cablebandit

iTrader: (37)

I noticed that on a stock 4l80e, it has a rpm limitation of 5200rpms. Why is that? What gets messed up if you go over that and what is done to a built 4l80e to allow you to rev higher?

12secSS

iTrader: (30)

That is just GM recommendation for max rpms, just like the 4L60E has a max rpm of 6100 rpms. That doesn't mean that it can not spin higher, my 2002 1500HD (now) has a redline of 5800 rpms and shift (at WOT) at 5600 rpms. This (OE max RPM) applies to factory stock vehicles only, with factory stock power.

jimmyblue

iTrader: (11)

I know when the 4L65 came out with its 5-pinion
planetary they recommended it be shifted lower,
some deal about oiling differences (less lubrication
up in there). This may be the same deal, maybe
GM didn't foresee this grunt-duty trans being put
behind screamer motors (forward-thinking as they
are).

cablebandit

iTrader: (37)

Jimmyblue....i know you are right about the 4l60 vs the 65....i guess its the same for the 4l80....i think the 85 has 5 gear planets as well which may be the reason for the 5200 limit. Question then is, how to overcome that

FastKat

iTrader: (10)

Perhaps we can call some trans shop that builds high performance 4L80Es and see what they do.... (sponsors chime in!) they have to have a way to make it safe or whatever to run in the higher RPM bands.

NBM2001z28

iTrader: (43)

THere's a few people on here spinning the 65's to over 7000 rpm. I know their transmissions are doing very well and have seen them come off the line with 4000+ stall yank converters in them.

Yank

iTrader: (181)

The stock converter is over 65 LBS
when a lighter converter is used the RPMs at shift can be higher

cablebandit

iTrader: (37)

hmmphh....didnt know that. Thanks for the update Yank. How are you guys coming with the 4l80 crossmember/torque arm mount?

nosfedgta

whats up jerry... so what did you do with the 400 I got ya?

cablebandit

iTrader: (37)

Drew.....I am still running it
Jerry