Lookin for NHRA Stock Class ET/MPH from 1970-71

bill dedman · 06-27-2016, 03:04 PM

The dual-coupling units were used in their OEM applications because that was the NHRA class rule for Stock, but I never saw one in a Gas Coupe or Modified Production race car. Those cars would have (if they were not a manual-transmission car) an aftermarket, earlier model "Dual-Range" HydraMatic which only had a single fluid coupling.
There were several companies that sold modified units for street/strip duty and racing; the most popular was built by B & M (whose "Hysro-Stick" was a ruaway hit in the marketplace,) but, there were several others (Bee-Line, Vitar, Quartermaster, C & O Hydro, and a few whose names I can't recall at the moment.)

Though there were a lot of really fast Pontiacs (mostly,) in the "dual-coupling" period of time (1956-1963) virtually all of the HydraMatics in Gassers, Street Roadsters, Altereds and Modified Production race cars were of the earlier, "Dual-Range," single-coupling type.

BTW, "Dual-Range" was a sales gimmick, nothing more. In 1952, They (G,M,) added another position to the shifter indicator; the letter "S", for "Super." Putting the selector in that position simply kept the transmission from up-shifting into 4th (top) gear, making the car more responsive. It could also be used as a braking device at hiway speeds. Big deaL...

06-27-2016, 03:04 PM	#31
bill dedman VIP Member Join Date: Feb 2002 Location: Conway, AR Posts: 1,739 Likes: 0 Liked 6 Times in 4 Posts	Re: Lookin for NHRA Stock Class ET/MPH from 1970-71 The dual-coupling units were used in their OEM applications because that was the NHRA class rule for Stock, but I never saw one in a Gas Coupe or Modified Production race car. Those cars would have (if they were not a manual-transmission car) an aftermarket, earlier model "Dual-Range" HydraMatic which only had a single fluid coupling. There were several companies that sold modified units for street/strip duty and racing; the most popular was built by B & M (whose "Hysro-Stick" was a ruaway hit in the marketplace,) but, there were several others (Bee-Line, Vitar, Quartermaster, C & O Hydro, and a few whose names I can't recall at the moment.) Though there were a lot of really fast Pontiacs (mostly,) in the "dual-coupling" period of time (1956-1963) virtually all of the HydraMatics in Gassers, Street Roadsters, Altereds and Modified Production race cars were of the earlier, "Dual-Range," single-coupling type. BTW, "Dual-Range" was a sales gimmick, nothing more. In 1952, They (G,M,) added another position to the shifter indicator; the letter "S", for "Super." Putting the selector in that position simply kept the transmission from up-shifting into 4th (top) gear, making the car more responsive. It could also be used as a braking device at hiway speeds. Big deaL... __________________ Bill Last edited by bill dedman; 06-27-2016 at 03:10 PM.