TC lock up question???
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From: Live Oak, FL - in the woods where the creatures lurk.
Re: TC lock up question??? Experiment cruising at slightly higher speeds and see where it locks at.
I have an ST3500/2.73 and mine locks into OD @ 50 mph after a few seconds IF cruising at very mild acceleration. The higher the acceleration, the longer it takes to lock. In 3rd, it locks up around 35 at very mild throttle, other times 45 but will stay locked down to around 30 mph.
Hope this helps. It's all kind of subjective until you log real numbers. If you have a 2.73 I would -guess- that sounds about right.
Different TCs behave differently.
I have an ST3500/2.73 and mine locks into OD @ 50 mph after a few seconds IF cruising at very mild acceleration. The higher the acceleration, the longer it takes to lock. In 3rd, it locks up around 35 at very mild throttle, other times 45 but will stay locked down to around 30 mph.
Hope this helps. It's all kind of subjective until you log real numbers. If you have a 2.73 I would -guess- that sounds about right.
Different TCs behave differently.
11 Second Club
Joined: Jan 2003
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From: Bridgeport OH
Re: TC lock up question??? I just put a 3800 in from TCS. I bought it from a fella here on the boards. I can tell there is a higher stall converter in there. But anyway....before I ramble. When your converter locks up, does it lock up hard? I am just curios. Currently the PCM is in the stock config as well. It's just that when the converter locks up, I can feel it. Besides hearing it in the motor, etc. It's not a thump, wham, crunch, shudder, etc, but it is definately much more noticeable compared to a stock setup.
Thanks,
Kim
Thanks,
Kim
Thread Starter
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Joined: Feb 2002
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From: Loganville, GA
TC lock up question??? Just installed a new TCI SSF 3800. The prob is that it seems that when in OD driving about 45-50 it will be unlocked and 5-6 mins after cruisin at that speed it will jsut lock up and drop the rpms back to normal? right now, THE PCM IS STOCK. Just had it flashed back to stock to retune completely.
any suggestions? does it sound like a bad TC? <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" />
any suggestions? does it sound like a bad TC? <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" />
Re: TC lock up question??? Of course its going to be much more noticable Kim, think about it. With the stock converter you're unlocked at 40 mph in OD, and unlocked the RPMs around 1800 or so (just guessing on this), and when the converter locks it only drops down a few hundred RPMs to say 1000 RPMs. You're only getting a difference of 800 RPMs. With a higher stall like a 3800, cruising at 40 mph lets say you're at 2500 RPMs, and then it locks and drops to 1000 RPMs, you're dropping 1500 RPMs with the higher stall, almost double the drop you'd see with the stock converter. With the stock converter locking to me it just feels like it's shifting another gear. The only time I really notice it is in cold weather when I drive for about 5 minutes with the converter unlocked before it gets to operating temp and then locks, otherwise I don't notice it. When I get my TCS 3500/2.5 installed next weekend I fully expect to notice the lock up.
Best thing to do to my understanding is that while in town or keeping varying speeds and under 55 mph, just keep the car in 3rd, but if you're going to be holding 55 mph for a while or will exceed that speed, go ahead and bump the car to OD. Seems to be the best way for the converter to stay locked while cruising, BLKWS6 even mentioned the difference between 3rd and OD in his post.
As I said I don't yet have a converter in yet, but thats the info I've gathered. May 3rd I'll be able to get some more firm first hand experience. Hope I was of some help though.
Best thing to do to my understanding is that while in town or keeping varying speeds and under 55 mph, just keep the car in 3rd, but if you're going to be holding 55 mph for a while or will exceed that speed, go ahead and bump the car to OD. Seems to be the best way for the converter to stay locked while cruising, BLKWS6 even mentioned the difference between 3rd and OD in his post.
As I said I don't yet have a converter in yet, but thats the info I've gathered. May 3rd I'll be able to get some more firm first hand experience. Hope I was of some help though.
Thread Starter
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Joined: Feb 2002
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From: Loganville, GA
Re: TC lock up question??? Thanks guys...i'll try those sugestions. Right now, its hard to tell what exact mph i'm going (3.23 stock pcm ratio - 3.73 actually in there)
And i cant use my EDIT yet..need an adapter <img border="0" title="" alt="[Frown]" src="gr_sad.gif" />
And i cant use my EDIT yet..need an adapter <img border="0" title="" alt="[Frown]" src="gr_sad.gif" />
11 Second Club
Joined: Jan 2003
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From: Bridgeport OH
Re: TC lock up question??? josh99ta,
Cool. Thanks for the thought on that. It makes sense, something that I had not thought about. It now gets locked away and thought of as "normal". Let me know how you feel about your converter when it goes in!
Kim
Cool. Thanks for the thought on that. It makes sense, something that I had not thought about. It now gets locked away and thought of as "normal". Let me know how you feel about your converter when it goes in!
Kim
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From: Jersey boy
Re: TC lock up question??? sorry for digging up old posts but: your saying if your cruising at like 60mph at around 1,800rpm and your stall is like 2,800 it will lock up and drop a few rpm? i always thought the converter never locks under its stall speed. plz respond i never knew it worked that way and would reeaaaly like some confirmation or something
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TECH Apprentice
Joined: Sep 2002
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From: west coast
Re: TC lock up question??? Yes converter locks up under stall speed. I have 2002 WS6 also with stock 1600 stall converter. If I ease it up to about 40 I'm turning about 1200rpm then it locks up and drops to 1000.
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From: Jersey boy
Re: TC lock up question??? ok one more question. if a converter is over its stall speed is it automatically locked up?
if so, theoretically, i could buy a high stall converter and wire a micro switch from my tach so that when i reach like 1,000rpm it will send a signal to the soelonoid(sp?) and lock up like a 1,000rpm converter? i could then put a toggle switch in series with the micro switch so when i want to drive normally i can lock up at 1,000 and when i want to race i can let the converter do whatever it wants.
if so, theoretically, i could buy a high stall converter and wire a micro switch from my tach so that when i reach like 1,000rpm it will send a signal to the soelonoid(sp?) and lock up like a 1,000rpm converter? i could then put a toggle switch in series with the micro switch so when i want to drive normally i can lock up at 1,000 and when i want to race i can let the converter do whatever it wants.
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From: Live Oak, FL - in the woods where the creatures lurk.
Re: TC lock up question??? No. For example, at WOT, the converter will NOT lock up.
The A4 WILL lock up under the rated stall speed at mild throttle.
Can you wire a lock up switch? Yes, at least a manual lock up switch. I dunno if you can wire one off tach input.The signal output from the simple sending units like water temp seem to be sensitive enough to extra impedance to skew the output to extra gauges.
I see what you're saying, though. Sounds interesting, and if you discover a way to do it, post your results.
The A4 WILL lock up under the rated stall speed at mild throttle.
Can you wire a lock up switch? Yes, at least a manual lock up switch. I dunno if you can wire one off tach input.The signal output from the simple sending units like water temp seem to be sensitive enough to extra impedance to skew the output to extra gauges.
I see what you're saying, though. Sounds interesting, and if you discover a way to do it, post your results.
On The Tree
Joined: Jan 2003
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From: Pontotoc, MS
Re: TC lock up question??? There are two ways people use the term lock-up for a converter. The first way is what every body described here. The 4L60E, 700R4, 2004R, and TH-350C are all lock-up transmissions, meaning that the converter has a lock-up piston and clutch assembly. The converter will lock-up (applies the piston in the converter) when the computer or valve body commands it.
The other way lock-up is used by most people is that the converter is a fluid coupler. The torque converter has a pump, turbine, and stator in it (nonlock-up converter). The pump pumps fluid to the turbine and back to the stator. The stall speed for a converter, let's say is 3500, and then the converter's pump and turbine will be lock-up at 3500. The proper term for this is coupled.
A converter with a lock-up assemble has 100% efficiency when the converter lock-up piston is applied. The nonlock-up converter will never have 100% efficiency, even when the converter is coupled (lock-up). So, people use the term lock-up both ways. I am guilty of it myself!
Kevin Steele
TCI
Product Engineer
The other way lock-up is used by most people is that the converter is a fluid coupler. The torque converter has a pump, turbine, and stator in it (nonlock-up converter). The pump pumps fluid to the turbine and back to the stator. The stall speed for a converter, let's say is 3500, and then the converter's pump and turbine will be lock-up at 3500. The proper term for this is coupled.
A converter with a lock-up assemble has 100% efficiency when the converter lock-up piston is applied. The nonlock-up converter will never have 100% efficiency, even when the converter is coupled (lock-up). So, people use the term lock-up both ways. I am guilty of it myself!
Kevin Steele
TCI
Product Engineer
On The Tree
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From: KC
Re: TC lock up question??? Thanks Kevin, good info. Still, if somone made a couple switch they'd sell a ton of them. A huge stall that could be coupled by driver input instead of pure pcm control would be awesome. Coupled-stocklike in tight city traffic, hit the onramp and turn on the normal stall behavior would be heaven, plus let everyone go with huge stalls without the unwanted looseness. Hit a switch and feel like the pipe just opened on a dirt bike? WOOOHOOO 
On The Tree
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From: Pontotoc, MS
Re: TC lock up question??? megathumpzilla,
The couple is not computer controlled. The torque converter works by the pump pumping fluid into the turbine, which drives the input shaft. EXAMPLE: If two fans are facing one another and you turn one on (pump), the other fan (turbine) will start slowly spinning from the air being blown by the first fan (pump). The 2nd fan (turbine) will never spin at the same rpm as the 1st fan (pump). This called torque converter slippage. ALL torque converters have this slippage. The coupling effect of a converter is related to the efficiency of the converter. Lets say that your stall is 3500 and the efficiency of the converter is 95%. Then at rpms lower than 3500 the converter efficiency is less than 95%. The converter is coupled or "locked-up" is when the converter is at the max efficiency.
The efficiency of the converter is determined by the type of stator and fin angles of the pump and turbine (not computer). So, by the example above the converter is not coupled or "lock-up" until 3500 rpms.
A lock-up converter that has the piston/clutch assembly is 100% efficiency WHEN the piston applies the clutch to the front of the TC. This "locks" the turbine that drives the input shaft to the front of the TC which is bolted to the flywheel. So, the input shaft spins at the same rpms as the motor. BUT, UNTIL THIS HAPPENS THE CONVERTER WILL BEHAVE THE SAME AS THE EXAMPLE ABOVE.
Kevin Steele
TCI
Product Engineer
The couple is not computer controlled. The torque converter works by the pump pumping fluid into the turbine, which drives the input shaft. EXAMPLE: If two fans are facing one another and you turn one on (pump), the other fan (turbine) will start slowly spinning from the air being blown by the first fan (pump). The 2nd fan (turbine) will never spin at the same rpm as the 1st fan (pump). This called torque converter slippage. ALL torque converters have this slippage. The coupling effect of a converter is related to the efficiency of the converter. Lets say that your stall is 3500 and the efficiency of the converter is 95%. Then at rpms lower than 3500 the converter efficiency is less than 95%. The converter is coupled or "locked-up" is when the converter is at the max efficiency.
The efficiency of the converter is determined by the type of stator and fin angles of the pump and turbine (not computer). So, by the example above the converter is not coupled or "lock-up" until 3500 rpms.
A lock-up converter that has the piston/clutch assembly is 100% efficiency WHEN the piston applies the clutch to the front of the TC. This "locks" the turbine that drives the input shaft to the front of the TC which is bolted to the flywheel. So, the input shaft spins at the same rpms as the motor. BUT, UNTIL THIS HAPPENS THE CONVERTER WILL BEHAVE THE SAME AS THE EXAMPLE ABOVE.
Kevin Steele
TCI
Product Engineer
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From: Jersey boy
Re: TC lock up question??? so it would still be a viable option to run a switch that would lock up the converter (not couple it) when driving normally right? also what would happen if you left it locked up and never unlocked it except to race? would i burn out the piston or something or have no effect as long as you didnt get on it too hard?
