TCI 6-speed auto
#6
TECH Fanatic
iTrader: (1)
This has been done before. Believe it or not, Jet (remember jetchip.com?) sold a valvebody kit that made a 4L80-E six speeds back in the late 90's. It never was popular because the conversion made it manual-shifting if I remember right.
Technically, a 4L80-E has always been capable of eight forward ratios because it has three planetary gear sets.
Stock 1st = Forward engaged
Stock 2nd = Forward engaged & Intermediate engage
Stock 3rd = Forward & Intermediate engaged, Direct engage
Stock 4th = Forward & Intermediate & Direct engaged, Overdrive engage
I can only guess they're doing something like this:
1st = Forward engaged
2nd = Forward engaged, Overdrive engage
3rd = Forward engaged, Overdrive disengage, and Intermediate engage*
4th = Forward & Intermediate engaged, Overdrive engage
5th = Forward & Intermediate engaged, Overdrive disengage, Direct engage*
6th = Forward & Intermediate & Direct engaged, Overdrive engage
* Note that third and fifth are both now dual-event shifts. Stock, a 4L80-E has no multi-event shifts - a major reason why they shift so solid.
Technically, a 4L80-E has always been capable of eight forward ratios because it has three planetary gear sets.
Stock 1st = Forward engaged
Stock 2nd = Forward engaged & Intermediate engage
Stock 3rd = Forward & Intermediate engaged, Direct engage
Stock 4th = Forward & Intermediate & Direct engaged, Overdrive engage
I can only guess they're doing something like this:
1st = Forward engaged
2nd = Forward engaged, Overdrive engage
3rd = Forward engaged, Overdrive disengage, and Intermediate engage*
4th = Forward & Intermediate engaged, Overdrive engage
5th = Forward & Intermediate engaged, Overdrive disengage, Direct engage*
6th = Forward & Intermediate & Direct engaged, Overdrive engage
* Note that third and fifth are both now dual-event shifts. Stock, a 4L80-E has no multi-event shifts - a major reason why they shift so solid.