kanewolf

Okay, got an A-4, I know my OEM torque converter kicks in 3rd & 4th gear. But can I get one that is always engaged (e.g. 1st-4th), if so, anyone know what imact that has? (driveability, timing, performance, etc...)

Gold Z

iTrader: (3)

A torque converter is always "engaged". It is the fluid coupler between your engine and transmission. You might say it takes the place of the clutch disc and pressure plate in manual transmission equiped cars. A lockup torque converter, suc as in your car, only locks up in 4th gear to maximize effeciency and mileage. An aftermarket conveter is usually measured by it's "stall speed" which is rated by engine rpms, such as 2400, 3000, 4200. The higher the stall rating the higher the converter lets the engine rev as you accelerate, kinda like slipping the clutch to keep your rpms up. This lets you accelerate faster. When your tranny finally shifts into high gear the car will drive the same as with a stock converter. A midrange aftermarket converter, 2800 rpm to 3400 rpm, is the first mod anybody with an automatic tranny should put on their car. It will usually drop your quarter mile times by a full half second and will put a stock 4th gen F-body on traction tires in the 12s while being hardly noticeable in normal driving.

Wesmanw02

iTrader: (4)

So basically you want a torque converter that will automatically engage the lockup clutch in any gear above a slow roll. I've thought of that concept myself before, and I think it makes a lot of sense. It would basically be similar to a manual in that there would always be a direct connection to the wheels once the car is moving, which means more power, less heat buildup, and better fuel economy.

Sequential manuals operate on the same concept. The computer controls the clutch, and then once the car is moving, the engine remains engaged to the wheels.

I've never heard of a torque converter that does this though, and therin lies your problem.

BlackHawk T/A

iTrader: (3)

It would probably be pretty hard on it I would imagine.

DeltaT

iTrader: (5)

The TCI tranny controller will let you lock up your 4L60E or 4L80E under WOT in any gear but 1st.
You can see a major difference on the dyno in a 3rd gear run between locked and unlocked. Programmable by speed (mph point), and TPS.

Jim

BlackHawk T/A

iTrader: (3)

But what about added stress, possible failure...?

I've read some dyno shops won't run your car locked because of the chance of it breaking?

8a8mfh

iTrader: (3)

You need a strong converter thats built for this type of use. The damper springs in the clutch hub will most likely break using it like this. I've seen the insides of converters with broken springs and it's not a pretty sight.
You'd also want the largest diameter converter you can find.

I had a manual switch on a 700R4 once and accidentally left the converter locked up during a wot run, it makes the shifts brutal. You could simply put a check ball in the snout of the lock up solenoid, this will make it lock up right after the 1-2 shift but you'd have no control over it this way, might be better off doing it with a switch.

koolrayz

iTrader: (26)

you can lock up any converter in any gear with tuning. I lock up my converter At WOT in third gear. I have a midwest converter that is made to lockup at WOT. There are many others that make converters that will handle the abuse. As far as leaving it locked while shifting, I dont think any trany will hold up to that. It would also defeat the purpose of the "stall" in an aftermarket converter. while you could tune it to lock up directly after shifting the fuel economy gains would be small IMHO. also the stock tune has the converter locking in 3rd and 4th not just 4th as was posted above

Ragtop 99

iTrader: (7)

You can lock-up in second gear and first, but be VERY careful. The risk is to the tranny, not the converter. If you use lock-up in second gear, I'd have it release by 33% TPS. I would not lock through the shifts either.

Wesmanw02

iTrader: (4)

Are automatics really that weak internally?? I figured a built auto would be able to handle plenty of power going through a locked converter, apparently not though.

kanewolf

Exactly! I was thinking that the "direct connection" would be a good thing. Now I'm hearing I'm gonna burn up my tranny (as if I needed to punish it any more than I already do)
Gold Z said "midrange aftermarket converter" is a must have. But I'm not aware of seeing it in Jegs, SLP, etc... for my specific application. Can anyone suggest a specific web site or manufacturer that makes a midrange converter for an "01 LS-1 A-4? Also, do I need to be a tranny expert to swap converters, 'cause I'm ok in the garage, but I'm not a supertech as some of you folks are. (obviously not considering my quandry)

Gold Z

iTrader: (3)

My recommendation would be a Vigilante 3200 by Precision Industries. Do a search on Vig 3200 for lots of information. It's actual stall speed will be closer to 3500 rpm and they work great as a street/strip converter. I'm running 6.7s in the 1/8th with mine. Several of our sponsors sell them. I think I've tried almost every brand out there except Fuddle and the Vigilante is the best brand on the market for long life and performance in my opinion. They cost a little more but you get what you pay for. Here is a link to their website, http://www.converter.com/. TCI, Yank, and Fuddle sell converters to fit your car also. Stick to a converter in the 3000 to 3500 range and you'll go alot quicker and drive decent on the street too.

kanewolf

Thanks Gold Z, I'll check them out.