Seller suggests a 2800-3000 stall torque converter. Do you experts agree?

jerry S

New Member
Sep 3, 2003
1,365
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52.22N 5.12E
here is my dyno. the blue run waswith the torker II intake. The red and green were with the RPM Air Gap (current set up).

<img src="http://forums.mightymustangs.net/index.php?act=Attach&type=post&id=7611" WIDTH=1000HEIGHT=1400>
 
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sounds good to me, if you go with a 3000 stall you only ~500 rpm until your torque peak. 3000 stall is still plenty streetable too if it matters, I run a 3500 and love it. If its a street car, be sure to tell whoever is building it that you need it to be a 'tight' 3000, that way you'll still have good response when driving at lower than 3000 rpms.

Be sure its a good quality piece, when it comes to torque converters you really do get what you pay for. If you've ever driven a car with a well built auto and the right converter, you'll never want to deal with a manual trans again, especially for drag racing.
 
thanks guys. The mfg is Edge Racing Converters. I have heard a lot of good things about them. If you feel really strongly about one converter over another, I would be pleased to hear your opinions.

As for 12Sec67's question, here is my build. Keep in mind that these numbers are rear wheel behind a c6. I would not say that I am not making little hp. That 300 hp at the rear wheels is about 400 at the fly. Not bad.


-351W bored .040 over, 10.5 CR
-stock crank honed, polished, rebalanced.
-Eagle forged I beam rods (5.956 inches)
-SRP forged flat top pistons, part number 138731
-Edelbrock RPM Performer cylinder heads, part #60259 60 cc combustion
chamber, 170 cc intake runner, 60 cc exhaust runner
-comp cams pro magnum roller rockers, part # CCA-1332-16
-comp cams high tech push rods, part # CCA-7965-16
-Edelbrock RPM Air Gap intake manifold
-crower cam:

Adv. Dur. Intake: 297º, Lift: 0.538
Adv. Dur Exhaust: 308º, Lift: 0.534

Duration at .050"
Intake: 236
Exhaust: 242

-hooker comp. cermanic coated long tube headers (1 5/8" collector)
-dual exhaust (2.5")
-MSD pro-billet dizzy
-MSD 6AL ignition
-holley 650 cfm vacuum secondary carb, part #0-80783C
-C6 auto with a crappy TQ.

Those numbers are with only 28 degrees total timing. I am expecting more power once the engine breaks in (just a few hundred miles on it) and once I advance the timing and send the carb to Jet Performance for a stage 3 work up.
 
jerry S said:
As for 12Sec67's question, here is my build. Keep in mind that these numbers are rear wheel behind a c6. I would not say that I am not making little hp. That 300 hp at the rear wheels is about 400 at the fly. Not bad.
.

your in the same boat i'm in with my AOD ... damn slush box:lol:

i didn't mean little hp.. just little compared to you torque- :flag:
 
Jerry's setup is very similar to mine, we built for torque and average output rather than HP and peak output. I put a 2800 into mine.

YellowMach, if you have an automatic transmission you HAVE a torque converter. The question is what RPM does it "stall" at. Factory C4s are in the 1400-1600 range, mild performance TCs are generally in the 2200-2600, more agressive ones are 2800+.
 
If you have a current, good quality torque convertor you can have it rebuilt to change the current stall to 3-3.5k for about $180 as compared to a new one for about $650. The company is PTC and they did a very good job on mine. They update the internals and replace all bearings to make it new again. Just a thought...........
 
thehueypilot said:
If you have a current, good quality torque convertor you can have it rebuilt to change the current stall to 3-3.5k for about $180 as compared to a new one for about $650. The company is PTC and they did a very good job on mine. They update the internals and replace all bearings to make it new again. Just a thought...........

I wish I did but I don't. Thanks for the tip though. As always, I value your input.
 
I dont know anything about stall converters, more less Torque converters. Ok back to the question about how would you know if you had 1, and what are the benefits of having a aftermarket than stock? I know that its better, but do you get more low end torque or what?
 
This is only an analogy, I am not saying they are the same...

Think of the torque converter as a clutch. If it stalls at 1500RPM then that is where the clutch is let out and the gear fully engaged (not the RPM where you begin to let the clutch out). If it stalls at 3000RPM then that is where the gears are fully engaged.

A TC slips until it reaches the stall rating, this is what allows you to be at a complete stop with the car in gear, which you cannot do in a manual without putting the clutch pedal down.
 
jerry S said:
thanks guys. The mfg is Edge Racing Converters. I have heard a lot of good things about them. If you feel really strongly about one converter over another, I would be pleased to hear your opinions.

As for 12Sec67's question, here is my build. Keep in mind that these numbers are rear wheel behind a c6. I would not say that I am not making little hp. That 300 hp at the rear wheels is about 400 at the fly. Not bad.


Well if you get 3K get a good tranny cooler to save the $ you put in the trans, dont just depend on the one in the radiator....

Oh and 300 whp is about 350-360 at the flywheel, unless you are figuring 25% drivetrain loss. :nonono:

DD
:flag: :nice:

(my 5.0 makes 300 whp with h/c/i)
 
ddonaca351 said:
Well if you get 3K get a good tranny cooler to save the $ you put in the trans, dont just depend on the one in the radiator....

Oh and 300 whp is about 350-360 at the flywheel, unless you are figuring 25% drivetrain loss. :nonono:

DD
:flag: :nice:

(my 5.0 makes 300 whp with h/c/i)

I already have a B&M transmission cooler on there. Also, I have just ordered a B&M alum transmission oil pan with an extra 2 quart capacity.

As for my power assumptions, there is no way to know for sure without hooking up to an engine dyno. However, since I am getting my numbers from a chassis dyno, I have to extrapolate and to answer your question, I am figuring a 25% drive train loss. The C6 is the biggest, heaviest tranny out there and eats more power than anything else. I know of a guy with a similar build as mine and he went from an AOD making 301 rwhp to a TKO making 357 rwhp. He figures 11% drive train loss through his TKO for 401 hp at the fly.

I posted my build earlier in the thread. Most people who have reviewed it postulate that I have between 400-450 hp. I will be conservative and go with 400 and be happy.

The issue of HP loss through drivetrain has been discussed here before. I found this on the internet.

http://www.superstang.com/horsepower.htm

Real World Example #2: (added 9/29/2003)

The November 2003 issue of Car Craft has a great article titled "The Brutal Truth" by Jeff Smith (page 40). In the article they place two engines on an engine dyno and then dyno the engine again once it is installed in the vehicle. One engine is a 357 cubic inch Ford Windsor engine and the other is a 455 Buick. The Ford 357 was installed in a 63 Comet using an AOD transmission and Ford 9" rearend with 3:50 gears (exact combination of drivetrain in my Mustang except my AOD is a non-lockup which means it is even less efficient or should lose even more horsepower). The 455 was installed in a 70 Buick GS with a Muncie 4-speed and a 12 bolt rearend with 2.73 gears. The point of the article was to show how things like a belt driven cooling fan or poor vehicle exhaust could affect the engine output in the vehicle but was equally as valid for showing drivetrain induced power loss.

Without reading any further it would be my assumption that the Ford combination would lose a larger percentage of power through the drivetrain. Not only is the AOD an Automatic it is also a 4 speed Automatic that has substantial weight and rotating mass. The 9" rearend is also larger and heavier than the 12 bolt Chevrolet.

The Ford 357 produced 371 horsepower on the engine dyno at 5,000 RPM. On a 1990 Mustang that came stock with an AOD and a 3.27 8" rearend (more efficient than the 9") the rear wheel horsepower is typically 180 hp. That represents a loss of 45 horsepower given the rated 225 flywheel horsepower on that vehicle. Using this 45 horsepower and even giving it another 5 for the 9" rearend the 357 would have produced 321 peak horsepower on the chassis dyno. Well, it didn't! Even after removing all the factors that could have contributed to extra power loss in the vehicle (removing the belt powered cooling fan) the chassis dyno only showed 283 hp. In fact over the entire power curve the difference between the engine dyno and the chassis dyno was 24%. This provides more evidence that the power loss through common drivetrain remains a percentage even as power is increased rather than remaining a static loss value.
 
Is the C6 actually worse than an AOD? I'm suprised by that. The C6 is essentially a beefed up C4, which is considered quite efficient for a slushbox. The AOD has more internal mass than the C6 too, due mainly to the 4th gear.

I don't expect them to be far off from one another regarding parasitic loss but was just wondering if anyone really knows the difference.
 
Edbert said:
Is the C6 actually worse than an AOD? I'm suprised by that. The C6 is essentially a beefed up C4, which is considered quite efficient for a slushbox. The AOD has more internal mass than the C6 too, due mainly to the 4th gear.

I don't expect them to be far off from one another regarding parasitic loss but was just wondering if anyone really knows the difference.

The AOD I spoke of was a lock-up tranny so it should be more efficient than the C6, which is a non-locking tranny.

I read in one magazine where the author put his his C6 with converter, flexplate and fluid on a scale and it weighed 218 lbs. I don't know how much the AOD would weigh.