Converter upgrade worth it?

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Freezerman

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In my Dart I have a stock '74 360 with x heads on it. They are 68cc, I have measured to approximately 8.4 CR it has a xe268 cam with 3.55 suregrip, 904 transmission, 25 inch tires. Runs well now with a stock 1800- 2000? stall converter. Would I find a noticeable improvement with a custom converter?
 
I went with a 3500 stall unit on my Duster last year. Really perked it up. Tight enough to allow me to cruise around town and a blast when I stand on the loud pedal. Trans cooler is a good idea anyway, but especially if you go to a higher stall.

Pat
 
Ok,thanks. It runs great, just sluggish acceleration from 20 to 40 or unless push hard enough to downshift, then it's like switch on. I'll make a call or 2 to a converter company.
 
I'm not sure, I got them as part of a different deal and they were in great shape so I used them. ( only have about $400 in the whole motor super low budget). I measured 2 chambers on each head so pretty sure on that 68cc.
 
Off the line it's pretty good, as is from a standing start it will lay a 60' patch. So it won't really have any effect after the car is moving?
 
While mine certainly helps off the line (almost too much = no traction), it also really improved the performance from a roll, lower rpm/partial throttle. Flashes right up to the sweet spot/powerband. Can spin them from a 20-30 mph roll whereas I didn't before. YRMV

Pat
 
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In my Dart I have a stock '74 360 with x heads on it. They are 68cc, I have measured to approximately 8.4 CR it has a xe268 cam with 3.55 suregrip, 904 transmission, 25 inch tires. Runs well now with a stock 1800- 2000? stall converter. Would I find a noticeable improvement with a custom converter?

Stock Stall speed for 1974 360hp is spec'd 2300-2600rpm. So you're a bit tighter than stock. So yeah, it'd help.
 
Ok,thanks. It runs great, just sluggish acceleration from 20 to 40 or unless push hard enough to downshift, then it's like switch on. I'll make a call or 2 to a converter company.
Call more than 2 converter companies and find out what they recommend for you and what you intend to do with your car. Make sure you give them ALL the specs that they ask for. B.S. them about anything and the converter will not perform properly. Only a high stall builder can really tell you what you need. Just because a certain converter stalls perfectly in my car, doesn't mean it will do the same in yours, unless your car is identical to mine in everyway. JMHO
 
Granted a higher stall converter affects take off the most it can also help some when moving. I never have to give it enough gas to kick down for it to accelerate good at most any speed. The correct converter for your car can make a big difference
 
I actually talked to Frank at Dynamic, he recommended 3200 stall and Andre at Edge recommended 3000 stall. Andre is making one for me right now. So after the snow is gone I will be testing
 
I started the snowball rolling on my GTX when I decided to change the shifter pivot seal. From there it blossomed into an entire rebuild, and I had a new TCI Streetfighter converter on hand, so I threw it in there in place of the original stock unit. Woke up the whole car, and the neighborhood, with much increased off the line and midrange performance. It was not spec’d for the motor in any way, I just bought it at an auction for $20 so I thought I would try it. Glad I did!
 
In my Dart I have a stock '74 360 with x heads on it. They are 68cc, I have measured to approximately 8.4 CR it has a xe268 cam with 3.55 suregrip, 904 transmission, 25 inch tires. Runs well now with a stock 1800- 2000? stall converter. Would I find a noticeable improvement with a custom converter?
What's her cylinder pressure, 130 psi?
 
Update. Disappointing, the new converter does flash to 3k as specified and works well that way. The problem is from idle to 2500 or so I lost alot of throttle response, if I didn't know better it's almost like transmission is slipping. The engine has to rev more for the same amount of motion as before. I'm not saying anything wrong with the TC because it does hit at 3k. Just maybe not want I needed. The car was way more fun to drive before. I will be putting old TC back in.
 
That's how hi-stalls work. They slip more, to get to where the power starts. Cuz your engine has a fair bit more power at 3000 versus at 2200.
At just 140 psi cylinder pressure tho, I'm surprised you didn't call the bottom end soft. I would have thought the 3000 would be the instant cure with 3.55s.
You know, that with a 3000TC you can, or probably want, to reshape your timing curve, and open the secondaries sooner. Before you pull that TC out, I would highly recommend a retune.

Ok,thanks. It runs great, just sluggish acceleration from 20 to 40 or unless push hard enough to downshift, then it's like switch on. I'll make a call or 2 to a converter company.

In second gear;20 to 40 is 1360 to 2720 zero-slip; at Part Throttle before KD, say 1430 to 2860. So this is right in the sluggish zone for that 268 cam and 140 psi cylinder pressure.
At KD into first gear, now WOT, this might be
2570@20 going to 5140@40;so, I get your disappointment. In second gear, if your engine is soft (140psi), then that new TC is not gonna make a huge difference. And at KD even less, because the engine is already at 2570@20 mph, and that soft bottom-end (140psi), is not gonna react with fury. By 24 mph, the Rs would have already been over 3000 with the old TC.
The problem is not the TC, but rather; A) the 140psi and/or B) the 3.55 gears which lock you into that soft 140psi zone, and/or C) that 268 cam with it's late-closing intake, that is creating the soft 140 psi together with the low Scr.
The cheapest fix is more rear gear, like 4.10s, which would get you, about
2970@20 going to 5940@40 in first @WOT, and,in second at PT; from 1680 to 3360.
The proper fix is more cylinder pressure, like 155/160 with open-chamber iron heads.
I like that 268 cam, but it is a principle player in the low cylinder pressure. And really, it power-peaks up near 5300, and wants to be shifted at around 5600, so if yur not going there..... then there is not much reason to keep it. A smaller cam will get you more pressure, and more torque and more performance below 60 mph, cuz right now 5500 is ~46 mph in first/76 in second, and should be spinning 25s all the way thru first, but at 140 psi, I bet it can't.
That's my opinion

That cam wants about 9.8Scr at your 950 ft elevation, Which would increase the VP from around 117(sick-teener) to 140 ( sick-fun)
Read about VP here;
V/P Index Calculation
 
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Thanks, I guess I will save this one for the day I can put in a stroker.
 
Call Andre and tell him what is going on. I don’t think the converter is right at all. They missed it on this one. That’s how the old converters worked way back when they would just bend the fins for more stall. Get them to make it right. Kim
 
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