I’m trying to determine if I have a mechanical problem or if I just need a programming change for a Monster Box with the Total Domination Torque Converter.

Is the Monster Box supposed to just drop in and drive correctly?

I’ve heard of others having a higher stall put in that had to change the TC lock up points to keep it from floating around?

This is my third Monster Box, the first two were bad out of the box. The first one had a bad torque converter and the second one had a bad batch of weak springs in the valve body. After diagnosis, Jasper replaced these combos and I couldn’t be happier with their customer service. But right now I’m just trying to find out where the problem with the third one exists.

This last one seems to work mostly correct but not completely. It functions perfectly at WOT snatching the shifts firmly without banging. Also the 1-2 shift is perfect at any throttle position.

The problem I seem to be having is that during light throttle driving during the 3-4 shift I can feel the transmission shift nice and firm but then the TC takes about 3-4 seconds to fully engage to complete the shift. Where it is noticeable and extremely inconvenient is during a part throttle kick down at highway speeds. It will often hunt for which gear it wants to be in 3rd or 4th. Also, the TC won’t lock up while it’s in 3rd so while you are in 3rd passing somebody at a medium throttle the RPM is varying depending on how steady you are able to gas. It will also do this in second gear too.

It seems like the transmission is working properly and I can feel the shifts are nice and firm in all throttle and speed conditions. If I had to guess I would say that the TC isn’t performing correctly, but if I load it up it seems to work right, so that has me questioning whether this is a mechanical problem or something that just needs a program adjustment.

 

dont have an answer for you but that is kind of scary. i am about to install mine soon. i thought they were all dyno tested to make sure they work properly??

 

The engineer there told me that they are all dyno tested, but all that means is that they put in on the machine with a relatively small load and make sure it runs through all the gears then they drain it and ship it.

 

I'd be livid pulling the tranny out three times. Scares the heck out of me.

I had a similar problem with my tranny clunking back and forth between 3rd and 4th gears under acceleration. Try reloading your tune back into the truck if you are using a flash tuner. I actually restored the factory tune back into the truck, which simultaneously cleared out the Predator, then I reloaded my custom tune onto the Predator from my PC, and then from the Predator back into the truck. Problem solved. It was almost as if the computer somehow became corrupt by itself.

 

Can't hurt to try, I've been wanting to do the upgrade on the predator software anyway, this will give me a good reason.

 

stock tune for 10k.

 

This is from a post I just started over on NLOC

I've been chasing what I feel is an issue with my MB for the past year since this third one has been put in. Here is some datalog graph that I believe that shows a problem. The yellow is Engine RPM, the Red is the TC output, and the Green is Transmission output. The TC output seems to be chasing behind the Engine RPMs by about 300-700 RPMs all the way through the gears until about 3-4 seconds after the 2-3 shift then it fully engages. You can feel this too, it certainly doesn't feel natural because you can feel the shift then right after you can feel this second TC engagement that takes about 2-3 seconds all during WOT. It just feels like the motor is disconnected from the transmission not matter what the driving conditions are except for cruising when the TC is under mechanical lockup. This doesn't seem right to me, isn't the TC ratio supposed to be close to 1:1 after the engine reaches the stall speed even if it's not under mechanical lockup mode?

http://www.svtgalleries.net/gallery/...hp?photo=16376

Your're right about the lock up 100% in my case 90% a little after the 3rd gear shift. I did a little more investigating my data. My readings show the signal for lock up doesn't come until after the 2-3 shift like you said.

This computer management may be fine and have minimal slippage for a stock Stall and engine power configuration, but it is certainly not acceptable if you lose an additional 20% of your power through Torque convertor slip in addition to the normal 15-20% for the total drive train. All that energy is going to heat and none to the wheels.

This issue explains a lot though. I make good horsepower numbers at the dyno with the truck is locked into 3rd gear (420) but my track times and specifically tracks speeds, that are in the 101-102 mph range, correspond to what other trucks are running that have 380-390 HP.

What you're saying is that this is how the factory program is setup? because my next step would be to pull my pulley so I can make a WOT datalog with the factory tune to see if the Torque Convertor Clutch Modulation output (TCC) gives me the same output as it does with my custom tune.

It should because, I was told nothing is different in my tune as far as the transmission goes except that I have Torque reduction turned off, but that's more of an engine cutting the power thing than a transmission control.

Clearly this is not acceptable operation with my setup to lose so much to slippage because we aren't talking about slippage at the launch, it's slippage through out the entire run. How can the tuner compensate for this? In other words how should the torque lock up strategy change?

 

What this comes down to is that there is supposed to be a certain amount of slippage before the torque converter lock up occurs. After reading a couple of TC manufacturer's websites the number of 3% comes up. So at 5400 RPM's of the motor, based on 3%, I should only lose 160 RPMS through my TC. This is consistant with 200 RPM difference Alan B told me over the phone as a maximum for converter slippage. SO we go pack to mine: At WOT I have a minimum slippage of 400 RPM's during 1st gear about 600RPMs through second and almost 800 RPM's during 3rd gear before the Torque converter clutch locks up and puts me at 1:1 with no slippage.

So what does this mean? Other than making the truck feel like crap to drive because it is so mushy, the main thing this means is that I'm losing power. This slippage that I am refering to (not to be confused with the slip during stall) is energy lost to heat which is taking directly away from engine power. So if my TC was in spec and was not loose I would only get 3% slippage like everybody else which would correspond to a 12HP power loss at 420RWHP. In my case I get between 400-800 RPM's of slip. That corresponds to a 30-60 HP loss. NOT COOL!

Why is it that noone really talks about this when they are talking about convertors? The only thing you see discussed is the stall speed.
Clearly I got a bad convertor. The Warranty techs are telling me that there is supposed to be a certain amount of slippage. In one conversation they started by saying 200RPMs like Alan B and by the time we got off the phone it has worked it's way up to 400RPM as being acceptable.

 

3% seems a fair arbitrary number for slip on most applications, but our torqe may cause a higher slip rate.
I am willing to bet that modifying lock up in the tune will yield a more satisfying driving experience.
I run a PI 2800 stall and Jim at JDM took extra time to dial in my lockup points thinking I would not like the extra slip around town. Truthfully I would be ok with the additional slip,having run many higher stall converters in the past. As a matter of fact I chose a higher stall than most run to better match my MP blower's power curve.
Jim

 

From what I understand, slip and stall are two different things, just because you have a higher stall doesn't mean you have to have a higher slip. They might be somewhat related, but don't have to be directly related to each other. I had considered doing something like you are doing with the tune for driving around town once I get a good convertor. However, I don't think it's a good idea to have the clutch engage during WOT or a hard run. You have to have some buffer in there otherwise you'll rip something apart.

 

I get very confused with torque converters... My tuner told me that my torque converter wasn't FLASHING until 4300 rpms and that was way too high... What is flashing and is that easily seen by a tuner on a dyno? I need to yank out my torque converter for the second time it seems... I was told it might be a bad stator or something...

 

He means the Flash stall. I'm not an expert, but this is what I understand. The Flash stall is the closest practical way to measure the stall of the TC. Just spooling the engine up with the brake on is off a little. To get a flash stall you do a hard launch and it is the slip in the TC the instant (flash) before the wheels break loose.

 

So since my TC is supposed to be a 2600-2800 stall, that 4300 flash is BAD and I might as well get ready to yank it? The good thing, is the vendor has been top notch and stated they will take care of me...

 

It this kinda what your talking about ???

Notice how lose it is even up at 60 -70 MPH

CLICK HERE

In this one you'll see it starts off with the Convertor Locked and Trans in OD
but then a few sec's into the Vid, it's unlocked and in 3rd
CLICK HERE


And this last one will give you an idea of how lose it can be in first gear
CLICK HERE

I DO NOT have a MB, but I do have the FTVB and Total Domination Convertor
It DEF took some getting use to, and now that Sal has tweaked my shift points, down shifts, convertor lock ups, it's pretty much NOW un-noticable.
Those Vids were when I first put it in before those teaks. It truly was waaaaaaaaaaaaaaay too lose and not too good on the MPG if you know what I mean. The truck was at 3500-4500 RPM 24/7 BEFORE Sal worked his magic,
(unless you were in OD in the parkway, and I dont use OD on the street).

I truly love this Convertor and it's NOW totally diff that those Vids show it,
so to answer your question YES you can DEF tune the Chip to that combo,
WE DID. You just need a good tuner to work with you. I can also say I found 55 MPH is PERFECT to let it shift into OD, then as said a sec or two later lock the convertor. Mine also will come out of OD and UNLOCK at exactly 45 MPH (if I dont do it myself by pushing down on the pedal first) It took some trial and error, and Sal worked with me over and over on it, but now it's perfect.
In those Vids' it was NOT.

EDIT
Dont mind the gurrgling sound, I had a cooked plug that night (AS USUAL) (@$@$(%@$@$%(@$%(@$^%(@$^%@$

 

But when I mention it not flashing until 4300 rpms, that is totally different, correct? Like I said, i don't know a thing about torque converters and don't want to yank mine out if I don't have too...