Converter Slippage at top end - Page 2

Jeff Stout · 10-17-2019, 03:25 PM

Quote:

Originally Posted by Dan Fahey

Have not used the lock up !!

YET !!

Dan

Any reason why you haven't tried lock up?

Dan Fahey · 10-17-2019, 04:00 PM

Quote:

Originally Posted by Jeff Stout

Any reason why you haven't tried lock up?

Thought of it.
No need with current 4.56's and 28 inch tires.

The Yank was designed with an extra large clutch.
Have calculated adding more gear and using existing Converter.
Sure would launch hard with 5.38's.

Would ET closer to the K-L/SA Index with the current Blueprinted cam.
Mostly cool weather near sea level tracks.
Thinking if the car used the Stocker cam would not need so much converter.

D

ss3011 · 10-17-2019, 06:56 PM

4L60 has a 3.06 first gear and a huge ratio change from 1gear to 2nd gear . Might want to checkout the Sonnax gearset that reduces 1st gear into the 2.8 range . Are you planning on using 4th gear ?
Back in the mid 80's I ran a Olds Cutlass with a 307 and a 200-4R with a 2.74 first gear , 5.57 rearend gear , and a 28" bias tire . The problem with all that ratio is the engine can't rev up that fast . Much of the engine power was trying to accelerate the drivetrain , and not the car . Ran better with a 5.38 ratio , and swapped in a different overdrive ratio (.72) and that helped a bunch . Converter clutch was worth 2 mph !

Dan Fahey · 10-17-2019, 09:15 PM

Quote:

Originally Posted by ss3011

4L60 has a 3.06 first gear and a huge ratio change from 1gear to 2nd gear . Might want to checkout the Sonnax gearset that reduces 1st gear into the 2.8 range . Are you planning on using 4th gear ?
Back in the mid 80's I ran a Olds Cutlass with a 307 and a 200-4R with a 2.74 first gear , 5.57 rearend gear , and a 28" bias tire . The problem with all that ratio is the engine can't rev up that fast . Much of the engine power was trying to accelerate the drivetrain , and not the car . Ran better with a 5.38 ratio , and swapped in a different overdrive ratio (.72) and that helped a bunch . Converter clutch was worth 2 mph !

Depending on what I do...
5.38 will work with existing PS cam with OD or Locking Yank 4400PT..
In fact would be good with Stocker Cam holding rpm below 7000rpm. Preferably 6800 rpm with existing 28 inch slick.

Want keep the rpm 7000 or under.
Speaking to Don Compolito their J/SA crosses at 7500 rpm
Car would need better rods for that rpm.

10-17-2019, 06:56 PM	#13
ss3011 Senior Member Join Date: Feb 2002 Location: Southeast Michigan Posts: 885 Likes: 63 Liked 221 Times in 102 Posts	Re: Converter Slippage at top end 4L60 has a 3.06 first gear and a huge ratio change from 1gear to 2nd gear . Might want to checkout the Sonnax gearset that reduces 1st gear into the 2.8 range . Are you planning on using 4th gear ? Back in the mid 80's I ran a Olds Cutlass with a 307 and a 200-4R with a 2.74 first gear , 5.57 rearend gear , and a 28" bias tire . The problem with all that ratio is the engine can't rev up that fast . Much of the engine power was trying to accelerate the drivetrain , and not the car . Ran better with a 5.38 ratio , and swapped in a different overdrive ratio (.72) and that helped a bunch . Converter clutch was worth 2 mph !