Launch rpm vs converter flash

is there any kind of magic number on the relationship?

converter flash 6200, launch is 5500, blown sbc 14:71 30lbs, powerglide 1.81, 34.5x17 goodyear, 5.14 rear 2600lbs, 1.02 1.03 60'

should launch be closer to flash or farther away

 

You're talking about two different numbers. Launch rpm is whatever you set it at. Converter flash is relative to the converter, then allllll the other factors, especially horsepower. Although first gear ratio, rear end ratio, and weight will determine where the stall will lay. As far as how close they should be would probably be up to your car and how it launches. But i'm no chassis guy!

 

converter

ATI says leave as low as you can + still get a good reaction time. Let the converter do what it is suppose to do. But then most of us have big cu in. or high torque motors. so it is different. I leave @ around 2200 /2300 RPM's. But then it idles @ around 2000 or so. depending on the timing / fuel management. Don

 

Doesn't the engine get a run at the tire if you leave at a much lower rpm than the stall? I always thought you should have your launch with in 500 rpm of stall. I know that flash is way different, but I still think you should be on the upper end of the converter at the hit. My tranny guy also wants the rpm up so the pump is making enough pressure so to not slip. Just a thought. Chuck.

 

Easy way to suss that out is to stick a gauge on the servo and see what RPM the pressure peaks at. It won't be anywhere near stall, unless you've got other problems...

 

I think the best rpm to leave at is determined by the timeslip.

I agree with ATI if you can drive into the converter and let it do its job that is great, I just don't think with a lot of high power blown combos this is an option.