geeze,
all my posts are being back from the dead today

 

That can be a blessing...or a curse.

 

Wow. I can't quite understand all the info but for some reason my car only put out between 313 and 319 horse at the rear wheels last Saturday at http://www.newenglanddyno.com

Torque was between 380 and 425.

It "appeared" the converter was actually stalling at around 4400 but it was a TCI 3600 that I purchased. That following Day I ran 12.12 back to back at 109. The car weighed 3623 at Englishtown for the GM High Tech Shootout this past Tuesday. Something doesn't seem right. I have been looking for a direction to go in and right now I am thinking the converter isn't right... I would have tried locking it up in third but lockup only works in 4th (overdrive) on the 700R4.

 

There was an extensive discussion a while back don't remember which section. That discussed the fact...well i don't remember but it made since at the time, that it is a percentage and not a set HP of loss. Had to do with the more work that was done the more lost energy that was associated with that work. Jeese wish i could remember for ya.

Later,
JoMo

 

what did you normally dyno?

how did the shoot out go

 

tnthub:

I was always under the impression that "rear wheel torque" on an automatic with a high stall, high torque multiplier, non-locking convertor was almost meaningless with regard to actual engine torque. I know Second Street won't even plot torque on a setup like that. It obviously is a measure of how fast the car will be accelerating at any given point in time, but it is more a measure of the drivetrain torque multiplication than it is a measure of engine torque. And obviously the more torque the engine makes, the more torque the rear wheels make.... but in general, it isn't a direct measure of engine performance.

That's why you are getting huge rw torque numbers and seemingly mediocre rwHP numbers. Your tranny, unlocked with high stall could easilly be losing 20%..... and that costs you a bit on MPH. Your ET indicates you were probably close to 400 flywheel, and with 20% loss, that's 320rwHP. You would normally expect that HP level to put you around 112MPH trap speeds, so your "slip" seems to be costing you maybe 3MPH

Dave88LX:

As far as actual DT loss for a T56, I can only repeat the dyno numbers I have posted many times before, which confirm that DT loss has both fixed losses and losses that are proportional to torque.

Motor: 425rwHP/486fwHP = 12.6% loss
1-stage N2O: 555rwHP/633fwHP = 12.3% loss
2-stage N2O: 670rwHP/762fwHP = 12.1% loss.

So, to make your magical 400rwHP with a T56, you need about 458flywheelHP.

JOMO-eng:

The thread you refer to was right here on Advanced Tech:

Why is drivetrain loss a percentage?

You summary is a bit "off"......

 

Thanks for the summary.

The car dynoed 320/320 before the stroker shortblock was installed and was running 12.5's-12.7's at the time.

The Shootout was great fun. There are some discussions at http://www.ls1tech.com and ls1.com about the results. I basically ran 12.2's and 12.3's (I think (no slips)).

I was questioning the converter because last fall I blew up the tranny and converter. I had a best of 11.86 at 112 with that combo. Since the new TCI tranny and converter I have a best of 12.12 at 109 in like weather conditions. 60' times are also off by about ,03 consistently from what it was before the new tranny and converter.

 

ok, the inevitable question-
what was the fastest car there and did rich make it out there

 

I wish I had, my car is not quite ready. Actually, we fired it up for the first time last night. It would have been great, but it's still good to have it running. We will start tuning Saturday, with any luck.

Rich Krause

 

That's funny! Guess it's one of them things that just kinda happen when people use the SEARCH function

So I can figure around 12-13%? Sweet thanks!