How To Choose A Torque Converter?

[Carlwalski]

Hi guys, I'm going to build my TF727 up for war for my next project car. It will run a Turbo Action manual valve body (Part # 17675 or 76). Now, my question, how do I choose the right stall converter for my engine/needs? I know you need to use your cam specs and/or engine power band. I have provided my engine dyno sheets below. The power/torque is flat and comes in very low, a good street brawler. I'm not sure how high up the rpm range I need to go or what I need to select the "perfect" stall range? The car will be a full street car, no track work (maybe once for a #).

I've never really understood fully what a stall converter does so may as well learn about it now I'm on to that stage. As far as I'm aware it allows you to foot brake the car (on the spot of course, at the lights etc) add throttle, at which point the car won't move or creep forward but rather hold that power at the selected/transmission stall speed. Let go of the brakes as quick as you can and WOT it for a good take off, it's all about the launch. Have I got that right?

I want to stay with Turbo Action Cheetah, here is what Jegs have, 4 TF727 options, 3 10" and 1 11".
www.jegs.com/p/Turbo-Action/869733/10002/-1 what size do I need? 10" or 11" converter?




Thanks,
Carl

[72hemi]

What I did was give my cam specs to Spec Rite Converters and they made me a converter to match it. I've only had it in for about a week, but so far I am extremely pleased. http://www.specriteconverters.com/

[Chryco Psycho]

your dyno curve starts at 3500 so it is of no help
 basically the converter stays unlocked allowing the engine to flash up to a given RPM before locking up & putting load on the engine , you do not want it to flash too high & remain unlocked on the highway so gearing needs to be taken into consideration as well typically a 2400 RPM is about as high as you want to go with most street combos

[Carlwalski]

Thanks guys.


Neil, I just checked and on my engine dyno sheet stuff, that is as low as any of them go (3,500). My rear end gearing in the D60 is 3.54:1 and at this stage will stay that way. So around 2,750rpm with 28 OD tyres I plan to run. To be safe, bank on 3,000rpm max. I talked to Tim who said his engine will be fine at those rpms. Don't want to run a GV (for obvious reasons lol) and don't want an A518, too heavy, power hungry and for this car don't want 3 pedals, aiming for a street line straight weapon, no show, all go. 

[ShelbyDogg]

Carl,
The smaller you go the hotter it gets.  If you can get a stock 10-3/4 converter that Road Runners and other high performance Mopars used, I think you will be happy with the performance with that torque and HP number.  As long as you don't run a trans brake, you don't need a $1000 converter. 

Rob

[Carlwalski]

Thanks Rob. You mean like these MP converters?
They list 3 styles, I think the 166K sounds like the converter I need.

145K = 1900-2100 stall speed

166K - 2250-2350 stall speed

175 = 2400-2500 stall speed

 http://chucker54.stores.yahoo.net/mopper41.html


Thanks!

[ShelbyDogg]

Thanks Rob. You mean like these MP converters?
They list 3 styles, I think the 166K sounds like the converter I need.

145K = 1900-2100 stall speed

166K - 2250-2350 stall speed

175 = 2400-2500 stall speed

 http://chucker54.stores.yahoo.net/mopper41.html


Thanks!

I think that stall speed would be a good starting point. If you go too high on your stall, you'll just spin your tires even more. A big block has so much torque to begin with. The word "econo" in their listing worries me though.   Seems like a good price, as long as it comes with some kind of warranty.

Rob

[Carlwalski]

Hi Rob, I found this chart, while it makes sense, I think it may make a wee bit more to you lol. I plan to build the TF727 I get IN my project car. It'll be a D32 HD TF727, stock. I'm not sure what they came with but it'll more than likely be from behind a 440. Is it worth considering keeping the stock converter? I just thought that since I'm building it up that I should cover all bases. Below is the Turbo Action Hemi converter chart, 10 and 11".


http://www.turboaction.com/converters.html


They list Hemi 11" converters and they note: Converter reconditioned from stock. Incorporates slightly more stall speed than the stock 11" Hemi converter. but they have those listed at: 3,000 and 3,600rpm stalls.

[ShelbyDogg]

I like Turbo Action. When I raced, I used the Tubo action "J" converter with the anti ballon plate for use with a trans brake. But I also used a cooler half the size of my radiator to cool it.  Just remember that the "smaller-higher stall-loose" you go, the more slippage and heat you will generate just cruising around.  The stock mopar converters, 10" and 11", were actually 10.75" and 11.75. More like 11" and 12".
Behind my street 440 cars, I always used the stock 10.75 units and dumped the 11.75s.  The stall was high enough to always easily break my L-60, 275-60s street tires loose and were everywhere at swap meets or junk yards. Using slicks changes everything.
 
I'm all about 4 speeds now so you'll have to ask some of the automatic guys here what they recommend. I would stick with a lower stall because the torque of a big block raises that stall rpm anyway. The only time I bought a new converter was to race, and I wasn't going to cheap out and buy 2 of them.
Here is a link to Jeg's Turbo Action page.  Good luck picking one. I don't know if their 10" means 10.75"  anymore.
http://www.jegs.com/p/Turbo-Action/869733/10002/-1
Rob

[tactransman]

NZ, I really would like to see you go with a CRT LBA V.B. Did you call John and talk to him?

[Carlwalski]

NZ, I really would like to see you go with a CRT LBA V.B. Did you call John and talk to him?

Hi Terry, I did indeed, twice but no answer so I just gave up lol.PM if you have an ideal converter size, you're the trans guy around here and I've heard and seen your work and many happy customers.

[ShelbyDogg]

I would go with the valve body that Terry recommends. I've used the Turbo Action Manual valve body and buy them at swap meets for $75, but Terry says that these do not have the "low band apply" feature that keeps your sprag from being shocked so badly. If you plan on doing nice take-offs, which start in first gear. Get one with this feature. We all show off in our cars now and then.

Rob

[tactransman]

I would try calling him again,he answers every time I call.    Ask him about a converter also.

[Ck[FIN]]

I would go with the valve body that Terry recommends. I've used the Turbo Action Manual valve body and buy them at swap meets for $75, but Terry says that these do not have the "low band apply" feature that keeps your sprag from being shocked so badly. If you plan on doing nice take-offs, which start in first gear. Get one with this feature. We all show off in our cars now and then.

Rob

Remember to use bolt in sprag if you use cheetah valve body.

[moparniac]

Okay first off...  Terry is right as I have a cheetah MVB with NO LBA.... I dont believe the LBA cheetah was around when I got mine... I am going to get one eventually  cause when you downshift to 1 it takes a neutral affect and gears up to like 4000 and some people drop it down in 1 hard and smash the pedal and blow the sprag out.... you have to be at almost a dead stop to get it to engage at 1 fully from the go!

2nd
BUY a custom converter ITS WORTH IT......... With todays technology i disagree with some of the above comments saying you cant run a 4000 stall on the street/highway or whatever....
simply not true !!! why cause I run more than that with NO issues..

your question was for the "how do I choose the right stall converter for my engine/needs?" get a custom one.....

Atlantic Coast Converters did mine and a guy that runs mid 9's all day long at the track and NO issues on the street in a 70 hemi cuda 3800lbs ALL motor... has the same

I have a tranny cooler and made my own braided tranny cooler lines also.... 

Oh yea. His name is Chip Owens here a vid..... I can hook you up with him if your still a non believer..... tell him jason sent you from moparts as he'll know who I am..... 

 

http://www.youtube.com/watch?v=aCQt_cATHLk

BTW my custom 9" drives better than my off the shelf coan 11" did ...and your engine decides the stall point not you thats why they say 2800-3200 stall as its just a ball park range