Re: A good day at the dyno...
 

WOW,nice job:dancing
I just have a couple questions since you don't have corrected numbers then maybe you should dyno in the summer on a 100 degree day with 100% Humidity and tell us what the numbers are on that day.
This is why we have corrected.

Dennis,something is going on with the fuel or wideband?

Show me your 1/4 MPH i'll tell you your corrected WHP. :fahne:
Pete

Re: A good day at the dyno...
 

Very interesting article on parasitic losses. I don’t believe u can have a fixed loss # regardless of power. More power=more heat which = greater loss. Plus there’s a difference between steady state and one where u are constantly accelerating which is typical for chassis dyno.
Not disputing Todd’s observations, but I gotta think GM has seen enough of this stuff to make an “educated” guess.

Anyway, here’s a good read.

http://www.superstreetonline.com/how...in-power-loss/

Re: A good day at the dyno...
 

Who's got some Dyno results from bone stock cars? Comparing those numbers to the factory eating (375 or 405) should give us a better idea of our driveline losses. My first Dyno run back in the day with cat back exhaust only was 363 RWHP. Guessing 350 RWHP bone stock. That would be about a 14% loss.

Re: A good day at the dyno...
 

Seems to me losses should be proportional to rpms. Might not be exact, but maybe good enough for govt work.

Sent from my SM-N920V using ZR-1 Net Registry mobile app

Re: A good day at the dyno...
 

Here ya go, this is a stock California smog car with no cat backs. The time slips are not my best but consistent.

Re: A good day at the dyno...
 

Pete and I were noodling this a bit, and based on typical trap speeds(~112mph) for stock LT5s for 375 hp motors, we figure motor is actually more like 400chp.
Typical chassis dyno results for stock 375hp motor have been ~ 330RWHP.
That's ~17-18% loss, so GM assumption appears to work out.
Makes you want to get your hands on those original dyno sheets.

Re: A good day at the dyno...
 

Re: A good day at the dyno...
 

Perhaps a Christmas card to Betty at the NCM would help?

Re: A good day at the dyno...
 

Here's a very good example of a stock 91 dyno. It was of a previous member Don Yoakem. 334rwhp

Re: A good day at the dyno...
 

That's with flowmaster exhaust and possibly a tune...