converter ?

D72CamaroZ28

Veteran Member
Lifetime Gold Member
Mar 26, 2006
185
The Mile high City
Oh an Continental said it should stall at 4800-5200 an on the transbrake it goes to 6200. I've been shifting at 6800. Thanks again for trying to help me figure this thing out!
 

1980RS

Veteran Member
Jun 17, 2006
6,355
MN
D72CamaroZ28 said:
Oh an Continental said it should stall at 4800-5200 an on the brake it goes to 6200. I've been shifting at 6800. Thanks again for trying to help me figure this thing out!

That combo you have should run 9.90 IMO as you have way more power that I did, But I think you should get a new converter. 6000 stall is too high just like when I ran my Big Block years ago, I just drove through the converter right of the line, got 40 feet out the had to shift. Sucks you will have to spend the money but the ET will be worth it.
 

rustbucket79

Veteran Member
May 29, 2003
9,076
British Columbia, Canada
D72CamaroZ28 said:
Oh an Continental said it should stall at 4800-5200 an on the transbrake it goes to 6200. I've been shifting at 6800. Thanks again for trying to help me figure this thing out!

Time for a phone call I think. If they missed the mark by a thousand RPM, that's a huge miss IMHO. Has the engine been dyno'd? I would assume with the big cubes that engine would peak in the low 6000 range. The car might be quickest letting it's tongue hang out through the traps, but 6200 stall I'm guessing that's the HP peak. For drag racing I like to see around a 1500 RPM spread between converter stall and shift point.
 

D72CamaroZ28

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Lifetime Gold Member
Mar 26, 2006
185
The Mile high City
Well after talking to Continental yesterday I found out that the transmission shop I use told them to loosen my converter 1000 when they had it appart to install the mechanical diode! But Peter was really cool about it and said to send it back to them an they would fix it for free! Now that's customer service. Thanks again for all the help gentleman!
 

Rich Schmidt

Veteran Member
Mar 27, 2010
4,285
Denville NJ
The run them loose with the mechaical diode for 2 reasons. First,they are normally only used in very light cars,where the stall speed is typically about 1000 rpm lower then the shift point,and second,the mechanical diode doesnt multiply torque as efficently so the car will leave softer unless you add stall.

Here is how I select convertors for maximum E. T. I dont worry about torque peak at all. Torque peak is for street guys who want to run the minimum stall possible and have some kind of decent launch. Race cars work best using the "top down" approach. Use as much stall speed as you can and still get reasonable lockup after each gear change and at the finish line RPM. Basically with a 7500rpm engine in a 1800 pound dragster with a glide I would use about a 6500 stall because the engine wont drop that much rpm on the gear change and 1000 rpm is enough to lock the convertor up at 7500rpmhe same engine in a 2400# super gas door car would run abut 6000 stall,because when you move the shifter the engine speed will drop further and it will drive into the convertor and slip while the convertor tries to lock up again. The same engine in a 3200# car with a glide would run about 5500rpm stall because it will loose even more rpm on the gear change,and the weight an aero drag can also slip the convertor more at the top end. With a 3 speed I would run maybe 200rpm more stall for no other reason then the fact that while the gear change drop will be less,the aero and weight drag thru the traps will still slip a looser convertor. With 7000 rpm thru the traps in a 3200# car with a 3 speed,I would run about 5300rpm stall with a trans brake and a 4000 rpm chip in the 2 step. Use a traditional convertor with a sprag,and cast stator unless you are running nitrous,then use a steel stator.

Good luck.
 

rustbucket79

Veteran Member
May 29, 2003
9,076
British Columbia, Canada
QUOTE:With 7000 rpm thru the traps in a 3200# car with a 3 speed,I would run about 5300rpm stall with a trans brake and a 4000 rpm chip in the 2 step. Use a traditional convertor with a sprag,and cast stator unless you are running nitrous,then use a steel stator.

That's funny, you nailed my combo in terms of RPM's and weight. I was footbraking though (changing to a brake/400 for 2012) with anywhere from 2500 to 3400 on the 2 step. I already own the fancy torque, it has a steel stator and the mechanical diode. HP peak was 6000/6100, but engine is only down about 15 at 6500 so the car improved with a gear change, from 4.10 to 4.56. Your theory works Rich!
 




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