05-25-2012, 11:02 AM | #2003 | |
Drives: 2005 STi corn fed Join Date: Jul 2008
Location: Colorado
Posts: 2,997
|
Quote:
I think there will be more than one 11 sec pass this fall by owners. The car is capable. I think at some point you'll see 11.8s out of the z. Hopefully MM&FF does a comparo on a good surface with great conditions. I can see smith getting 11.8s out of the z and 11.4-5s out of the gt500. |
|
05-25-2012, 11:40 AM | #2004 | |
Drives: 2012 ZL1 - #670 Join Date: Jun 2009
Location: Seminole, Fl.
Posts: 8,009
|
Quote:
And yes if the ratio is 1 to 1 a 80hp efficiency rating machine would take a force greater than 80hp to move. Once again that's where ratios come to play.
__________________
|
|
05-25-2012, 11:46 AM | #2005 | |
Drives: 2013 A6 GT 5.0 Join Date: Nov 2009
Location: Edmond, OK
Posts: 2,909
|
Quote:
__________________
BLK/BLK 1SS/RS Ordered 11-01-2009 Took delivery 12-22-2009. Heads/cam/converter/bolt ons. SOLD Feb 2015 to fund 6th gen LT1 SS with 8L90E.
|
|
05-25-2012, 12:06 PM | #2006 |
Banned
Drives: 4 Wheels, Gasoline Engine Join Date: Jul 2010
Location: USA
Posts: 1,007
|
This, or at least on a very favorable weather day in an area of the country where median temps are not high and humidity is relatively low.
Is there really anyone who does not believe the ZL1 will hit high 11's on the factory Goodyears? I don't recall very many, if any, people disputing that probability, even the die-hard Mustang guys. |
05-25-2012, 12:21 PM | #2007 |
Banned
Drives: SHELBY GT 500 Join Date: Apr 2012
Location: Houston, TX
Posts: 96
|
Maybe it does on it's absolute best run under perfect conditions. But on averege the ZL1 is what it has shown to be, which is a low 12 sec car. There is nothing wrong with that.
|
05-25-2012, 12:24 PM | #2008 | |
Banned
Drives: SHELBY GT 500 Join Date: Apr 2012
Location: Houston, TX
Posts: 96
|
Quote:
|
|
05-25-2012, 12:49 PM | #2009 |
Banned
Drives: 1986 Buick Grand National Join Date: Apr 2012
Location: West Monroe, LA`
Posts: 19
|
|
05-25-2012, 01:01 PM | #2010 |
Banned
Drives: various Join Date: Apr 2012
Location: Florida
Posts: 66
|
Never... but the percent/ratio of driveline-loss is increasingly diluted as you add more power...
I don't know how to explain it, I just know that it's a physics thing, exponential math and such... Imagine a team of horses pulling a big sled... You add a horse, and 100% of the horse's power is not being translated directly into the "work" factor of the physics equation. But it does lessen the load for the other horses and makes the work easier for all. The percentage of horse-power versus the effort it takes to make the sled move is reduced. |
05-25-2012, 01:09 PM | #2011 | |
I just like V8s
Drives: 2007 Corvette Z06 Join Date: Mar 2007
Location: Stuttgart, Germany
Posts: 919
|
Quote:
So now you make 440 rwhp, and using 20% as a factor you might claim to make 550 bhp at the engine now with your mods. But that would mean your drivetrain (which is exactly the same as before) now suddenly requires 110 hp to do the same work it did before to spin the exact same drivetrain. That would imply your drivetrain actually became more inefficient even though the percentage of loss didn't change. Similarly if you took a stock Mustang and put in a one-piece aluminum driveshaft over the two-piece, you would see some improvement in rwhp, but the engine is still untouched and is not suddenly stronger than before. But someone trying to back calculate engine hp based on a new rwhp number might think the engine is more powerful or underrated.
__________________
"Anyone know who sells the driver mods?"
2007 Corvette Z06: Le Mans blue, 2LZ |
|
05-25-2012, 01:21 PM | #2012 | |
Banned
Drives: 1968 Ford Galaxie Join Date: Mar 2010
Location: San Jose
Posts: 630
|
Quote:
|
|
05-25-2012, 01:32 PM | #2013 | |
I just like V8s
Drives: 2007 Corvette Z06 Join Date: Mar 2007
Location: Stuttgart, Germany
Posts: 919
|
Quote:
Now if peak horsepower shifted from say 5800 rpm to 6300 rpm, then that could incur more losses because now we are talking different/faster engine speeds when comparing before and after peak horsepower ratings. But that is all the more reason why you can't try to figure out what power an engine is making based on rwhp or dyno results, and try to make any meaningful claims from it.
__________________
"Anyone know who sells the driver mods?"
2007 Corvette Z06: Le Mans blue, 2LZ |
|
05-25-2012, 01:35 PM | #2014 | |
Remember the Charleston 9
Drives: 2004 KME PREDATOR, 2014 2SS/RS/1LE Join Date: Nov 2008
Location: Summerv1LE SC
Posts: 5,381
|
Quote:
__________________
BRING BACK THE B4C POLICE CAMARO!
2002 V-6 5 speed rally red (current camaro) Also driven:1992 Z-28 305 auto Red w/ black stripes (anniversary), 2001 V-6 auto light pewter metallic,1991 RS V-6 auto Black |
|
05-25-2012, 01:38 PM | #2015 |
Drives: 2005 STi corn fed Join Date: Jul 2008
Location: Colorado
Posts: 2,997
|
Loss to heat as a percentage of power output decreases as power increases because inertia of the drivetrain and friction remain the same regardless of power output. This does not mean loss is a constant because some forces are variable, but the impact of constant forces become less apparent as power increases. These are just hypothetical and in no way accurate as it leaves out a loooottt of variables, but as an example
Let's say I is the force required to overcome the inertia of the drivetrain, it is a constant. Y is the total power output of the engine and X is the power at the wheels. Just for simplicity we will assume a 12% loss due to variables other than inertia. In this oversimplified example the function of total power output to determine wheel hp would be X = 0.88Y-I As Y increases, I remains the same. So, let's say I is 10hp, and Y is 400hp. X = 0.88(400)-10 X = 342 or 85.5% of crank horsepower. Now we'll increase crank output, Y, to 500 X = 0.88(500)-10 X = 430 or 86% of crank horsepower. As power increases, power at the wheels will approach, but never reach, 88% of crank horsepower. Now, again this is massively oversimplified, but you get the idea. Some of the factors that drain hp are constant and some are variable. As you increase power, the constants have less of an impact as far as percentage loss is concerned. This is much better explained using calculus, but I figure this would be easier understood for some. Hope it helps. Any engineers, feel free to correct me. My expertise lies in econometrics, not engineering. Last edited by 8cd03gro; 05-25-2012 at 01:51 PM. |
05-25-2012, 01:39 PM | #2016 | |
Drives: 2013 A6 GT 5.0 Join Date: Nov 2009
Location: Edmond, OK
Posts: 2,909
|
Quote:
On my paticular setup I dont know if I'm loosing 110 RWHP but I can tell you for a fact that its alot more than the 80RWHP. There is no one on here that could make me believe that once you get to X amount of horse power that after that you are not loosing any more through the drivetrain. I never said the engine HP would go up from a 1 piece carbon fiber vs a 2 piece steel driveshaft I said the drivetrain LOSS would be less thus showing RWHP gains.
__________________
BLK/BLK 1SS/RS Ordered 11-01-2009 Took delivery 12-22-2009. Heads/cam/converter/bolt ons. SOLD Feb 2015 to fund 6th gen LT1 SS with 8L90E.
|
|
Post Reply
|
|
|