Trans low gear set.

Adger Smith · 11-23-2013, 01:26 PM

Joe,
That first trans 1-2 ratio drop is 35%. The second Trans 1-2 drop was 40%.
When you had recovery problems on the shift could the engine combination get away with taking the 1-2 shift point higher? Say your best runs with the 2.52 were made @ a 1-2 shift point of 6500. Your 35% drop put you at or near 4225 RPM. (no clutch slip considered). To get to the same drop point your 1-2 shift with the 2.70 would have been 6,825. If you tried that and it didn't work I would suspect it was the engine "Going over" with the added 325 RPM. Could it have been the difference in your 12.30 Vs 13.18 final drive ratio in low gear causing a little too much tire slip on the hit?
Back in the early 70's I ran an F/S 302/290 combination and the 7" tires kept me from running the 2.70 all the time. When we got on a "Real Good" track I could take my heavy flywheel out and put the lightest wheel I could find in the bell housing and slide the clutch a little. It would haul it when I got it hooked. We worked out hind ends off working with wheel width, flywheels/clutches, tranny ratios & shift points back in those days.
(Hey Dwight, you remember those days?)
Back then it sure would have been easier if we had some data besides 60' and 1/8 mile (no 1/8 MPH) and quarter mile E.T (W/ MPH at the good tracks). A good computer in the car might have made life easier at the track. That computer would have been real easy to tell what was happening when we started a clutch control program.
We thought we had hit the jackpot when the LTM came out!! :~)
I'm glad my buddies and I were young when we were doing all that work.
I sure couldn't do it today like we did it then.
At this stage of life just getting a combination ready in the shop and going to the track, hoping it was right, is tough to do.
Well, so much for the Sat. morning 'Run Through the Memories'

11-23-2013, 01:26 PM	#11
Adger Smith VIP Member Join Date: Dec 2001 Location: Texarkana Ark/TX Posts: 2,370 Likes: 473 Liked 696 Times in 271 Posts	Re: Trans low gear set. Joe, That first trans 1-2 ratio drop is 35%. The second Trans 1-2 drop was 40%. When you had recovery problems on the shift could the engine combination get away with taking the 1-2 shift point higher? Say your best runs with the 2.52 were made @ a 1-2 shift point of 6500. Your 35% drop put you at or near 4225 RPM. (no clutch slip considered). To get to the same drop point your 1-2 shift with the 2.70 would have been 6,825. If you tried that and it didn't work I would suspect it was the engine "Going over" with the added 325 RPM. Could it have been the difference in your 12.30 Vs 13.18 final drive ratio in low gear causing a little too much tire slip on the hit? Back in the early 70's I ran an F/S 302/290 combination and the 7" tires kept me from running the 2.70 all the time. When we got on a "Real Good" track I could take my heavy flywheel out and put the lightest wheel I could find in the bell housing and slide the clutch a little. It would haul it when I got it hooked. We worked out hind ends off working with wheel width, flywheels/clutches, tranny ratios & shift points back in those days. (Hey Dwight, you remember those days?) Back then it sure would have been easier if we had some data besides 60' and 1/8 mile (no 1/8 MPH) and quarter mile E.T (W/ MPH at the good tracks). A good computer in the car might have made life easier at the track. That computer would have been real easy to tell what was happening when we started a clutch control program. We thought we had hit the jackpot when the LTM came out!! :~) I'm glad my buddies and I were young when we were doing all that work. I sure couldn't do it today like we did it then. At this stage of life just getting a combination ready in the shop and going to the track, hoping it was right, is tough to do. Well, so much for the Sat. morning 'Run Through the Memories' __________________ Adger Smith (Former SS)