6L80E in a 4th gen?
Thread Starter
Joined: Sep 2009
Posts: 979
Likes: 13
From: League City, TX
6L80E in a 4th gen? Hey guys I'm no transmission pro by any stretch of the imagination but I remember hearing a few years back on here that the 6L80E found in the vettes would not be able to work on our cars and wouldn't be able to withstand the high horsepower levels a lot of people's cars on here tend to produce. But things have definitely changed since then and with the 6L80E in the new Camaro and with a slightly larger aftermarket for it (Did someone say "Circle D"?) I have to quench my curiosity. Would it be possible to have a 6L80E built and somehow mated to an Fbody? Would it work? I realize you'd have to get a custom faceplate for the transmission, but what about the real technicalities behind it? I wondered since it can bolt up to an LS3 if it could also work with an LS1 or LS2? If not, what are the reasons it couldn't be done?
And I wonder how you would go about tuning for that as well...?
Thanks for looking, you know you're curious!
And I wonder how you would go about tuning for that as well...?
Thanks for looking, you know you're curious!
Hey guys I'm no transmission pro by any stretch of the imagination but I remember hearing a few years back on here that the 6L80E found in the vettes would not be able to work on our cars and wouldn't be able to withstand the high horsepower levels a lot of people's cars on here tend to produce. But things have definitely changed since then and with the 6L80E in the new Camaro and with a slightly larger aftermarket for it (Did someone say "Circle D"?) I have to quench my curiosity. Would it be possible to have a 6L80E built and somehow mated to an Fbody? Would it work? I realize you'd have to get a custom faceplate for the transmission, but what about the real technicalities behind it? I wondered since it can bolt up to an LS3 if it could also work with an LS1 or LS2? If not, what are the reasons it couldn't be done?
And I wonder how you would go about tuning for that as well...?
Thanks for looking, you know you're curious!
And I wonder how you would go about tuning for that as well...?
Thanks for looking, you know you're curious!
The 6L80e is stronger (In STOCK form) and will bolt up to an LS1. The price of wiring, crossmember modification and purchase price of the transmission will exceed the price of even our best built 4L60e. The gear spacing in a 6L80e is worse than a 4L80e for the 1-2 shift. The overdrive is no better. My best advise is to go drive a car or truck with a 6L80e in it. They are always shifting. It is very annoying IMO. The cost and headache involved in swapping a 6L80e into a 4th gen is not worth it what so ever.
not only that but with the low gear of the 6l80e if you have traction and power you are going to climb right up the ring gear everytime you launch. if you dont have traction you are going to spin to the 200 ft mark. I have driven a few of the ls3 vettes at work with the 6l in them and 1st gear is usless.
11 Second Club
Joined: Feb 2008
Posts: 317
Likes: 2
From: TN
Educate me on RPM drop and why the 6L80 gear spacing is worst than a 4L65 or 4L80.
Based on the below info as a reference point, using a 3.27 rear gear, with 28.0 inch Dia tire and Max RPM of 6500, does the 4L65E's gear splits really provide the engine with a mechanical advantage over the 6L80E's in the gears that would be used on the street or strip?
If so why?
Looks like the 6L80E gear splits aren't that bad to me, all things being equal except 6L80e will shift one more time in a 1/4 mile race.
My thinking is based off driving a tractor trailer in city pickup and delivery and the best way to get weight to speed the fastest is tighter gear splits that allow engine to rev quicker.
6L80E
1st gear 4.03, MPH @ 6500 RPM = 41.1
2nd gear 2.36, MPH @ 6500 RPM = 70.19
3rd gear 1.53. MPH @ 6500 RPM = 108.27
4th gear 1.15, MPH @ 6500 RPM = 144.04
4L65E
1st gear 3.06, MPH @ 6500 RPM = 54.13
2nd gear 1.62, MPH @ 6500 RPM = 102.25
3rd gear 1.00, MPH @ 6500 RPM = 165.65
4L80E
1st gear 2.48, MPH @ 6500 RPM = 66.79
2nd gear 1.48, MPH @ 6500 RPM = 111.92
3rd gear 1.00, MPH @ 6500 RPM = 165.65
With a 4l80e you need a 3.70 rear gear just to match mechanical advantage wise of the 4L65E non OD gearing, an around a 3.90 rear gear to even come close to matching up with the 6l80E's non OD gearing.
If I remember right, gas mileage is about keeping engine in it's power band so you don't have to use as much throttle to move the weight, especially when you do a lot more in town driving than you do interstate. If I remember correctly that is the basis behind the 6L80E's gearing.
Based on the below info as a reference point, using a 3.27 rear gear, with 28.0 inch Dia tire and Max RPM of 6500, does the 4L65E's gear splits really provide the engine with a mechanical advantage over the 6L80E's in the gears that would be used on the street or strip?
If so why?
Looks like the 6L80E gear splits aren't that bad to me, all things being equal except 6L80e will shift one more time in a 1/4 mile race.
My thinking is based off driving a tractor trailer in city pickup and delivery and the best way to get weight to speed the fastest is tighter gear splits that allow engine to rev quicker.
6L80E
1st gear 4.03, MPH @ 6500 RPM = 41.1
2nd gear 2.36, MPH @ 6500 RPM = 70.19
3rd gear 1.53. MPH @ 6500 RPM = 108.27
4th gear 1.15, MPH @ 6500 RPM = 144.04
4L65E
1st gear 3.06, MPH @ 6500 RPM = 54.13
2nd gear 1.62, MPH @ 6500 RPM = 102.25
3rd gear 1.00, MPH @ 6500 RPM = 165.65
4L80E
1st gear 2.48, MPH @ 6500 RPM = 66.79
2nd gear 1.48, MPH @ 6500 RPM = 111.92
3rd gear 1.00, MPH @ 6500 RPM = 165.65
With a 4l80e you need a 3.70 rear gear just to match mechanical advantage wise of the 4L65E non OD gearing, an around a 3.90 rear gear to even come close to matching up with the 6l80E's non OD gearing.
If I remember right, gas mileage is about keeping engine in it's power band so you don't have to use as much throttle to move the weight, especially when you do a lot more in town driving than you do interstate. If I remember correctly that is the basis behind the 6L80E's gearing.
Last edited by poorhousenext; Jan 31, 2011 at 11:02 PM.
not only that but with the low gear of the 6l80e if you have traction and power you are going to climb right up the ring gear everytime you launch. if you dont have traction you are going to spin to the 200 ft mark. I have driven a few of the ls3 vettes at work with the 6l in them and 1st gear is usless.
600rwhp LS7 running 9.950:
http://www.youtube.com/watch?v=r-UgQDkNvlc
440rwhp LS2 running 10.85:
http://www.youtube.com/watch?v=cMIS7espgtM
Same LS2 pulling the wheels off the ground a little bit
http://www.youtube.com/watch?v=PQZ4AcLISRk
Trending Topics
Thread Starter
Joined: Sep 2009
Posts: 979
Likes: 13
From: League City, TX
There have been a lot of questions raised recently about this swap. My first question is, Why? There are more than enough 4L60e builders out there proving the capabilities of the 4L60e day in and day out (RPM being one of them).
The 6L80e is stronger (In STOCK form) and will bolt up to an LS1. The price of wiring, crossmember modification and purchase price of the transmission will exceed the price of even our best built 4L60e. The gear spacing in a 6L80e is worse than a 4L80e for the 1-2 shift. The overdrive is no better. My best advise is to go drive a car or truck with a 6L80e in it. They are always shifting. It is very annoying IMO. The cost and headache involved in swapping a 6L80e into a 4th gen is not worth it what so ever.
The 6L80e is stronger (In STOCK form) and will bolt up to an LS1. The price of wiring, crossmember modification and purchase price of the transmission will exceed the price of even our best built 4L60e. The gear spacing in a 6L80e is worse than a 4L80e for the 1-2 shift. The overdrive is no better. My best advise is to go drive a car or truck with a 6L80e in it. They are always shifting. It is very annoying IMO. The cost and headache involved in swapping a 6L80e into a 4th gen is not worth it what so ever.
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo
Launching!
Joined: Jan 2005
Posts: 272
Likes: 1
From: Northern NJ
Transmission gearing/gear ratios is only part of the equation. Everything has to be looked at as a whole system AND as individual components.
Plain and simple...more is better. It's why we went from 2 speed Gowerglides, to 3 and 4 speed automatics. It's why we progressed from 3 speed manuals to 4 speed manuals to 5 and 6? Last I checked, no one is building a project car and preferring to install a cherry Muncie 3 speed over a T56.
The 6L80 first gear is NOT useless. Ask the people who drive 'em. I don't think GM would bother making this their universal trans if the first gear was useless. Granted generous throttle will not doubt easily spin the tires behind my 330HP LH6, 3.42, on 20", but otherwise it makes for very nice acceleration in a 4500lb+ truck. Last I checked, most engines don't come into their torque curve until over 2k RPM.
Now if you're making 300+ lb/ft of torque at idle/launch, have 4.10+ rears, are brake rev'ing or locking up your torque converter, then nailing the accelerator EVERYtime you accelerate, then, yeah...you might have little use for a 4.xx first gear. But for the average DD car, you want as much torque multiplication in first gear as you can get to get your ride moving WITHOUT sacrificing between gear shifting momentum and top end speed/fuel economy.
From a more practical standpoint, the objective in having a low (numerically high) first gear is that you won't have to spend the extra money, effort and R&D messing around with more expensive gears (3.73, 4.10, etc) and high stall torque converters. I don't know about the rest of you, but if I can make one mod that gives me great acceleration and overdrive withOUT pulling my hair out on which converter to get and ripping apart my rear end (setting up rear gears AIN'T fun)...I'll take it! And instead of spending time and money on all the other components necessary to go fast, I can add bolt-ons.
Last but not least, neither of the 4 speed automatics have a 'hand-off' clutch design between shifts. The main reason you HAVE to build up a 4 speed trans is because the hand off between gears puts the motor into a momentary 'free rev' condition. In order words, between shifts, your motor is reving, but the car ain't accelerating...it's losing momentum and speed due to wind and tire resistance. To counter that momentary lag, you have to raise the pressures inside the trans to 'fast shift'...that hard bang-shift we have acclimated ourselves to associate with 'power'. When you do that with a stock trans, fragile parts go
In a 6L80/90 trans, between shift hand offs, clutches are still engaged, meaning your engine is still connected to the drivetrain and you're accelerating BETWEEN shifts. Then adding back in the previously stated "better/evenly" spaced gearing, and you can clearly see it's better than a manual or typical automatic! Those precious tenths, hundredths and thousandths of a second each shift make the trans untouchable. Doing more with less is the lesson here.
Plain and simple...more is better. It's why we went from 2 speed Gowerglides, to 3 and 4 speed automatics. It's why we progressed from 3 speed manuals to 4 speed manuals to 5 and 6? Last I checked, no one is building a project car and preferring to install a cherry Muncie 3 speed over a T56.
The 6L80 first gear is NOT useless. Ask the people who drive 'em. I don't think GM would bother making this their universal trans if the first gear was useless. Granted generous throttle will not doubt easily spin the tires behind my 330HP LH6, 3.42, on 20", but otherwise it makes for very nice acceleration in a 4500lb+ truck. Last I checked, most engines don't come into their torque curve until over 2k RPM.
Now if you're making 300+ lb/ft of torque at idle/launch, have 4.10+ rears, are brake rev'ing or locking up your torque converter, then nailing the accelerator EVERYtime you accelerate, then, yeah...you might have little use for a 4.xx first gear. But for the average DD car, you want as much torque multiplication in first gear as you can get to get your ride moving WITHOUT sacrificing between gear shifting momentum and top end speed/fuel economy.
From a more practical standpoint, the objective in having a low (numerically high) first gear is that you won't have to spend the extra money, effort and R&D messing around with more expensive gears (3.73, 4.10, etc) and high stall torque converters. I don't know about the rest of you, but if I can make one mod that gives me great acceleration and overdrive withOUT pulling my hair out on which converter to get and ripping apart my rear end (setting up rear gears AIN'T fun)...I'll take it! And instead of spending time and money on all the other components necessary to go fast, I can add bolt-ons.
Last but not least, neither of the 4 speed automatics have a 'hand-off' clutch design between shifts. The main reason you HAVE to build up a 4 speed trans is because the hand off between gears puts the motor into a momentary 'free rev' condition. In order words, between shifts, your motor is reving, but the car ain't accelerating...it's losing momentum and speed due to wind and tire resistance. To counter that momentary lag, you have to raise the pressures inside the trans to 'fast shift'...that hard bang-shift we have acclimated ourselves to associate with 'power'. When you do that with a stock trans, fragile parts go
In a 6L80/90 trans, between shift hand offs, clutches are still engaged, meaning your engine is still connected to the drivetrain and you're accelerating BETWEEN shifts. Then adding back in the previously stated "better/evenly" spaced gearing, and you can clearly see it's better than a manual or typical automatic! Those precious tenths, hundredths and thousandths of a second each shift make the trans untouchable. Doing more with less is the lesson here.
Transmission gearing/gear ratios is only part of the equation. Everything has to be looked at as a whole system AND as individual components.
Plain and simple...more is better. It's why we went from 2 speed Gowerglides, to 3 and 4 speed automatics. It's why we progressed from 3 speed manuals to 4 speed manuals to 5 and 6? Last I checked, no one is building a project car and preferring to install a cherry Muncie 3 speed over a T56.
The 6L80 first gear is NOT useless. Ask the people who drive 'em. I don't think GM would bother making this their universal trans if the first gear was useless. Granted generous throttle will not doubt easily spin the tires behind my 330HP LH6, 3.42, on 20", but otherwise it makes for very nice acceleration in a 4500lb+ truck. Last I checked, most engines don't come into their torque curve until over 2k RPM.
Now if you're making 300+ lb/ft of torque at idle/launch, have 4.10+ rears, are brake rev'ing or locking up your torque converter, then nailing the accelerator EVERYtime you accelerate, then, yeah...you might have little use for a 4.xx first gear. But for the average DD car, you want as much torque multiplication in first gear as you can get to get your ride moving WITHOUT sacrificing between gear shifting momentum and top end speed/fuel economy.
From a more practical standpoint, the objective in having a low (numerically high) first gear is that you won't have to spend the extra money, effort and R&D messing around with more expensive gears (3.73, 4.10, etc) and high stall torque converters. I don't know about the rest of you, but if I can make one mod that gives me great acceleration and overdrive withOUT pulling my hair out on which converter to get and ripping apart my rear end (setting up rear gears AIN'T fun)...I'll take it! And instead of spending time and money on all the other components necessary to go fast, I can add bolt-ons.
Last but not least, neither of the 4 speed automatics have a 'hand-off' clutch design between shifts. The main reason you HAVE to build up a 4 speed trans is because the hand off between gears puts the motor into a momentary 'free rev' condition. In order words, between shifts, your motor is reving, but the car ain't accelerating...it's losing momentum and speed due to wind and tire resistance. To counter that momentary lag, you have to raise the pressures inside the trans to 'fast shift'...that hard bang-shift we have acclimated ourselves to associate with 'power'. When you do that with a stock trans, fragile parts go
In a 6L80/90 trans, between shift hand offs, clutches are still engaged, meaning your engine is still connected to the drivetrain and you're accelerating BETWEEN shifts. Then adding back in the previously stated "better/evenly" spaced gearing, and you can clearly see it's better than a manual or typical automatic! Those precious tenths, hundredths and thousandths of a second each shift make the trans untouchable. Doing more with less is the lesson here.
Plain and simple...more is better. It's why we went from 2 speed Gowerglides, to 3 and 4 speed automatics. It's why we progressed from 3 speed manuals to 4 speed manuals to 5 and 6? Last I checked, no one is building a project car and preferring to install a cherry Muncie 3 speed over a T56.
The 6L80 first gear is NOT useless. Ask the people who drive 'em. I don't think GM would bother making this their universal trans if the first gear was useless. Granted generous throttle will not doubt easily spin the tires behind my 330HP LH6, 3.42, on 20", but otherwise it makes for very nice acceleration in a 4500lb+ truck. Last I checked, most engines don't come into their torque curve until over 2k RPM.
Now if you're making 300+ lb/ft of torque at idle/launch, have 4.10+ rears, are brake rev'ing or locking up your torque converter, then nailing the accelerator EVERYtime you accelerate, then, yeah...you might have little use for a 4.xx first gear. But for the average DD car, you want as much torque multiplication in first gear as you can get to get your ride moving WITHOUT sacrificing between gear shifting momentum and top end speed/fuel economy.
From a more practical standpoint, the objective in having a low (numerically high) first gear is that you won't have to spend the extra money, effort and R&D messing around with more expensive gears (3.73, 4.10, etc) and high stall torque converters. I don't know about the rest of you, but if I can make one mod that gives me great acceleration and overdrive withOUT pulling my hair out on which converter to get and ripping apart my rear end (setting up rear gears AIN'T fun)...I'll take it! And instead of spending time and money on all the other components necessary to go fast, I can add bolt-ons.
Last but not least, neither of the 4 speed automatics have a 'hand-off' clutch design between shifts. The main reason you HAVE to build up a 4 speed trans is because the hand off between gears puts the motor into a momentary 'free rev' condition. In order words, between shifts, your motor is reving, but the car ain't accelerating...it's losing momentum and speed due to wind and tire resistance. To counter that momentary lag, you have to raise the pressures inside the trans to 'fast shift'...that hard bang-shift we have acclimated ourselves to associate with 'power'. When you do that with a stock trans, fragile parts go
In a 6L80/90 trans, between shift hand offs, clutches are still engaged, meaning your engine is still connected to the drivetrain and you're accelerating BETWEEN shifts. Then adding back in the previously stated "better/evenly" spaced gearing, and you can clearly see it's better than a manual or typical automatic! Those precious tenths, hundredths and thousandths of a second each shift make the trans untouchable. Doing more with less is the lesson here.
actually the 4l80e does the handoff also. when it shifts from 1st to second the intermediate clutches come on and in third they stay on and the intermediate sprag overuns. you also have to look at cost ratio on doing a 6l80e which in stock form are not all that strong I see at least one broken 6l a day at the shop. to have it built to be able to handle abuse of racing and to get a trans first of all you are looking in the 4k range then to have it built another 1500 or so then the swapping and then the electronics and the converter you are well into the 6500 dollar range whereas with a simple 4l80 which aside from the 1st gear really isnt that much different in final drives than a 6l will go right in and handle whatever power you will decently make on the street and with just a simple reflash. and for less than 3k
11 Second Club
Joined: Feb 2008
Posts: 317
Likes: 2
From: TN
Got a question.
Remind me again of how great everyone thought the 4L60/65 and the 4l80 were when they first came out.
How many years has it taken to get those transmission capable of handling the power they can today? Hell, isn't the after market still coming up with changes to trying an push the 4L6's to a reliable 650 HP capability?
Didn't this kind of non constructive discussions occur when going from Non Electronic controlled transmission to Electronic control ones?
How many 4L60/65E professional built transmission are still failing when put behind engines with less HP & TQ than claimed rating?
Aren't the 6L's just going through the same pains as the 4L's?
Just as back then there are those that are willing to pay the price to grow the knowledge it takes to make a 6L more bullet proof. If some of us don't do it just as before, why would it be worth the investment in time and money required by aftermarket to make them capable of handling more than their stock designed capability.
Yes I believe people need to know there are problems with 6L's ability to handle abuse and that they present problems when you try to install them in older cars due to the way they are designed. People do need to realize it may cost them more than expected when it comes to maintenance if they plan on abusing them so they can make the right decision for their circumstance. Course some of that's true for 4L6's if you abuse them.
I hate to say this, but either I fell off the Turnip Truck coming in from the north forty, are some body needs to rethink what the difference in cost is when it comes to installing a 4L6 or 4L8 in a car and a 6L80/90. I either ripped myself off or its damn near the same.
I'm doing a 6L80 (6 speed auto novelty of) build as well a 4L Based (novelty of) build on same style cars. I've got about the same material/equipment cost and most of the same install problems with both.
Install wise one needed top of tunnel raised because of it's design (6L80) and the other needed the tunnel widen so I could plug in the main wire harness plug on one side an on the other side, so I could run cooling lines because of it's design. For the life of me I just can't understand why GM didn't think about us Hot Rodders when they built these older cars and made the trans tunnels taller and wider.
Both needed cross member work to fit them too. I got the idea how to do that from all the aftermarket ones made to transplant A4 in other cars not designed to fit them...
Kevin, this ones for you.
Why would you want to take a 4L80E, Give it 5 non overdrive gears that almost gear it the same as a 6 speed T56 manual trans, except for a 1:1 5th gear and only 1 OD gear thats 0.75 instead of 0.67, or at least a 0.70?
I'm sure from post people have made on this site and others, People realize that they are going to be screaming down the road at 150 RPM higher than if 6th gear was 0.70 if they swap to a 4l80E or 4L80E based 6 speed.
Thats way to many RPM to accept for a stronger transmission.
Never mind they probably need the extra mechanical advantage of it to help the engine overcome the 4 X 8 Sheet of Plywood in a Hurricane aerodynamic of the older cars they want to install it in.
Litte more gear comparsion to get people thinking. A 1.15 or 1.18 4th gear ratio may be of help when trying to decide on what rear end ratio you can get away with vs if you have a 1:1 4th, both at strip and on the street.
If you don't have a 1:1 final drive trans gear, then you might want to watch what your top speed will be at max RPM with some gear ratios are stay away form longer runs of more than 1/4 mile are you may find you are going to be in O.D. sooner than you thought and the car passing you is still in a 1:1 gear.
6L80E
1st gear 4.03, MPH @ 6500 RPM = 41.1
2nd gear 2.36, MPH @ 6500 RPM = 70.19
3rd gear 1.53, MPH @ 6500 RPM = 108.27
4th gear 1.15, MPH @ 6500 RPM = 144.04
4L80E Based 6 Speed/TCI 6X
1st gear 2.97, MPH @ 6500 RPM = 55.77
2nd gear 2.23, MPH @ 6500 RPM = 74.28
3rd gear 1.57, MPH @ 6500 RPM = 105.51
4th gear 1.18, MPH @ 6500 RPM = 140.38
5th gear 1.00, MPH @ 6500 RPM = 165.65
4L65E
1st gear 3.06, MPH @ 6500 RPM = 54.13
2nd gear 1.62, MPH @ 6500 RPM = 102.25
3rd gear 1.00, MPH @ 6500 RPM = 165.65
4L80E
1st gear 2.48, MPH @ 6500 RPM = 66.79
2nd gear 1.48, MPH @ 6500 RPM = 111.92
3rd gear 1.00, MPH @ 6500 RPM = 165.65
4L80E Based 6 Speed/TCI 6X Same 28.0" dia Tire rear gear of 3.70
1st gear 2.97, MPH @ 6500 RPM = 49.29
2nd gear 2.23, MPH @ 6500 RPM = 65.65
3rd gear 1.57, MPH @ 6500 RPM = 93.25
4th gear 1.18, MPH @ 6500 RPM = 124.06
5th gear 1.00, MPH @ 6500 RPM = 146.40
T56 - C6 & Z06 Manual Trans Gearing
1st gear 2.66, MPH @ 6500 RPM = 62.27
2nd gear 1.78, MPH @ 6500 RPM = 93.06
3rd gear 1.30, MPH @ 6500 RPM = 127.42
4th gear 1.00, MPH @ 6500 RPM = 165.65
Remind me again of how great everyone thought the 4L60/65 and the 4l80 were when they first came out.
How many years has it taken to get those transmission capable of handling the power they can today? Hell, isn't the after market still coming up with changes to trying an push the 4L6's to a reliable 650 HP capability?
Didn't this kind of non constructive discussions occur when going from Non Electronic controlled transmission to Electronic control ones?
How many 4L60/65E professional built transmission are still failing when put behind engines with less HP & TQ than claimed rating?
Aren't the 6L's just going through the same pains as the 4L's?
Just as back then there are those that are willing to pay the price to grow the knowledge it takes to make a 6L more bullet proof. If some of us don't do it just as before, why would it be worth the investment in time and money required by aftermarket to make them capable of handling more than their stock designed capability.
Yes I believe people need to know there are problems with 6L's ability to handle abuse and that they present problems when you try to install them in older cars due to the way they are designed. People do need to realize it may cost them more than expected when it comes to maintenance if they plan on abusing them so they can make the right decision for their circumstance. Course some of that's true for 4L6's if you abuse them.
I hate to say this, but either I fell off the Turnip Truck coming in from the north forty, are some body needs to rethink what the difference in cost is when it comes to installing a 4L6 or 4L8 in a car and a 6L80/90. I either ripped myself off or its damn near the same.
I'm doing a 6L80 (6 speed auto novelty of) build as well a 4L Based (novelty of) build on same style cars. I've got about the same material/equipment cost and most of the same install problems with both.
Install wise one needed top of tunnel raised because of it's design (6L80) and the other needed the tunnel widen so I could plug in the main wire harness plug on one side an on the other side, so I could run cooling lines because of it's design. For the life of me I just can't understand why GM didn't think about us Hot Rodders when they built these older cars and made the trans tunnels taller and wider.
Both needed cross member work to fit them too. I got the idea how to do that from all the aftermarket ones made to transplant A4 in other cars not designed to fit them...
Kevin, this ones for you.
Why would you want to take a 4L80E, Give it 5 non overdrive gears that almost gear it the same as a 6 speed T56 manual trans, except for a 1:1 5th gear and only 1 OD gear thats 0.75 instead of 0.67, or at least a 0.70?
I'm sure from post people have made on this site and others, People realize that they are going to be screaming down the road at 150 RPM higher than if 6th gear was 0.70 if they swap to a 4l80E or 4L80E based 6 speed.
Thats way to many RPM to accept for a stronger transmission.
Never mind they probably need the extra mechanical advantage of it to help the engine overcome the 4 X 8 Sheet of Plywood in a Hurricane aerodynamic of the older cars they want to install it in.Litte more gear comparsion to get people thinking. A 1.15 or 1.18 4th gear ratio may be of help when trying to decide on what rear end ratio you can get away with vs if you have a 1:1 4th, both at strip and on the street.
If you don't have a 1:1 final drive trans gear, then you might want to watch what your top speed will be at max RPM with some gear ratios are stay away form longer runs of more than 1/4 mile are you may find you are going to be in O.D. sooner than you thought and the car passing you is still in a 1:1 gear.
6L80E
1st gear 4.03, MPH @ 6500 RPM = 41.1
2nd gear 2.36, MPH @ 6500 RPM = 70.19
3rd gear 1.53, MPH @ 6500 RPM = 108.27
4th gear 1.15, MPH @ 6500 RPM = 144.04
4L80E Based 6 Speed/TCI 6X
1st gear 2.97, MPH @ 6500 RPM = 55.77
2nd gear 2.23, MPH @ 6500 RPM = 74.28
3rd gear 1.57, MPH @ 6500 RPM = 105.51
4th gear 1.18, MPH @ 6500 RPM = 140.38
5th gear 1.00, MPH @ 6500 RPM = 165.65
4L65E
1st gear 3.06, MPH @ 6500 RPM = 54.13
2nd gear 1.62, MPH @ 6500 RPM = 102.25
3rd gear 1.00, MPH @ 6500 RPM = 165.65
4L80E
1st gear 2.48, MPH @ 6500 RPM = 66.79
2nd gear 1.48, MPH @ 6500 RPM = 111.92
3rd gear 1.00, MPH @ 6500 RPM = 165.65
4L80E Based 6 Speed/TCI 6X Same 28.0" dia Tire rear gear of 3.70
1st gear 2.97, MPH @ 6500 RPM = 49.29
2nd gear 2.23, MPH @ 6500 RPM = 65.65
3rd gear 1.57, MPH @ 6500 RPM = 93.25
4th gear 1.18, MPH @ 6500 RPM = 124.06
5th gear 1.00, MPH @ 6500 RPM = 146.40
T56 - C6 & Z06 Manual Trans Gearing
1st gear 2.66, MPH @ 6500 RPM = 62.27
2nd gear 1.78, MPH @ 6500 RPM = 93.06
3rd gear 1.30, MPH @ 6500 RPM = 127.42
4th gear 1.00, MPH @ 6500 RPM = 165.65
Launching!
Joined: Jan 2005
Posts: 272
Likes: 1
From: Northern NJ
actually the 4l80e does the handoff also. when it shifts from 1st to second the intermediate clutches come on and in third they stay on and the intermediate sprag overuns. you also have to look at cost ratio on doing a 6l80e which in stock form are not all that strong I see at least one broken 6l a day at the shop. to have it built to be able to handle abuse of racing and to get a trans first of all you are looking in the 4k range then to have it built another 1500 or so then the swapping and then the electronics and the converter you are well into the 6500 dollar range whereas with a simple 4l80 which aside from the 1st gear really isnt that much different in final drives than a 6l will go right in and handle whatever power you will decently make on the street and with just a simple reflash. and for less than 3k
Launching!
Joined: Jan 2005
Posts: 272
Likes: 1
From: Northern NJ
Stock for stock...yes...lighter too at 240 lbs vs. 295 lbs
4L80 Specs:
440 lb-ft (597 Nm) (MT1) Maximum Engine Torque
885 lb-ft (1200 Nm) Maximum Transmission Torque (output)
4L85 Specs:
460 lb-ft (624 Nm) (MN8) Maximum Engine Torque
885 lb-ft (1200 Nm) Maximum Transmission Torque (output)
6L90 Specs:
520-550 lb-ft (720-746 Nm) Maximum Engine Torque
885 lb-ft (1200 Nm) Maximum Transmission Torque (output)
From what I've gathered, "essentially" what you're doing with a clutch upgrade on a 6L80 is adding the 6L90 clutches. Still not the same as a 6L90, as a built 4L70 will not be the same as a 4L80.
4L80 Specs:
440 lb-ft (597 Nm) (MT1) Maximum Engine Torque
885 lb-ft (1200 Nm) Maximum Transmission Torque (output)
4L85 Specs:
460 lb-ft (624 Nm) (MN8) Maximum Engine Torque
885 lb-ft (1200 Nm) Maximum Transmission Torque (output)
6L90 Specs:
520-550 lb-ft (720-746 Nm) Maximum Engine Torque
885 lb-ft (1200 Nm) Maximum Transmission Torque (output)
From what I've gathered, "essentially" what you're doing with a clutch upgrade on a 6L80 is adding the 6L90 clutches. Still not the same as a 6L90, as a built 4L70 will not be the same as a 4L80.
I would say if you have that much money to spend for a daily driver do the 6l80e I am not saying that they are not a good trans or a good mod but its not for every car and for mosty high HP cars 800-900 hp its going to be too much gear in 1st why do you think alot of the high hp guys try to get into the glides and the th400s....for instance good freind of mine out in orlando has a mustang with a 488cid SBC and a **** ton of gas he used to run the th400 but everytime he launched it would high noon the front end of the car. he went to a powerglide and the car will aunch now and went from the 8s into the 7s wit ha transmission change and a higher geared trans at that. this is the point i matrying to make while the 6l might be good for some its not the next big thing for all cars. most likely with 800hp and a 6l you are going to mop the track up or look at the sky everytime you launch. also the trans hasnt been proven IMO and do you really wanna break a 5k^ setup to only say damn i should have got a 4l80e which is proven? honestly if i had your car with 800 hp it would have a th400 in it anyways myself or a glide if it was light enough. With the tires you will need to keep traction most likley 28s or 29s and the right gear the 400 would be that bad 
11 Second Club
Joined: Feb 2008
Posts: 317
Likes: 2
From: TN
What do you call fit? Anything can be fitted, so it depends on what your willing to do to "make it fit".
Bolt in with no body modifications to tunnel and trans cross member. Work with your existing ECM and stock wire harness?
Don't think so. But a quick test to see if it will fit with out having to modify the tunnel, is to see if your hand will fit between the top of your transmission and top of tunnel from front of bell housing to back of top of your trans.
If it does then take a 2 1/2 inch tall block of wood and see if you can do the same with it.
If you can do that, you may have a chance of not having to cut your tunnel so it will fit. I say may, because the 6L does not taper down at rear like A4 does. It stays tall to about 2.0 inches for it's end.
Next problem will be room for the Yoke to fit. They are larger than your stock A4.
If you think I'm jerking you around, then maybe just maybe you have not seen a 6L transmission.
I have not see a conversion done with a 4th gen car on this site. I would check all the Camaro Forums and see if someone has done it on one of them.
If I were you, I would do a search in Conversions & Hybrid section here on 6L80 or 90E. Read and I mean read everyone of them, and then make up your mind if you want to take conversion on.
Here are a few educational pictures on 6L's. I borrowed them form mmebers 6L90E in install in a 1st gen thread in Conversion & Hybrid section. Pan sits lower on my car than engines oil pan.
Think how much ground clearance you would have if you used a deep pan on your A4. It will be close to the depth of 6l's truck pan. G8 pontiac pans will give you 1/2"-3/4" more clearance.
Cutting tunnel as we lower body down on chassis of my 66. You can see it hit at back first.
Bolt in with no body modifications to tunnel and trans cross member. Work with your existing ECM and stock wire harness?
Don't think so. But a quick test to see if it will fit with out having to modify the tunnel, is to see if your hand will fit between the top of your transmission and top of tunnel from front of bell housing to back of top of your trans.
If it does then take a 2 1/2 inch tall block of wood and see if you can do the same with it.
If you can do that, you may have a chance of not having to cut your tunnel so it will fit. I say may, because the 6L does not taper down at rear like A4 does. It stays tall to about 2.0 inches for it's end.
Next problem will be room for the Yoke to fit. They are larger than your stock A4.
If you think I'm jerking you around, then maybe just maybe you have not seen a 6L transmission.
B. Has it been done
If I were you, I would do a search in Conversions & Hybrid section here on 6L80 or 90E. Read and I mean read everyone of them, and then make up your mind if you want to take conversion on.
Here are a few educational pictures on 6L's. I borrowed them form mmebers 6L90E in install in a 1st gen thread in Conversion & Hybrid section. Pan sits lower on my car than engines oil pan.
Think how much ground clearance you would have if you used a deep pan on your A4. It will be close to the depth of 6l's truck pan. G8 pontiac pans will give you 1/2"-3/4" more clearance.
Cutting tunnel as we lower body down on chassis of my 66. You can see it hit at back first.
Launching!
Joined: Jan 2005
Posts: 272
Likes: 1
From: Northern NJ
A 6L80/90 was not conceived to be a high HP, drag racing transmission. It was designed to be an all around transmission that allows smaller-power engines to run high hp performance numbers. So if someone has the funds and plan to build an 800hp car, it's already apparently he is doing so A) for bragging rights and/or B) to drag race. More significant, it's clear that money is no object to him, so whatever transmission option he chooses, he can afford to 'make it work'.
Now for the rest of us who live in budget and are presumably starting with budget friendly, OEM parts filled, stock HP engines between 250-400HP, granny/economy final drive ratio, then there is NO other transmission option that will get you increased acceleration from a single component swap ALONE. 4L80's may be strong, but only after you build it up. And in a stock powered car you're all but guaranteed to lose ET's. So
So again, when starting from scratch, NO single drivetrain component or mod will give you this level of consistent acceleration gains, without additional component wear and tear, while maintaining daily driveability. NONE. It's the ultimate bang for the buck.
Re:fitment in a 4th Gen. I don't believe anyone has done it. It would be a tight fit, no doubt, and then you'd be forced to do the torque arm relocation kit. The upside is it would really wake up those 3.23 geared vehicles and push a little weight to the back for better distribution.
Now for the rest of us who live in budget and are presumably starting with budget friendly, OEM parts filled, stock HP engines between 250-400HP, granny/economy final drive ratio, then there is NO other transmission option that will get you increased acceleration from a single component swap ALONE. 4L80's may be strong, but only after you build it up. And in a stock powered car you're all but guaranteed to lose ET's. So
So again, when starting from scratch, NO single drivetrain component or mod will give you this level of consistent acceleration gains, without additional component wear and tear, while maintaining daily driveability. NONE. It's the ultimate bang for the buck.
Re:fitment in a 4th Gen. I don't believe anyone has done it. It would be a tight fit, no doubt, and then you'd be forced to do the torque arm relocation kit. The upside is it would really wake up those 3.23 geared vehicles and push a little weight to the back for better distribution.