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Discussion Starter · #1 ·
Before I broke my stock tranny I could "powerbrake" and do a burnout pretty easily. Had my tranny built and told them I would prob only be towing with it but wanted support for 500-600 horse. Got tranny in, it tows AWESOME with the smarty but I can't do a burnout to save my life now! At about 2500 rpm it feels like it quits putting power to the ground. Also, if I have the smarty on with my tst it's a rocket but with the tst by itself on any setting the power comes on so hard and fast that my rpms shoot over 2500, my engine is screaming but it don't feel like the power is getting to the ground. I talked to the place that built the tranny and they said they built it for towing like I wanted and I should gain a little mpg and about 500 rpm in overdrive which I have but do I have to give up power on the top end for that? Is the tc stall even the issue or what? I'm confused.
 

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I feel the same way about mine some times doesnt seem to get the power to the ground but I can still do a good burnout. It will take some juice to get those big tires smokin though...
 

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Discussion Starter · #3 ·
That's partly why I'm baffled... I could smoke the tires pretty easily with the stock tranny (before it broke:w:)
 

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the 37s dont help,but what tranny and TC did you get?I had a suncoast in my Ford with a triple disk lower stall TC and acceleration went down as well as off the line power but at idle I had to keep a good bit of pressure to keep it from moving,and once up and going very efficient.Lower stall wont help you,your stock tranny had a higher stall that helped get things going.Do you still have the 373 gears,if so that probably isnt helping any comboed with the tighter lowe stall TC.
 

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Discussion Starter · #5 ·
Yeah, I've got 3.73's. I have noticed it takes a little more brake pressure to hold at a light. If it's a long one I put it in neutral cause I get tired of pushing on the brake. Doing a burn out isn't high on my list of must haves just trying to figure out if lower stall is the issue. If it is, I'm fine with that. I told the builder I wanted to TOW and the more weight I hook to it the better it responds.:thumbsup
 

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More than likely you have a tight converter. I do. With a stock converter it jumps up into the upper rpms and jumps the power to the wheels. Tight converters won't jump up like loose ones. The higher the power the more your going to "push" through the stall.
 

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do I have to give up power on the top end for that? Is the tc stall even the issue or what? I'm confused.
Don't think they did you any favors with that converter. If you can hit 2500 rpms and not spin the tires you are defueling and driving right thru the fluid coupling.

You need a tighter converter that has better TQ multiplication than what you got.
 

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Discussion Starter · #8 ·
More than likely you have a tight converter. I do. With a stock converter it jumps up into the upper rpms and jumps the power to the wheels. Tight converters won't jump up like loose ones. The higher the power the more your going to "push" through the stall.
Great. So cranking up the power will just make it worse huh.

Don't think they did you any favors with that converter. If you can hit 2500 rpms and not spin the tires you are defueling and driving right thru the fluid coupling.

You need a tighter converter that has better TQ multiplication than what you got.
When the converter is locked the thing scoots like it's going out of style. Is getting a tc with better tq multiplication gonna hurt any of my towing ability? Sorry if thats a dumb question. I'm fairly mechanically inclined but this tranny might as well be rocket science.:ah:
 

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When the converter is locked the thing scoots like it's going out of style. Is getting a tc with better tq multiplication gonna hurt any of my towing ability? Sorry if thats a dumb question. I'm fairly mechanically inclined but this tranny might as well be rocket science.:ah:
Yes, with the TC locked you are not slipping thru the loose fluid coupling so it will haul the mail. :thumbsup

If you get a TC that is designed correctly you can go much tighter with the fluid coupling and still be fine towing. In fact it helps your towing abilities considerably.

The stock TC stalls at 2100 rpms with stock fueling, higher the more power you add. Anything over 2000 rpm's and zero wheel speed the ECU will go into defuel mode, chopping 50-60% of the fuel delivery. Unless you turn off these features all your DL'ers and boxes won't make a difference.

I have a custom TC with stall speed set to about 1700 rpms and roughly 85% efficiency. On a brake stand, as soon as I hit 7 lbs of boost and 1700-1800 rpm's the rear tires will light off and you cannot hold them with the brakes. With a load and aggressive acceleration the rpms flare to about 2500 and holds when the fluid coupling engages. The acceleration with 5-7k is comparable with the stock TC with empty truck.

I have what is called a 10 blade left cut stator and it works great. The other popular stator is 15 blade left cut but unless you run lots of power and TQ management delete it will bog the engine towing.

You have too loose a converter with just slightly better TQ multiplication. Its probably all right for a stock truck minimal power and stock tires. With your combination you need more hook lower in the rpm range. :thumbsup
 

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Cerberusiam, where did you get your converter from? Sounds like I could use one of those bad boys...
 

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Yes, with the TC locked you are not slipping thru the loose fluid coupling so it will haul the mail. :thumbsup

If you get a TC that is designed correctly you can go much tighter with the fluid coupling and still be fine towing. In fact it helps your towing abilities considerably.

The stock TC stalls at 2100 rpms with stock fueling, higher the more power you add. Anything over 2000 rpm's and zero wheel speed the ECU will go into defuel mode, chopping 50-60% of the fuel delivery. Unless you turn off these features all your DL'ers and boxes won't make a difference.

I have a custom TC with stall speed set to about 1700 rpms and roughly 85% efficiency. On a brake stand, as soon as I hit 7 lbs of boost and 1700-1800 rpm's the rear tires will light off and you cannot hold them with the brakes. With a load and aggressive acceleration the rpms flare to about 2500 and holds when the fluid coupling engages. The acceleration with 5-7k is comparable with the stock TC with empty truck.

I have what is called a 10 blade left cut stator and it works great. The other popular stator is 15 blade left cut but unless you run lots of power and TQ management delete it will bog the engine towing.

You have too loose a converter with just slightly better TQ multiplication. Its probably all right for a stock truck minimal power and stock tires. With your combination you need more hook lower in the rpm range. :thumbsup
Great Post for people with auto trans, the torque converter is a very mysterious component in our Cummins trucks. The best advertised units are not always the best performing.
 

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Cerberusiam, where did you get your converter from? Sounds like I could use one of those bad boys...

Idaho Transmission Warehouse, Boise Idaho.

They build them locally so I know who to track down if I have a problem. :lol3:

Goerends, DTT, Suncost, Dunrite, to name a few, can do the same thing at varying prices. I would NEVER put a TC in one of these trucks unless it was from one of the recognized vendors and I talked with them about how they build the TC.

I don't trust any run of the mill trans shop. Too many issues with them.
 

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Discussion Starter · #13 ·
:CRY: So much for saving money!! Now what should I do? Go back to the place that built it and try to talk them into fixing the issue or just eat it and get a good converter?
 
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