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Higher Stall torque Converters vs stock in a rock crawler

welndmn

Well Done Man
Joined
May 21, 2020
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1008
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698
Loc
Concord, CA
Advantages?
My transmission is coming back out so I thought I'd change out the convertor while it's out as it's suspect.
Who has switched to a higher stall and what your feedback?
I'd like a little more get up and go, but I not wanting to hear the engine rev up all the time while I am out crawling.
 
My opinion is to properly match the converter stall speed to where in the RPM range your engines makes peak power. For instance, I run a stock 5.3L LM7 and a "stock" stall convertor in my TH400 and love it. Nothing I'd change at all. You really need to know the flow specs on your intake, heads, cam, know where the engine makes power, know the truck's weight, and account for gearing to properly determine stall. I'm probably missing other factors too. Switching to a higher stall than required for your engine pointless. More slippage creates more heat which is a whole issue within itself.
 
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Call a couple different converter builders and see what they recommend. They're going to ask you a million questions, use their years of experience and hundreds of converter builds (if not more) to give you a recommendation.

Stall rpm is not the rpm that the vehicle starts moving.
 
I'll always run a 2400ish stall in a buggy, going to try a full size next time as the 9.5 i had before got hot easy.
 
I have always wondered this. I’ll be following....I run a stock stall now.
 
Call a couple different converter builders and see what they recommend. They're going to ask you a million questions, use their years of experience and hundreds of converter builds (if not more) to give you a recommendation.

Stall rpm is not the rpm that the vehicle starts moving.

That's what made me ask here.
I asked, Summit Racing, Huges, TCI, and Boss Hog.
I got answers from stock, 2200, and 3000.
 
My opinion is to properly match the converter stall speed to where in the RPM range your engines makes peak power. For instance, I run a stock 5.3L LM7 and a "stock" stall convertor in my TH400 and love it. Nothing I'd change at all. You really need to know the flow specs on your intake, heads, cam, know where the engine makes power, know the truck's weight, and account for gearing to properly determine stall. I'm probably missing other factors too. Switching to a higher stall than required for your engine pointless. More slippage creates more heat which is a whole issue within itself.

I've got a 5.3/TH400 rig.
Going to a properly stalled converter was one of the best things I've done.

Stock stall is garbage.

PS : Since no converter shop could give me a solid answer, I tried 3 different ones to make my mind.
PS2 : A 9" 3000rpm stall converter or a 11" 3000rpm stall converter won't react the same way not generate the same amount of heat.
 
I've got a 5.3/TH400 rig.
Going to a properly stalled converter was one of the best things I've done.

Stock stall is garbage.

PS : Since no converter shop could give me a solid answer, I tried 3 different ones to make my mind.
PS2 : A 9" 3000rpm stall converter or a 11" 3000rpm stall converter won't react the same way not generate the same amount of heat.
What made it garbage? What stall and converter size did you end up with?
 
I had a Hughes Street Rod converter behind a stock LQ4 in my buggy and it was great and also cheap. I think 2000 to 2100 stall. I called PTC and had one built for my new engine after giving them all the specs and they nailed it. I had to add a lot more cooling though.
 
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What made it garbage? What stall and converter size did you end up with?
With the stock converter it felt like I lost a ton of hp.
Definitely not as quick out of the hole and would absolutely drag the engine down when you need it to move up in the rpm band.

See my second PS in my message. My particular stall number won't matter much if you don't have the same setup as I do. But if you have to know, it's a 9" that PTC built and restalled for 2600-3000 range. I had a 2400-2800 before and it didn't feel as good.
 
My buddy built a rig on Rockwells with pretty much whatever he had kicking around. Used his old drag racing converter. Not sure how high it was, but he was miserable getting around the woods. :laughing:
 
I guess I was hoping to hear from someone that had a stock convertor, changed nothing on the engine or setup, then switched to a higher stall.

I have a TCI Saturday night special in mine (2000-2400 ish) and it just failed so I have to replaced it.
I never liked the converter when I put it in, but I didn't hate it enough to pull the transmission before, now I have to.
 
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Maybe call TCI and tell them what you didnt like about it and they can provide input on a better unit?
 
LQ9, th350 here. I had 2300 and didn't like the heat or revving on inclines. Went back to a 1800-1900 Hughes and am much happier. I can crawl right off idle with a lot more control. Plenty of hp and not a drag racer so no issues with hole shot. No regrets............
 
Roadkill is always pimping Yank converters, someone else to try and call
 
I run a 2000-2200 and it is perfect for my application. built 466, 40s, 4.10 gears, 6000#.

Some more info on your motor, trans, gearing, weight and so on would be helpful.
 
I guess I was hoping to hear from someone that had a stock convertor, changed nothing on the engine or setup, then switched to a higher stall.

That's what I did.
Started with a 11" stock stall, went to a 9" then had it re-stalled again.
 
I guess I was hoping to hear from someone that had a stock convertor, changed nothing on the engine or setup, then switched to a higher stall.

I have a TCI Saturday night special in mine (2000-2200 ish) and it just failed so I have to replaced it.
I never liked the converter when I put it in, but I didn't hate it enough to pull the transmission before, now I have to.

What don't you like about the manners of the converter you have? What would you like to have it do different?

Basically you already have a baseline, your present converter.
 
When I built my Landcruiser with an LQ4, T400, and 4.3 Atlas, it had a stock converter in it, and I hated it. My problem was it would drive through the brakes in 4low. I talked to the guys at TCS in Arizona and told them what I had and they built me a converter that stalled around 2400. It worked well and never had a problem with it.
 
As others have said, the gear ratio, weight of vehicle, HP, foot torques, all matter. I think I decided on a simple Summit 2400-2700 converter. The stall numbers are not equal among different sizes and internals of converters. Pick something close, get some seat time and then tell the trans shop what you want to change about it.
 
What don't you like about the manners of the converter you have? What would you like to have it do different?

Basically you already have a baseline, your present converter.
I feel like I really have to rev up the motor to get it to move, it builds a ton of heat too while doing so.
 
As others have said, the gear ratio, weight of vehicle, HP, foot torques, all matter. I think I decided on a simple Summit 2400-2700 converter. The stall numbers are not equal among different sizes and internals of converters. Pick something close, get some seat time and then tell the trans shop what you want to change about it.
The TCI I have now is a 2000-2400 stall.
It's a Early Bronco, 5.0 motor, (stock, maybe 200 hp), Ford C4, with 5.13, last weight was 4200 lbs.
I never ran a stock convertor, TCI talked me into their convertor and I was never happy with it, but had enough cooler on it to always keep it cool, but man it liked to build heat.

I think having a stock like engine I have talked myself into putting in a stock convertor.
MY main concern is having a 5:1 T case I will be driving though the brakes.
 
buy a summit 1800-2000 stall and put it in and go from there.
 
For crawling most people that mess with something other than stock seem to have issues or regret it. They build heat and revving up engine to get into the power are couple of the big things that cause issues on the crawling side. Some figure it out right away and others don't even after multiple transmissions. Anything that makes less heat is better imo. I would echo what Samy said.
 
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