Convertor Lockup
11-24-2007, 01:20 AM
#1
Convertor Lockup Alrite this is what I got...
Right now the Car is set to Lockup at 3rd@30mph, and 4th@40mph. I have been playinq with it and getting into it about 1/4 Petal locked in 3rd at about 2500RPM's. It un-locks at 3/4 Throttle, so I have been cklicking it into 3rd and letting it cruise out locked up. I have ran it up to 100mph in 3rd still locked up, and it doesn't take long to get there from a 45mph roll..even at 1/4 petal.
What I'm thinking of doing is wiring in a Manual Switch to lock up the Convertor anytime Manually. I intend to use it for high-way digs, and probably to lock 3rd up at the Track.
I have some friends that have done it with some older cars, and they scoot. I know it has to be un-locked at a stop or in any low RPMs in first, so the Switch for it will be one of the ones that you press in when you want to do it.
What's do you guys think...it sounds like a good Idea to me.
Right now the Car is set to Lockup at 3rd@30mph, and 4th@40mph. I have been playinq with it and getting into it about 1/4 Petal locked in 3rd at about 2500RPM's. It un-locks at 3/4 Throttle, so I have been cklicking it into 3rd and letting it cruise out locked up. I have ran it up to 100mph in 3rd still locked up, and it doesn't take long to get there from a 45mph roll..even at 1/4 petal.
What I'm thinking of doing is wiring in a Manual Switch to lock up the Convertor anytime Manually. I intend to use it for high-way digs, and probably to lock 3rd up at the Track.
I have some friends that have done it with some older cars, and they scoot. I know it has to be un-locked at a stop or in any low RPMs in first, so the Switch for it will be one of the ones that you press in when you want to do it.
What's do you guys think...it sounds like a good Idea to me.
11-24-2007, 08:47 AM
#3
Well it looks like you found your answer. For the rest of the listening audience however, I will try to answer the questions you raised.
There is an inherent problem with putting large amounts of energy into the converter clutch. That problem is it can and will roast! Unless of course it was designed as a multi disc or otherwise custom setup designed for the task.
The Torque Converter clutch was originally designed to be a device that would allow the torque converter / transmission input shaft to lock to the engines crankshaft eliminating the fluid coupling entirely. There are benefits to doing so.. increased fuel economy, less strain on the converter, less heat in the transmission and so on.
What happens in todays high performance world is guys see that they can increase lap times by locking the converter, but it is a trade off most of the time. Better lap times at the cost of a converter. The converter clutch is a one disc setup that is on average about 1/2 wide. That single clutch disc is asked to take the full amount of torque the engine can deliver. If it begins to slip at all it will continue to do so and will fail in a very short period of time. Many times we see multi disc setups that have failed as well.
Another thing to consider is the hydraulic circuit feeding the converter clutch piston. If there is any fluid bypassing or it is not getting the proper feed pressure, the clutch can fail. We address this issue when we build all of our lock up units!
I have a very nice high performance converter from a vendor many here will recognize that has been in service a while and was recently restalled by another vendor here. We removed it from a car just yesterday, it has a burnt lock up clutch disc. I will post pics of it here next week when I get back to the shop. How do I know it has failed without cutting it open you ask? Simple, the paint is now discolored on the outside of the front cover from the heat generated by slipping, it is the classic symptom of a slipping converter clutch.
Hope that helps.
g
There is an inherent problem with putting large amounts of energy into the converter clutch. That problem is it can and will roast! Unless of course it was designed as a multi disc or otherwise custom setup designed for the task.
The Torque Converter clutch was originally designed to be a device that would allow the torque converter / transmission input shaft to lock to the engines crankshaft eliminating the fluid coupling entirely. There are benefits to doing so.. increased fuel economy, less strain on the converter, less heat in the transmission and so on.
What happens in todays high performance world is guys see that they can increase lap times by locking the converter, but it is a trade off most of the time. Better lap times at the cost of a converter. The converter clutch is a one disc setup that is on average about 1/2 wide. That single clutch disc is asked to take the full amount of torque the engine can deliver. If it begins to slip at all it will continue to do so and will fail in a very short period of time. Many times we see multi disc setups that have failed as well.
Another thing to consider is the hydraulic circuit feeding the converter clutch piston. If there is any fluid bypassing or it is not getting the proper feed pressure, the clutch can fail. We address this issue when we build all of our lock up units!
I have a very nice high performance converter from a vendor many here will recognize that has been in service a while and was recently restalled by another vendor here. We removed it from a car just yesterday, it has a burnt lock up clutch disc. I will post pics of it here next week when I get back to the shop. How do I know it has failed without cutting it open you ask? Simple, the paint is now discolored on the outside of the front cover from the heat generated by slipping, it is the classic symptom of a slipping converter clutch.
Hope that helps.
g
11-24-2007, 09:51 AM
#4
I always smile when I hear people making a manual lockup switch. You can program the converter to lockup at WOT in any gear. I lockup in third when im using my 26" street tires because I run out of gear in third. I have done this for 3 years with this car. There are 2 things to consider IMHO one is the converter must be designed to lock up at WOT Second, yes it is hard on the converter and will make it a higher maintenance item that it was.
Last edited by koolrayz; 11-24-2007 at 10:34 AM.
11-24-2007, 10:15 AM
#5
So it boils down to expectations and one's tolerance for swapping converters! For me, it is not a big deal. For someone who races in a class and is looking for a specific number it is no big deal... but for the average enthusiast on a budget, it can be a huge PITA digging converters out every few months or so.
g
11-24-2007, 10:33 AM
#6
I had mine religned last winter, That was after 2 years ( it was still funtioning) a far cry from every couple months. You are IMHO right about it not being worth it to the average consumer. Jerking a converter is nothing to me, to the average user it seems like the end of the world.
11-24-2007, 10:40 AM
#7
I would suspect that you spent good money for your converter if it lasted 2 years lockiing up at WOT. You got your monies worth indeed. And apparently it was built for that purpose as well.
Most guys here aren't going to spend the $$$ for a billet covered multi disc converter that can withstand that punishment. Some will, and do though!
Tell us about your converter.... specs, mfgr and cost if you don't mind. I think it would help some guys who are on the fence about this.
Thanks for chiming in koolrayz!
g
Most guys here aren't going to spend the $$$ for a billet covered multi disc converter that can withstand that punishment. Some will, and do though!
Tell us about your converter.... specs, mfgr and cost if you don't mind. I think it would help some guys who are on the fence about this.
Thanks for chiming in koolrayz!
g