[Formulajones]

Originally Posted by johnta1

Formulajones, do you run slicks at the track?

Both stock tires and drag radials. The car runs the same.

For the car to really react to a converter it just simply needs "more" converter.

It's still kind of boggy even with the 2600 flash stall off the line, much like it does with the stock converter. It needs a converter that gets the engine up into it's peak torque area right from the start. Then it actually might hit the tires harder, requiring a good tire, and then I might see an improvement in 60 foot times.
https://youtu.be/er1z7PpqsnY

[ta man]

Originally Posted by PontiacJim1959

I see you are still hooked on the "race application." We are going to have to agree to disagree on this one.

It also has to do with having fun with the car feeling more power, laying rubber and general mayhem! A good convertor can lull your passengers to sleep on a cruise and slam them into the seat under full power from a stop.

[Will]

Originally Posted by Formulajones

Since you have both converters sitting there my vote is to try both of them. If you don't like one, it's only an afternoon to switch to the other converter and have a go at that one.

....

My thought, exactly. Converter swaps are pretty easy.

[PunchT37]

He`s got the converters already. It`s not like he`s going out to spend money on something that`s going to ruin his car. We already know what a stock converter feels like. Why not try the "other" one.

I don`t think that converter is going to "slip down the road". It`s not that small and that motor is not a powerhouse.

[OCMDGTO]

X10 go with the 10"/higher stall with a trans cooler

[moontower69]

I hate to be the contrarian, but i've had that SAME situation and i sort of hated the 2500 stall with that kind of a 400 with 8.5 compression and 067/068 type cam specs.

I do a lot of street driving and deal with traffic. I dumped the Hughes 2500 and then went with a custom 2000 stall and honestly that was perfect. Lots of fun and just a little bit more tire spinning from even 10 or 15 mph or rolling starts.....but 2500 just moaned like a boat.

[NeighborsComplaint]

Stock convertor FTW. No need for higher stall, You'll waste 1500 RM of low end powerband and torgue. Below the stall speed you won't be fully coupled and the car will feel lazy.

[NeighborsComplaint]

Originally Posted by tjs72lemans

My rebuild is close to what you have. I ended up with 310 hp and 400 ft lbs torque.

1967-1970 with 4-Barrel Carb
Max Brake Horsepower: 330@ 4800rpm
Max Torque: 430 @ 3000 rpm
Stroke: 3.75
Bore: 4.1212
Compression: 10.5
Firing Order: 18436572
Camshaft 067

1967-1970 High Output with 4-Barrel Carb
Max Brake Horsepower: 335@ 5000rpm
Max Torque: 430 @ 3400 rpm
Stroke: 3.75
Bore: 4.1212
Compression: 10.5
Firing Order: 18436572
Camshaft 068

1967-1970 Ram Air III with 4-Barrel Carb
Max Brake Horsepower: 345@ 5000rpm
Max Torque: 430 @ 3400 rpm
Stroke: 3.75
Bore: 4.1212
Compression: 10.5
Firing Order: 18436572
Camshaft 744

I am always amazed that people can do a stock rebuild on a low compression engine with equivalent camshaft specs and expect to make more HP than the factory did with high compression heads running 93 octane.

[lust4speed]

We have members in our club that have converters that flash to 3,400 to 3,600 RPM and you would never know that driving their cars. Converters were by Continental and some by Munsinger and they simply work great. Acted like a standard converter until the foot was to the floor. I had a 2,800 stall in front of a 200-4R that cruised at 2,200 RPM at 70 MPH and it always felt nicely hooked up at anything less than full throttle.

Getting back to the limited horsepower discussed above, I would rather have 300 foot pounds at 2,600 available than 200 at 2,000 when I nail the throttle.

[Cliff R]

I've had enough converters in my Ventura to easily fill the bed of a full size pick-up truck. Dating clear back into the later 1980's I've been buying and testing them. I've ran B & M, TCI's, Coan, Continental and a variety of "no-name" shelf stuff. I even used the Ventura to test prototypes and 10" variants of the EXCELLENT Continental "Jim Hand" 10" converter.

Despite the good reviews the Hugh's get on here I find them "mushy" for street use. They are even worse behind low compression "mild" engines. Some folks rave about them simply because they just happen to fit the bill nicely for their particular application where some additional torque multiplication helps the engine move the car effectively. At best, for what you are doing here a 25 Hughs would just be OK and I'll bet you'd wished you'd have left the stock converter in after your first tank of fuel.

For higher compression engines making great power a converter that locks nearly solid past the flash stall speed is going to be the best one you'll ever have in there.

My Continental 10" is the top of the pile for ALL the converters I've had in the Ventura. You would never even know it's in there if you stole the keys and took off with the car. It doesn't even "flash" up anyplace for "normal" driving unless you get into it pretty hard going under 40mph in high gear to climb a hill or steep grade. Even then it barely goes past 2000rpms or so and you might be able to "push" it to 2400rpm's for a second or two till the vehicle speed catches up.

Holding the brakes as hard as you can it will overcome the tires at 1900rpm's. So it's nearly as "tight" as a stock full size converter everyplace.

Go to the track, heat up the DOT's, stick it hared and it flashes to 3600rpm's on a full throttle launch and yields 1.59-1.61 60' times! Past the stall speed it's locked solid, goes thru the top end around 5300rpm's up near 120mph. It was closer to 5100rpm's when I ran 28" tall tires. Do the math:

MPH x GEAR RATIO x 336 divided by TIRE DIAMETER. 120 x 3.42 x 336 divided by 26 is 5303rpm if my calculator is working correctly this early in the morning.

Anyhow, as it relates to this thread I'd use the larger converter. 10" units can be a "crap shoot" with this sort of thing and you'll most likely love it pulling away from stoplights at full throttle and hate it everywhere else, at least from what I've seen with this sort of thing........FWIW.......Cliff


https://www.youtube.com/watch?v=6zVdoLR-VzM

[Formulajones]

Originally Posted by lust4speed

We have members in our club that have converters that flash to 3,400 to 3,600 RPM and you would never know that driving their cars. Converters were by Continental and some by Munsinger and they simply work great. Acted like a standard converter until the foot was to the floor. I had a 2,800 stall in front of a 200-4R that cruised at 2,200 RPM at 70 MPH and it always felt nicely hooked up at anything less than full throttle.

Getting back to the limited horsepower discussed above, I would rather have 300 foot pounds at 2,600 available than 200 at 2,000 when I nail the throttle.

You are exactly right. A tight converter that doesn't flash very high will do nothing for you in a RAIII based 400 engine that makes peak torque around 3500 anyway. There is nothing you are missing in a stock 400 below that rpm, trust me.

It's apparent there are still quite a few that don't understand how a good converter is supposed to work, and have been victims of very poor coupled converters that drive horrible around town.

Surprising as much as everyone has hung around this forum and have seen how much a good converter is preached about around here.

[Schurkey]

Originally Posted by Schurkey

OTOH, if I had a modern, efficient "performance" converter, I'd probably try it and see what happens. If this was an older, mass-market sloppy-loose converter, it'd go on the scrap pile or perhaps I'd see if the guts could be reworked into something usable.

Originally Posted by Cliff R

Despite the good reviews the Hugh's get on here I find them "mushy" for street use. They are even worse behind low compression "mild" engines...

...Anyhow, as it relates to this thread I'd use the larger converter. 10" units can be a "crap shoot" with this sort of thing and you'll most likely love it pulling away from stoplights at full throttle and hate it everywhere else, at least from what I've seen with this sort of thing........FWIW.......Cliff

Originally Posted by Formulajones

It's apparent there are still quite a few that don't understand how a good converter is supposed to work, and have been victims of very poor coupled converters that drive horrible around town..

As for the 10" converter that the OP already owns: It's not really a matter of stall speed so much as it's a matter of sloppy vs. tight/efficient.

If that's a sloppy converter, you'll hate it. If it's a good converter, you'll love it. My suspicion is that it's a mass-market junker, but I suppose there's no way to tell without installing it and driving the car some.

Was it stored properly? No chance that debris fell into the neck? How did it work in your friend's car? Where did he get it?

[AJ-]

Again, thank-you for all the responses. I see some people love them a good converter discussion! The converter is "good" in that I pulled and stored it myself and know it works fine. I think Shurkey nailed, though, about whether or not it's a good one. It is just an "off the shelf" one. I have made a few passes in the car it was in and driven it briefly on the street. It was fun on the track but my recollection from the street it is that it is not as tight as what some of you are describing.

I think my plan is going to be keep the stock one in for now and make sure I get the new motor broken and dialed in before making other changes. My guess is the stock converter should give better tuning feedback. I'll keep the 10" in my back pocket in case I want to try it out later and see the difference.

[PunchT37]

Originally Posted by AJ-

Again, thank-you for all the responses. I see some people love them a good converter discussion! The converter is "good" in that I pulled and stored it myself and know it works fine. I think Shurkey nailed, though, about whether or not it's a good one. It is just an "off the shelf" one. I have made a few passes in the car it was in and driven it briefly on the street. It was fun on the track but my recollection from the street it is that it is not as tight as what some of you are describing.

I think my plan is going to be keep the stock one in for now and make sure I get the new motor broken and dialed in before making other changes. My guess is the stock converter should give better tuning feedback. I'll keep the 10" in my back pocket in case I want to try it out later and see the difference.

Sounds like a plan.

[Will]

Originally Posted by Formulajones

...
It's apparent there are still quite a few that don't understand how a good converter is supposed to work, and have been victims of very poor coupled converters that drive horrible around town.

...

Seems like most people don't understand this. The education level is a little higher here on the forum, but in general if you tell someone to spend the money on a quality 3000-3400 stall converter you'll get all kinds of pushback.

Meanwhile my Formula 60' at 1.6-1.7 on street tires with a Coan and you'd never know it's in there in normal driving.

[tjs72lemans]

I am always amazed that people can do a stock rebuild on a low compression engine with equivalent camshaft specs and expect to make more HP than the factory did with high compression heads running 93 octane.


I do have a bit different cam (Lunati voodoo 701 with .454 lift) and don't know exact specs of the 67 cam referenced. With the stock rebuilt 7k3 heads and .03 over bore block, it was actually whistled at 7.8 comp. Dyno readout is way above the 220 hp stock motor. I was happy to see 310 hp and 400 ft lbs.