Competition Looser or Tighter Torque Converter for track?? 3rd gen.

[ChrisKringle]

I'm going with a DTT transmission (unless somebody tells me otherwise) for my 2004 and I need to know what torque converter set up to go with. Will a looser '89 percent' or a tighter '91 percent' converter get ya down the track quicker?





Should I do the flexplate as well? DTT doesn't recommend it, says the money should be put toward the output shaft if anything (assuming I'm going with the billet input as well). Is it gonna go with 6-700hp?

 

[COMP461]

Looser or tighter has nothing to do with percent slip, a looser converter means that the converter will achieve stall at a higher RPM, and tighter means it will achieve stall at a lower RPM. IMO most of the diesel converter builders haven’t a clue as to what a torque converter is really for in a drag racing environment. Most try and put as much clutch in the converter in the can as possible, and use it like a slider clutch, completely overlooking the abilities of a converter. As in my HP VS. TQ discussions ,hp is a constant figure you have from the flywheel to the tread of the tire, and everything in-between is used to manage this torque to achieve maximum acceleration.



First a torque converter is just that a torque converter ,its is a variable gear ration , and when it is not 1 to 1 it is multiplying torque , that’s right you feed in a given hp and get the same hp out but at a reduced speed , and now have greater torque at the out put shaft . now as to converter selections if you are going to use this as a drag race , pro street type then I would suggest having it stall where it makes power , keep in mind that as your power level goes up so dose the stall. I stall at peak power , around 4500 Rpms , as the 03 truck you have will not rev that high you might pick something a little lower , My suggestion would be to talk to people that have been building Drag racing converters for decades , COAN Engineering . I have talked to Jason and he has been working on diesel converters for a good while, you might be surprised who really dose the big name diesel converter for a few diesel transmission company’s. My converter locks up with in 3 % and it doesn’t have any clutches. Jason number is 765. 456. 3957

http://www.coanracing.com/

 

[mcoleman]

Chris, I wouldn't recommend the 91% or the 93% if your going to be doing any towing. The 89% will still allow the motor to build boost and tow and you can lock the tc clutch with a mystery switch once you are in 2nd gear at the track anyway. Give Bill K. a call and talk to him about it. You won't need the flexplate with DTT converters. Go with the billet input and output shafts. I made the mistake of going with just the input shaft and hub and sheared the output on the 2nd 10 pound launch.

 

[ChrisKringle]

Looser or tighter has nothing to do with percent slip, a looser converter means that the converter will achieve stall at a higher RPM, and tighter means it will achieve stall at a lower RPM. IMO most of the diesel converter builders haven’t a clue as to what a torque converter is really for in a drag racing environment. Most try and put as much clutch in the converter in the can as possible, and use it like a slider clutch, completely overlooking the abilities of a converter. As in my HP VS. TQ discussions ,hp is a constant figure you have from the flywheel to the tread of the tire, and everything in-between is used to manage this torque to achieve maximum acceleration.



First a torque converter is just that a torque converter ,its is a variable gear ration , and when it is not 1 to 1 it is multiplying torque , that’s right you feed in a given hp and get the same hp out but at a reduced speed , and now have greater torque at the out put shaft . now as to converter selections if you are going to use this as a drag race , pro street type then I would suggest having it stall where it makes power , keep in mind that as your power level goes up so dose the stall. I stall at peak power , around 4500 Rpms , as the 03 truck you have will not rev that high you might pick something a little lower , My suggestion would be to talk to people that have been building Drag racing converters for decades , COAN Engineering . I have talked to Jason and he has been working on diesel converters for a good while, you might be surprised who really dose the big name diesel converter for a few diesel transmission company’s. My converter locks up with in 3 % and it doesn’t have any clutches. Jason number is 765. 456. 3957

http://www.coanracing.com/

So should the converter stall at the engines hp peak or the engines torque peak. I know the horse power peak is going to be close to redline, I think 3000 rpms or so. That's where the engine can do the 'most' amount of work in a given time, correct? Well the torque peak is much lower, probably 1500-1800 rpms or something like that. I read the engine should be kept in the torque peak for racing, is that wrong?

 

[OPoole]

DTT 91% call up stefan 1 866 504 4002 he can help you!!

 

[Bandit1]

with my current mods i wish i would have gone with the 91% with this new transmission, not that they 89 is loose bc it def isnt. i just spool it so fast that it is touchy to drive, if you stay stock or close to it 89 mild to wild bombs go with the 91 or 93. my . 02

 

[Huff N Puff]

I'm going with a DTT transmission (unless somebody tells me otherwise) for my 2004 and I need to know what torque converter set up to go with. Will a looser '89 percent' or a tighter '91 percent' converter get ya down the track quicker?





Should I do the flexplate as well? DTT doesn't recommend it, says the money should be put toward the output shaft if anything (assuming I'm going with the billet input as well). Is it gonna go with 6-700hp?

We need alot more info,to figure out what torque converter to run. If your turbos are on the laggy side run the 89% if you spoolup quick the 91% will be nice at the track and on the street. If the turbos are really laggy the 91% might make you slower thru the 1/4. If your turbos light well the 91% will be quicker thru the 1/4. I have a stock flex plate its held up to lots of 1/4 mile passes.

 

[Cooker]

What gear ratio do you have? How tall of tires are you running?

 

[JBlock]

WHy don't you ask BIll, he the master who builts and design them. As state other place, you need HP for the tighter ones. I was was told stock and DDT don't consider anything over a 89%.

 

[ChrisKringle]

Well I just bought a TCS torque converter for $495! Half the price of DTT! I got and 89%, part #4889. Confirmed, was DTT's supplier of converters 'till recently. Even though ATS has the triple disk clutch area, I'm thinking I might be happier with TCS's stator drive charactersistics. From what I've read, ATS just has no fluid coupling.



So now I've got some extra change, should I do the billet output? Inputs a given.



Flexplate... , was told billet units do not flex, FLEX plates should, so billet units create additional stress to other componentry.





Any opinions?

 

[JBlock]

ChrisKingle



You indicated you got an 89% unit. I read the following on their site"



"Up to 950 RPM drops between shifts versus OEM 100-350 RPM drops!



I am a little confused, It does note say 89% on their site, but it hinted at with 1-2 mile per gallon increase, which implys to me a high efficiencey.



You will have to let us know it performs, the real ticket is the slipage between unlocked and locked.



thanks jeo.