NukeC5

Just wanted to share some information to anyone considering a torque converter upgrade. As much as I researched and asked questions, this never came up and I never knew a thing about it. Now I have a fully built car with an improper stall converter in it that dogs out of the hole because I didn't know the difference between brake and flash stall.

By recommendation from everyone on here, and at "Yank" performance, and several online reads, I went with a 3200 stall. Would make sense that my cam that kicks in at about 3k rpm would be matched well to this right? I even asked about that. WRONG!

The 3200 will only brake stall to 2100-2200 rpm. Which means I have to launch at 2000rpm and wait for the rpm to climb before the cam kicks in.

So anyone into drag racing, know that converters are rated in flash stall, which according to Yank Converters is always around 1000 stall speed more than brake stall. You need brake stall when hitting it from a dead stop.

Sorry to rant, but I put a lot of money into this car and have a $hitty performer because no one knew what the hell they were talking about. Yank has a great reputation, but they certainly sold me the wrong converter. I told them what the car would be used for and the cam I was going with. But this is not even to down them. Its my fault in a lot of ways for not being informed (even though they are the experts).

Just saying. If you are going to do a cam and converter swap. Matching them means finding out what rpm the power-band starts. And getting a converter that "BRAKE" stalls to that RPM so you can launch at full power.

Was that so hard? I cant believe I asked about this for almost a year, and never had that come up. Flushed my money down the toilet . Ok rant over.

Got uid0

Are you flashing the converter or stalling it when you launch.

NukeC5

Actually Ive tried both numerous times. It will get 2200 rpm at best. The only way it seems to flash right is if your already driving and then stab it. Not at all what I had in mind.

Chris Stewart

You can send em back to be adjusted.

NukeC5

Yes, huge job and a lot of time and money. It will be done, but the point is, this should not have happened. And I hope no one else goes through this that reads this thread.

Chris Stewart

They might do 1 restall for free, like Precision does. If you do it yourself, the labor is free. Then you're just looking at shipping cost. Still a pita, I've adjusted mine twice while looking for the perfect setup, and probably will do it again.

RedZMonte

sorry to hear your experience, i have been there on other cars. I had a custom converter in my Monte Carlo Z34 Turbo made from Colorado Torque Converters in loveland CO. I asked for a 3000 stall and when I would brake stall and it would do exactly that... Brake+Gas=~3000RPM at a stand still. Boost would build up to 2-3PSI and over power the stall and it would actually FORCE my stall RPMS up as much as 5500RPM (did it once WOW CRAZY!) launch and boost built to 8-9PSI and the tires would blow off.

Sorry to hear your experience was bad. Specialized Venders should know their stuff and even when they have a good reputation its still only takes a extra couple of min to ASK.. "What are you trying to achieve" and get it right.

S

CactusCat

Nuke, are you running a trans brake? If not, wouldn't this resolve your issue? Trans brake would allow you to max your TC to its max rated stall, then when released, you'd be in your power band at launch. I'm not an expert in this however, so please correct me if I'm wrong. I'm also interested in the correct answer here as my setup is very similiar to yours.
http://www.hotrod.com/newproducts/hr...g_trans_brake/

123sugey

Who matched your converter to your motor, weight and gear ? This will dictate the stall ....
A 3200 stall in a 400rwhp car may stall at 2200 but in a car with 500+ could stall 2800-3600
Always go with the best company you can afford with converters. I like higher than normal stalls. For example a bolt on LS1 I would use a 4000+ stall.

lionelhutz

That sucks. You should be disappointed you gave your motor info and what you wanted to Yank and they gave the wrong converter recommendation. Flash and brake stall shouldn't always be 1000rpm different. It would vary depending on engine power and the converter.

I'm not sure what you were reading, but I would have though people would give the brake stall rpm if you were asking. Overall, unless you know the engine details, converter model and brake stall, getting a converter recommendation based on someone else saying it works well for them is not much use.

NukeC5

Yank is willing to "work with me" on the re-stall. I am just in a bad place to be ripping into the car and strapped for time. So the situation is upsetting. But I think I will be asking for a 3800-4000 stall this time.

No, no trans brake. I'm sure there are a number of tricks out there. I just feel like I should not have to deal with that if the converter was correct for my setup. I'll look into it though, thanks.

The car was built bit by bit, but whats in it now, is what I told Yank, and they made their recommendation. I think what they were hung up on was the fact that I use it as a driver some. But even so.. 3200 is completely wrong for the car. 3600 would have been similar driveabilty but with much more torque multiplication. But I think I need bigger than that if I;m going to get a good launch.

Ya, I wish I knew a little more at the time. Could have avoided this I'm sure.

Rookieracer

If they are willing to work with you, hopefully that means they will send another converter before you tear the car apart.

NukeC5

No they are not about to do that. They want to do a re-stall

ajrothm

All you should be concerned with is your "flash speed"..... Not your foot brake speed or your advertised "stall speed"....

What the converter flashes due is dictated on the converter, the weight of the car, the gear ratio and ofcourse the hp/tq/rpm band of the engine.

Flash and foot brake speeds have no correlation. My Coan "3600" only foot brakes to 2300.... Yet it will flash to 5100 or so from a 1900 rpm launch... It will go 5200 rpms on the trans brake.

My point is, you can't go by advertised stall ratings, and the converter company needs as much info on your car as you can give them. And even then its still a guessing game. There is a lot more too it then just stall ratings... There is also stall ratios involved. Lot of science behind them.. That's why off the shelf converters usually don't work that great.

I'm about to pull my converter back out and swap it for a custom FTI converter. Mine launches damn good but its a LITTLE loose going down the track, and pretty sloppy around town above 30% throttle...

I hate to pull it apart but..... gotta be done. I'm with you. A performance car needs to perform.

NukeC5

I don't understand.. if my 3200 stall converter flashes to 3200, why should I be concerned with that? In drag racing its about the rpm you launch at right? I have a cam that kicks in right around 3000rpm, so shouldn't I be concerned with my brake stall so I can launch at 3000rpm? The car is launching at 2100ish rpm and ******* out of the hole until the cam's power band kicks in at 3000rpm. Wasting at least half a second or more. Really upsetting.

Please do tell me anything you can about this!

cv67

Sucks but its one of those things like said you may have to try a few times to get to your liking. Every car is different.

Put the same 3000 stall in a sbc then a BBC (more tq)and they will act completly different. Just part of the game. Expensive, pita just part of it thats all.

thought about going auto but to make right launching probably need a 5000 stall or higher (cam starts making beans around 4-4500 that would be about it for street driving. no mas

NukeC5

Thats exactly why I tried to keep the stall low. I thought 3200 would be perfect for launching at that rpm and not dealing with a loose converter on the street. Good thing I rid my CBR600 most the time and can probably deal with a large stall in the car now.

RonSSNova

I launch my car at 1700-1800 rpm. The converter flashes to about 3700. Higher when the air is killer. I can clearly see the converter behavior in the HPT logs I take of every run. It will brake stall to near 3000, but if I launch higher than I do, it will spin violently.

Converter is a Yank SS3600 btw.

I made it to the tens this year just shy of 124. That was a 6.99 @ 99 in the 1/8 mile. Drives a bit loose on the street, I love it!

I remember your questions from before when you chose the 3200. I was thinking that was a bit conservative.

Converters are tough to choose. Yank acted on your inputs the best they could. Don't be so pissed at them.

Ron

NukeC5

Its sounding like there is a problem with my converter maybe. You guys are saying you launch at a lower stall and then it shoots up to the flash stall? Mine does not do this.. Upon launch, the rpm stays around where I brake stall and struggles to climb for a little bit.

chaase

I did a lot of drag racing and never power braked my car that hard with an auto to hold it on the line. I always left slightly off idle, just enough to load the drive line (1100-1200rpm) and then let the hammer down on the 3rd yellow.

The converter should jump to the stall speed immediately. My friends even notice it when they drive it on the street. If it isn't doing that, I suspect that there may be a fault with the converter.