Please share your experiences with various brands or torque converters.. It would be great if you can post your locked vs unlocked dyno numbers TQ and HP.. This will tell alot.. Lets discuss stall, STR, and where your particular converter likes to be foot stalled..

I have a Precision Industries Vigilante 3200.. Actual LS1 stall speed is 3800.. 2.17 STR.. It likes to be flashed ok at the track, but have had the best luck stalling(foot brake) it to 1100 rpm..

locked and unlocked numbers are:

365 hp and 384 tq

and

385 hp and 389 tq


365/384 = 0.987

0.948 x 100 = 94.8 %

Is this the correct way to measure converter efficiency? Use the HP or TQ locked vs unlocked?

The larger vigs are not very efficient, but mine seems fairly decent..

I'm trying to understand why my torque seems fairly close between locked and unlocked pulls and my friends torque drops like a rock..

His numbers locked and unlocked.. His drops 26 tq? what gives?

400 hp and 436 tq

and

420 hp and 410 tq

Thanks
Michael

 

You can measure efficency 2 ways:

1) peak HP locked vs unlocked (what I do)
2) Input rpm compared to output rpm, after the converter has coupled up.

for you efficency = 365 / 385 = 94.8%

My YTP 4200 lost about 13 hp on 380.

 

Sweet.. added heads to the mix and the little vig3200 seems to be fairly efficient..

408.6 unlocked hp and 425.1 locked hp..

408.6/425.1 = 96.1%