Torque converter question?

Tommio RS · Post by **Tommio RS** » Fri Sep 19, 2008 11:48 pm

Hey thar! Is there a mod to LOCK your torque converter manually while driving with switch? Because i really want the torque converter to lock up WAY! sooner while im driving.

It will take like 10 mins of highway driving for the car to lock the torque converter......

SO that KILLS my MPG. Going down the highway at 3000rpm's sounds cool with a TBE but the gas mileage sucks!

is there anyway to lock the torque converter while im driving?

Thanks!

BTW: i know the car when cool will slip lots more than when warm.

ericem · Post by **ericem** » Sat Sep 20, 2008 12:25 am

Shouldn't slip alot to a point where you notice it. When the power light comes on does it feel locked?

Tommio RS · Post by **Tommio RS** » Sat Sep 20, 2008 5:22 am

well yes it does. But i want to have controlle of it. if there is any way to do it.

93forestpearl · Post by **93forestpearl** » Sat Sep 20, 2008 7:25 am

Yes you can do it. Find the wires by looking at the wiring diagrams, and wire a switch in. I don't know if it is switched power or switched ground, but either way, its not a big deal.

One thing to keep in mind, if the transmission shifts while the torque converter is locked, it will be a very violent shift. Locking the torque converter is like getting a bunch of free hp though. Just unlock it before your shift point, and it will flash and shift to the next gear.

Tommio RS · Post by **Tommio RS** » Sun Sep 21, 2008 5:17 pm

Hmmm very interesting. So if i engage the torque converter in 3rd gear then, it shifts to 4th it will be hella hard shift!

I just want my rev's to drop off sooner while im high way driving. By adding this switch that would do it for me! Full lock up in 4th gear is all im after.

Where would i find these wiring diagrams for the 4eat anyways??

Thanks for your words of wisdom 93forestpearl!

93forestpearl · Post by **93forestpearl** » Mon Sep 22, 2008 5:21 am

Post by **Legacy777** » Wed Sep 24, 2008 12:56 am

I would recommend you don't mess with the lockup function on the transmission.

The desired functionality will be sketchy at best.

93forestpearl · Post by **93forestpearl** » Wed Sep 24, 2008 5:38 am

It only really hurts anything if you are doing it when the tranny is cold, or if you let it shift with it locked up. Don't let it shift with the converter locked unless you are competent in rebuilding transmissions every once in a while.

Manually locking the torque converter is very common with the V8 guys. The converter saps a ton of power at higher speeds.

Buffman · Post by **Buffman** » Wed Sep 24, 2008 5:45 am

93forestpearl wrote:It only really hurts anything if you are doing it when the tranny is cold, or if you let it shift with it locked up. Don't let it shift with the converter locked unless you are competent in rebuilding transmissions every once in a while.

Manually locking the torque converter is very common with the V8 guys. The converter saps a ton of power at higher speeds.

If you have some inefficient POS converter maybe, but a custom well built unit will be very efficient in the upper RPMS, even more so when the converter is locked. The stock units are faily efficient for what they are. Not sure on new GM setups, but on my 4l60e, stock the converter was never fully locked. It was a gradual on/gradual off thing. When I had the trans built, that function was disabled and made the lockup function either ON/OFF.

It makes no sense in any automatic with a Lockup Clutch not to have it lock at highway speeds. Otherwise it's just generating more heat.

I guess it depends on what V8 guys you're talking about (lockup converters are a newer thing, not common to PowerGlides, TH400, etc), but I don't have to worry about manually locking mine (and neither do most others) as I just tune the lockup tables where I want the converter to lockup

Don't need no manual switch

.

As mentioned keeping it locked during downshifts or an upshift is not the greatest idea.

altron23 · Post by **altron23** » Wed Sep 24, 2008 5:51 am

sounds like u got a torque converter problem, my old AT used to go in and out of lockup on command down the freeway no problem. time for a 5mt swap or a tranny rebuild.

93forestpearl · Post by **93forestpearl** » Wed Sep 24, 2008 5:58 am

Buffman wrote:If you have some inefficient POS converter maybe, but a custom well built unit will be very efficient in the upper RPMS, even more so when the converter is locked. The stock units are faily efficient for what they are. Not sure on new GM setups, but on my 4l60e, stock the converter was never fully locked. It was a gradual on/gradual off thing. When I had the trans built, that function was disabled and made the lockup function either ON/OFF.

I guess it depends on what V8 guys you're talking about (lockup converters are a newer thing, not common to PowerGlides, TH400, etc), but I don't have to worry about manually locking mine (and neither do most others) as I just tune the lockup tables where I want the converter to lockup Don't need no manual switch .

Maybe IPT just sucks at converters then, I dunno. A couple friends have higher stalls in their Subarus and they can't stand the converter over 80mph. They dog out up there pretty bad. The manual lockup is really nice when you are putting the wood to it, as you already know, since it's like an extra 1000rpm in their power band. One has a manual lockup switch and it works really really well. He also build tranny's and is also a manual valve body and reverse spool from being the full BMS(rigoli) setup.

Yeah, I should have specified on what V8 guys I was taking about. A friend on mine with a SBC swapped FC RX-7 has a lockup switch, and I wanna say its a 700r4 or something like that. Don't quote me on it. I haven't been into that stuff in about 10 years. That doesn't mean I won't return though...

Buffman · Post by **Buffman** » Wed Sep 24, 2008 6:06 am

my 9.5" 3000 (flashes to 3400rpm) is fine all the way up to 130+ mph

IIRC (have to check logs) I'm showing a 94% efficiency unlocked at 5300rpm in 3rd gear

700r4 would be the one. Without the ECU, he'd need the manual lockup switch.

93forestpearl · Post by **93forestpearl** » Wed Sep 24, 2008 6:10 am

So your 9.5" 3000 is for a V8 car, or a Subaru? I dunno what the deal is with Derek's and Matt's converters. Dereks flashes up to about 3200. When he spools at about 5k and gets to about 5500, he hits the switch and the car seriously surges forward, and the rpm's dipp a bit. Its pretty damn sweet. The thing is gonna be nasty once hydra fixes his new ECU (which he is very pissed about) and gets the vanes working in his turbo. GT3782 VNT.

Buffman · Post by **Buffman** » Wed Sep 24, 2008 6:14 am

I'm talking about my v8 car

(car video is in sig)

Tommio RS · Post by **Tommio RS** » Wed Sep 24, 2008 11:22 pm

Ho Ho!!! Thats what im talking about... The diagram people!

I told this probably 3 times already! I just want this when i hit 4 gear. The car will shift into the lock up torque converter after like 15 mins of driving. By then im at my destination. So crap gas mileage down the highway. 100km plus 3000rpms = cool sound but, same gas mileage as in the city. Soo that like 19mpg when the car is rated for 24 highway.

Tommio RS · Post by **Tommio RS** » Thu Sep 25, 2008 12:38 am

Ok people before i start to hack and cut tell me if this circuit is right!

http://s449.photobucket.com/albums/qq21 ... thLTCS.jpg[/img]

93forestpearl · Post by **93forestpearl** » Thu Sep 25, 2008 1:24 am

The whole point of your torque converter not locking up is that it is trying to get to operating temp as fast as possible.

Tommio RS · Post by **Tommio RS** » Fri Sep 26, 2008 12:25 am

Ooo i know thats why auto transmision slip. But if your trying to drive your auto for fuel economy this slipage eats up a fair chunck of economy. If you try to accelerate by reving the car under 2000rpm's cold, the car will slip FOREVER!!!

Im not joking! Try it your car will not use the lock up function for a long time. Thats if you drive your car very very easy not hard. I drive my leggy turbo nice and easy for the best fuel economy. You be amazed to how good this cars fuel economy is if you dont accelerate fast!

SO this leads to the lock up torque converter thing. If you can manualy engauge the lock up you could improver everything! You would just need to know what you are doing!

So last thing here.
Where can i find the TCU on my 93 Leggy turbo??

Thanks people!

Post by **Legacy777** » Fri Sep 26, 2008 2:20 am

I don't mean this in a bad way, but I'd really question whether you know if your torque converter is locking up.

There is always some amount of lockup. Even when cold, unless it's very very cold. I say this because I have watched the lockup duty % via the select monitor when my car was still an auto.

I'd very highly recommend you don't mess with this.

To answer your question, the TCU is just to the left of the driver's steering column. Here's a pic

http://www.main.experiencetherave.com/s ... cuhide.jpg

Tommio RS · Post by **Tommio RS** » Sun Sep 28, 2008 1:12 am

Cool. Thanks for the location of the TCU. But yes, I really dunno if my torque converter has a problem. I think i should look it to this alittle bit more. I get my subi mechanic to take it for a drive.

Thanks!

legacycentral bbs

A forum for 89-94 BC-BF(BJ) Legacy Owners and Fans

Torque converter question?

Torque converter question?