Why did they stick with torque tubes in racing (up to modern sprint cars) long after open drive came out? I'm told it's just a safety thing, but that seems too simple. Thanks!
I'm wondering if it might have something to do with traction. Every old torque tube Chevrolet I ever owned behaved like a limited slip differential when I spun the tires.
Lighter, simpler suspension etc. The clue is in the name. Final drive torque is not reacted through the suspension arms and frame. Torque tubes are still used to this day in various forms or anothet in high performance road cars.
I never liked the idea of an open spinning shaft between my legs. However, there was a time when the hot thing was getting rid of the torque tube and using an axle from an Indy car as the drive shaft. The first time a u-joint failed they gave up on that idea.
I’ve seen 50s euro racers using aluminum TTs and modern sprinters doing the same but is that really lighter than open drive? Obviously, 1 u joint is more efficient than 2…. So I could see that as a possible reason… With a lot of these setups, they have a slip joint at the front like GM and sprints…. Does that defeat some of the torque transfer benefit?
I believe it is because of the rear suspension set up. Modern Midget, Sprints, Sliver Crown and until five or ten years ago North East Dirt Modifeds all ran torsion bars, they run/ran two outer adjustable bars and a torque tube. Now the North East Mod have gone coil overs, 4 Link, left side panard bar and open drive shaft.
Torque tubes work well on Sprint Cars, and chassis set ups have developed around this combination. The parts evolved from OEM applications, probably Ford. To use an open drive on a sprint car, would require adding drive shaft loops, and a torque arm. Weight is a huge issue in these cars. Open drives have been tried, a few people got broken ankles as a result. Currently prohibited under the sprint car rules. Open drives work well, on DIRT Modifieds, but they weight at least twice as much.
"Ohio" George Montgomery used a torque tube to win a lot of A/GS nationals titles against some of the biggest names in the sport. He seemed to get off the line better than others. I personally think that it acted like a traction bar.
I was away racing in Oregon when Dave Bradway Jr lost his life in a torque arm equipped sprinter during Dirt Cup @ Skagit. I believe not long after, torque arms were outlawed. Grant
Does anyone know what tubing was used for the steel 2.3" racing tubes? It seems like such an odd size. I'd assume they ran some sort of better alloy like 4130 or 4140 but nothing seems readily available in that OD. Was there some sort of oem tubing that that size originated from? Into the 1990s Speedway Motors offered lengths of the 2.3 diameter tubing in their catalogs. The 1930s Chevy torque tubes are close at about 2.28" OD but still not exactly the 2.3 that seemed to be the big car standard thru the 60s and 70s prior to the big 3" modern setups.
You sure it's actually 2.3" and not a nominal size designation? 2.375" is 2" pipe, 60mm (actual, not nominal) is a common metric tube size.
yep and modern midget ones are still 2.3". Now maybe they were taking schd 80 pipe and turning the OD but theyre definitely not 2.375 Here's a modern midget alum one with ID and OD specs https://www.speedwaymotors.com/Winters-Performance-6844-25-Midget-Torque-Tube-and-Collar,40643.html
Just looked at a 1970 CAE catalog to see what their torque tubes were made out of. All it says is high strength seamless tube, ground full length to the finished size. No od is listed. I’ve got an older CAE IN/out box that has a ball joint. I’ll measure the id, and post it here later today.
Thanks Dave. I have a couple old racing balls that measure right around 2.310". Curious what your ball measures. OEM Chevy balls were typically set up for 2". Vintage racing torque balls all seem to have the 4.25" diameter ball that the mid 30s-1954 Chevy used.
I wonder if one of the variations of Model T torque tube was 2.3". It seems like some of the real early midgets used cut down T axles. Maybe something like that caused it to become the size.
I really do plan on getting out in the garage and measuring the id of the torque ball! Just stuff keeps getting in the way…
The answer is, 2.30. Now just what was the question? Of yeah, right, id of the torque ball! Sorry everyone. There’s a bearing at the u-joint end, I didn’t disassemble it from the in/out box, so I don’t have its id. Also there’s an o-ring at the outer end to keep dirt out of the joint between the torque ball and the torque tube so it will not bind up.
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