Effect of RPM's on a 4L60E
08-21-2006, 09:30 AM
#1
Tech Resident
Thread Starter
Effect of RPM's on a 4L60E there's always talk on "what is the max power my 4L60E can take" or "what can i do to make my 4L60E last?"
i've been doing a lot of thinking lately. most people say a 4L60E won't last past 400rwhp...but yet there are a few out there that do.
these are the things i have noticed:
- stock f-bodies rarely break a 4L60E
- bolt-on cars rarely ever break a 4L60E
- cammed cars break 4L60E's all the time
now, A4's generally cannot reach 400rwhp with a bolt-on car. they reach 400rwhp once they add a cam. most people then start seeing trans problems. i got to thinking, and what if the power isn't really the biggest problem here? maybe the biggest problem is once people put in cams, they change their shift points and rev limiter? what if the biggest reason why 4L60E's break is cammed cars generally move their shifts from 6000rpm's stock to 6800+rpms?
people blame the failing 4L60E's on:
- heat
- power
what if RPM's are worse than the horsepower level? what if RPM's are the REAL serial killer? maybe these stock 4L60E's putting down 450rwhp are lasting because the shift points haven't been changed.
no one can argue that heat and power ARE factors of failing 4L60E's, but what if RPM's are the biggest problem of all? what if we can preserve our 4L60E's simply by keeping our shift points stock?
i just thought this could spark some interesting conversation.
i've been doing a lot of thinking lately. most people say a 4L60E won't last past 400rwhp...but yet there are a few out there that do.
these are the things i have noticed:
- stock f-bodies rarely break a 4L60E
- bolt-on cars rarely ever break a 4L60E
- cammed cars break 4L60E's all the time
now, A4's generally cannot reach 400rwhp with a bolt-on car. they reach 400rwhp once they add a cam. most people then start seeing trans problems. i got to thinking, and what if the power isn't really the biggest problem here? maybe the biggest problem is once people put in cams, they change their shift points and rev limiter? what if the biggest reason why 4L60E's break is cammed cars generally move their shifts from 6000rpm's stock to 6800+rpms?
people blame the failing 4L60E's on:
- heat
- power
what if RPM's are worse than the horsepower level? what if RPM's are the REAL serial killer? maybe these stock 4L60E's putting down 450rwhp are lasting because the shift points haven't been changed.
no one can argue that heat and power ARE factors of failing 4L60E's, but what if RPM's are the biggest problem of all? what if we can preserve our 4L60E's simply by keeping our shift points stock?
i just thought this could spark some interesting conversation.
08-21-2006, 10:16 AM
#2
Nobody with a sizeable cam is going to shift at 6k rpm. Would you put a $1k nitrous system in your car and then never fill up the bottle? Bigger cams make power at higher rpms, you'd be wasting your time/money shifting that low. Interesting thought though! 
08-21-2006, 10:26 AM
#3
Tech Resident
Thread Starter
Originally Posted by jmm98LS1
Nobody with a sizeable cam is going to shift at 6k rpm. Would you put a $1k nitrous system in your car and then never fill up the bottle? Bigger cams make power at higher rpms, you'd be wasting your time/money shifting that low. Interesting thought though!
if the 4L60E grenading is rpm-related, you could get heads instead of a cam. you'd still get the power without having to raise your shift points/rev limiter to take advantage of it. it could save a lot of trannies in the long run.
08-21-2006, 11:09 AM
#5
On The Tree
Join Date: Dec 2005
Posts: 174
Likes: 0
Received 0 Likes
on
0 Posts
hmmm, good point. i think he might be on to something.....
GM high tech performance has 2 4l60e cars (04' gto and a TA, both supercharged) that are making insane amounts of power, and it looks like they're using stock 4l60's. also i say maintance is a big thing when it comes to preserving an auto tranny
just my 2 cents
GM high tech performance has 2 4l60e cars (04' gto and a TA, both supercharged) that are making insane amounts of power, and it looks like they're using stock 4l60's. also i say maintance is a big thing when it comes to preserving an auto tranny
just my 2 cents
08-21-2006, 11:48 AM
#6
Tech Resident
Thread Starter
Originally Posted by TAwhore
hmmm, good point. i think he might be on to something.....
GM high tech performance has 2 4l60e cars (04' gto and a TA, both supercharged) that are making insane amounts of power, and it looks like they're using stock 4l60's. also i say maintance is a big thing when it comes to preserving an auto tranny
just my 2 cents
GM high tech performance has 2 4l60e cars (04' gto and a TA, both supercharged) that are making insane amounts of power, and it looks like they're using stock 4l60's. also i say maintance is a big thing when it comes to preserving an auto tranny
just my 2 cents
yet throw on a H/C package and it blows up in a week. why? H/C packages make about the same power as a supercharger.
i say it's not so much the power, it's the fact that you're now revving at 7 grand instead of 6 grand with a H/C package and with a supercharger you keep the stock shift points and never pass 6k.
anyone on here running a FI setup with a stock 4L60E? if you are, how has it held up and how long have you been running it?
08-21-2006, 02:01 PM
#7
I concurr... i recently added a cam 232/236 .595 .601 LS6 Ported Heads, FAST 90/90..
My tranny is starting to slip quite badly now and i just had my tranny rebuilt back in Feb...
Could also be My Yank SY3500... I lost count of all of the miles on it... i'd say it has @ least 90-100K on it..
My tranny is starting to slip quite badly now and i just had my tranny rebuilt back in Feb...
Could also be My Yank SY3500... I lost count of all of the miles on it... i'd say it has @ least 90-100K on it..
Trending Topics
08-21-2006, 04:16 PM
#8
As per a GM Powertrain Engineer I know.
... our transmissions are limited by RPM because the rotating inertia of the part, combined with a sudden change in RPM, cause the parts to break. Those RPM limits are set to avoid having shift changes break parts. Say an RPM change from 6500 down to (for example) 3000, this is what break (OE) parts.
08-21-2006, 04:31 PM
#9
Moderator
iTrader: (11)
Join Date: Mar 2002
Location: East Central Florida
Posts: 12,605
Likes: 0
Received 6 Likes
on
6 Posts
That, and when you slam from 6500 to 3000 (OK,
never happen, but) and climb up on the multiplication
of your 2.7 STR converter at full un-managed motor
torque, you put about 50-100% more grief on the guts
than the engineer had to design to. Anyone who uses
shift extension to manage their powerband is flashing
some large torque out the back.
never happen, but) and climb up on the multiplication
of your 2.7 STR converter at full un-managed motor
torque, you put about 50-100% more grief on the guts
than the engineer had to design to. Anyone who uses
shift extension to manage their powerband is flashing
some large torque out the back.
08-21-2006, 11:32 PM
#11
From a thread back in January of this year:
Originally Posted by Patrick G
RPM is one of the biggest killer for 4L60Es. You can put 600 rwhp to a stock 4L60E and if you shift it at 5500 rpm, it will last a long time. But a 350 rwhp motor shifted at 6800 will tear one up in a short time. Been there, done that. Joel and Predator-Z are saavy enthusiasts and know the pitfalls that come with a motor turning lots of rpm. For maximum street miles, it's best to shift the 4L60E at or below 6000 rpm.
08-22-2006, 07:53 AM
#12
Tech Resident
Thread Starter
see i freakin' knew it! i would always say to myself, "why are there always these full bolt-on cars putting down 380rwhp that have stock trannies that run fine, but there are cammed cars with 400rwhp breaking them left and right?" it's those damn 6800+rpm shift points you set after the cam! a guy not too long ago just bought a blowered car with god knows how many miles with a stock 4L60E. no wonder the tranny lasted. wow, i'm REALLY curious to find out what a stock 4L60E can take power-wise. power doesn't seem to be the real issue here! apparently, the way to make a strong 4L60E is NOT to build it to hold power, but to build it to hold RPM's!
08-22-2006, 08:32 AM
#13
id go with those ideas....instead of heat and power, id say heat and changing the function of the tranny....to many people esp. down here in the damn heat, push there tranny just as hard as they would when its cooler, fluid breaks down and theres just so much of it in there, that when it starts going it screws everything, changing the rpm range and shift points is something ive always looked at to...raising the rpm range also slams the hell out of the tranny more when it shifts....i wont even start on what nx will do....good point taco
08-22-2006, 08:25 PM
#15
Tech Resident
Thread Starter
yea see, these trannies shift points are being pushed to the max straight out of the box. all you guys putting in cams blowing 4L60E's isn't because you broke the 400rwhp mark, it's because you upped your shift points. wow, i wonder how long a 4L60E would last behind a 500rwhp car with shift points at 5500rpm's. i bet a long time. this is getting interesting, keep it coming.
still looking for FI guys running stock 4L60E's!
still looking for FI guys running stock 4L60E's!
08-22-2006, 11:02 PM
#19
FYI the #1 failure on these transmissions is burnt clutches. And the #1 cause of burnt clutches is fluid problems. The stock EPC reduces line pressures significantly at higher rpms, especially over 5000rpms. Rather than drop the shift point to 5500rpms like you suggest, why not address the problem? Changing the pump spring will get you 95% of the way there.
Oooohhh... 550rwhp, through a 4l60e (obviously through a loose converter), and at 5500rpms.
My built 4l60e shifts at 6500rpm, and I make over 400rwhp through a loose converter. Never dyno'd on the spray. I beat the crap out of this trans on a daily basis, doing all the things people around here say you shouldn't (WOT in 4th lockup, 4-1, 4-2 downshifts, manually downshifting to D without throttle input) and its performed flawlessly.
Oooohhh... 550rwhp, through a 4l60e (obviously through a loose converter), and at 5500rpms.
My built 4l60e shifts at 6500rpm, and I make over 400rwhp through a loose converter. Never dyno'd on the spray. I beat the crap out of this trans on a daily basis, doing all the things people around here say you shouldn't (WOT in 4th lockup, 4-1, 4-2 downshifts, manually downshifting to D without throttle input) and its performed flawlessly.
08-23-2006, 05:03 AM
#20
TECH Addict
iTrader: (3)
Join Date: Nov 2005
Location: Lincoln, NE
Posts: 2,869
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by Marc 85Z28
My built 4l60e shifts at 6500rpm, and I make over 400rwhp through a loose converter. Never dyno'd on the spray. I beat the crap out of this trans on a daily basis, doing all the things people around here say you shouldn't (WOT in 4th lockup, 4-1, 4-2 downshifts, manually downshifting to D without throttle input) and its performed flawlessly.