ATX Tweecer tuning question (D4U1)

[1993MTXSHO]

Hey guys, I have been messing with the tweecer on my atx recently, and I am starting to get a good shift program I like. But the one thing I am kind of confused by are the lock and unlock functions for the converter. I am going to be dynoing my car possibly this weekend, and would like to be able to lock the converter down low to get an accurate dyno of what kind of power I am making at lower rpm's as well. I assume I can only lock it in 3rd since there is no 2nd gear lock function, so how would I go about getting the converter to be at full lock at WOT in 3rd gear at say 1500rpm or so (this would be a dyno only tune).

Also what are your opinions on hard shifts? I have my line pressure set to 400 (to command highest line pressure possible) at 80 and 95 load at everything after 2000 rpm. I have also raised my tv pressure a little bit too in each gear. I had it at one point damn near chirping the 1-2 shift (added 10 to each 1-2 shift number as per the tweecer manual recommendation), but I was worried that would **** my tranny, so I backed the tv pressure off a bit so it's a stiff shift, but there is still a little slippage. Am I better off having it slam the 1-2 hard to avoid any 100% throttle slippage, or is a stiff shift with some slippage better for the trans? I am going for longest tranny life here, and I know high throttle slippage is bad especially because it causes excessive heat. But what do some of your veterinarians recommend? I'm am a manual transmission guy I don't know a whole ton about autos, but boy has this atx gotten fun since I have been writing this program.

 

[somedude_001]

as far as I know you cannot command TC lock functions with the tweecer. this has been my big issue with it for quite some time and is the reason I overheat mine so damn fast. I had mine on a switch for a while then the switch melted after 3-4 weeks, then the 12ga wires got all hot and melty then the PCM fuse keeps popping. I later was locking it using a supra headlight on a switch which is completely ludicrous but it did seem to work for a little while but this was all around the same time I killed my trans from the 8500rpm pulls.

nobody seems to know how to put the converter on a switch which is REALLY what I want but to my knowledge the tweecer will not do it either unless I missed a update.

 

[hawkeye18]

You can command TQ lockup schedules on 3rd and 4th gears with the new 10A definitions. PM Axianator for details.

Those "400" values are not line pressure values. That table tells the ECU how much torque the engine is producing at those RPMs and loads. Putting the top right 8 at 400 tells the ECU to program the tranny for 400 lb/ft of torque, which ups the pressures and decreases shift times to reduce slippage. Putting the rest of the cells at 400 will more than likely break a few hard parts after a few shifts.

Nick, I wish I could help you but I've been balls deep in this rear suspension (now that sounds dirty ) all damned weekend. I've managed to break not only the rear pinch bolt but the subframe bushing bracket bolt as well...

 

[1993MTXSHO]

as far as I know you cannot command TC lock functions with the tweecer. this has been my big issue with it for quite some time and is the reason I overheat mine so damn fast. I had mine on a switch for a while then the switch melted after 3-4 weeks, then the 12ga wires got all hot and melty then the PCM fuse keeps popping. I later was locking it using a supra headlight on a switch which is completely ludicrous but it did seem to work for a little while but this was all around the same time I killed my trans from the 8500rpm pulls.

nobody seems to know how to put the converter on a switch which is REALLY what I want but to my knowledge the tweecer will not do it either unless I missed a update.

What did you do for that switch, is there something easy I can do and then just pull it back off or is that switch install pretty involved? I only would want it for the dyno run.

You can command TQ lockup schedules on 3rd and 4th gears with the new 10A definitions. PM Axianator for details.

Those "400" values are not line pressure values. That table tells the ECU how much torque the engine is producing at those RPMs and loads. Putting the top right 8 at 400 tells the ECU to program the tranny for 400 lb/ft of torque, which ups the pressures and decreases shift times to reduce slippage. Putting the rest of the cells at 400 will more than likely break a few hard parts after a few shifts.

Nick, I wish I could help you but I've been balls deep in this rear suspension (now that sounds dirty ) all damned weekend. I've managed to break not only the rear pinch bolt but the subframe bushing bracket bolt as well...

oh yeah, I knew that (about the 400 values) but yeah I appreciate everythign man, I feel like I am bothering you to much which is why I just made a thread haha. But yeah I want to get my shift program down first before I start messing with converter locking and such. But I just wanted to try to figure out how to do it for this dyno run to get some solid numbers. If I do a 3rd gear run to 7500 or so I think I'll have to pull the snow tires off, I don't wanna blow a tire on the dyno

 

[whiteguy3]

What type of gains have you seen from the tweecer on the ATX?

Just wondering if you've felt any differences even before getting official dyno results.

 

[1993MTXSHO]

What type of gains have you seen from the tweecer on the ATX?

Just wondering if you've felt any differences even before getting official dyno results.

Well when I leaned it out up high and ran 93 octane with a 5 degree spark advance, my butt and 2 friends said it seemed faster, and one said it sounded healthier. But honestly, it's entirely possible it's all in my head But my atx is a pretty strong runner to begin with, I will have a stock dyno run soon with only 4 degrees of advance, the leaned out fuel tables, and a k&n air drop in. I will then have a dyno run with EH and then acid ported runners both coupled with BBB. See the link in my sig for the dyno's and info on that soon.

BTW, if you're thinking of getting a tweecer it is TOTALLY worth it on an atx especially. If you're up at Brians again at some point when I'm there, I will take you for a ride, you can write some pretty wicked tranny programs and it makes it a completely new car. No more kicking into gears, it's already downshifted into the gear for the turn and it just goes when you get on it, no more mushy shifts, and for me a 2500 rpm neutral rev limiter to prevent me from acting like an ass hat in public, and to prevent me from burning up my converter in the process.

 

[hawkeye18]

The tweecer is worth its volume in Gold (it doesn't weigh much) on an ATX. the amount of control you get over the tranny is incredible. You can make it shift like a caddy (old skool) or you can make it shift like a ******* ***** ape. The way I have mine set up is very, er, firm, but I like it, and I outshift most manuals, even those that are shifted well. I can set when it shifts at any given throttle application. Minimum upshift speeds, minimun DOWNshift speeds, etc. etc. Mine downshifts into 2nd at 30 mph so every time I slow down to make a 90 degree turn, I'm already in 2nd when I'm coming out of it - no slamming required. Makes coming out of turns fun!

 

[1993MTXSHO]

The tweecer is worth its volume in Gold (it doesn't weigh much) on an ATX. the amount of control you get over the tranny is incredible. You can make it shift like a caddy (old skool) or you can make it shift like a dang ***** ape. The way I have mine set up is very, er, firm, but I like it, and I outshift most manuals, even those that are shifted well. I can set when it shifts at any given throttle application. Minimum upshift speeds, minimun DOWNshift speeds, etc. etc. Mine downshifts into 2nd at 30 mph so every time I slow down to make a 90 degree turn, I'm already in 2nd when I'm coming out of it - no slamming required. Makes coming out of turns fun!

I can vouch for all of that, and out shift MOST manuals? I think the way mine is set up there is no way in **** a human can shift that fast

actually if I get a chance maybe I'll try to post up a crappy cell phone video of how fast the sucker slams gears.

 

[whiteguy3]

I'm definately going to have to move that up on my "upgrade" list!!!

I think by then I will have a couple of other mods (udp, 80mm maf & maybe MTX cams??) and be ready when I get a tweecer.

 

[1993MTXSHO]

I'm definately going to have to move that up on my "upgrade" list!!!

I think by then I will have a couple of other mods (udp, 80mm maf & maybe MTX cams??) and be ready when I get a tweecer.

Come take a ride in my car and you'll sell your body to get one I guarantee it

 

[somedude_001]

What did you do for that switch, is there something easy I can do and then just pull it back off or is that switch install pretty involved? I only would want it for the dyno run.

that is just it. I have not had a successful switch in my car. I have been trying to find someone that knows what needs to be done for over 2 years now. Doug said to use a resistor and had the size listed and I have zero luck using resistors. I don't know what the PCM does to lock the converter without melting wires.

 

[1993MTXSHO]

ah ok, well does anyone know how to get it to lock using the tweecer? A dyno run with an atx wont show any of the usage of the primary's because the converter will be unlocked. There has to be a way to do it using the 3rd gear converter lock function, I am just confused by the graph and what I would have to put in to command a lock for low rpm at WOT.

 

[1993MTXSHO]

So no one has any Idea how to get the tq converter to lock? Has anyone ever even messed with the tq converter lock functions?

 

[hawkeye18]

Set all Y values to 20-25 (depending on how comfortable you are with lugging your engine - remember, this is how the MTX dudes blow rod bearings!) on the Sealevel Converter Lock - 3rd table.

Then, make all 1-2 shift table Y values say 15, 2-1 shift table Y values say 13, 2-3 shift tables set to 20, and 3-2 shift tables set to 18.

Set all the 3-4 shift table Y values to 127 and 4-3 tables to 120. This will pretty much lock your car in 3rd gear at the lowest speed it can sustain it.

The 20-25 value may be off; I'm just winging that number. Try it out, but lightly - you don't wanna bog it out too much. If it's too low, increase every number from 3-2 on down up a few mph as needed to get the car shifting into 3rd so that it's at at least 1500 at the bottom of it. You'll want the torque converter engaging around 2Krpm.

 

[1993MTXSHO]

Set all Y values to 20-25 (depending on how comfortable you are with lugging your engine - remember, this is how the MTX dudes blow rod bearings!) on the Sealevel Converter Lock - 3rd table.

Then, make all 1-2 shift table Y values say 15, 2-1 shift table Y values say 13, 2-3 shift tables set to 20, and 3-2 shift tables set to 18.

Set all the 3-4 shift table Y values to 127 and 4-3 tables to 120. This will pretty much lock your car in 3rd gear at the lowest speed it can sustain it.

The 20-25 value may be off; I'm just winging that number. Try it out, but lightly - you don't wanna bog it out too much. If it's too low, increase every number from 3-2 on down up a few mph as needed to get the car shifting into 3rd so that it's at at least 1500 at the bottom of it. You'll want the torque converter engaging around 2Krpm.

ok cool thanks I'll give that a shot. I'm not worried about bogging the engine this is going to be a one time dyno run thing only. Plus my rod bearings only have about 3k miles on them so I'm not worried.

 

[somedude_001]

Set all Y values to 20-25 (depending on how comfortable you are with lugging your engine - remember, this is how the MTX dudes blow rod bearings!) on the Sealevel Converter Lock - 3rd table.

Then, make all 1-2 shift table Y values say 15, 2-1 shift table Y values say 13, 2-3 shift tables set to 20, and 3-2 shift tables set to 18.

Set all the 3-4 shift table Y values to 127 and 4-3 tables to 120. This will pretty much lock your car in 3rd gear at the lowest speed it can sustain it.

The 20-25 value may be off; I'm just winging that number. Try it out, but lightly - you don't wanna bog it out too much. If it's too low, increase every number from 3-2 on down up a few mph as needed to get the car shifting into 3rd so that it's at at least 1500 at the bottom of it. You'll want the torque converter engaging around 2Krpm.

As soon as my car gets a replacement transmission I will give this a shot.

1993MTXSHO if you get a chance to try it out first let me know how it goes.

 

[hawkeye18]

a friendly reminder: set the TQ lock table values 1-2mph higher than the 2-3 shift values. You want to give the engine a chance to stabilize before the TQ locks up on it.

 

[1993MTXSHO]

As soon as my car gets a replacement transmission I will give this a shot.

1993MTXSHO if you get a chance to try it out first let me know how it goes.

Will do man, I'm writing a tranny shift program and such now and will be doing the tq converter thing next on a separate tune. I'll see how it goes probably at some point this week.

 

[1993MTXSHO]

Well guys I ran the dyno tune just now and the car stayed in 3rd at any throttle position, but anything past 1/4 throttle it would unlock the converter. I am at a loss on how to get this converter to stay locked. Anyone else got any ideas?

 

[1993MTXSHO]

bump, anyone have any other ideas how to get the converter locked, I really wanna dyno this car asap.