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SignUp Now!Not entirely true.
Below the point where the converter 'couples' part of the 'slippage' is generating torque multiplication.
The only way to know the true efficiency is with a torque converter dyno.
Thanks bison, I appreciate your input. Here is the problem IMO, My car makes a ton of power between 4000-5000 rpm. If the converter is not coupled hard to the trans at that point, It just dumping the power off as heat.
the converter looks like its doing its job to me.
Bob
The power is most likely not being dumped off as heat. If you had an accelerometer you would see that the g force is usually much higher at the highest slip %.
You can still get a converter slip number without a converter dyno. You need a driveshaft speed sensor. There is no more accurate way to do so. The slip is likely 40-50% at 5000 rpm then it couples and winds up being around 5% or better up top.
Me too. More average g force = a quicker car. Im at about .7 g's@90mph at 750-800hp. Id like to see the data from your 181mph pass Dusty. Id bet its over .8g at the eighth trapI'm not concerned what the rpm trace is doing, compared to the actual acceleration of the car.
Alrighty fellas, here is what we been waiting for. Things feel a little better tonight. Tell you what, 5800 rpm is the end of the line.![]()
Your MAF signal is a little wobbly in spots. You still running that blow-thru setup?
The RPM's drop to 5000 on the shift. Stay flat momentarily, then start rising.
Looks all good to me.
Bob
The other thing to look at is overall rpm. If it never climbs over 5200, your springs are shot. I never ran less than 981's on a flat tappet cam because the spring pressure after several heat cycles wasn't enough for boost and rpm. I sent 3 boxes of 981's back when I did my last flat tappet motor. Very few of the 3 boxes were close to the advertised spec. Had I not checked the spring pressure myself before putting the engine together, I would have had rpm issues.
I started using a Sealed Power spring from the local parts store. They all checked between 100-110# at 1.7 installed height.
Alrighty fellas, here is what we been waiting for. Things feel a little better tonight. Tell you what, 5800 rpm is the end of the line.![]()
dusty any chance you have that part # on those springs? the sealed power ones. thank you very much
dusty any chance you have that part # on those springs? the sealed power ones. thank you very much
The PTC 9.5 is definately a much different converter than anything I have used before. It's the first time I have seen rpm drop 1-2 seconds after the 2nd/3rd shift. Pretty cool! I concur with Bison on the g-force number, at about 20psi I was seeing about .67 G's.