0.50 overdrive

[deckofficer]

Is anyone runnig a 0.50 overdrive transmission? This one is a bit pricey, any other retailers that you guys know of ?.................

http://www.ddperformance.com/shop/product_info.php?products_id=188cPath=107_124

After driving 2500 miles in the T last week, I have decided to swap out my tranny. First reason is to cut cruise rpms at 80 mph from 3050 down to 1525 rpms. 2nd is to pull the M20 and sell it back to the original owner/builder before my new found torque in the new 383 (516 ft/lb @ 2800 rpms) ruins that sweet little Muncie. Has anyone been down this road before, so that I might learn from your experiance?

Bob

 

[Screaming Metal]

Its a great trans....but had a little bit of trouble getting the clutch to 'pedal correctly'. It wasn't a problem with the trans, or the clutch assembly....they'd given us the wrong dia. cylinder, so I had to un-fabricate all my stuff and redo it.
From what others have said, they too have encountered this problem a few times....but was easily corrected....

 

[deckofficer]

Its a great trans....but had a little bit of trouble getting the clutch to 'pedal correctly'. It wasn't a problem with the trans, or the clutch assembly....they'd given us the wrong dia. cylinder, so I had to un-fabricate all my stuff and redo it.
From what others have said, they too have encountered this problem a few times....but was easily corrected....

Aw, I hit pay dirt. That is what I like about this forum. Sreaming Metal, please tell me more. Did you go for the deep overdrive of 0.50? How do you like your ride with the T56? Also, since most of us are sitting in a "gorilla stance" in our T's, how do you like the narrow gates of the T56? I've driven Vettes and Vipers with this tranny and sitting in a perfect position due to Detroit engineering, I still find the gates a bit narrow.

Bob

 

[one finger john]

Bob, before you spend a lot of money on any transmission have you found the "sweet spot" as far as cruising is concerned? I define that sweet spot as the RPM where the engine is happy, runs freest and gets the best lbs. per hour use of your fuel. Sometimes dropping the rear gear (or incorporating an overdrive) will get you worse gas mileage than better. All engines have frequencies where they run the most efficiently. If you know what that RPM is then you might not need to drop it down to 1525 rpms (with the possible attending engine, exhaust, frame, or body resonances).I know that that low, under load growl is neat, but try using the trans a little more. Instead look at maybe 2200 rpms with engine, exhaust system, etc. producing less of a fatiguing resonance along with better gas mileage. Something to consider.

John

 

[deckofficer]

John,

Thanks for the heads up. I do have a resonance around 1900 rpms that I avoid. This engine has a peak torque @ 2800 rpms and a peak hp @ 4050 rpms. The sweetest rpm seems to be 1100 to 1400 rpms. I used a "speed in gears" calculator to see where my cruising speed would be in 5th and 6th gears. Using the Viper derived T56 with its .74 and .50 gives me many cruising rpm choices. Now in the M20 4th at 1.00, 70 mph works out to 2800 rpm, my peak torque of 516 lb/ft is at 2800, so my passing capabilities leaving it in 4th gear is totally outrageous. Speed change at full throttle from 75 mph to 140 mph takes all of 7 seconds. The M20 will not live long behind 516 lb/ft, so the original owner/builder wants to buy it back.

Bob

 

[Ted Brown]

Hi Bob, I used to love driving down the freeway around 60 and find a fellow that wanted me to get-it-on a bit, so I always pull it back into low gear and stand on the pedal for a few seconds... They are always very surprised, even the HighwayP, as he wanted me to goose it one day... hehe Love the horsepower with the R's up there... I myself would not trade my High gears and turbo 400 for anything different... may be OLD school, but this works wonders on the street for me.

 

[Screaming Metal]

Hi Bob, I used to love driving down the freeway around 60 and find a fellow that wanted me to get-it-on a bit, so I always pull it back into low gear and stand on the pedal for a few seconds... They are always very surprised, even the HighwayP, as he wanted me to goose it one day... hehe Love the horsepower with the R's up there... I myself would not trade my High gears and turbo 400 for anything different... may be OLD school, but this works wonders on the street for me.

If you got the power, thats the way to go! Want more acceleration, mash on the pedal a little harder....



Aw, I hit pay dirt. That is what I like about this forum. Sreaming Metal, please tell me more. Did you go for the deep overdrive of 0.50? How do you like your ride with the T56? Also, since most of us are sitting in a "gorilla stance" in our T's, how do you like the narrow gates of the T56? I've driven Vettes and Vipers with this tranny and sitting in a perfect position due to Detroit engineering, I still find the gates a bit narrow.

One of the drivers on our sponsors team had this old drag altered he was gonna rebuild for the Nostalgia Drags later....He then changed his mind to do a street/strip car....a kinda T, if you will.
Well, we had to build a new frame, then took his drivetrain and installed it, leaving out the origional trans and putting the 5 speed in it. I tried talking him out of it and putting in a auto....but he wouldn't hear of it. After all was said and done....the car was cool and worked good....though....a bit unruley for my tastes on the street.
By that I mean you can only get so much travel in a 4-link suspension and have it sitting like a altered, within the fiberglass body and have it function correctly.
We pulled it off.... even put the old looking street legal slicks on it....

I was suprised though when you shift without a clutch with the trans with the short throw....works good. But that tight of a gate takes some getting used to.
Just depends on what you like....or want....

 

[Screaming Metal]

I was suprised though when you shift without a clutch with the trans with the short throw....works good. But that tight of a gate takes some getting used to.
Just depends on what you like....or want....

The gate characteristics reminded me of driving a old Honda Prelude I used to have when I wasn't driving one of my hotrods....really short crisp throws, hardly no arm movement at all....you can shift it by only moving your wrist!

The only problem we had was the diff. in size between the cyl. dia.'s on the throwout bearing and on the pedal cylinder. Theres also a certain amount of shiming that has to be done on the pancake cyl. on the clutch....or at least what the directions said. I just machines it down to fit and work correctly. Its no biggie, theres just a X tolerance and you gotta make Y cylinder fit in there correctly.
Of course....we we mating this to 426 Hemi with a alum adaptor, so on and so forthn, and the motor was really nasty, way over the top.... :wacky: