Why not go 1:1?

[turbocamino1]

I know some ODR guys and some X275 guys and i crew a big tire outlaw car. The DR guys are 75/25 non lock but work with fluid restricters to get coupling where they need it (varies from surface to surface) Its hard to argue with a guy going 4teens on a small tire. He wants motor speed(RPM) just ahead of driveshaft speed . Another says BS to that..and wants locked (1:1) ASAP...around 2.5 into run....by 330. Camps seem split on this. My question/ thoughts an this is why dont we see more in our community opt for locking it asap..multi-disc conv. with a str0ng 200 ...locking maybe sometime in 3rd gear...or even 2nd? I am to this point now as i need a new trans/conv. set-up and keep going back and forth on this.

 

[bison]

I know some ODR guys and some X275 guys and i crew a big tire outlaw car. The DR guys are 75/25 non lock but work with fluid restricters to get coupling where they need it (varies from surface to surface) Its hard to argue with a guy going 4teens on a small tire. He wants motor speed(RPM) just ahead of driveshaft speed . Another says BS to that..and wants locked (1:1) ASAP...around 2.5 into run....by 330. Camps seem split on this. My question/ thoughts an this is why dont we see more in our community opt for locking it asap..multi-disc conv. with a str0ng 200 ...locking maybe sometime in 3rd gear...or even 2nd? I am to this point now as i need a new trans/conv. set-up and keep going back and forth on this.

 

[bison]

Going to 1:1 ASAP slows the car down. If the converter is right the engine speed will be at or near peak output as long as possible. The cars all seem to go faster when converter slip is 5-7%. Of course if there's anything wrong with the engine those numbers won't mean much. My slow car ran it's quickest times with a 5100 flash stall (@30psi) and 5600 rpm shift. Only a 500 rpm window. About 5% slip at the end of the pass. Peak power was at 5150 on the dyno. My fast car flashes to 5500@ 25psi and I shifted at 5900-6000. Again a 500 rpm window. Slip 6.5% at the end of the pass in. 3rd. Shifting later on both cars slowed them down.

 

[Dusty Bradford]

Totally different applications.

When a converter is locked it can not multiply torque or flash. For a nitrous Pro-mod where you can lock the converter and throw everything you have at it, that's not a problem. For a V6 you need to multiply that torque and get some flash rpm to help the boost come in.

Also with an engine trying to spool twin 94's, you need some stall speed to get it all going, but it makes 3500-4000hp which makes it difficult to couple that power without making it impossible to spool. This is why they control converter charge pressure. They can change the stall speed as needed. In our case I have come up with a converter that does this for us. Spool's well but couples well also. In our Buick world we have no need for this converter charge control until you get into into 88mm+ sized turbo's on a low rpm motor. The TSO racers have proven that the proper combo will still work without having to control charge pressure.