It's Official: 2011 Ford Mustang GT has 5.0-liter V8
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Joined: Jul 2001
Posts: 3,132
From: Santa Clara, CA
More info: http://blogs.insideline.com/straight...ang-gt-50.html
I'll stick by my opinion, but they did at least state that it was SAE and on a 248.
I'll stick by my opinion, but they did at least state that it was SAE and on a 248.
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Joined: Nov 1998
Posts: 3,252
From: Knoxville, TN
I have nothing to really base my suspicions on. I guess I just have a hard time believing the numbers. If accurate, it would be the most under-rated performance engine since the LS1.
Just color me skeptical until more data comes in.
Just color me skeptical until more data comes in.
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Joined: Jul 2001
Posts: 3,132
From: Santa Clara, CA
Just for reference, what are people getting for a stock M6 Camaro SS? My recollection is around 375. Of course, so much depends on the dyno that you really need something to compare to.
It'll be fun to read about the back-to-back Camaro SS vs Mustang GT dyno.
If 395 RWHP holds up, does this mark the beginning of the end for OHV? I can't see how you can get the precise valve timing control without two separate camshafts.
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Joined: Dec 1999
Posts: 2,022
From: MD
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Joined: Oct 2006
Posts: 654
From: Snow Belt, PA
Yeah, 4th gear numbers don't count. Maybe I'll post up some of my 1st gear torque numbers when I hit the dyno this summer too.
Also, why was everything claiming the mustang had a 7k rpm redline? The article said the fuel cuts at 6850.
Also, why was everything claiming the mustang had a 7k rpm redline? The article said the fuel cuts at 6850.
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Joined: Mar 2005
Posts: 3,123
From: Melbourne, Australia
Jason Kavanagh replied to comment from rrocket
10:14 PM, 03/24/10
The Dynojet itself doesn't care what gear the car's in. Remember, there's a final drive gear reduction after the transmission, which further alters the wheelspeed - engine speed relationship beyond what the transmission does, so there's nothing magical about 1:1.
In fact, dynoing in a gear that's 1:1 usually results in a hair less (yes, less) driveline loss as its a more (the most) efficient ratio in the gearbox. That's why a lot of dyno operators like the 1:1 ratio. Plus, when using an inertia dyno like a Dynojet, higher gear ratios have a lower rate of acceleration, so less power is soaked up in accelerating the rotating masses, which further props the numbers up.
Higher gears do tend to result in higher tire losses since the wheelspeed is higher... at this point all you're doing is trading off one loss mechanism for another. Generally, though, what I've seen come out in the wash is that on an inertia dyno, higher gears will result in higher numbers than lower gears.
Furthermore, higher gears also load the engine for a longer duration, requiring more cooldown, plus put more heat stress on driven tires. As the dyno operator, I don't like either of those things.
10:14 PM, 03/24/10
The Dynojet itself doesn't care what gear the car's in. Remember, there's a final drive gear reduction after the transmission, which further alters the wheelspeed - engine speed relationship beyond what the transmission does, so there's nothing magical about 1:1.
In fact, dynoing in a gear that's 1:1 usually results in a hair less (yes, less) driveline loss as its a more (the most) efficient ratio in the gearbox. That's why a lot of dyno operators like the 1:1 ratio. Plus, when using an inertia dyno like a Dynojet, higher gear ratios have a lower rate of acceleration, so less power is soaked up in accelerating the rotating masses, which further props the numbers up.
Higher gears do tend to result in higher tire losses since the wheelspeed is higher... at this point all you're doing is trading off one loss mechanism for another. Generally, though, what I've seen come out in the wash is that on an inertia dyno, higher gears will result in higher numbers than lower gears.
Furthermore, higher gears also load the engine for a longer duration, requiring more cooldown, plus put more heat stress on driven tires. As the dyno operator, I don't like either of those things.
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Joined: Jul 2001
Posts: 3,132
From: Santa Clara, CA
From the page, http://blogs.insideline.com/straight...ang-gt-50.html
But I'm no dyno expert, and I don't know the particulars of the Dynojet, other than I've read that they tend to give the highest numbers.
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Joined: Mar 2005
Posts: 3,123
From: Melbourne, Australia
If it's just accelerating a roller, then I think the author is right and the gear would not matter. In 4th gear, the engine would spin up faster, but the wheels won't.
But I'm no dyno expert, and I don't know the particulars of the Dynojet, other than I've read that they tend to give the highest numbers.
But I'm no dyno expert, and I don't know the particulars of the Dynojet, other than I've read that they tend to give the highest numbers.
Then again, we calculate from rwhp using a 30% drivetrain loss calculation to arrive at the fwhp number down here... so go figure!
At the end of the day, dyno numbers mean very little. The road is where the BS stops.
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Joined: Jul 2001
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From: Santa Clara, CA
How much higher was the 4th gear number?
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Joined: Jun 2000
Posts: 3,463
From: SoCal
Well regardless of the why they feel the results are not skewed the idea is that you dyno a manual transmission car in a 1:1 gear if for nothing more than standardization. Dyno numbers are never the end all and many have so many variables that it's hard to even compare them but one thing shouldn't be questioned is what gear the car was tested in.
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Joined: Nov 1998
Posts: 3,252
From: Knoxville, TN
If what gear the tranny is in is irrelevant to the dyno, then it is also irrelevant to the results and to this discussion.
Personally, I've never dyno'd my car in any gear other than 4th. I have, however, dyno'd with different rear gears - including a change from 3.27 to 4.30. The difference was ~1% (300 RWHP car). That's small enough that other variables could have easily been responsible for the difference.
Personally, I've never dyno'd my car in any gear other than 4th. I have, however, dyno'd with different rear gears - including a change from 3.27 to 4.30. The difference was ~1% (300 RWHP car). That's small enough that other variables could have easily been responsible for the difference.
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Joined: Jul 2001
Posts: 1,808
From: FL/MI
I can't fathom why a company would lowball the HP number.
Insurance companies don't care about HP numbers they way they once did.
The SAE standard is intended to end the nonsense of highballing and lowballing.
You don't help sales by stating low HP numbers.
If that's the case with this engine? Ford is not helping themselves.
I'm not a dyno expert. I would think you would "see" more torque in a gear lower than a one to one ratio.
Perhaps I have been mistaken, but I assumed gearing under 1:1 is used to multiply available torque. I believe a chassis dyno is a torque measurement device which extrapolates HP.
Insurance companies don't care about HP numbers they way they once did.
The SAE standard is intended to end the nonsense of highballing and lowballing.
You don't help sales by stating low HP numbers.
If that's the case with this engine? Ford is not helping themselves.
I'm not a dyno expert. I would think you would "see" more torque in a gear lower than a one to one ratio.
Perhaps I have been mistaken, but I assumed gearing under 1:1 is used to multiply available torque. I believe a chassis dyno is a torque measurement device which extrapolates HP.
Last edited by 1fastdog; Mar 25, 2010 at 09:08 AM.
