dyezak
20+ Year Contributor
- 100
- 1
- May 22, 2002
-
Fredrick_MD
Ok, before my post a little history. Back in the late 60's early 70's in drag racing there was a new tranny to hit the market...the Lenco. It was the first sequential transmission of it's kind. Once this tranny came out everyone who used it would dominate their class because the clutch was only used to launch the car...all the shifts were done at WOT with just a pull of a lever. Shift times were in the miliseconds. Problem was these transmissions were very expensive (and still are, $20K for a sequential for our cars...Quaife).
Solution. Racers of the 60's quickly got around this problem by taking a TH400 (most commonly used trany in this aspect), put a manual valve body on it, put tighter bands and extra clutches in it, and (here's the wierd part)...PUT A CLUTCH IN IT INSTEAD OF A TORQUE CONVERTER!! It required a custom input shaft and modification (grinding) to the bellhousing but it worked flawlessly. It was able to compete with the Lenco's for a 1/10th the cost.
In the early 70's transmissions started coming with synchro's so the "PoorMan's Lenco" died out. Before that the tranny's had no synchro's and had to be rev matched to be shifted, thats why almost everyone used an automatic tranny, but as we all know...power loss through the converter...
Fast forward to today. Even though the DSM's have synchro's it's still a ##### to get that 1-2 shift without hurting something. And even then, once we are making decent power we must granny shift every gear to keep from replacing tranny's after every weekend. But our automatic bretheren don't have this problem...they have a different one...the crappy torque converter . Other than that they can handle full power full throttle upshifts in a 10sec car for 3 years completely stock (Russ Cox, 10sec automatic 96 AWD). Russ has used the same tranny for 3 years with no problems...other than a consistantly shitty 60' (2.0 range with 4 slicks).
If anyone see's where I'm going with this .
Solution. Racers of the 60's quickly got around this problem by taking a TH400 (most commonly used trany in this aspect), put a manual valve body on it, put tighter bands and extra clutches in it, and (here's the wierd part)...PUT A CLUTCH IN IT INSTEAD OF A TORQUE CONVERTER!! It required a custom input shaft and modification (grinding) to the bellhousing but it worked flawlessly. It was able to compete with the Lenco's for a 1/10th the cost.
In the early 70's transmissions started coming with synchro's so the "PoorMan's Lenco" died out. Before that the tranny's had no synchro's and had to be rev matched to be shifted, thats why almost everyone used an automatic tranny, but as we all know...power loss through the converter...
Fast forward to today. Even though the DSM's have synchro's it's still a ##### to get that 1-2 shift without hurting something. And even then, once we are making decent power we must granny shift every gear to keep from replacing tranny's after every weekend. But our automatic bretheren don't have this problem...they have a different one...the crappy torque converter . Other than that they can handle full power full throttle upshifts in a 10sec car for 3 years completely stock (Russ Cox, 10sec automatic 96 AWD). Russ has used the same tranny for 3 years with no problems...other than a consistantly shitty 60' (2.0 range with 4 slicks).
If anyone see's where I'm going with this .