4T80e Update (broken)
4T80e Update (broken) Alright guys....I am taking a few minutes to share some information with you and let you know where my car stands. This is a long winded post and I am going to jump around a little bit so bare with me....
So as you probably already know, I am running a 2005 Monte Carlo SS with a LS4 conversion and 4T80e swap. I am using a blue/green PCM to control the motor and transaxle (not the typical T42 you would find in the OEM LS4 applications).
I have had the car together and running for about a month now while we slowly sort out the issues and creep up on the power. Obviously....the big thing most of you have been interested in is the 4T80e.
The transmission:
There has been a little confusion in regards to the actual transmission in my car. Originally we were going to run a fresh stock rebuild which I believe was referenced early in my build thread, but instead we ended up running the unit as-is from an Oldsmobile Aurora. The transaxle had 100k miles and was using the OEM Aurora converter. The history or operational condition of the transaxle was unknown when installed. This was a 3.71 FDR model. The plan here was to creep up on the power, sort out the tune and find the weak link.
The Tuning Process:
The transmission I am running is a 2002-2003 model with the PWM TCC. The biggest issue off the bat was that no 4T80e tune is available prior to the 2007 model year transitions which were controlled by T42 TCM. I was using an older traditional LS1 style PCM and had no base to start with for a Force current motor, line pressure or shift times. All I had was a "4L80e" segment which would at the minimum allow me to control the solenoids correctly.
To simplify tuning for the time being, we disabled the TCC lock-up all together. This eliminated one variable as we sorted through the initial drivability and WOT tuning.
I scaled a Force Current Motor table from a 2008 table to the best of my ability and entered the values into my PCM, however I am not confident in those values. One major issue I had with the transaxle is that I could never get it to shift into OD even if I manually commanded it to do so with the VCM controls. This leads me to believe there was an existing mechanical failure inside of the trans (kinda unlikely), or I had the incorrect force numbers not allowing me to grab the gear. Either way....I wasn't too concerned for the time being as I was concentrating on maximum power and track times....so OD was not on the top of the priority list anyways.
For shift times, I started with basic scaling from my original 3800/ 4t65 tune which put me in an excellent position for the drivability. It was very much like stock around town. Line pressure was increased under higher torque loads and shift times were reduced. With this basic information loaded up we were ready to make some shake down passes at the track.
On the track rental day, I made a total of 7 passes on slicks. 4 passes were half-track, 3 passes were full track....all accompanied by a healthy burnout. The car had a lazy 1-2 shift which progressively got worst as the transmission warmed up...and the 2-3 was nothing worth writing home about either...however the transmission did complete the shifts under full boost. Again....ruling out the possibility of preexisting internal failure, I can only assume that my Force Motor table simply wasnt completely ironed out. Regardless, at a race weight of 3710 the car managed to trap 133mph which means it was in the vicinity of 650-700whp on those passes. All of those passes were made on 17-19psi on low timing and running out of fuel.
After the track outing, I continued to sort out the tune on the street (concentrating on the engine side of things). I added an additional fuel pump during this time period to keep up with the added boost, and I also turned the turbo up to 22psi. The car now had significantly more power than the original track outing, and along with the power some of the transmission issues started to magnify. It became very difficult to complete shifts without lifting in between, and the converter was getting drivien right through. The transmission slowly started sounding more and more like a CVT trans as it came up on boost (would peg 6200-6800 and hold it there regardless of gear). Heat became a major issue and I knew that the trans was coming apart, but I tried several other things to keep it together as we progressed and continued to tune the car.
Last night was the beginning of the end. After beating the car pretty hard for a few hours, as I was working on the two-step the passenger side axle finally decided to let go not far from the hit (this was on the slicks with a little Dr. Pepper)....
I got the car back together with a new axle today, and continued my assault at lunch. After a healthy 3rd gear pull, the transmission finally had enough. Reverse had failed and was now a semi-forward gear, neutral was loaded, and drive was locked either in between gears or locked in a high gear (3rd?). Either way, the case let go and spilled some transmission on the ground.
Obviously, for a stock unit this transmission took one hell of a beating. Anybody who knows me knows that I push my cars really hard, and this project was no exception. Almost every time we went out, we were leaning on this thing a little harder. More boost, more timing, more two-step etc. My best guess is that the car is making north of 750-800hp on the current setup.
For the time being, I am slapping another Aurora trans in from a 2002. I am going to manually use a line pressure gauge and attempt to rebuild the force motor table and see if I cant get some better results. The goal here is to just finish off the season and thoroughly bury this car into the 10s. In the mean time, my transmission guy is going to tear this unit apart and start making a check-list of where we can improve. Between all my data logs, and the mechanical evidence, I am confident we can make this a viable option for the community with some time.
Either way....hope you enjoy the update.
Going to get this thing apart and back together so we can make it to the track this weekend.
So as you probably already know, I am running a 2005 Monte Carlo SS with a LS4 conversion and 4T80e swap. I am using a blue/green PCM to control the motor and transaxle (not the typical T42 you would find in the OEM LS4 applications).
I have had the car together and running for about a month now while we slowly sort out the issues and creep up on the power. Obviously....the big thing most of you have been interested in is the 4T80e.
The transmission:
There has been a little confusion in regards to the actual transmission in my car. Originally we were going to run a fresh stock rebuild which I believe was referenced early in my build thread, but instead we ended up running the unit as-is from an Oldsmobile Aurora. The transaxle had 100k miles and was using the OEM Aurora converter. The history or operational condition of the transaxle was unknown when installed. This was a 3.71 FDR model. The plan here was to creep up on the power, sort out the tune and find the weak link.
The Tuning Process:
The transmission I am running is a 2002-2003 model with the PWM TCC. The biggest issue off the bat was that no 4T80e tune is available prior to the 2007 model year transitions which were controlled by T42 TCM. I was using an older traditional LS1 style PCM and had no base to start with for a Force current motor, line pressure or shift times. All I had was a "4L80e" segment which would at the minimum allow me to control the solenoids correctly.
To simplify tuning for the time being, we disabled the TCC lock-up all together. This eliminated one variable as we sorted through the initial drivability and WOT tuning.
I scaled a Force Current Motor table from a 2008 table to the best of my ability and entered the values into my PCM, however I am not confident in those values. One major issue I had with the transaxle is that I could never get it to shift into OD even if I manually commanded it to do so with the VCM controls. This leads me to believe there was an existing mechanical failure inside of the trans (kinda unlikely), or I had the incorrect force numbers not allowing me to grab the gear. Either way....I wasn't too concerned for the time being as I was concentrating on maximum power and track times....so OD was not on the top of the priority list anyways.
For shift times, I started with basic scaling from my original 3800/ 4t65 tune which put me in an excellent position for the drivability. It was very much like stock around town. Line pressure was increased under higher torque loads and shift times were reduced. With this basic information loaded up we were ready to make some shake down passes at the track.
On the track rental day, I made a total of 7 passes on slicks. 4 passes were half-track, 3 passes were full track....all accompanied by a healthy burnout. The car had a lazy 1-2 shift which progressively got worst as the transmission warmed up...and the 2-3 was nothing worth writing home about either...however the transmission did complete the shifts under full boost. Again....ruling out the possibility of preexisting internal failure, I can only assume that my Force Motor table simply wasnt completely ironed out. Regardless, at a race weight of 3710 the car managed to trap 133mph which means it was in the vicinity of 650-700whp on those passes. All of those passes were made on 17-19psi on low timing and running out of fuel.
After the track outing, I continued to sort out the tune on the street (concentrating on the engine side of things). I added an additional fuel pump during this time period to keep up with the added boost, and I also turned the turbo up to 22psi. The car now had significantly more power than the original track outing, and along with the power some of the transmission issues started to magnify. It became very difficult to complete shifts without lifting in between, and the converter was getting drivien right through. The transmission slowly started sounding more and more like a CVT trans as it came up on boost (would peg 6200-6800 and hold it there regardless of gear). Heat became a major issue and I knew that the trans was coming apart, but I tried several other things to keep it together as we progressed and continued to tune the car.
Last night was the beginning of the end. After beating the car pretty hard for a few hours, as I was working on the two-step the passenger side axle finally decided to let go not far from the hit (this was on the slicks with a little Dr. Pepper)....
I got the car back together with a new axle today, and continued my assault at lunch. After a healthy 3rd gear pull, the transmission finally had enough. Reverse had failed and was now a semi-forward gear, neutral was loaded, and drive was locked either in between gears or locked in a high gear (3rd?). Either way, the case let go and spilled some transmission on the ground.
Obviously, for a stock unit this transmission took one hell of a beating. Anybody who knows me knows that I push my cars really hard, and this project was no exception. Almost every time we went out, we were leaning on this thing a little harder. More boost, more timing, more two-step etc. My best guess is that the car is making north of 750-800hp on the current setup.
For the time being, I am slapping another Aurora trans in from a 2002. I am going to manually use a line pressure gauge and attempt to rebuild the force motor table and see if I cant get some better results. The goal here is to just finish off the season and thoroughly bury this car into the 10s. In the mean time, my transmission guy is going to tear this unit apart and start making a check-list of where we can improve. Between all my data logs, and the mechanical evidence, I am confident we can make this a viable option for the community with some time.
Either way....hope you enjoy the update.
Going to get this thing apart and back together so we can make it to the track this weekend.
under normal circumstances i would just say that, this is kinda what i expected from a stock 4t80, but these arent normal circumstances lol and frankly im amazed it didnt snap the output shaft and broke the case instead LOL
Alright guys....I am taking a few minutes to share some information with you and let you know where my car stands. This is a long winded post and I am going to jump around a little bit so bare with me....
So as you probably already know, I am running a 2005 Monte Carlo SS with a LS4 conversion and 4T80e swap. I am using a blue/green PCM to control the motor and transaxle (not the typical T42 you would find in the OEM LS4 applications).
I have had the car together and running for about a month now while we slowly sort out the issues and creep up on the power. Obviously....the big thing most of you have been interested in is the 4T80e.
The transmission:
There has been a little confusion in regards to the actual transmission in my car. Originally we were going to run a fresh stock rebuild which I believe was referenced early in my build thread, but instead we ended up running the unit as-is from an Oldsmobile Aurora. The transaxle had 100k miles and was using the OEM Aurora converter. The history or operational condition of the transaxle was unknown when installed. This was a 3.71 FDR model. The plan here was to creep up on the power, sort out the tune and find the weak link.
The Tuning Process:
The transmission I am running is a 2002-2003 model with the PWM TCC. The biggest issue off the bat was that no 4T80e tune is available prior to the 2007 model year transitions which were controlled by T42 TCM. I was using an older traditional LS1 style PCM and had no base to start with for a Force current motor, line pressure or shift times. All I had was a "4L80e" segment which would at the minimum allow me to control the solenoids correctly.
To simplify tuning for the time being, we disabled the TCC lock-up all together. This eliminated one variable as we sorted through the initial drivability and WOT tuning.
I scaled a Force Current Motor table from a 2008 table to the best of my ability and entered the values into my PCM, however I am not confident in those values. One major issue I had with the transaxle is that I could never get it to shift into OD even if I manually commanded it to do so with the VCM controls. This leads me to believe there was an existing mechanical failure inside of the trans (kinda unlikely), or I had the incorrect force numbers not allowing me to grab the gear. Either way....I wasn't too concerned for the time being as I was concentrating on maximum power and track times....so OD was not on the top of the priority list anyways.
For shift times, I started with basic scaling from my original 3800/ 4t65 tune which put me in an excellent position for the drivability. It was very much like stock around town. Line pressure was increased under higher torque loads and shift times were reduced. With this basic information loaded up we were ready to make some shake down passes at the track.
On the track rental day, I made a total of 7 passes on slicks. 4 passes were half-track, 3 passes were full track....all accompanied by a healthy burnout. The car had a lazy 1-2 shift which progressively got worst as the transmission warmed up...and the 2-3 was nothing worth writing home about either...however the transmission did complete the shifts under full boost. Again....ruling out the possibility of preexisting internal failure, I can only assume that my Force Motor table simply wasnt completely ironed out. Regardless, at a race weight of 3710 the car managed to trap 133mph which means it was in the vicinity of 650-700whp on those passes. All of those passes were made on 17-19psi on low timing and running out of fuel.
After the track outing, I continued to sort out the tune on the street (concentrating on the engine side of things). I added an additional fuel pump during this time period to keep up with the added boost, and I also turned the turbo up to 22psi. The car now had significantly more power than the original track outing, and along with the power some of the transmission issues started to magnify. It became very difficult to complete shifts without lifting in between, and the converter was getting drivien right through. The transmission slowly started sounding more and more like a CVT trans as it came up on boost (would peg 6200-6800 and hold it there regardless of gear). Heat became a major issue and I knew that the trans was coming apart, but I tried several other things to keep it together as we progressed and continued to tune the car.
Last night was the beginning of the end. After beating the car pretty hard for a few hours, as I was working on the two-step the passenger side axle finally decided to let go not far from the hit (this was on the slicks with a little Dr. Pepper)....
Turbo LS4 Swap Monte Carlo Breaks a Axle - YouTube
I got the car back together with a new axle today, and continued my assault at lunch. After a healthy 3rd gear pull, the transmission finally had enough. Reverse had failed and was now a semi-forward gear, neutral was loaded, and drive was locked either in between gears or locked in a high gear (3rd?). Either way, the case let go and spilled some transmission on the ground.
Obviously, for a stock unit this transmission took one hell of a beating. Anybody who knows me knows that I push my cars really hard, and this project was no exception. Almost every time we went out, we were leaning on this thing a little harder. More boost, more timing, more two-step etc. My best guess is that the car is making north of 750-800hp on the current setup.
For the time being, I am slapping another Aurora trans in from a 2002. I am going to manually use a line pressure gauge and attempt to rebuild the force motor table and see if I cant get some better results. The goal here is to just finish off the season and thoroughly bury this car into the 10s. In the mean time, my transmission guy is going to tear this unit apart and start making a check-list of where we can improve. Between all my data logs, and the mechanical evidence, I am confident we can make this a viable option for the community with some time.
Either way....hope you enjoy the update.
Going to get this thing apart and back together so we can make it to the track this weekend.
So as you probably already know, I am running a 2005 Monte Carlo SS with a LS4 conversion and 4T80e swap. I am using a blue/green PCM to control the motor and transaxle (not the typical T42 you would find in the OEM LS4 applications).
I have had the car together and running for about a month now while we slowly sort out the issues and creep up on the power. Obviously....the big thing most of you have been interested in is the 4T80e.
The transmission:
There has been a little confusion in regards to the actual transmission in my car. Originally we were going to run a fresh stock rebuild which I believe was referenced early in my build thread, but instead we ended up running the unit as-is from an Oldsmobile Aurora. The transaxle had 100k miles and was using the OEM Aurora converter. The history or operational condition of the transaxle was unknown when installed. This was a 3.71 FDR model. The plan here was to creep up on the power, sort out the tune and find the weak link.
The Tuning Process:
The transmission I am running is a 2002-2003 model with the PWM TCC. The biggest issue off the bat was that no 4T80e tune is available prior to the 2007 model year transitions which were controlled by T42 TCM. I was using an older traditional LS1 style PCM and had no base to start with for a Force current motor, line pressure or shift times. All I had was a "4L80e" segment which would at the minimum allow me to control the solenoids correctly.
To simplify tuning for the time being, we disabled the TCC lock-up all together. This eliminated one variable as we sorted through the initial drivability and WOT tuning.
I scaled a Force Current Motor table from a 2008 table to the best of my ability and entered the values into my PCM, however I am not confident in those values. One major issue I had with the transaxle is that I could never get it to shift into OD even if I manually commanded it to do so with the VCM controls. This leads me to believe there was an existing mechanical failure inside of the trans (kinda unlikely), or I had the incorrect force numbers not allowing me to grab the gear. Either way....I wasn't too concerned for the time being as I was concentrating on maximum power and track times....so OD was not on the top of the priority list anyways.
For shift times, I started with basic scaling from my original 3800/ 4t65 tune which put me in an excellent position for the drivability. It was very much like stock around town. Line pressure was increased under higher torque loads and shift times were reduced. With this basic information loaded up we were ready to make some shake down passes at the track.
On the track rental day, I made a total of 7 passes on slicks. 4 passes were half-track, 3 passes were full track....all accompanied by a healthy burnout. The car had a lazy 1-2 shift which progressively got worst as the transmission warmed up...and the 2-3 was nothing worth writing home about either...however the transmission did complete the shifts under full boost. Again....ruling out the possibility of preexisting internal failure, I can only assume that my Force Motor table simply wasnt completely ironed out. Regardless, at a race weight of 3710 the car managed to trap 133mph which means it was in the vicinity of 650-700whp on those passes. All of those passes were made on 17-19psi on low timing and running out of fuel.
After the track outing, I continued to sort out the tune on the street (concentrating on the engine side of things). I added an additional fuel pump during this time period to keep up with the added boost, and I also turned the turbo up to 22psi. The car now had significantly more power than the original track outing, and along with the power some of the transmission issues started to magnify. It became very difficult to complete shifts without lifting in between, and the converter was getting drivien right through. The transmission slowly started sounding more and more like a CVT trans as it came up on boost (would peg 6200-6800 and hold it there regardless of gear). Heat became a major issue and I knew that the trans was coming apart, but I tried several other things to keep it together as we progressed and continued to tune the car.
Last night was the beginning of the end. After beating the car pretty hard for a few hours, as I was working on the two-step the passenger side axle finally decided to let go not far from the hit (this was on the slicks with a little Dr. Pepper)....
Turbo LS4 Swap Monte Carlo Breaks a Axle - YouTube
I got the car back together with a new axle today, and continued my assault at lunch. After a healthy 3rd gear pull, the transmission finally had enough. Reverse had failed and was now a semi-forward gear, neutral was loaded, and drive was locked either in between gears or locked in a high gear (3rd?). Either way, the case let go and spilled some transmission on the ground.
Obviously, for a stock unit this transmission took one hell of a beating. Anybody who knows me knows that I push my cars really hard, and this project was no exception. Almost every time we went out, we were leaning on this thing a little harder. More boost, more timing, more two-step etc. My best guess is that the car is making north of 750-800hp on the current setup.
For the time being, I am slapping another Aurora trans in from a 2002. I am going to manually use a line pressure gauge and attempt to rebuild the force motor table and see if I cant get some better results. The goal here is to just finish off the season and thoroughly bury this car into the 10s. In the mean time, my transmission guy is going to tear this unit apart and start making a check-list of where we can improve. Between all my data logs, and the mechanical evidence, I am confident we can make this a viable option for the community with some time.
Either way....hope you enjoy the update.
Going to get this thing apart and back together so we can make it to the track this weekend.
.Good luck on the next track visit, and keep us posted of the progress. Trending Topics
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine
Verdad Gallardo
7 Most Reliable High-Performance Engines GM Has Ever Built
Verdad Gallardo
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin
Verdad Gallardo
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
