Coan Two-Speed Transmission: A Closer Look
 

Sparked by the Speed Racer remake story, http://speedonthewater.com/new-boats...oser-look.html.

Nice Work

so it's a modern powerglide?

When I drove Speed Racer a couple of weekends ago with Bob Christie (the owner) handling the throttles and shifters, the boat was completely docile around the docks. Now and then when traffic got heavy, we went down to one engine (that wouldn't have worked so well in a rudder boat with crash boxes) to go extra slow, but even on two engines forward speed at idle was mellow for a big-horsepower blower boat. The gear reduction in reverse made things even easier for Bob.

It might not be for everyone, but the Potter engines, two-speed trannies and No. 6 drives made for an easy to operate package that, so far, hasn't had a lick of trouble.

Inside Speed Racer:
http://sharkeyimages.zenfolio.com/im...12319505-4.jpg

http://sharkeyimages.zenfolio.com/im...52412429-4.jpg

I'm guessing it's a reduction then direct as the final drive?

Great question. I will ask Mr. Coan and get you an answer tomorrow.

thanx for pics tim . :coolcowboy:

The answer to your question, from Dave Coan of Coan Engineering:

"Yes, low gear is 1.82:1 (reduction) and high gear is 1:1(direct). Reverse is 1.61:1(reduction)."

I see it is a powerglide, most likely a aftermarket case with a shortie conversion, a aftermarket pump casting and a direct pump drive kit, any race trans shop could build this, it's not exclusive to Coan. As far as low gear ratios, there is a wide selection of super heavy duty aftermarket gear sets anywhere from a 1.68 to 2.18 and in between. Very simple trans, it's funny how popular they still are being they haven't put one in a car since 1973, Smitty