you which clutch i would go with, The Spec Star Stage III. Comes in three flavors: Kevlar (street/strip), Carbon Fibre (HD street/strip), and Ceramic (strip ONLY). I killed the stock Z06 clutch in my 6-speed after a few months of launching on ET Streets and Drag Radials. The Star Stage 3 Carbon took about a month to break in, and chattered a little doing so, with it being fully dis-engaged 1&quot; from the floor. that is normal until it breaks in and &quot;settles&quot; and if feels like the std. clutch afterwards. There is NO slip what so ever in these clutches, so, it will take some getting used to. Contact Spec at www.starclutch.com . If you want more opinions on the clutch, check out www.ls1.com's drivetraion section.

 

[Zapster]

Don't forget, it's just not your transmission that needs beefing up. Axles, mounts, bearings, springs, etc.

 

[yakko]

What kind of car is this going into shadow?