Transmission Question (1 Viewer)

[Mr. Fix It]

Got to enjoy the Nitro Jam Races at San Antonio Raceway this past weekend. There were three extremely nice Top Sportmen cars from one Texas team there that caught my eye. As I looked at their new Camaro bodied car I noticed the air shifter controlled a 3 speed transmission. Later as the car made a pass, sure enough it shifted twice. My question is: What kind of transmission might these cars be running?

The cars run in the mid 6 second range @ over 200 MPH so the transmissions must be something pretty tough. Do they run a transbrake? What advantage would a 3 speed transmission be to cars capable of such ET and MPH? Why wouldn't they run a 4 or 5 speed transmission instead?

 

[d'kid]

Well,
30 years ago, in the bb/fc, we'd had a pair of 2spds bolted together, and the air shifter buttons on the butterfly... both out 1st, push one for 2nd, push the next for high... by having a different low in each tran, would change your 2nd by which button you pushed first....

d'kid

 

[Mr. Fix It]

The shifters in these cars looked a lot like a powerglide shifter. The had pneumatic solenoids on them. What caught my eye was to see 1-2-3 on the shifter.

No buttons like you might see on a promod car.

 

[Super Mod]

The Rossler turbo 400 is one that has been used

 

[Crew Chief Pro]

There are new cases manufactured to make the turbo 400 safe enough to run. It gives more gear choices. I believe it gives some teams an extra .025 - .05 in ET. Not cheap though ( nothing is in this sport ).

 

[Mr. Fix It]

Thanks for the info. I'm fascinated with the way these transmissions can be modified to deal with such power. As to costs, even JR dragsters can get out of hand pretty quickly.

 

[Jeff]

The powerglide side of the house got a bit excited with all of the movement to 2 speed turbo 400's. As I understand it, the reason was because there is a 1.47 first gear available for the T400. Not certain, but understand a fully loaded unit from Rossler tickles $8k.

The powerglide has a really strong 1.80 gearset, and a reasonable strong 1.69 (we could make it maybe 150 passes) ... Finally got "the latest" (which has be out for a bit but in very limited production runs) ... a 1.58 first gear for the powerglide:

Sonnax - Aftermarket replacement transmission, torque converter, and high performance automotive parts

There is also a long version. Heading out to my shop to install my new tranny right now ... I hope this solves the spin into shake issue I've had with my new lighter Spitzer with more Reher power. I killed the leave and got down to a 4.17 1/8th mile at a recent XDRL event, but every time I tried to drop the next .05 it lit the tires up before I could coax it through the 60ft.