*? Benefits of Converter Lockup?*
Thread Starter
Senior Member
iTrader: (10)
Joined: Apr 2007
Posts: 773
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From: The Pocono Mountains, PA
Car: 1987 Firebird, Dad bought it new
Engine: 5.7L Vortec w/ LT4 Hot cam
Transmission: 700r4 transgo shiftkit 2600 stall
Axle/Gears: 3.42 '02 SS 6 spd rear
*? Benefits of Converter Lockup?*
Has anyone tested a "converter lockup switch" w/ real track data?
In 1999 my best friend and I installed a switch on his 1987 IROC in an attempt to get into the 13s with a stock 305 for cheap. We thought we gained one tenth from it, but with consecutive runs it was gone (probably due to heat!?). We were not and still aren't fully aware of the benefits of locking the converter, what it actually does etc. We did however break the 13s after icing down the intake for a full hour of cool down time.
details:
*paid $3K for stock IROC 120k 5.0L TPI w/700r4 stock posi w/3.23 gears
= 14.7 @ 92mph very consistent
*mods*
$100 Competition Engineering SFC's
$0 boxed RCA's (Gpops steel stock)
$0 modded stock air box
$0 home ported plenum
$0 gasket matched runners,plenum and intake
$0 MAFS screens delete
$0 hollow 3" cat
$5 TB coolant bypass
$10 160 degree thermo
borrowed Hypertech Thermomaster chip
borrowed TB airfoil
$75 battery relocation kit
$350 255/60 R16 Drag Radials
$15 toggle switch, relay and wire for lockup switch
$0 front sway bay delete
$0 fog lights delete
$15 junk yard ducting for fog light holes
=14.0 @ 98mph
$10 ice
=13.9 @ 99mph
car had AC and full interior and passed NJ inspection
later on we swapped in a vette L98 long block and B&M shift kit
=13.2 @ 106mph
all @ Atco, NJ
In 1999 my best friend and I installed a switch on his 1987 IROC in an attempt to get into the 13s with a stock 305 for cheap. We thought we gained one tenth from it, but with consecutive runs it was gone (probably due to heat!?). We were not and still aren't fully aware of the benefits of locking the converter, what it actually does etc. We did however break the 13s after icing down the intake for a full hour of cool down time.
details:
*paid $3K for stock IROC 120k 5.0L TPI w/700r4 stock posi w/3.23 gears
= 14.7 @ 92mph very consistent
*mods*
$100 Competition Engineering SFC's
$0 boxed RCA's (Gpops steel stock)
$0 modded stock air box
$0 home ported plenum
$0 gasket matched runners,plenum and intake
$0 MAFS screens delete
$0 hollow 3" cat
$5 TB coolant bypass
$10 160 degree thermo
borrowed Hypertech Thermomaster chip
borrowed TB airfoil
$75 battery relocation kit
$350 255/60 R16 Drag Radials
$15 toggle switch, relay and wire for lockup switch
$0 front sway bay delete
$0 fog lights delete
$15 junk yard ducting for fog light holes
=14.0 @ 98mph
$10 ice
=13.9 @ 99mph
car had AC and full interior and passed NJ inspection
later on we swapped in a vette L98 long block and B&M shift kit
=13.2 @ 106mph
all @ Atco, NJ
Senior Member
Joined: Jun 2008
Posts: 1,298
Likes: 2
From: Norfolk VA
Car: 85 Camaro IROC
Engine: 5.7 TPI
Transmission: 700-R4
Axle/Gears: open rear, 3.42 gears
Re: *? Benefits of Converter Lockup?*
torque converter lockup will give you about a tenth at the track in the 1/4 but locking up in second gear at WOT is VERY VERY hard on the clutch, so i would not be suprised if it trashed the lockup after consecutive runs.
lockup is more meant for the street where it creates less heat and lowers RPMs by about 250 rpms on the highway (depending on gearing of course)
lockup is more meant for the street where it creates less heat and lowers RPMs by about 250 rpms on the highway (depending on gearing of course)
Supreme Member
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Joined: Aug 2006
Posts: 2,491
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From: Cleveland, Ohio
Car: 89' IROC-Z
Engine: LO3
Transmission: 700R4
Axle/Gears: 10-Bolt/2.73
Re: *? Benefits of Converter Lockup?*
I had to say this.
But read this.
http://ezinearticles.com/?Torque-Con...ckup&id=113485
Originally Posted by Keiichi Tsuchiya
I drift not because it is a quicker way around a corner, but the most exciting way.
http://ezinearticles.com/?Torque-Con...ckup&id=113485
Originally Posted by Ezine Articles
Although the torque converter clutch is not part of the engine, it can make the car feel like the engine has a problem. The torque converter clutch is also known as a lock up converter. The lockup clutch has many purposes and is part of the transmission. A regular converter in an automatic transmission is made to slip at idle so that the car doesn't move. As the accelerator is pressed the RPM's raise and the torque converter will start to lockup or engage. When the converter engages the car will move.
Even though the torque converter is engaged it never completely engages the way a manual transmission car clutch will. It will always slip a little, which is not very efficient. This is why a manual transmission car gets better gas mileage and has more power than an automatic transmission car. To increase power and mainly fuel mileage, a TCC is added to an automatic transmission.
The torque converter clutch is an electronic clutch that will engage the engine and drivetrain 100 percent. The TCC is made to engage usually only in the top gear when the car is cruising, not accelerating. The lock up converter will disengage when the accelerator is pressed hard enough. Over time the clutch will wear out especially if the vehicle ever towed anything and was operated in overdrive (top gear). This will wear the clutch out prematurely. If you have a tachometer you will see the RPM's drop a few hundred when it engages.
If the TCC is bad one of three things will usually happen. First, the vehicle will tend to rev up and down as it engages and disengages, not being able to keep the converter clutch locked up. Second, the converter clutch will engage randomly in gears that it shouldn't even engage in usually. Third the clutch doesn't want to disengage. As you slow down the vehicle won't downshift and if you try to accelerate the RPM's will be so low that the vehicle will have difficulty moving quickly. In extreme cases the lockup converter will try to keep the vehicle moving as you try to stop at a stop light, or will stall out and die.
Many people think that this problem is coming from their engine because it causes the car to stall. The check engine light will not always show an error for the TCC. Most lockup converters are controlled by a wire or wires that plug into the transmission. It is possible on some models to simply disconnect this plug. This is not a problem and will only cause you to lose a little gas mileage. The RPM's will run slightly higher than before but will not harm anything or be an issue.
Jerry Lemke is the owner of a website called http://www.freeengineinfo.com. A site dedicated to engine information and repair related topics.
Even though the torque converter is engaged it never completely engages the way a manual transmission car clutch will. It will always slip a little, which is not very efficient. This is why a manual transmission car gets better gas mileage and has more power than an automatic transmission car. To increase power and mainly fuel mileage, a TCC is added to an automatic transmission.
The torque converter clutch is an electronic clutch that will engage the engine and drivetrain 100 percent. The TCC is made to engage usually only in the top gear when the car is cruising, not accelerating. The lock up converter will disengage when the accelerator is pressed hard enough. Over time the clutch will wear out especially if the vehicle ever towed anything and was operated in overdrive (top gear). This will wear the clutch out prematurely. If you have a tachometer you will see the RPM's drop a few hundred when it engages.
If the TCC is bad one of three things will usually happen. First, the vehicle will tend to rev up and down as it engages and disengages, not being able to keep the converter clutch locked up. Second, the converter clutch will engage randomly in gears that it shouldn't even engage in usually. Third the clutch doesn't want to disengage. As you slow down the vehicle won't downshift and if you try to accelerate the RPM's will be so low that the vehicle will have difficulty moving quickly. In extreme cases the lockup converter will try to keep the vehicle moving as you try to stop at a stop light, or will stall out and die.
Many people think that this problem is coming from their engine because it causes the car to stall. The check engine light will not always show an error for the TCC. Most lockup converters are controlled by a wire or wires that plug into the transmission. It is possible on some models to simply disconnect this plug. This is not a problem and will only cause you to lose a little gas mileage. The RPM's will run slightly higher than before but will not harm anything or be an issue.
Jerry Lemke is the owner of a website called http://www.freeengineinfo.com. A site dedicated to engine information and repair related topics.
Senior Member
Joined: Jun 2008
Posts: 1,298
Likes: 2
From: Norfolk VA
Car: 85 Camaro IROC
Engine: 5.7 TPI
Transmission: 700-R4
Axle/Gears: open rear, 3.42 gears
Re: *? Benefits of Converter Lockup?*
not to hijack, but since we are talking about it anyway:
can you tell if a torque converter has lockup capability from looking at it?
my transmission has wiring for lockup.
but my car NEVER goes into lockup mode.
even with the terminals of the ALDL jumped, it wont do it.
is it possible that my converter is not capable of locking up or is it more likely that the chip is at fault.
all this would be the fault of the PO, so i am playing catch up at this point
can you tell if a torque converter has lockup capability from looking at it?
my transmission has wiring for lockup.
but my car NEVER goes into lockup mode.
even with the terminals of the ALDL jumped, it wont do it.
is it possible that my converter is not capable of locking up or is it more likely that the chip is at fault.
all this would be the fault of the PO, so i am playing catch up at this point
Thread Starter
Senior Member
iTrader: (10)
Joined: Apr 2007
Posts: 773
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From: The Pocono Mountains, PA
Car: 1987 Firebird, Dad bought it new
Engine: 5.7L Vortec w/ LT4 Hot cam
Transmission: 700r4 transgo shiftkit 2600 stall
Axle/Gears: 3.42 '02 SS 6 spd rear
Re: *? Benefits of Converter Lockup?*
sorry dragon no clue im guessin it just got burned like ours did... im not getting emails about my threads for some reason so i just realized this was here
Supreme Member
Joined: Jul 1999
Posts: 3,484
Likes: 56
From: Calimesa, California, U.S.
Re: *? Benefits of Converter Lockup?*
If you gain anything by locking up the torque converter in the quarter mile with a normally asperated motor, then the torque converter was not built correctly. I have "never" seen a gain locking up the torque converter with a normally asperated motor, when the torque converter is right. With super or turbo charging, I have seen very slight gains, but this is also very hard on the gear train. Once you lockup the torque converter, you have "no more" torque multiplication "at all", just the pumping losses of the automatic.
Thread Starter
Senior Member
iTrader: (10)
Joined: Apr 2007
Posts: 773
Likes: 0
From: The Pocono Mountains, PA
Car: 1987 Firebird, Dad bought it new
Engine: 5.7L Vortec w/ LT4 Hot cam
Transmission: 700r4 transgo shiftkit 2600 stall
Axle/Gears: 3.42 '02 SS 6 spd rear
Re: *? Benefits of Converter Lockup?*
so what if you had a stock converter and not the "right" torque converter?
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Supreme Member
Joined: Jul 1999
Posts: 3,484
Likes: 56
From: Calimesa, California, U.S.
Re: *? Benefits of Converter Lockup?*
It would depend on where you lock it up, as to how much you will slow down. Stock torque converters still multiply torque at WOT when unlocked. Once locked up there is no more torque multiplication, just the pumping losses of an automatic transmission.
Thread Starter
Senior Member
iTrader: (10)
Joined: Apr 2007
Posts: 773
Likes: 0
From: The Pocono Mountains, PA
Car: 1987 Firebird, Dad bought it new
Engine: 5.7L Vortec w/ LT4 Hot cam
Transmission: 700r4 transgo shiftkit 2600 stall
Axle/Gears: 3.42 '02 SS 6 spd rear
Re: *? Benefits of Converter Lockup?*
so it would be better to have a switch, and keep the switch on "unlocked" for 1/4 mile passes?
Thread Starter
Senior Member
iTrader: (10)
Joined: Apr 2007
Posts: 773
Likes: 0
From: The Pocono Mountains, PA
Car: 1987 Firebird, Dad bought it new
Engine: 5.7L Vortec w/ LT4 Hot cam
Transmission: 700r4 transgo shiftkit 2600 stall
Axle/Gears: 3.42 '02 SS 6 spd rear
Re: *? Benefits of Converter Lockup?*
Last edited by FlippindaBird; Feb 15, 2010 at 09:31 PM.
Thread Starter
Senior Member
iTrader: (10)
Joined: Apr 2007
Posts: 773
Likes: 0
From: The Pocono Mountains, PA
Car: 1987 Firebird, Dad bought it new
Engine: 5.7L Vortec w/ LT4 Hot cam
Transmission: 700r4 transgo shiftkit 2600 stall
Axle/Gears: 3.42 '02 SS 6 spd rear
Re: *? Benefits of Converter Lockup?*
so that settles it... torque converter lockup switches SUCK! big waste of money, dont do it
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