Torque Converter unlocking and locking
Thread Starter
Teching In
Joined: Apr 2013
Posts: 29
Likes: 0
From: West of Chicago
Torque Converter unlocking and locking Looking for a little assistance if possible.
I have a 73 Camaro with a 2005 GTO drivetrain, I'm using a Fitech controller to run the engine and trans and have a 2800 stall converter with 3.73 gears.
At about 50 to 55, the TC will unlock and lock back in within a matter of seconds, when it does, I can see in the data log that the mph spikes to like 120 mph for a millisecond, any thoughts?
Also, any concerns running the 2800 stall with just a trans cooler in the radiator?
Thanks
Fleet
I have a 73 Camaro with a 2005 GTO drivetrain, I'm using a Fitech controller to run the engine and trans and have a 2800 stall converter with 3.73 gears.
At about 50 to 55, the TC will unlock and lock back in within a matter of seconds, when it does, I can see in the data log that the mph spikes to like 120 mph for a millisecond, any thoughts?
Also, any concerns running the 2800 stall with just a trans cooler in the radiator?
Thanks
Fleet
Last edited by mrfleet12; Dec 29, 2018 at 07:43 PM.
TECH Apprentice
Joined: May 2010
Posts: 361
Likes: 0
I have no experience with the fitech but with a stock pcm and a stall there are some tables that have to be adjusted to get the lockup working correctly again. So has it been tuned for the stall? And I personally would not run the trans cooler built into the radiator. Just get a separate cooler for the trans
Thread Starter
Teching In
Joined: Apr 2013
Posts: 29
Likes: 0
From: West of Chicago
DRJ thanks for the reply, not professionally tuned, planning that in the spring.. Was thinking about adding a second fluid cooler on the radiator support inline with the one in the radiator..
TECH Junkie
Joined: Dec 2012
Posts: 3,620
Likes: 1,331
From: Iowa
the MPH spike is just noise from the jolt to the driveline when the converter locks/unlocks
Since you're logging...can you tell us if lockup is being commanded on/off....or if it's a mechanical issue causing the lock/unlock
If it's being commanded...then it's pretty easy to change in the tune to get more desired lockup characteristics.
Since you're logging...can you tell us if lockup is being commanded on/off....or if it's a mechanical issue causing the lock/unlock
If it's being commanded...then it's pretty easy to change in the tune to get more desired lockup characteristics.
TECH Apprentice
Joined: May 2010
Posts: 361
Likes: 0
As as far as the cooler goes just run a standalone cooler and omit the radiator cooler from the circuit. The radiator will have higher temperatures than you want the trans fluid to see. You want to keep the trans temp below 200f if possible. I have a separate cooler for the trans and it doesn’t get above 200f even after hot laps at the drag strip.
Thread Starter
Teching In
Joined: Apr 2013
Posts: 29
Likes: 0
From: West of Chicago
Another thing that's a bit odd with this trans, I get trans fluid on the floor pan right by the output shaft, the output seal is dry, pan gasket's dry, the shift seal is new and dry, checked the vent, it lets air flow through as I blew air down the dipstick and it came out of the vent, also the vent tube was dry as well.. It doesn't really show that I'm losing fluid on the stick, just the wet spot on the floor pan.
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
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Speaking from personal experience don’t drive it much in scenarios that have it lock up then unlocked repeatedly. This will tear up the lock up clutch do to the heat it endures. Been there done that luckily the supplier rebuilt it under warranty in my case. After I got it back I tuned it so it operated properly and now have a 4000ish miles on it with no issues.
As as far as the cooler goes just run a standalone cooler and omit the radiator cooler from the circuit. The radiator will have higher temperatures than you want the trans fluid to see. You want to keep the trans temp below 200f if possible. I have a separate cooler for the trans and it doesn’t get above 200f even after hot laps at the drag strip.
You may be able to keep fluid temps in check if your just drag racing the car, but try getting stuck in traffic in southern summer heat.....it wont fare well.
Thread Starter
Teching In
Joined: Apr 2013
Posts: 29
Likes: 0
From: West of Chicago
KFX
Thanks for the reply, this is basically a street car, we go to the track maybe once a year to mess around on test and tune days.. Really built it to drive every day there isn't rain.. Was thinking of running an external inline with the cooler in the rad, had that on my 69 Chevelle TH400, that car saw a bit of track time..
Thanks for the reply, this is basically a street car, we go to the track maybe once a year to mess around on test and tune days.. Really built it to drive every day there isn't rain.. Was thinking of running an external inline with the cooler in the rad, had that on my 69 Chevelle TH400, that car saw a bit of track time..
KFX
Thanks for the reply, this is basically a street car, we go to the track maybe once a year to mess around on test and tune days.. Really built it to drive every day there isn't rain.. Was thinking of running an external inline with the cooler in the rad, had that on my 69 Chevelle TH400, that car saw a bit of track time..
Thanks for the reply, this is basically a street car, we go to the track maybe once a year to mess around on test and tune days.. Really built it to drive every day there isn't rain.. Was thinking of running an external inline with the cooler in the rad, had that on my 69 Chevelle TH400, that car saw a bit of track time..
i have a 3400 stall. 78mm turbo. 4l60e that I built. Factory radiator with cooler and an external add on cooler. The trans temps stay around 176-178, even in traffic it doesn’t get much hotter than that. I drive my car slot and it gets hot down here in Louisiana.
Thread Starter
Teching In
Joined: Apr 2013
Posts: 29
Likes: 0
From: West of Chicago
KFX
Any thoughts on the leak issue I have, the trans itself is bone dry but I know it's trans fluid.. None of the seals are even damp, the shift shaft seal is new, nothing on the pan and the vent tube is dry... With all that in mind, there shouldn't be anything on the floor pan..
Any thoughts on the leak issue I have, the trans itself is bone dry but I know it's trans fluid.. None of the seals are even damp, the shift shaft seal is new, nothing on the pan and the vent tube is dry... With all that in mind, there shouldn't be anything on the floor pan..
TECH Addict
Joined: Oct 2016
Posts: 2,513
Likes: 480
From: PDX-OR-USA
Sorry but this is very poor advice. water cooler will always work better. I made the mistake once of buying a radiator without a trans cooler and two very large external units could not control the temps. Water cooling will make it more stable. If you were to theoretically keep it cooler than the water temps, then you'd not evaporate the moisture that collects in the trans.....which is not a good thing. If keeping a trans much cooler than the engine were an ideal thing, the OEM's would be doing it.
You may be able to keep fluid temps in check if your just drag racing the car, but try getting stuck in traffic in southern summer heat.....it wont fare well.
You may be able to keep fluid temps in check if your just drag racing the car, but try getting stuck in traffic in southern summer heat.....it wont fare well.
Cheers
TECH Junkie
Joined: Nov 2013
Posts: 3,913
Likes: 366
From: White Bear, Mn
Sorry but this is very poor advice. water cooler will always work better. I made the mistake once of buying a radiator without a trans cooler and two very large external units could not control the temps. Water cooling will make it more stable. If you were to theoretically keep it cooler than the water temps, then you'd not evaporate the moisture that collects in the trans.....which is not a good thing. If keeping a trans much cooler than the engine were an ideal thing, the OEM's would be doing it.
You may be able to keep fluid temps in check if your just drag racing the car, but try getting stuck in traffic in southern summer heat.....it wont fare well.
You may be able to keep fluid temps in check if your just drag racing the car, but try getting stuck in traffic in southern summer heat.....it wont fare well.
4400 stall here that does not lock until 4th gear at 55 mph and I do not see above 160 degrees in traffic in August heat. Highest temp I have seen was 195 degrees on a road course in August.
Thread Starter
Teching In
Joined: Apr 2013
Posts: 29
Likes: 0
From: West of Chicago
Thanks for the reply.. Nice looking TA..
By passing the stock cooler in the radiator and adding a nice plate style cooler will result in lower temps. I advise everyone I talk with to just run a nice stand alone cooler.
4400 stall here that does not lock until 4th gear at 55 mph and I do not see above 160 degrees in traffic in August heat. Highest temp I have seen was 195 degrees on a road course in August.
4400 stall here that does not lock until 4th gear at 55 mph and I do not see above 160 degrees in traffic in August heat. Highest temp I have seen was 195 degrees on a road course in August.