Why don't they rate these things at stall RPM like car convertors?

I'm going to be running a 2WD truck that will have a raceweight of about 6100lb, which is substantially lighter than most trucks with the Allison.

I want this truck to stall at 2100rpm with only about 500ftlb worth of boost on the launch. Otherwise the tires probably won't hold.

Which convertors are "looser" and "tighter"?

On the Suncoast website it says that Joe will build you a converter to whatever spec. you want. They build all their converters in house.

McRat, Talk to Mike L. He has the low down on what Joe is doing with converters these days.

Why don't they rate these things at stall RPM like car convertors?

I'm going to be running a 2WD truck that will have a raceweight of about 6100lb, which is substantially lighter than most trucks with the Allison.

I want this truck to stall at 2100rpm with only about 500ftlb worth of boost on the launch. Otherwise the tires probably won't hold.

Which convertors are "looser" and "tighter"?


I thought you ordered a ATS? Talk to Clint he'll take care of it. ;)

DTT has a very tight single disc.

DTT has a very tight single disc.

That's what you said before.......... where is yours.):h

Tight is not necessarily good. It's a function of the impeller and stator design. For RV use, tight is what you want. For racing, you need a looser convertor. How loose? I have no idea. I can stall a stock convertor at 2500 using 375rwhp in 7500lb 4x4.

That's what you said before.......... where is yours.):h

Mine?
The old prototype I ran was DTT's property. I never paid a nickle for it so it was not mine to keep. They wanted testing done on it for Stage 1 and Stage 2 of trans. The new product is being built based on the provided information. And until it is ready I will live with this 'pop slippity' stocker.

Tight is not necessarily good. It's a function of the impeller and stator design. For RV use, tight is what you want. For racing, you need a looser convertor. How loose? I have no idea. I can stall a stock convertor at 2500 using 375rwhp in 7500lb 4x4.

I beg to differ...................the TTS triple is one of the "tightest" out there for the allison and it is doing exceptionally well on my truck. Maybe a loose converter is desirable in a 2wd with little to no traction but deffinately not in a 4wd.

I know Tomac ;) Well you ask him :)

The more HP you make the tighter you need depending on the RPM window and weight of vehicle. With a limited RPM range, you want the best fluid coupling you can get and the least amount of drop between fluid coupling and lockup (from what dragracers agree on) You don't want your 1100 BHP 9300 RPM motor with a stall speed of 1700 RPMs (that engine makes no power that low). you want it to 'flash' in the meat of the powerband so when the tree drops, you are in the meat of it.
On the other hand, the Diesel. Since we do not have a bajillion revs and high horsepower, our acceleration relies heavily on Torque to move our heavy weight down the 1320.
If we had more revs to play with, and more HP than torque, perhaps looser is better. Other things factor in as well. Tighter convertors load lower in the RPM band. Can you spool your turbo adequately?


Just a couple thoughts. I am sure there are many points i have not considered, feel free to correct me Steve, Mike, Bill, Smoop or anyone else.

The converter only has one job, to convert engine power into the transmission. It does this and when done properly will multiply the torque by a given amount. Once you leave the line and go into second gear the Allision locks the converter clutch and the job of torque multiplication is over and done at a drag strip. So when at the drag strip the converter in a allision will not show what it is truely made of unless it's really bad in design. Where you can really tell is when after adding a converter you must depress the throttle more to get a given load moving, if this is the case you've lost torque mulitplication. A simple test is to drive the vehicle with very light throttle pressure and see if the hood raises when you lightly depress the throttle on start off from a stop. If it feels like you are being pushed from behind rather than pulled from in front then its not a good converter. Just remember one the converter clutch is locked they are all equal unless one is slipping.

on edit: fix spelling

Can you spool your turbo adequately?

Well kyle has got to have the loosest convertor in a dmax and he still uses the e-brake to try and spool. lol

Well kyle has got to have the loosest convertor in a dmax and he still uses the e-brake to try and spool. lol

Does the Aurora take that much time to spool? or is this a bigger turbo?

I was watching the pulling vids, AWESOME!

My old TC would stall at 1950 RPMs. Just below my dynoed torque peak. When you let go of the brakes ... wow. What fun!

Converters can be manipulated with extreme power. At this time I am running an ATS converter that I stole from Trippin who is now running TTS. When I am in the TTS Extreme program with this converter I must launch at 2100 rpm to keep from bogging. If I had the TTS converter I would haze the tires at 1700 rpm. I am able to launch with any converter( almost) with the power that I have. The problem is, at 2100 and above rpm the truck dances too much off the line and my 60 ft time sucks. Converter choice should be carefully discussed with your tech. Tire size has a lot to do with this along with your program of choice. If you do your homework properly you can enhance your power program big time. I am in the process of helping McRat do some neat things with his new truck so that he can kick my butt. :banghead: :duh: ):h I will learn some new things with this testing. McRat has visions of 11s :eek: and I will help him get there.

I am in the process of helping McRat do some neat things with his new truck so that he can kick my butt. :banghead: :duh: ):h I will learn some new things with this testing. McRat has visions of 11s :eek: and I will help him get there.

Knowing McRat, 11's won't be enough. :eek:

High 10's would be more realistic....:ro) Gotta beat Meanie at it's own game....

Tom :pig:

High 10's would be more realistic....:ro) Gotta beat Meanie at it's own game....

Tom :pig:

Leave my car out of this :Moon:

McRat has visions of 11s :eek: and I will help him get there.

Just PULL him down the track, that way u both can be in the 11's ):h ):h