[71 Chevy]

so, the other thread prompted me to ask this question

I bought a b&m 2400 stall that the experts said would stall around 3000rpms behind a bbc.

so, why is it that when i jumped on it(floored it instantly) that thing would start moving at 1200 rpms?

I had a vacuum can on it at the time, and 4.10 gears with a th350.

 

[jason snyder]

so, the other thread prompted me to ask this question

I bought a b&m 2400 stall that the experts said would stall around 3000rpms behind a bbc.

so, why is it that when i jumped on it(floored it instantly) that thing would start moving at 1200 rpms?

I had a vacuum can on it at the time, and 4.10 gears with a th350.

because a 2400 stall is hardly even noticable ! But you can footbrake it and see how high the rpms will go before it breaks the tire loose. this will be close to the actuall stall.

 

[71 Chevy]

because a 2400 stall is hardly even noticable ! But you can footbrake it and see how high the rpms will go before it breaks the tire loose. this will be close to the actuall stall.

I must have weak brakes because it started moving around 1200 rpms lol.
what do you mean by hardly noticeable? I know its a mild converter but if it had actually waited till 2400rpms to start moving the car would be beastly.

 

[bowtie0069]

Most of those "One size fits all" converters seem to fall on the low side in that rpm range. Torque, vehicle weight, and gear ratio can make a huge difference in how the converter responds. A big cam in a small engine will have a hard time getting any rpm out of a typical 2400-2800 unit.
I borrowed a 9" Art Carr from a buddy, it went 6000 rpm in his car, stalled my engine when I put it in gear! He had an 8-71 blown big block--I had a 406 with a [email protected] roller......big difference in torque output. It was like driving a stick, it would actually lug the engine in high gear if going slow.

 

[72GreenRally]

Lot's of info in the Best of Drivetrain

http://stevesnovasite.com/forums/showthread.php?t=36630

 

[dh63ss]

because a 2400 stall is hardly even noticable ! But you can footbrake it and see how high the rpms will go before it breaks the tire loose. this will be close to the actuall stall.

Not necessarily, most converters won't footbrake within 700-800 rpm of its true stall behind any given combo. Without a trans brake, flashing the converter from about 30 mph in high gear will give you a pretty good idea of the converter's true stall in your setup.

By the way, I also had a B&M 2400 and it did the same thing behind a pretty torquey 383. I don't think they are much more than a stock converter slightly tweaked for a little flash.

 

[NOVACA1N]

Those converters are crap

I know others will say that theirs' is great, but I'm telling you from experience. Crap.

 

[bowtie0069]

Those converters are crap

If you spent less than $500 on the converter, it will probably fall into that category! I got very lucky when I picked up the 8" Munsinger in my car for $200 used. Best part on the car! I think it would be over $800 today.

 

[jason snyder]

Not necessarily, most converters won't footbrake within 700-800 rpm of its true stall behind any given combo. Without a trans brake, flashing the converter from about 30 mph in high gear will give you a pretty good idea of the converter's true stall in your setup.

By the way, I also had a B&M 2400 and it did the same thing behind a pretty torquey 383. I don't think they are much more than a stock converter slightly tweaked for a little flash.

i agree 100% , i also think the 2400 stall behind a bigblock should see more than 1200 footbraked .

I personally think a 3000 stall is a good STARTING point for ANY performance oriented street/strip car . IMO .

 

[ALLT4]

I don't get why you really want to stall that high anyway. I guess if you have a low torque motor. With the ZZ383, 3.40 gears and cheap mild TCI Breakaway 2500 I can send the hides to rubber Heaven at almost off idle. What good would it do to waste all that low end torque with something that waits until 4000 to flash? From 2500 to 4500 peak torque it's pretty flat, I just don't get it. Then the shifts get mushy and everything that sucks about having a stall too high. Heat, RPM etc...

Nothing like a loud bark shifting to second and third. I suppose if I wanted that uber launch I would go a little higher, but the car isn't meant strickly for the track. More for street comfort.

I don't care what anyone says you go with a real high stall you will run into some of the drawbacks associated with it. At some point there is diminishing returns. Just like a cam, go too big and it's just as bad as too small, go too high with a converter it's a waste of torque, go too low and it grunts.

Long ago I had a B&M Superholeshot 3000, it was ridiculous! More like a holeshot 6000, but it was in a VERY heavy car. '77 Monte Carlo, those things weigh tons literally.

 

[bowtie0069]

I guess if you have a low torque motor

My 410 small block makes at least 500 ft. lbs from 3900-6300 rpm and I launch at 6000 rpm. Dragging the bumper is a lot more impressive than spinning some little street tires down the block! You do it your way, we'll go fast.

 

[dh63ss]

Those converters are crap

I know others will say that theirs' is great, but I'm telling you from experience. Crap.

I totally agree.

 

[LIL NOVE]

Those converters are crap

I know others will say that theirs' is great, but I'm telling you from experience. Crap.

X3 on this one....... :yes::yes::yes: i guess what people still dont realize till they get one built is that a well built converter doesnt feel all sluggish on the street. mine flashes to 4500 w/o a pill in the 2step, but will drive like it has low stall, moves around 2200 & doesnt make a lot of heat in the trans. just like Bowtie, 6000 on the street & :no::no::no: problems...

LIL JOHN

 

[ALLT4]

I'll cruise at 80 mph comfortably and still have this... all with the benefits of a properly tuned centrifugal advance, vacuum advance and a VS carb. You go on pretending that race car is fun on the highway. It's all what you want.

Slug

 

[71 Chevy]

I'll cruise at 80 mph comfortably and still have this... all with the benefits of a properly tuned centrifugal advance, vacuum advance and a VS carb. You go on pretending that race car is fun on the highway. It's all what you want.

Slug

I agree with everything you said except that I prefer a locked out distributor,no advance of any kind, and mechanical secondaries. matter of fact, my secondaries are 1:1

I dont know why on earth people would have recommended me a 2400 stall converter in the past. I said I had a street car, but I think they heard a "daily driver" not so

btw, ALLT4, nice burn out, but next time do it on a street that is not "traction limited" lol jk

btw, check this thread out
http://www.chevelles.com/forums/showthread.php?t=280825

 

[fasteddie]

I'll cruise at 80 mph comfortably and still have this... all with the benefits of a properly tuned centrifugal advance, vacuum advance and a VS carb. You go on pretending that race car is fun on the highway. It's all what you want.

Slug

Why don't you lock out your distributor and put a 4000 stall in the car and try that same thing, you may just change your stuborn ways!!:yes:

 

[ALLT4]

Because I have 3.40 gears and Fastburn heads. A lot of time is spent under 3000 rpm on the street cruising. The Fastburn heads would detonate like a SOB at full advance under 3000 rpm. It would idle hot, run hot and suck gas from being over advanced tooling around. With vacuum advance the motor runs more efficiently at cruise saving even more fuel and running cooler from not burning fuel out the exhaust ports. Without vacuum advance you're burning late at cruise rpm, the engine has little load on it so why not take advantage and add in more advance? It just doesn't make sense to not to, the vacuum advance can is perfect load sensing device to control the amount of advance providing a motor that's always running at peak efficiency.

FWIW the centrifugal part of the dizzy is locked out but there's an MSD timing computer handling the RPM part of advance. It's dead nutz accurate and I don't even have to think about it or ever fuss with it. The only thing that moves in my dizzy is the vacuum advance arm on the stator. No one will ever convince me to take something out that provides so many benefits at cruise RPM.

As far as the torque converter and VS carb go; I didn't build the car to be the fastest thing at the track. If that were the case it would have 4.11 gears and yes probably a higher stall. The heads would be modified to accept a bigger cam, longer winded moving the RPM range up more. Right now the Fastburn heads are almost at the limit of what they can take cam wise. Maybe a GM 847 cam would work without checking the specs on the heads again.

However then I'm getting into more of a strip car, not what I want. I want the best of both worlds and think I'm pretty close.

It's a pretty fun car the way it is, 13.1 on street tires at 106 MPH and I can make back to back runs at 180° all day in any heat. Probably faster if I could have had more runs and actually tried tuning it. Don't mess with success. Not the fastest thing but it's reliable and a pleasure on the street.

 

[bowtie0069]

all with the benefits of a properly tuned centrifugal advance, vacuum advance and a VS carb

When we had my engine in the Dart, it had centrifugal advance, vacuum advance, a 750 VS carb,and a tight converter. It was a slug off the line, but ran 11.40/119--with my setup (no advance, mech. sec. and my converter) it's a mid 10 sec. car. I much prefer the 10 sec. version.

 

[fasteddie]

Because I have 3.40 gears and Fastburn heads. A lot of time is spent under 3000 rpm on the street cruising. The Fastburn heads would detonate like a SOB at full advance under 3000 rpm. It would idle hot, run hot and suck gas from being over advanced tooling around. With vacuum advance the motor runs more efficiently at cruise saving even more fuel and running cooler from not burning fuel out the exhaust ports. Without vacuum advance you're burning late at cruise rpm, the engine has little load on it so why not take advantage and add in more advance? It just doesn't make sense to not to, the vacuum advance can is perfect load sensing device to control the amount of advance providing a motor that's always running at peak efficiency.

FWIW the centrifugal part of the dizzy is locked out but there's an MSD timing computer handling the RPM part of advance. It's dead nutz accurate and I don't even have to think about it or ever fuss with it. The only thing that moves in my dizzy is the vacuum advance arm on the stator. No one will ever convince me to take something out that provides so many benefits at cruise RPM.

As far as the torque converter and VS carb go; I didn't build the car to be the fastest thing at the track. If that were the case it would have 4.11 gears and yes probably a higher stall. The heads would be modified to accept a bigger cam, longer winded moving the RPM range up more. Right now the Fastburn heads are almost at the limit of what they can take cam wise. Maybe a GM 847 cam would work without checking the specs on the heads again.

However then I'm getting into more of a strip car, not what I want. I want the best of both worlds and think I'm pretty close.

It's a pretty fun car the way it is, 13.1 on street tires at 106 MPH and I can make back to back runs at 180° all day in any heat. Probably faster if I could have had more runs and actually tried tuning it. Don't mess with success. Not the fastest thing but it's reliable and a pleasure on the street.

So are you speaking from experience or is this just how you think it would be with a locked out dist and big stall? I have been running my dist locked out for 2 maybe 3 years and have never had any negative issues because of it and my 4000 stall does not hurt the driveability of my car in the least!:no:

 

[71 Chevy]

As far as the torque converter and VS carb go; .

have you clicked on that link lately. he just picked up 3 mph and .4 switching to a double pumper. I think there is no more arguement for a VS carb except for use on a daily driver. did gm ever have vacuum sec carbs on factory cars? even they knew better with the qjet