Dyno Numbers: 4R70W vs C4

[Kurt2002]

I did the C4 swap and nothing else beside a retune. Everything else was the same.

Old 4R70W combo:
DirtyDog Performance 4000rpm stall Converter (reworked PI converter)
282rwhp and 304TQ (locked converter)

New PA C4:
DirtyDog Performance 5000rpm stall 8" converter
280rwhp and 367tq (no lockup)

The only thing I did different was the trans swap, no other mods. Both combos have 29 degrees of timing and a/f 12.7-12.9. Of course these TQ numbers are skewed by the TQ multi. and stall but I was really curious how efficient the converter would be being unlocked. It looks like it is very efficient which is what I was wanting.

The one weird thing was my rwhp peak increase from 6100rpm to 6500rpm. Not sure how the trans/converter swap would effect the peak rpm. Anyone know why?

Again dyno numbers means nothing on high stall converters, it is just a tuning tool but still wanted to share.

 

[DBMSTNG]

it's tough to compare a locked to non-locked converter numbers. my guess on the peak numbers with the C4 is that the trans and converter may have less rotating mass, thus more efficient.

 

[CobraRed_96_GT]

it cant be a 64rwtq difference - the TC isn't locking up (spinning at the same speed as the flywheel) so hence it's still multiplying torque. With just a difference in tranny your peak tq should more or less be at the same rpm as before, i bet you it's not because of this multiplication - after all that's what they are supposed to do

 

[Kurt2002]

yeah according to PA they said the less rotating is what increased the peak rpm. Now it is time for the real test, a ET slip