Tight vs Loose Torque Converters

[Moparfiend]

So at times I have received recommendations on getting a tight and loose converter for say the same stall range. How does one specify a tight or loose? For example: Can I get a tight 3000-3800 TC and a loose 3000-3800 TC? What makes a TC loose vs tight?

 

[Kern Dog]

While I will likely never profess to be an expert, basic common sense tells me that Tight/loose might refer to how the converter acts at light throttle.
I had a 9 3/4" converter that was a slippy, sloppy performer at light throttle. I hated it. At wide open throttle, (WOT) it was great but at any other time, it slipped enough to make the car feel lazy.

 

[33 IMP]

If they start with a larger (physically) converter body, then modify it internally to get more stall, it will generally be looser, or sloppier than a smaller converter of the same stall. The smaller converter body just natually stalls more because of less volume of fluid in it, so it can be built tighter. A four grand 11 inch might go down the road at 3000 grand while a four grand 9 inch might go 2500, even though they both stall 4000. The nine will probably cost twice the 11 inch., or more, but work twice as well.
Edit , i had a 11" that was supposed to be 3200. It stalled at 4000, and drove down the road at 3500 in any gear. I could hold it at a fixed rpm and put the trans in first second or third, without changing speed or rpm. Beyond awful. Utter garbage (but it was cheap!). The nine in my car now drives pretty good, and the newer ones are even better.
2nd edit: Hughes performance has a series of videos on you tube about converters and stall speed. Highly recommended. Especially see #5, stall speed.

 

[Moparfiend]

While I will likely never profess to be an expert, basic common sense tells me that Tight/loose might refer to how the converter acts at light throttle.
I had a 9 3/4" converter that was a slippy, sloppy performer at light throttle. I hated it. At wide open throttle, (WOT) it was great but at any other time, it slipped enough to make the car feel lazy.

Makes sense that sounds like a crappy match up even if it had the right stall. So what I am wondering is can we quantity the TC looseness/tightness? I bet we cant and only the guys that make them have a secret recipe.

 

[Moparfiend]

If they start with a larger (physically) converter body, then modify it internally to get more stall, it will generally be looser, or sloppier than a smaller converter of the same stall. The smaller converter body just natually stalls more because of less volume of fluid in it, so it can be built tighter. A four grand 11 inch might go down the road at 3000 grand while a four grand 9 inch might go 2500, even though they both stall 4000. The nine will probably cost twice the 11 inch., or more, but work twice as well.
Edit , i had a 11" that was supposed to be 3200. It stalled at 4000, and drove down the road at 3500 in any gear. I could hold it at a fixed rpm and put the trans in first second or third, without changing speed or rpm. Beyond awful. Utter garbage (but it was cheap!). The nine in my car now drives pretty good, and the newer ones are even better.
2nd edit: Hughes performance has a series of videos on you tube about converters and stall speed. Highly recommended. Especially see #5, stall speed.

Thanks I’ll check the vids out! So TC diameter plays a role in the equation. But one does not see much range in TC diameters 9-10 range typically. It sounds like KD’s TC was too loose for his set up. It appears that drag racers must like tight converters and street cars a little looser but how could KD’s have been so mismatched? His TC diameter wasn’t that large to be so loose. It appears I am missing something in this equation. How can we select the right TC if we only have stall to choose from? Thats what I am actually getting at.

 

[Moparfiend]

While I will likely never profess to be an expert, basic common sense tells me that Tight/loose might refer to how the converter acts at light throttle.
I had a 9 3/4" converter that was a slippy, sloppy performer at light throttle. I hated it. At wide open throttle, (WOT) it was great but at any other time, it slipped enough to make the car feel lazy.

So what was the set up with that TC? What did you replace it with to get it worked out?

 

[Kern Dog]

Ultimate Converter concepts built an 11" converter that allows the car to drive like a new car. At cruise and light throttle, the car responds nicely. Hammer down from a stop, the tires spin.
It is a win-win.

 

[33 IMP]

I would talk to a good converter company, (Cope, and A&A are mopar specialists, and if they don't build converters, can certainly recommend someone) and fill out a tech card with as much honest, accurate information as you can give them, about your car, and how you drive it, and what you expect.

 

[69 GTX]

I had PTC build mine. HP has a lot to do with the stall also! You might have a 3500 9 1/2 convertor but if it's made for 600 hp your stock 383 might only flash to 2750-3000. There are many variable that factor into a convertor, I don't profess to know how they all affect it but it's best to get one built instead of off the shelf if your looking for performance. Just my 2 cents.

 

[Photon440]

It's too bad that there wasn't a Mopar version of GMs switch pitch torque converter from the mid 60s. I always liked that idea.

 

[66Satellite47]

Numerous things go into the "stall speed". IMHO not really a good parameter to guide me. Talk to one of the top manufacturers. The case diameter is a main factor in performance characteristics, along with internal fin and stator design. Turbo Action had three versions of their Mopar 10". Tight, medium & loose. My '66 Satellite came with a Turbo Action 10" was the "tight" version, behind my 500" motor. Performed excellent. Fairly tight on the street, lots of response when I floored it. I've had many Turbo Action 8 3/4" in my bracket cars worked very good till I broke them (that's racing), a Coan that worked very well, a 10" B&M in mid 70's that worked real good, sent it back & they modified it for even better performance (don't think B&M is same today). My current converter is a Frank Lupo Dynamic 9 1/2". Works great. Talk to the top names, not cheap but you get what you pay for.

 

[threewood]

If you have questions, call John Cope (work number 219-374-0100), he will certainly help you pick one. That's what I did. He will ask you everything about you car to get one that works. He had a PTC 9.5" built for my GTX.
https://www.coperacingtrans.com/?product=ptc-9-5-inch-torque-converter

 

[wyrmrider]

b &m's old supplier is out of business
owner died
we bought from them too
I've tried to find the tech people without success

 

[66Satellite47]

I should have mentioned John Cope too. Bought lots of 727 parts from him & one complete 727 last few years, very satisfied.

 

[Curiousyellow71]

[QUOTE. It appears that drag racers must like tight converters and street cars a little looser....[/QUOTE]

It's just the opposite, drag racers only care about there e.t. and typically are not concerned with running a tight converter that slips less at highway speed. The 9 1/2 converters seem to be a good size for street driving and are efficient with better trap mph then a 10" but are capable of stalls nearing the speed of a 9". Converters have always been a "you get what you pay for" area, especially with big block torque. We are running a dynamic 9 1/2 currently on the street, fried a cheap 10" behind a 440 years ago, also have a loose turbo action 9" which is not fun on the street, but the wheel stand is fun with slicks at the track, definitely not a street converter. Sometimes tight converters will mph more going through the traps because they are slipping less, but I would stress "sometimes" cause there is a lot more to a car then the way the convertor is set up.

 

[Moparfiend]

[QUOTE. It appears that drag racers must like tight converters and street cars a little looser....

It's just the opposite, drag racers only care about there e.t. and typically are not concerned with running a tight converter that slips less at highway speed. The 9 1/2 converters seem to be a good size for street driving and are efficient with better trap mph then a 10" but are capable of stalls nearing the speed of a 9". Converters have always been a "you get what you pay for" area, especially with big block torque. We are running a dynamic 9 1/2 currently on the street, fried a cheap 10" behind a 440 years ago, also have a loose turbo action 9" which is not fun on the street, but the wheel stand is fun with slicks at the track, definitely not a street converter. Sometimes tight converters will mph more going through the traps because they are slipping less, but I would stress "sometimes" cause there is a lot more to a car then the way the convertor is set up.[/QUOTE]
Yeah after thinking about I see what your saying. Makes sense looks like I need a higher stall converter that is also looser than what I have. Have no clue what's in there. It could be the stock TC from the 315 maybe a 1500 stall? My engine makes power probably where its not ever at with this set up. I just put in 3,55:1 Sure Grip from a 2,71:1 peg leg and off the line not much difference!

 

[Curiousyellow71]

A convertor shop can "loosen" a converter or "tighten" a converter and change the stalls flash point where the converter is fully engaged. But that isn't really the idea between a tight or loose convertor for the street driving aspect. Repeating what others have said "tight" refers to the converters ability to move the car under light load, where a really loose converter wont hardly inch the car forward until it's at the stall speed. On our "loose" 5000 rpm stall, the car hardly moves till it gets past 3500, and even then it's just moving the car enough to get back to the pits down the return road at the track.
The idea behind the tight street converter is its tight enough to move the car at highway speeds and performs like a stock convertor. But when you mash it the converter flashes at a much higher rpm getting more torque to the tires for a hard launch. Most of the off the shelf converters you buy don't mention whether they are tight or loose, they only offer a stall speed range. When I've talked to dynamic and PTC they both mentioned that they have had more results with 9 1/2 being tighter then a 10" as far as building a tight converter. They suggested the 10" converters will slip more at cruising speed then a 9 1/2 even if they are rated at the same stall speed. But from my experience any stall in the 2200 to 2800 range will be fine for street driving and the tight/loose concept is not that important until you get up into the 3500 and higher stall speeds and your trying to cruise at 55.

 

[WileERobby]

Tight vs. loose. Tight vs. loose. Hmm, seem to recall that quandry, but had nothing to do with torque converters...

 

[Kern Dog]

Tight vs. loose. Tight vs. loose. Hmm, seem to recall that quandry, but had nothing to do with torque converters...

 

[Moparfiend]

I think this thread is officially kaput.....