Th-200 ?

[unboostedV6]

Having broken my share of TH-350's, I've since been using a Super Turbine 300 2 speed behind my bracket mill. The TH-200 3 speed used to have a very bad rep, but I see they're being used in Comp Eliminator. Anyone know how to make 'em hold up? Can a turbo spline converter be used? Don W., you seem to be a proponent of this tranny. Can you shed some light? GB

 

[Alky V6]

They can be modded to handle around 600hp reliably. I didn't find the input shaft to be the main weak point. The stator support shaft was the problem. It is a cast piece and enough torque will twist it like a pop and fresh dough boy biscuit container. There is another fella that is building them for the class you mentioned. Scott McClay or something like that. I pretty much stopped the R&D I was doing with the 200 3 speed when I determined I wouldn't be able to use it on my project (higher than 600hp). I ended up going with a TH475. When I made the swap from the 200 to the 475, I only lost about 1/10 on the time slip. Not as big of a loss as rumors would have you believe.

 

[unboostedV6]

Yeah, it's all about the application, though. Most Comp cars are 300+- cubic inch v8's or 150+- ci 4 cylinders turning 10-12,000 rpm and use 7 inch 7500-9000! rpm converters. With less than 350 ft-lbs or so of torque to get things moving, a seemingly small difference in driveline loss will yield a greater difference in et. My combo is in the 380-420 ft-lb range at 4700 rpm. With the extra gear, the 350's ran .10 quicker at 60', but the 300 runs 2 mph faster. Trying to get the best of both, but not at McClay's price. Best so far is 11.58, goal is 10.99.