The 4L60 to 4L80 experience...

[thunderkyss]

I've read several threads here, so I know many of you have done this. You're project worked out fine, you're happy with your car... blah, blah, blah.

What I want to know is what's the difference?

Any of you guys do just the Tranny Swap, no engine bolt ons or power adders, & experience a difference at the track? Looking at the gear ratios, I'd think the 4L60 shot you out of the hole quicker, but I've also heard the close ratio of the 4L80 keeps you in your power band for the 1-2 shift. Assuming both are true, did your ET/Trap speed benefit, or suffer because of the swap?

Both cars have overdrives, but the 4L60 is 31% overdriven where the 4L80 is only 25% overdriven. Daily driving has to be different. Are you revving higher to get moving in first? RPMs up while cruising at 40mph? What are your revs at 80mph?

Did you have to up your rear-end gear to compensate, or was it part of your original swap?

Are you using more gas?

Any other differences you care to share?

[CPT]

Our past experience has proven that if no other changes are made, the car will be guaranteed to slow down atleast 2/10s in the quarter mile, and lose 50 RWHP with the 4L80E. While I won't argue that the 4L80E is a stronger transmission in stock form than a 4L60E is. I don't agree that it's a practical transmission for a race application...Unless you're making over 1000 HP. We've proven that a 4L60E can be built to take consistent 9 second abuse and last for years. People are afraid of 4L60Es because many times they have builds done by the wrong people, using the wrong parts. Not only do you have to consider the HP loss and extra weight of a 4L80E, you also have to add in the expense of a new crossmember, and torque arm mount point.
You'll get arguments about the benefits and drawbacks to either trans. Facts are facts, though. We've proven our findings in 3 different vehicles. All were 4th gen F-Bodies, running in the low 12's to high 10's. Out of the 3 we did, 2 swapped back and 1 was so aggrivated, he sold the car. 1 of the on'e we swapped back magically found that 50 HP that he lost with the '80E when we swapped back. Don't let some disillusion you. nobody can bypass the laws of physics and facts. any 4L80E is going to have more rotating weight. Nobody makes lightweight parts for them, because they're a truck transmission. It's a proven fact that rotating weight kills horsepower. Add to that the fact that an '80E weighs 75# more, and you see why they ALL slow the cars down.
Now, before we get the crew in this post who claim that I'm trying to sell the 4L60E "because that's what I build". The reality of that is, I've also built 4L80Es since 1991. In truth, the 4L80E costs me LESS to build so my profit margin would be wider by selling more. The reason I don't suggest them is because I don't like dissatisfied customers.
The thought that a 4L80E is "bullet proof" is also a huge myth. The early one's had pressure issues as well as hard parts issues and the later ones had bushing failure issues. The bushing failures would usually lead to very expensive hard parts damage.
Yes, your 60 ft. times will suffer with a 4L80E because of the first gear ratios. The 4L60e will gain RPMs quicker and your 1-2 shift will occur quicker. By "quicker", I mean less into the run. However, it will occur at the same RPMs, which is determined by the computer. Some claim that the 4L80E "feels better" because it makes the 1-2 shift further down track...but...it ultimately slows the car down. The reason we gear a drag car the way we do is to get it to launch. The 3.06 1st gear ratio in the 4L80E helps that. The "better gear spread" of the 4L80E is a feeling that doesn't translate into quicker times.
I've been building transmissions professionally for 23 years. I've literally built hundreds of both 4L60Es and 4L80Es. You asked for exact finding between the 2, with no other changes. We've done that and all have come out with the same results.

Frank

[CPT]

27079

From top left. 9.8 second 4200# Impala SS with 5 year old 4L60E. The red wagon runs 10.7 with a 4L60E that's also 5 years old. The White 'bird is a "bolt on" car that runs 11.5 with a 4L60E that's 8 years old. The black Z in the lower right runs 10.5 with a 4L60E that is 6 years old. The Imp in the middle/bottom runs 10.9 with a 4L60E that is 7 years old. The 'bird in the left/bottom runs 11.0 with a 4L60E that is 7 years old...

[CPT]

http://youtu.be/FooccwqpmSM

This was on a soft nitrous hit. Car weighs 4200#, cuts 1.39 60 ft. times and traps 139 MPH

[CPT]

http://www.gmhightechperformance.com/features/ghtp_1211_1995_impala_ss_9s_with_carnage/

[Mystery Bird]

You don't need a different driveshaft.

[Sahara54]

4L60's are 27 spline and 80e's are 32 spine...I've had them side by side and they are different.

http://www.advanceadapters.com/tech-vault/gm-4l60e-/

http://www.advanceadapters.com/tech-vault/gm-4l80e/

[Mystery Bird]

4L60's are 27 spline and 80e's are 32 spine...I've had them side by side and they are different.

http://www.advanceadapters.com/tech-vault/gm-4l60e-/

http://www.advanceadapters.com/tech-vault/gm-4l80e/

I think you are just talking about the yoke. Driveshaft works, ask me how I know.

[shownomercy]

I think you are just talking about the yoke. Driveshaft works, ask me how I know.

Same, a certain someone owes me $1000 bucks for that assumption. Stock DS != stock yoke.

[CPT]

Um... Let's take a 4L60E driveshaft and try putting it in a 4L80E. It obviously WON'T work unless you change the yoke. So, what I stated was correct. I didn't say anything about the overall length.

Frank

[CPT]

You don't need a different driveshaft.

I have changed the way I worded my post above. You are correct. The driveshaft length is the same, but the yoke has to be changed to work with the '80E output shaft.

Frank

[dawdaw]

:horse::fart: 80e is for women.

[thunderkyss]

Our past experience has proven that if no other changes are made, the car will be guaranteed to slow down atleast 2/10s in the quarter mile, and lose 50 RWHP with the 4L80E.


Frank

Great post Frank, thanks. Are there any "extras" that need to be done to the 4L60E to handle the kind of power you're talking about? 10 second & lower cars? (Not that I plan to build anything like that).


Anyone else want to comment on the driveability of the 4L80E? Gas mileage difference?

FYI, I'm not planning on swapping a 4L80 into my LT1. I've got a 454/4L80 that I'm going to put in a '72 Camaro, & I'm actually wondering if I should stick with it, or get a 4L60E instead.

[Mystery Bird]

My experience with the 80 has been great and I have nothing but good to say about the swap in my car. Didn't notice any difference in gas mileage. I like the long first gear. The 80 has it's place, but so does the 60. I think at 60 MPH it is about 2-300 RPM's higher but makes my cam happier at those speeds.

[thunderkyss]

I'm putting a 454 in my car & wondering about gas mileage.

I know that sounds stupid. I'm not "worried" about gas mileage, just trying to consider all the differences.

[CPT]

Yes, there are many upgrades and modifications that need to be done to handle high HP and RPMs. This is an area where the 4L80E has an advantage because it doesn't take as much to get them to handle higher HP. What are your plans for the '72? Since you're starting pretty much from scratch either way, it's up to your preference. Both transmissions have their benefits and drawbacks. If you go with a 4L60E, you can use a factory 2nd gen TH400 crossmember. I'm not sure what crossmember will work for the '80E. The other question I have to ask is, what induction do you plan on using on the 454? Either of the 2 transmissions need a TPS signal to operate. What computer do you plan on using to operate either one?

Frank

[thunderkyss]

The 454 will pretty much be stock for a little while, I've got to get it running of course, but cam & headers are probably as far as I'll go with it until the car is finished.


When I bought the '72 the idea was to take the LT1/T56 out of my '96 & put it into the '72, which needs a full on resto. I was also going to take the interior from the '96 & graft it into the '72, disc brakes, & whatever else I wanted.

I bought the car over a year ago. When I got to the point of taking the '96 apart, I just couldn't do it. So I thought about getting another LT1/T56 combo to stick in the '72, then I thought I'd go LSx..... then I thought.... BigBlock.

Most of my time & money will go into restoring Camaro. I'll freshen up the 454, probably throw a cam in it, but I'll use a '99 Suburban's PCM & wiring harness to get it running. Stock intake until I get to that phase of the project. I know the intake limits it's HP potential, but 290hp, 410lb/ft..... it should be a hoot in stock form.

When it's all said & done, the '72 is going to be my weekend cruiser.

[1SlowFormula]

27079

From top left. 9.8 second 4200# Impala SS with 5 year old 4L60E. The red wagon runs 10.7 with a 4L60E that's also 5 years old. The White 'bird is a "bolt on" car that runs 11.5 with a 4L60E that's 8 years old. The black Z in the lower right runs 10.5 with a 4L60E that is 6 years old. The Imp in the middle/bottom runs 10.9 with a 4L60E that is 7 years old. The 'bird in the left/bottom runs 11.0 with a 4L60E that is 7 years old...

Man, you know how to make a man feel old... but you're right it was that long ago. And still a killer trans...

Sent from my SAMSUNG-SGH-I747 using Tapatalk

[CPT]

Man, you know how to make a man feel old... but you're right it was that long ago. And still a killer trans...

Sent from my SAMSUNG-SGH-I747 using Tapatalk

I pulled out the paperwork and realized it's actually been over 9 years ago (9/2004). Sorry to make you feel even older...LOL

Frank

[shownomercy]

So, lets try this again. Here is a semi decent back to back.

http://www.performancetrucks.net/forums/gm-drivetrain-suspension-22/4l60-4l80-dyno-results-503358/

Which I am sure will be ripped apart cause it was a locked up pull, but, have at it. If thats the losses for a much beefier trans, well, I can deal with that.

Discuss.

[1SlowFormula]

looking at that graph, the 80 is below the 60 across the board, meaning overall accelearation would be down across the board. That being said, even reading that post and how multiple people have reported 15 or more HP loss, I don't see a need for an 80 unless you are running stupid high power, or if you just wanted to have a beefy setup. Those guys with those heavy trucks and forced induction LS engines might just want a real truck trans in their truck, lol...