Picking a Converer

[Polara Pat]

So the converter that we bought when we had our transmission built is an 8" 5000 stall and is way too much converter for our 413. Although our motor is built very well by Dvorack, it's no 9 second missile. It is 13:1 with a fairly mild roller cam and very massaged iron heads with a port matched cross ram. Our car weighs about 3600# with me in it. The understanding that I have on testing a converter is to place the trans in 3rd gear and with your foot hard on the brake, you smash the gas. The needle on the tach will spike to your flash point, then drop down to your stall speed before choking the engine into dying. When I do this test I can flash to 5800 or 5900 but the tach doesn't drop and the motor doesn't die. It mostly just winces.
Knowing that we had too much converter I sent this 8" out and had it tightened up, then we took the re-freshed converter to Vegas for MATS to test it. Granted the air was dense and that track sits at over 2000' above sea level we ran slow with a best of 11.35 @ 114 mph. Boooo. Our best with the old combo at a good track was 11.1 @119mph. I feel like I need to start fresh with my converter program and was thinking of checking in with Turbo Action or TCI. Any recommendations as to stall or size or manufactured?

All input is appreciated

 

[Mike Gaines]

I tested the "flash" in my converter as a by product of strapping the car to a chassis dyno.
The dyno operator had the car in 3rd gear (torqueflite, of course) and at about 2500 rpm he floored it.
The "line" on the dyno chart went "in a straight line, straight up" to 5100 rpm before it started moving sideways....walla...proof of 5100 flash.

I was told by Chuck Loftgreen (transmission builder) that you cant have it both ways on a converter if your car weighs 3500 or more pounds.
If your car weights 3500 or so pounds or more and have a 5000 converter you will lose MPH because of the "converter slip" on the big end,
If you have a tighter converter you will lose 60' times but have a higher MPH.
Depends on what you want....
I am pretty sure I am repeating this correctly...it was kinda confusing at first.

From your results at MATS it seemed like changing the converter made not much difference at all.
You proably woulda went 11.35 at MATS even with your old converter....it was probably the air and altitude.
Do some other runs before you make any converter changes...maybe...just a thought from a NON-CONVERTER EXPERT such as myself.

 

[Polara Pat]

I am pretty sure I am repeating this correctly...it was kinda confusing at first.

From your results at MATS it seemed like changing the converter made not much difference at all.
You proably woulda went 11.35 at MATS even with your old converter....it was probably the air and altitude.
Do some other runs before you make any converter changes...maybe...just a thought from a NON-CONVERTER EXPERT such as myself.

I feel like you may be right about there being little or no change with the altitude and bad air in Vegas as far as e.t. and mph goes but we ultimately want better results all around and feel like this just isn't the converter for the combo.

 

[bobtile]

Call performance torque converter and give them your engine specs. I went from 12.1 to 11.3 with their recommendation. I have a 9.5 converter in a mild engine combo. They told me if I went to an 8 " that I would be at 11 flat. By the way, they told me I should run about 11.3 with the 9.5. Dead nuts on.

 

[Bigal75]

I really like my pro torque

 

[66Satellite47]

The high gear flash test is as you describe & 5800 seems mighty high. The MPH seems low for the ET indicating excessive slip. I had good luck with Coan & Turbo Action (for the most part). The Turbo Action in my current Satellite seems great. Call Cope, Dynamic, Coan or Turbo Action. There's lots of threads with opinions. Never knew any Mopar having good luck with TCI but.... I always gave it a couple times out before I proclaimed a converter junk, but yours sounds suspicious.

 

[383man]

The first thing catching my eye is your 11.35 @ 114 mph which is way low mph for that et. Did you lift early or did it feel like the converter was slipping on the top end ? Either one of them or the eng is dying some on the top end. It tells me when you get the mph back it should run a good bit faster. Myself I have used Turbo Action and Luppo's Dynamic converters and both have worked great for me. The converter in my 63 is a Luppo Dynamic which is their 9.5 street/strip converter as my car is a street car that I drive alot on the street. That Dynamic converter has been in my 63 since 2006 and still working good as it will flash about 4200 at the track and drive like a normal converter on the street. Ron

 

[Polara Pat]

This is all really good advice and confirms that either the converter or the trans is slipping at the big end. My '60 seems pretty accurate and the car launches straight and hard for a foot brake machine. BTW we switched over to 31x10 Hoosier radials and they kick ***. We had a Dynamic converter in our old race car and it did us no wrong. I have had really good dealings with Paul Forte at Turbo Action and long time racers like their converters but have also used them up. They have been described as an "old School" company compared to places like TCI.

 

[dvw]

High stall isn't always loose at the big end. Loose is generally quick. Your MPH could have been down do to being at Vegas. Do you keep track of altitude and weather? If not you need to test where you normally run. I once thought my 5800 converter was to loose in my Max Wedge (5800).
Car would go 10.30's, 10.15 in really good air. Tried to tighter converter, (5200 and 5400) car never ran better than high 10.30's in good air. We use either Lenny at Ultimate or Kenny at PTC. Both with excellent results.
Doug

 

[66Satellite47]

High stall isn't always loose at the big end. Loose is generally quick.
Doug

I found this quite true too. My loosest converters were just as efficient as the tighter ones when in good shape. Most of my converter failures were broken stators & the stall speed and torque multiplication went away killing ET not slipping.

 

[383man]

Pat what does the car 60 ft ? I have used Turbo Action and Dynamic converters and had good results with both. Ron

 

[cudatom]

Pat I like PTC, they built my convertor for my Cuda and also my last one for the Belvedere(not installed yet). The one in my Cuda was dead on w/what I requested. Very efficient at the top end and decent 60' times given that I had rear coil overs that were way to stiff for my application. I foot brake the car and was running 430's, 29.5" tall tires, shifted at 6300 and crossed the line at 6300-6350 and 60' was 1.41. Car was running 10 teens at around 130.

 

[Polara Pat]

Pat what does the car 60 ft ? I have used Turbo Action and Dynamic converters and had good results with both. Ron

1.54, 1.55 was pretty consistent in Vegas. That's our best 60' in this car but not as good as it could or should be if that makes any sense. Basically we're still tweaking the combo.

 

[bobtile]

1.57 was my best 60 ft. with [email protected]. My car weighs 3690

 

[Polara Pat]

1.57 was my best 60 ft. with [email protected]. My car weighs 3690

Those are really similar stats to us Bob but we're a bit lighter and our mph is off. I feel like all the slip is happening at the big end, my 60' is pretty close to what I think it should be. Dvorak on the other hand thinks we should be in the 1.4s for our 60'.

 

[383man]

I may have missed it Pat but are you running Cal Tracs or just SS springs ? Ron

 

[Polara Pat]

I may have missed it Pat but are you running Cal Tracs or just SS springs ? Ron

SS Springs, apparently reworked for our friends Stocker. They work o.k. for what we have which is probably only 650 hp but anything more I think they would be overwhelmed. I'd like to switch to Cal Tracs and mono leafs at some point but they look a bit out of place on a beast like ours.

 

[super-bee_ski]

Good thread,
Taught me something!
Tank you!

 

[Polara Pat]

Good thread,
Taught me something!
Tank you!

You and me both.

Here's what some of my other research has turned up. Firstly, I know a lot of people don't have a high opinion of Dan Dvorak but he has always been nothing but good to our team and has a lifetime worth of engine building and drag racing knowledge, so getting the info that is needed from the motor that he built so that we can customize our converter as closely as possible for our given comb is priceless. I also love hearing whacky stories from him about his crazy sister smashing frogs with a sledge hammer during a monsoon but we'll save that story for another thread. Also, Paul Forte from Turbo Action is another stand-up character who really knows his **** and has been building converters since the '70s. So he has literally watched the evolution of converter technology pass in front of his bench.
Alright, any thoughts on using a mechanical diode in our converter? I know a guy who used to be in the converter building business and he is willing to pretty much give us one. From my understanding they are suitable for much larger horsepower applications but is there a downside to using one behind our 413?

 

[bobtile]

Good thread,
Taught me something!
Tank you!

OK, you're welcome!

- - - Updated - - -

You and me both.

Here's what some of my other research has turned up. Firstly, I know a lot of people don't have a high opinion of Dan Dvorak but he has always been nothing but good to our team and has a lifetime worth of engine building and drag racing knowledge, so getting the info that is needed from the motor that he built so that we can customize our converter as closely as possible for our given comb is priceless. I also love hearing whacky stories from him about his crazy sister smashing frogs with a sledge hammer during a monsoon but we'll save that story for another thread. Also, Paul Forte from Turbo Action is another stand-up character who really knows his **** and has been building converters since the '70s. So he has literally watched the evolution of converter technology pass in front of his bench.
Alright, any thoughts on using a mechanical diode in our converter? I know a guy who used to be in the converter building business and he is willing to pretty much give us one. From my understanding they are suitable for much larger horsepower applications but is there a downside to using one behind our 413?

You too!