Recommended stall speed?

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81cutlass

Comic Book Super Hero
Feb 16, 2009
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Not to hijack but I have a PTC 1.85 STR (like 3400ish) 60e converter sitting on the shelf. It came out of an 11 sec camaro with 4 passes on before he changed it over to an ls3 t56.

If you are interested it's been on the shelf for 3 years and I've just never used it. I think it was mid 400's new? I've just never got around to using it.
 
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Canon_Mutant

Royal Smart Person
Aug 15, 2015
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Sorry if I missed it but do you already have that cam?

If not, for a family driver you are going to romp on occasionally, I would drop the cam size, lower the rpm of the torque curve you can use every day at every stop light, at the expense of potential top end HP the rest of your system likely won't be able to produce anyway, and get the converter stall back closer to what you started with, not more than 2400-2500. Should pull real hard from 2000-6000. Tuning matters but, with an otherwise completely stock motor, it is unlikely your entire system will be able to take advantage of that much cam though it will "sound" badass.
 
Oct 14, 2008
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Melville,Saskatchewan
As said, the LS motors are very soft down low. Rev them up and it is a different story. So don't go light on the stall and run enough gear. I know the 2800 PTC 2004R is supposed to be really nice, tight down low, same mid $400 price as that 3400 stall. That is the real key to a quality converter, normal tight operation till you stomp on it.
 
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Texas82GP

Just-a-worm
Apr 3, 2015
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Sorry if I missed it but do you already have that cam?

If not, for a family driver you are going to romp on occasionally, I would drop the cam size, lower the rpm of the torque curve you can use every day at every stop light, at the expense of potential top end HP the rest of your system likely won't be able to produce anyway, and get the converter stall back closer to what you started with, not more than 2400-2500. Should pull real hard from 2000-6000. Tuning matters but, with an otherwise completely stock motor, it is unlikely your entire system will be able to take advantage of that much cam though it will "sound" badass.
I agree with you in principal Garth but the Hot Cam (219/228) is not a big cam in a 6.0. Those engines have the LS3/L92 style rectangle port heads and flow very well stock. Stock they flow as well or better than a pricey aftermarket performance head for one of the legacy engines. Whether a cam is too big is subjective of course. I have the same cam in the 5.3 in my truck with a 3200 RPM stall speed converter and I daily drive it. It's really pretty tame except that it really woke the little motor up and sounds great. We have the same cam in my brother's 6.0 in his 78 Z28 and that engine really swallows that cam up.
 
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transman

Apprentice
May 17, 2015
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Western Canada
Keep in mind that just because a converter works well in my car or anyone elses doesn't mean it will work the same in your car.
I really don't care whose converter you choose to buy, but get it directly from the Company that builds it. From my past experience most resellers,but not all, lack the knowledge to ask you the right questions. It's not that they don't mean well, it's just they don't sell enough of them to really know all that is required to get the right converter for you. Converters to them are only an add on sale.
All converter builders will have (or should have) a specification sheet they want you to fill out and from the HONEST information you give them, they'll be able to build you what suits your setup best. While you're at it, ask about warranties (do they have one) and if it doesn't perform the way you want it, is there a charge for re-stalling it. They converter company that I worked for in the past offered warranties and one re-stall from the date of purchase.
Just my 2 cents worth.
 
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Dinosport

G-Body Guru
Jul 20, 2015
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Ct
Thanks Transman. Thats some good info right there. Ill have to see if they have something like that.
 

64nailhead

Goat Herder
Dec 1, 2014
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my dumb question of the day.....with a stall speed over the rpm of the cruise speed of 60 mph if you drove the car at 60 mph would the TC be slipping as you drove causing it to heat up?

ABSOLUTELY NOT if it's a correctly built converter (notice caps). Your question is usually an inaccurate statement made by the uniformed.

I see an enormous amount of discussion on forums such as this about stall speed. Stall speed is almost unimportant except when launching - and how often are you guys concerned about launching? I'll say most of us are concerned about 'drive-ability' and how the car reacts when you 'stand on it'. The term most pertinent is 'flash stall'. This is where the converter locks from a rolling WOT pull.

I'll reference my build and the AMAZING job done by FTI spec'ing my converter. The stall speed that they sold me was 2800 and the spec was referenced as a '2800 stall 9.5" billet converter with lock up for a 200-4R'. It 'dead stalls' from a stationary take off around 2700-2800 rpms, but it 'flash stalls' to 3700-3900 rpms. Our motor, cam, turbo, gears, tire size, etc, make max torque very near 4K rpms. So when driving if I stand on it the motor will rev to the flash stall (and build about 3-5psi on the way to the flash) and lock. Around 4100-4300 the turbo will be at 10-11psi and it feels seamless from converter lock up to full boost. Shift between 6200-6600 and hold the @%$# on.

With the street tires, 275/50R17, rolling roasty smokies are great fun :):)n


PontiacGP, this will cruise from 2000-2800 'locked up' with no converter slip from 65-80mph.It is sluggish on light throttle take-offs until around 1700-2000, but it makes the low rpm shifts somewhat smoother on a harsh shifting transmission.


I don't want to say that FTI is better than any other TC company, but they took the time to read my motor specs, wants and wishes AND then CALLED ME to discuss. We have a free re-stall coming, but I'm not going to need it as far as I'm concerned because they hit it on the first try.

Forgot to add the price - bought this last year for less than $800.
 
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pontiacgp

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Mar 31, 2006
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ABSOLUTELY NOT if it's a correctly built converter (notice caps). Your question is usually an inaccurate statement made by the uniformed.

I see an enormous amount of discussion on forums such as this about stall speed. Stall speed is almost unimportant except when launching - and how often are you guys concerned about launching? I'll say most of us are concerned about 'drive-ability' and how the car reacts when you 'stand on it'. The term most pertinent is 'flash stall'. This is where the converter locks from a rolling WOT pull.

I'll reference my build and the AMAZING job done by FTI spec'ing my converter. The stall speed that they sold me was 2800 and the spec was referenced as a '2800 stall 9.5" billet converter with lock up for a 200-4R'. It 'dead stalls' from a stationary take off around 2700-2800 rpms, but it 'flash stalls' to 3700-3900 rpms. Our motor, cam, turbo, gears, tire size, etc, make max torque very near 4K rpms. So when driving if I stand on it the motor will rev to the flash stall (and build about 3-5psi on the way to the flash) and lock. Around 4100-4300 the turbo will be at 10-11psi and it feels seamless from converter lock up to full boost. Shift between 6200-6600 and hold the @%$# on.

With the street tires, 275/50R17, rolling roasty smokies are great fun :):)n


PontiacGP, this will cruise from 2000-2800 'locked up' with no converter slip from 65-80mph.It is sluggish on light throttle take-offs until around 1700-2000, but it makes the low rpm shifts somewhat smoother on a harsh shifting transmission.


I don't want to say that FTI is better than any other TC company, but they took the time to read my motor specs, wants and wishes AND then CALLED ME to discuss. We have a free re-stall coming, but I'm not going to need it as far as I'm concerned because they hit it on the first try.

thanks...I would rather ask dumb questions than be uninformed.....:)
 
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melloelky

Comic Book Super Hero
Oct 22, 2017
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mass
i bought a converter from fti last week.the customer service was outstanding.all my emails were replied quickly and the "converter interview" was vehicle specific and i got a good feeling buying from them vs one off the shelf.i'm excited to have the rite converter in my car,should be fun.i'd recommend fti
 
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motorheadmike

Geezer
Nov 18, 2009
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Saskatchewan, Truckistan
Here is some basic math/theory on how increasing torque can impact stall speed:

http://kennedysdynotune.com/torque-converter-tech-tips-selection/

When I was talking to Coan they mentioned that they don't use STR, but K Factor instead - the same as GM's engineers do. So, if the converter going in my TBSS is rated at 3200 rpm behind a stock LS2 with 400ft/lbs and we add a Procharger that raises the torque figure to 550ft/lbs the converter will theoretically now stall at 3700ish rpm.
 
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