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 Post subject: Re: Converter stall??
 Post Posted: Sun Oct 31, 2010 10:05 pm 
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Joined: Sat Feb 07, 2009 4:12 pm
Posts: 1215
Location: Adelaide Australia
There must be an explanation for what you have experienced so it would be interesting to find the reason. I hope you do that in your testing. See thats the way I think, everything has a reason so you have to figure out why its occurring then you understand it more and then you can use it to a greater advantage.
If you have the facility for a bolt together it would be interesting to find out what small changes to the stator vanes do. I think its all in the wing shape of the vanes. The shaping of them and how they redirect the oil back into the pump and match it so the oil doesnt become excessively turbulent entering the pump would be a good thing to understand I think.
Using different viscosity oil should also alter stall. Synthetic oils would have a different latent heat phase, they can absorb more energy without a temperature rise. I have tested oils that have a static temperature even though your inputting energy whereas mineral oils respond like normal logic. Very interesting some oils. I would expect synthetic oil might transmit the energy more efficiently. Has anyone ever tried that sort of changes?

 Post subject: Re: Converter stall??
 Post Posted: Mon Nov 01, 2010 9:48 am 
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Joined: Mon Oct 29, 2007 7:07 pm
Posts: 1422
Location: Florida
Different viscosity oils do alter the stall, and some do use it to find a little power. Compressor or hydraulic oils are available with different viscosity ratings. Also passage mods in the pump can alter the amount of fluid through the converter and increase or decrease stall a little.
http://www.dragstuff.com/forum/viewtopi ... =16&t=4042

Stators and bolt together converters are also available, just a pain to change out for the guys that bracket race. In the thread I started below, you can see it's one of those things that are application specific, like carbs. ;-) So the bracket guys have to rely on the converter guys to get it close for the HP, vehicle weight, and sometimes track conditions. Too much power at the start can sometimes be detrimental, especially on big inch engines or lots of NOS, making traction control tough. A little softer start can make for better consistency.
http://www.dragstuff.com/forum/viewtopi ... =16&t=2365

 Post subject: Re: Converter stall??
 Post Posted: Wed Jan 19, 2011 1:44 am 

Joined: Thu Nov 25, 2010 10:39 pm
Posts: 55
There is a lot more to a converter than Stall speed. As most of you know a converter can make it work or not...work..
I'll try to post a little chart that we helped put together for some of my comp buddies. It is for A-1 7 inch converters and only their 7"....I also have a chart for the Coan 7" converters with either chart you can look at the numbers on a converter and tell what it is. If you know what it is and understand converters you can choos one that works instead of relying on companies that would like for you to believe there is "Black Magic" in there and sell you 2 or 3 before you get the right converter. There is a very lenthty thread where we discussed converters on the Speed Talk forum about a year ago. It had some great input...I hope Ken doesn't mind this link. I just found it. It is long and very informative: http://speedtalk.com/forum/viewtopic.php?t=19260

The numbering system for Coan 7 in converters.
Example ;
P X 32.51322C
P = Powerglide
X= Steel Stator
32.5 = degree of stator
15= Number of stator blades
22= Degree of blade angle
C= pump design
Pump efficiency
Positive -A B C D E - Negative

I see the A-1 chart didn't post correctly(jams everything up), maybe you will get the idea by the text.

A-1 7" Torque Converter Data

This chart is designed to assist in the interpretation of A-1 7" torque converter characteristics.
Refer to part number stamped into turbine case.
ALPG = Aluminum Power Glide case pump style.

There are many factors that affect torque converter stall and run characteristics in a particular vehicle.
These factors include but are not limited to any single factor. Listed are a few of the factors: Engine power
and power curve, engine style and intended usage, weight of vehicle, type of vehicle, aerodynamics of
vehicle and many additional factors. This chart is an attempt to assist in the understanding of the converter
characteristics such as stall changes, hit and down track efficiencies. None of the characteristics is an
absolute, but rather a combination of design parameters to achieve the best combination for performance.
The only absolute way to experience a converters nature is to test in the actual race vehicle at as close to
normal racing conditions as possible. Weather and track changes will also dictate the required torque
for the race on a particular day. So, again, the following data is for comparative differences in design.

1st 2nd 3rd
Designator Designator Designator

TIGHT A 300 30.0 D 1 TIGHT
(Hi Efficiency) 2 13
325 32.5 D 4

B 350 35.0 D 9 14

375 37.5 D
5 15
C 400 40.0 D

11 16
425 42.5 D 12

7 17
LOOSE D 450 45.0 D 8 LOOSE
(Low Efficiency)
* All Odd Number Stator Designators are STRAIGHT FIN = SOFTER HIT
* All Even Number Stator Designators are FULL FIN = HARDER HIT

Additional Characteristics and Designators:
" + " ADDS 250 - 300 RPM to Stall Speed
DOUBLE #'s ADD 250 to 300 RPM to Stall Speed
Example: a converter with designator of AE300-88+ should be 500 to 600 RPM
Higher stall speed than a AE-300-8 converter.
A = positive fin angleAE= Neutral fin angleN = Negative fin angle
An "N" Designator indicate a NEGATIVE FIN ANGLE which helps a
smaller cubic inch engine "stay up" after the shift especially in heavier cars.

A-300-8 = An "A" efficient pump (efficient down track) with a 30 degree fin angle (sets base stall) .
and a "loose" 17 fin with Harder Hit = FOR SMALL CUBIC INCH - HIGH STALL - Hard Hit -
Efficient Down Track - Light Car.

A-425-4 = An "A" efficient pump, 42.5 degree fin angle, (sets base stall) and 13 blade efficient - Hard Hit.
For LARGER CUBIC INCH engine. Hard Hit - Efficient down track. Also good for heavy car.


 Post subject: Re: Converter stall??
 Post Posted: Sun Feb 13, 2011 10:39 am 
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Joined: Sat Nov 03, 2007 4:44 pm
Posts: 1423
Location: Clawson, Mi.
Now this is some interesting reading, and Shrinker & rick360, WOW, gettin pretty deep in here now O:) but I am learning a few things from all this info, and some of it is starting to hit home. I asked a converter guy once about running a 7" conv. and he said no way will it work, well, I saw a Skylark with a big block and they had (3) 7" converters that they ran, all the same, one in the car, one in the trailer, and one always getting repaired in the shop, so I know they work, cost effective? heck no!!!!!! is too expensive for my little game plans, but they would work, just not to long in a heavy chassis and the skylark was a heavy chassis, and I don't know much about the engine but the thing screamed and went low 9's and I know it weighed in near 35-3600lbs. It was fun to watch this car too as it would launch like an old afx, style class car with a high whinding small block either V-8 or the V-6 version and boy did they ever scream and that was in like the late 1980's, but the class is long gone now, but it was neat to see how these cars ran.

I am going to head over to the speedtalk site and do some reading there too.

Great info you guys and thanks for sharing it all, and with the economy the way it is, I need to make the parts selection count even more as money is tight for me and many, many others.
Good stuff here. =D>


Thanks To;
Motor City Muscle
Fuelab Fuel System
D & S Engines
My Wife & Family

R.i.p. Doug Cunningham, gone, not forgotten.

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