ucrazymonkey

Take my dyno numbers listed in the sig. Will the torque converter change the output number for my RWHP? I would imagine that 290 RWHP is the true reading. As for the RWTQ of 347 is it mulitplying it up? where do I get my basis for my RWTQ numbers? From what RPM? And also when it spikes on the graph is the the torque conveter locking up?

rskrause

Most converters will not lock up under WOT. When you have an automatic on the dyno the torque spikes up when the converter flashes, then comes back down as the revs rise. Peak numbers, ignoring the "artificial" peak when the converter flashes, are 5-10% lower than with a manual tranny, you stop getting torque multiplication pretty quickly as the revs rise after you hit WOT.

The looser (higher stall) the converter, the greater to loss in rwhp. Cars with relatively poor power to weight ratios are quite a bit slower with automatics than with manual tranmissions. It's only at pretty high hp:lb that an automatic has an advantage at the track, but it's always lower on the dyno.

Rich Krause