Effect of RPM's on a 4L60E
10-03-2006, 10:12 PM
#81
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Originally Posted by ChocoTaco369
downshift into 3 or D. if you ever go WOT, get out of OD. shift into 3 or D with no throttle after you've let your RPM's fall a bit. a 4-1 and 4-2 shift is very bad i've heard many times. a 3-2 shift isn't harmful. as for 3-1, not sure but it's not as bad as the 4-1. remember, if you downshift from 4-1 and 4-2, you're still using that weak 3-4 band - and you're doing it under heavy power! that's DANGEROUS in a stock 4L60E. downshift to 3/D under no throttle since it's easier on the 3-4 band. then when you go WOT, you don't have to worry about harming the weakest bands in the tranny.
this is my opinion.
this is my opinion.
Recently I was leaning more towards the manual 4-3 being worse than the auto 4-2/4-1 (based on wear to the overrun clutches), but I dunno anymore.
It'd be nice to get a final conclusion on that. Maybe get all the top trans builders on here to fight it out till we get the best answer.
Either way I guess I'll probably end up sticking with the no-load manual downshift to 3rd prior to WOT just because the 3-1 or 3-2 downshift feels less sloppy.
10-03-2006, 10:37 PM
#82
Originally Posted by ChocoTaco369
downshift into 3 or D. if you ever go WOT, get out of OD. shift into 3 or D with no throttle after you've let your RPM's fall a bit. a 4-1 and 4-2 shift is very bad i've heard many times. a 3-2 shift isn't harmful. as for 3-1, not sure but it's not as bad as the 4-1. remember, if you downshift from 4-1 and 4-2, you're still using that weak 3-4 band - and you're doing it under heavy power! that's DANGEROUS in a stock 4L60E. downshift to 3/D under no throttle since it's easier on the 3-4 band. then when you go WOT, you don't have to worry about harming the weakest bands in the tranny. this is my opinion.
Originally Posted by James B.
A 4 to 2 downshift is easier for a 4L60-E to do than a 3-2 downshift. It is a single event of disengaging the 3-4 clutch pack. Downshifting from 3 to 2 has to release the 3-4 clutch pack and engage the band at the same time. There is a valve specifically for doing this just to make sure it doesn't let the engine over-rev trying to pull that off. Keep in mind that mechanically the 4L60-E is only a 2-speed auto with overdrive.
10-03-2006, 10:45 PM
#83
A couple of oldie but goodie threads on this subject:https://ls1tech.com/forums/showthread.php?t=293017; https://ls1tech.com/forums/showthrea...6&page=2&pp=20 especially the schematic in the post by joecar.
10-03-2006, 11:42 PM
#84
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Originally Posted by RevGTO
First of all, there is no 3-4 band; the band applies in 2nd and 4th. This post explains it:
i don't think we will ever know the correct answer to this question. i've heard from sooo many people on these boards the 4-2 downshift is so bad for the 4L60E and downshifting 1 gear at a time is so much safer than downshifting 2 gears. i will take my chances downshifting into 3. most trans builders say the 4L60E's problem lies in overdrive. i don't wanna put any heavy power through it.
Originally Posted by TwoFast4Lv
We started out by putting 700R4s in 454 four door duelly tow rigg's and learned from there. With a good driver they would last 60-100k miles no problem. Put one in OD and pull a hard hill (lot's of 10%+ grades here)with 15,000Lbs or so and it would be dead by the top of the hill Use 3rd and keep on trucking. We were testing parts that are common place now.
Use 3rd and keep on trucking. We were testing parts that are common place now.
he's built many of them. he's blown more 4L60E's than probably everyone in this thread put together. i'm sure he knows the biggest weaknesses in the real world. Last edited by ChocoTaco369; 10-03-2006 at 11:47 PM.
10-04-2006, 04:52 AM
#85
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Bringing it out of OD before going WOT is a good idea, however i've been advised not to take my foot off the gas. The only thing is going 3-2 takes forever, where as 4-2 is instant so this isn't very desirable unless you get a tune, which I think might fix it.
10-04-2006, 05:45 AM
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Originally Posted by BlackHawk T/A
The only thing is going 3-2 takes forever, where as 4-2 is instant so this isn't very desirable unless you get a tune, which I think might fix it.
But I do agree that it's probably a good idea to give it a very small amount of throttle (just enough to maintain current speed) if you're at highway speeds when going manually from OD to 3rd, to avoid engine-braking). At speeds under 45-50mph though, it probably doesn't matter much as the rpm change will be very small.
10-04-2006, 04:23 PM
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Mine does. If I put it down to 3, then go WOT, it takes the computer a second to unlock, then downshift. During this time someone can get a pretty good jump on me. It feels like 2 downshifts. If I leave it in 4th it will go immediately when I hit the throttle. Don't ask me why but I wish it was the other way around.
10-04-2006, 05:33 PM
#88
Originally Posted by BlackHawk T/A
Mine does. If I put it down to 3, then go WOT, it takes the computer a second to unlock, then downshift. During this time someone can get a pretty good jump on me. It feels like 2 downshifts. If I leave it in 4th it will go immediately when I hit the throttle. Don't ask me why but I wish it was the other way around.
3rd does not lock IIRC
10-04-2006, 06:00 PM
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Originally Posted by Stanger88
3rd does not lock IIRC
Does not lock in drive.
If you rode in my car you would know exactly when its locked and when its not. It is a night and day difference in feel, and sound, which is nothing like a stock car that you can barely notice.
10-04-2006, 07:55 PM
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Originally Posted by RevGTO
A couple of oldie but goodie threads on this subject:https://ls1tech.com/forums/showthread.php?t=293017; https://ls1tech.com/forums/showthrea...6&page=2&pp=20 especially the schematic in the post by joecar.
Will we ever get a FINAL ANSWER?!?!
The arguements are just too good on both sides......
10-04-2006, 08:01 PM
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Originally Posted by Stanger88
3rd does not lock IIRC
10-04-2006, 09:04 PM
#93
Originally Posted by RPM WS6
See, it's conflicting info like what's in those threads that always makes me doubt myself. Will we ever get a FINAL ANSWER?!?! The arguements are just too good on both sides......
Originally Posted by James B.
A 4 to 2 downshift is easier for a 4L60-E to do than a 3-2 downshift. It is a single event of disengaging the 3-4 clutch pack. Downshifting from 3 to 2 has to release the 3-4 clutch pack and engage the band at the same time. Keep in mind that mechanically the 4L60-E is only a 2-speed auto with overdrive.
10-04-2006, 10:59 PM
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Originally Posted by RevGTO
The reason that there are so many arguments about this is that they are centered on opinions rather than hard technical data. Many guys lack a basic understanding of how the 4L60e works, and so they advocate inaccurate ideas about things. I'm going to quote James B. again, because he explains clearly, succintly, and accurately how the downshifts work, and the basic architecture of the 4L60e. If you understand this, you'll see there is nothing to argue about.
Originally Posted by James B.
A 4 to 2 downshift is easier for a 4L60-E to do than a 3-2 downshift. It is a single event of disengaging the 3-4 clutch pack. Downshifting from 3 to 2 has to release the 3-4 clutch pack and engage the band at the same time. Keep in mind that mechanically the 4L60-E is only a 2-speed auto with overdrive.
Originally Posted by James B.
A 4 to 2 downshift is easier for a 4L60-E to do than a 3-2 downshift. It is a single event of disengaging the 3-4 clutch pack. Downshifting from 3 to 2 has to release the 3-4 clutch pack and engage the band at the same time. Keep in mind that mechanically the 4L60-E is only a 2-speed auto with overdrive.
10-04-2006, 11:07 PM
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Originally Posted by staringback05
id have to go with the 3-1 on the same principle
If the 4-2 is preferred over the 3-2, then why would the 3-1 be preferred over the 4-1?
Furthermore, if you're already in OD at the time, but at a speed where it would/will go back to 1st (like at 35mph in a 2.73 geared car), then you'd have to shift manually back to 3rd first, then go WOT to allow the auto downshift from 3-1.
So which is better?
1) Manual 4-3 under no load, then auto 3-1 at WOT
or
2) Auto 4-1 at WOT?
10-04-2006, 11:25 PM
#98
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Originally Posted by RPM WS6
Explain?
If the 4-2 is preferred over the 3-2, then why would the 3-1 be preferred over the 4-1?
Furthermore, if you're already in OD at the time, but at a speed where it would/will go back to 1st (like at 35mph in a 2.73 geared car), then you'd have to shift manually back to 3rd first, then go WOT to allow the auto downshift from 3-1.
So which is better?
1) Manual 4-3 under no load, then auto 3-1 at WOT
or
2) Auto 4-1 at WOT?
If the 4-2 is preferred over the 3-2, then why would the 3-1 be preferred over the 4-1?
Furthermore, if you're already in OD at the time, but at a speed where it would/will go back to 1st (like at 35mph in a 2.73 geared car), then you'd have to shift manually back to 3rd first, then go WOT to allow the auto downshift from 3-1.
So which is better?
1) Manual 4-3 under no load, then auto 3-1 at WOT
or
2) Auto 4-1 at WOT?
10-04-2006, 11:41 PM
#99
4-1: release the band and disengage the 3-4 clutch pack. 3-1: disengage the 3-4 clutch pack. But with the 4-1 downshift, the overun clutch is not applied; manually downshifting from 4-3 applies it, and then the 3-1 automatic downshift releases it. Although I don't think one is "safe" while the other is "destructive" to your tranny, on balance, I'd probably lean toward the manual 3 - automatic 1.
10-04-2006, 11:42 PM
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Originally Posted by ChocoTaco369
i don't think it matters. you can't do a 4-1 shift on even a 2.73 car. my car goes into 4th gear at ~40 mph and first gear won't kick down above ~36 mph. i don't think you can do a 4-1. i don't think there's a way to stay in 4th gear under 36 mph. i never tried, but i postulate you can't.