TC recommendation A999 (non lock up)

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Psychoduster

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Hi,

after finishing my 73 Duster I went out for some tuning.
But the third run caused serious problems.
After laying some incredible long patches, the transmission failed.
The A999 was the only thing, I didn't rebuilt, because the seller told me it has done shortly before.

I have a guy here who will build it to hold the power of the warmed 360.

The reason I'm posting this is because there is a terrible wrong and weak converter installed.
It's a CR8H - nearly stock TC - first the stall speed was somewhere 2400RPM, after the third run (changed jets on the carb) the stall speed rised to about 4000RPM....
Anyway, I will change the converter.
The car is driven mostly on the street, but sometimes on the quarter mile and I don't want it to be a dog from the line.

I am thinking of a Hughes 27/25 HD street strip or a 27/30 pro street.....

So what do you as experts recommend?

Specs of the Duster are:
360 engine, 0.030 bored over
speed pro pistons
292 comp cam (244,244 @0.05 - 292/292 duration), roller rockers
polished and ported heads
edelbrock air gap PRM
msd didgital 6AL2 igniton
Quick fues 750 SS AN
long tube headders, 2,5" dual exhaust
3.55 rear end in a 8 3/4 axle
Big cooler, twin derale fans
etc.

1973 Duster restauration and upcoming project 1966 Dodge Polara
IMG_20200404_151505.jpg
EB.PG.jpg
 
If a 1200 gets the tires squalking then that's enough.
As you found out, a 2400 lets the engine spool up to anything you want.
The two things you didn't mention are tire size and cylinder pressure. These will play a huge role in TC selection.
With skinny tires and 165psi yur screwed for TC cuz no matter what you put in there, you will have mega tirespin.
If your tires hook at 110 psi cylinder pressure,right at the line, yur gonna need more stall. Rather you can use more stall.
Tires and pressure are key ingredients.
__________________
I ran the Mopar 292/292/108 cam for one summer,which was already too long for me. With 3.55s and a 4-speed, the power in first gear didn't hit until the low 40s mph, with tirespin the whole way.In second gear the power was just coming on at 60mph, still with tirespin.
I went from 245s to 255s to 275s with very little change in tirespin.My cylinder pressure was in the low 180s (aluminum heads). It was a lotta fun, but waaaaay overkill for a streeter. Since the fuel-mileage was atrocious, I yanked and sold that cam to the first guy that showed interest, before the summer was over. That cam did not show it's worth until third gear after the tires stopped spinning. Finally I could feel the pull; whoa....... she trapped in third gear at 106, on the only pull it ever made. We came, we made the pull, we ate the track food, and made the return 3 hours home.Whatta day.

With adequate pressure, that cam in my combo, had no bottom end softness to her. In your combo with the 2.74 low gear and the TC multiplier, I can't see softness either, so long as the pressure is up decent. Yur gonna have some 60% more take-off ratio than my
2.66x3.55=9.44. It didn't take much clutch to set the tires on fire.
For you it looks like;
2.74x3.55=9.73, but you also have a multiplier in the TC, that varies automatically between about 1.8 and 1.1.. so at zero mph that ratio could start out at;
9.73 x1.8=17.51, which will instantly set your tires on fire. As soon as the tires spin, the multiplier in the TC will readjust it's ratio . Even if it could drop to 1.1 (which it won't), the ratio is still
9.73 x 1.1=10.70; but now your engine has spooled up, and by 2800 she is making major torque already, even with lousy cylinder pressure.
>Your cruise rpm is about 65=2870 locked up. So a 2800 TC would work fine, and is more stall than you need for taking off with.
But it's nice to have a 2800 at 30mph because, when cruising, your rpm will be ~1450 in Drive/~2040 in second, which will spool up with throttle to ~2800, and away you go; you don't have to use much throttle to play in traffic in second gear. But when the opportunity presents, a 2-1 KD into first will get you 3620, and the TC is already as stalled as it can get.And the 292cam makes plenty of power at 3600; that will be close to the torque-peak. In fact, it should light the tires up at 30 with a 750DP.
But for every one time you need a 2-1KD, there will be hundreds of times when you don't need or want a screaming engine, and that is where the 2800 comes into play. Your 360 has plenty of torque at 2800, and IMO, that is gonna be fun.
Does your 360 need a 2800? I doubt it. She can probably get away with a 2000 with adequate cylinder pressure. Or a 2400 with typical pressure. But the 2800loc-up, at 30mph, is gonna be a chitload of fun.

The thing is, with a lock up, you don't have to limit yourself to those smaller stalls, or even a 2800.
I just like the 2800,
and with your skinny tires, I feel that you'll never need more.
I like how the 2800 works behind my 318 winter-engine. It was tame enough for a DD, made pretty good fuel mileage (no loc-up), but when the 318 was asked to work, it was like stretching a flat-band snatch-rope between cars and winding it up. When it hit 2800ish, the stretch was gone, and POW!, she was pulling hard.And that was with a 1973 smogger-teen at 145psi. With 295/50-15s she wasn't much for spinning the tires (with 3.55s) but like I said; at 30 mph a 2800 is a lotta fun in second gear ( I put a manual-shift in her to prevent unwanted 2-1 downshifts.)

To be fair; I have never had a higher than 2800 stall TC.
This one has been following me around since the late 70s, going from car to car, as the bodies rotted, and I discarded them. It's always been on stock short-block 318s; except the time I put a 340 top-end and cam on one; in the which, a 2800 was not enough. In a C-body with 2.94s, that was a disaster,lol.
 
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Hi AJ/FormS,
thanks a lot for the information.....
I'm quite sure I will change to 15", somewhere arround 265 or 275.
I have to order a few parts and I live in germany (hope there aren't too much mistakes in my postings) and I have do decide the TC brand.
Do you have an advice for me?

Again, thank you very much :)
 
I have do decide the TC brand.
Do you have an advice for me?
I've been a stick-man my whole life since 1970, so the only TC I ever bought is the one I mentioned above. And that was in about 1978; I don't even remember the name of the company I bought it from. It MIGHT have been Trac-Action, or Trans-Go. I do remember the TC itself had a cool name; "Dirt-Jerker"
There are plenty of automatic guys on this Forum, so hang-tuff, someone will be along shortly.

But in response to this description
The reason I'm posting this is because there is a terrible wrong and weak converter installed.
It's a CR8H - nearly stock TC - first the stall speed was somewhere 2400RPM, after the third run (changed jets on the carb) the stall speed rised to about 4000RPM....
I have this one question;
Are you sure the TC is toasted?
It sounds more like the band was slipping, or the "Forward clutch is"
If you were happy with a 2400 stall, then I see no reason to change it. The power difference from 2400 to 2800 might only be 20 or so hp, so if you are getting a sustainable tirespin with a 2400TC already, then a 2800TC will benefit you nothing in first gear at take-off. You will just get a lil more tirespin a lil sooner,lol.
However,the second gear at 30mph that I talked about is still on the table.
So the question becomes; "will a new TC be worth the delivered cost?"
IMO, it kindof depends on if the current TC is really toasted.
So I know the summer is wasting, but you gotta get that A999 rebuilt first, to see what went wrong, and upgrade the guts as may be required. And if I'm right in the Diagnoses, then perhaps the current TC is still OK.
So then you have to decide if you liked the 2400 or not.
Now it becomes an "I want question" instead if an "I need question", and there is no good argument against wanting something,lol.

In any case, someone is likely to show up before long with a better answer to the question;
I have do decide the TC brand.
Do you have an advice for me?
 
Hi,

thank you.
No, the TC is gone for sure.
I checked both bands and they are within spec and not slipping.
I have no more reverse but drive, even in neutral.

The TC was first lower in stall speed and after the problem with trh reverse showed up, I thested it old school..... all weight on the brake an gave her a step on the gas pedal.... ended in about 4000+.
And as I wrote.... it is a low performance TC, not able to stand the power if the warmed 360.

Perhaps some of the TF-guys shows up :)

Regards, Eckhard
 
I run a Turbo Action 10" S800 on my street/strip 340. Flashes to 3200 with the 340. I ran it with a Magnum 360 and it flashed to 3400.
 
the best or my favorite converters i have purchased was an ultimate converters and turbo action and second was a Frank Lupo Dynamic converters .
 
I have no more reverse but drive, even in neutral.
This is a transmission problem; I'm pretty sure the forward clutch is piled up.

I'm not saying that the TC is not also bad.
Your trans has 2 clutches and 2 bands and a sprag(one way roller clutch)

1)To get reverse your trans energizes both the hi-clutch and the L/R band.
2)To get manual Low, the trans energizes the Forward-clutch and the L/R band.
3)To get Low in "Drive" position, only the Forward-clutch is energized which then gets first gear thru the sprag.
4)If the trans drives in Neutral, then the Forward-clutch and sprag are working. But the forward-clutch is NOT supposed to be engaged in Neutral.
5) in neutral all clutches and all bands are disengaged and all oil flow to these circuits is dumped into the pan.
6)If you have no reverse, then one or both, of either the hi-clutch or the L/R band is not working. OR the forward clutch is jammed up, which then selects two gears at once, and the car cannot move.
7)
From #4 we know your forward clutch is engaged,when it is not supposed to be. The only way this can happen is if the forward clutches are all welded together.

IMHO;
EITHER the Forward-clutch or the hi-clutch started slipping during the fun-time, and you probably finished the Forward clutch off, doing the brake stall test. So the Hi-clutch MAY also be bad .In any case;
IMO the trans has to be opened up
 
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Hi...

Transmission will go out on wednesday - not the problem.
I wrote Hughes and ask them for a recommendation.
Let's see, if they will answer.

Eckhard :D
 
Hi,

transmission is finaly out of the car (two funny screws - one at the starter and one between engine and oil filter)..... it took me 2 hours, including the driveshaft removal.
O.k. cheating..... I drained the ATF over night.
Geting the starter out was hard.... long tube headers - no further words needed!

I asked Hughes and Comp Cams and both recommended a 3500 stall converter.
I bought the 27/35-360BAL and a deep cast aluminum oil pan.
Next week, the A999 will be disassembled.

Regrads, Eckhard :thumbsup:
 
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