MauriSSio

quick question, i hear that having a locking converter can show up as more HP on a dyno.just wondering But is the converter ever locked while racing?

MikeG

iTrader: (33)

The converter is only locked during racing if you manually lock it.

BLK02WS6

iTrader: (2)

The converter is locked up by the PCM based on what is in the tune... you could put a switch in to manually lock it, but that is not the norm.

Some LT1 cars were set to lock the converter in 3rd at WOT. LS1 cars are not set to lock the converter at WOT. That can be changed in the tune.

MikeG

iTrader: (33)

Basically what I meant, just worded better.

MauriSSio

do you gain ET and MPH in the qurter with it locking?

BLK02WS6

iTrader: (2)

Some gain a little MPH, but not much ET - really depends on the setup. If locking the converter pulls it down out of the powerband, then it really won't help and could hurt. Plus, its hard on the lockup clutches so I wouldn't do it unless you have a good converter...

MauriSSio

i see, so why do people insist on dynoing a car with it locked then?

BLK02WS6

iTrader: (2)

Cause it makes higher numbers... and they care too much about bragging on the internet about what thier car made on the dyno... when the only real numbers are the ones on that big board at the end of the track!

I will only do it if a customer absolutely insists, and I warn them that I am in no way responsible for damage to thier transmission or converter. One thing that makes it a little easier on parts on the dyno is that you lock it up before making the pull and then make the pull nice and steady - its not as bad as locking up when you get in 3rd gear on the track under full throttle. But I have still seen them break on the dyno...

MauriSSio

i see, so it seems to be fueled mostly by ego. Thanks!

00pooterSS

iTrader: (40)

Torque converters work off fluid so they never fully lock unless you lock it, they always allow some amount of slip, but that little slip can sometimes keep you in a better RPM range actually making the car pull harder. So it will output higher numbers on the dyno when locked but like stated most converters do not have a strong enough lock up clutch to handle a WOT pull. When locked the tranny/converter acts more like a manual transmission, the slipping is why auto's put down lower numbers so auto guys like to lock them for higher dyno numbers.

And yes it can be about ego, but if you have a big sloppy stall its really gonna kill your numbers so if you lock it you can get a better idea of what your car would be putting out if the stall was not killing your numbers.

Squirts11

iTrader: (14)

When I had it tuned, I insisted all WOT runs be made unlocked until it was tuned. On the final pass we did a locked run to see the numbers it would put down (every run before this was merely for tuning, only the last run was I interested in numbers).