My set-up is front mounted t70 turbo 5.3 216/218 114lsa cam and old 4l60e w/2500 stall. After burning up my 3 gear clutches over 2yr I decide go with 4l80e w/2500 stall. So far I don't like my new set-up. Now when spool 6lb down low on the 4l80e the truck wont start pulling in till I get over 3k rpm. The old 4l60e would start pulling at 2200 rpm and would progress building boost though the rpm unlike the 80e once you get over 3k it comes on hard. The big thing I hate about the 4l80e is the delay in the lock-up. My mileage has drop as well with 4l80e too approx. 2mpg. So I'm think a bigger stall would help with boost lag or will hurt when needs to build boost. I'm just posting my finding and any ideas that would help. Thanks

 

With a stock converter the 4L80E really doesn't start to come alive until around 2500-3000. The rotating mass is huge and it takes a little bit to get it spun up. The 60e did it faster because it was lighter and has lower gearing in 1st and 2nd. Sounds like you need a little more converter slippage to bring your engine speed up some and get your boost up. Whats this about the delay in lockup? Are you saying the lockup speed is too high or the converter physically takes too long to lock? Maybe the TCC tables aren't what they need to be. A guy at work with a 6 liter HD tells me his won't lock until 53 mph. Mine is set to lock at 32 mph and mine has higher gearing then his does.

 

Good thread i been wondering the same thing.. Like if i have a built 4L60E, that has stood up behind a 11 sec motor, do i really need to go to a 4L80E??

 

Converter physically takes take too long to lock-up. When doing 80mph and get out of throttle and get right back in to it there is delay before lock-up again. is there a setting so doesn't do this or is normal for all 4l80e.

 

I've seen built 4l60e make it in to the 11sec but we talking $3,000+ for these trans.

 

It sounds like he already has a 60E in an 11-sec truck.

 

That sounds like more of a setting issue to me. Mine takes maybe half a second to a second to relock the converter. Its not instant but its fast enough I've never been bothered by it.

 

I will look throught setting again to see if can find anything.

 

Two step!!!!!!!

 

We are talking part throttle or quick burst of the throttle.