The 2011+ Mustang Thread

[mrray13]

Originally Posted by syr74

SAE net was the system used from the early 70's until the new system showed up recently. As for hard and fast differences, probably about a million of them. In a nutshell the high points are that the SAE claims that the under-rating that happened under the old SAE net system cannot occur under the new ratings system for several reasons including the SAE having to witness dyno runs, etc.

Ok, correct me if I'm wrong.

Old SAE was just motor, no accessories, with some sort of headers.

New SAE then is with all motor driven accessories attached and running. Again, using a header system instead of OEM manifolds, correct? I know I've read that somewhere.

Otherwise, the biggest difference is they have to witness the run? They don't calibrate the dyno? Check for "stock" tunes on the ECU? In other words, a company can "tank" the SAE test with a different dyno calibration, ECU map, exhaust setup, gas used, etc, etc. Correct? Or are all those things watched by the new standard as well? If not, it would be easy to under-rate a motor and get it certified.

[SLOWHITE]

Sorry, repost.

[SLOWHITE]

The rusults aren't suprising. I just wanted to see what they said about previous GT500s only being in the high 12's. Now all of the sudden they have a 12.4 GT500 they are talkin about. Not doubting it can't do it, but from what I remeber all the GT500's were 12.7-12.9 or only a tenth ahead of an SS on head to head test. Oh well, f,ing motor trend

[newagemuscle]

Originally Posted by DrVonkle

wow. pretty impressive, but its still a mustang.

That has to be one of the dumbest over used statements. The Camaro is impressive too, but it's still a Chevy. Most of you are a bunch of babies. What did you expect... a car with virtually around the same hp that weighs over 200 lbs less? They are both great american muscle cars. The bottom line from what I see is a drivers race when it come to strait line performance. Looks are in the eye of the beholder.

[81z28355]

Originally Posted by SLOWHITE

The rusults aren't suprising. I just wanted to see what they said about previous GT500s only being in the high 12's. Now all of the sudden they have a 12.4 GT500 they are talkin about. Not doubting it can't do it, but from what I remeber all the GT500's were 12.7-12.9 or only a tenth ahead of an SS on head to head test. Oh well, f,ing motor trend

GT 500 in 2010 was rated 12.3 from Ford if I remember. When you start getting into these high HP cars traction is a big problem and that is why the numbers for the GT500 are all over the map. I have seen an 11.9 - 12.8 for the big Ford.

[Chiefstang]

Originally Posted by ROD1

I see they already giving up to $3000 rebates on them. Thats confidence lol.

2010's dude. I wouldn't worry about FORD'S confidence right now...

[syr74]

Originally Posted by mrray13

Ok, correct me if I'm wrong.

Old SAE was just motor, no accessories, with some sort of headers.

No, that is the old, old system. (for lack of a better term) The SAE net system that was introduced in the early 1970's replaced the type of system which you are discussing. And now SAE net has been replaced by an even newer system.

Originally Posted by mrray13

New SAE then is with all motor driven accessories attached and running. Again, using a header system instead of OEM manifolds, correct? I know I've read that somewhere.

As far as I know all of that applies to both SAE net and the newest SAE ratings system.

Originally Posted by mrray13

Otherwise, the biggest difference is they have to witness the run? They don't calibrate the dyno? Check for "stock" tunes on the ECU? In other words, a company can "tank" the SAE test with a different dyno calibration, ECU map, exhaust setup, gas used, etc, etc. Correct? Or are all those things watched by the new standard as well? If not, it would be easy to under-rate a motor and get it certified.

The new system is, literally, a book of regulations the manufacturer has to go by, it's an engineers wet dream. The new standard supposedly watches everything from top to bottom, computer and all, and makes you conduct multiple pulls as well. To the best of my understanding the truly sweeping differences are that all of the testing has to be witnessed and the variables are all smaller.

Ultimately my argument is that they have yet to devise the system that can't be duped if that is your goal, particularly if the intent is to sabotage yourself for the sake of under-rating a motor which should be far easier than trying to over-rate a motor for obvious reasons.

Is the new engine under-rated? Who knows. My only issue is with those who say that under-rating is impossible under the new system as I personally am not inclined to take the SAE's word for it regarding the unchallenged accuracy of their new system.

[mrray13]

Originally Posted by syr74

No, that is the old, old system. (for lack of a better term) The SAE net system that was introduced in the early 1970's replaced the type of system which you are discussing. And now SAE net has been replaced by an even newer system.



As far as I know all of that applies to both SAE net and the newest SAE ratings system.



The new system is, literally, a book of regulations the manufacturer has to go by, it's an engineers wet dream. The new standard supposedly watches everything from top to bottom, computer and all, and makes you conduct multiple pulls as well. To the best of my understanding the truly sweeping differences are that all of the testing has to be witnessed and the variables are all smaller.

Ultimately my argument is that they have yet to devise the system that can't be duped if that is your goal, particularly if the intent is to sabotage yourself for the sake of under-rating a motor which should be far easier than trying to over-rate a motor for obvious reasons.

Is the new engine under-rated? Who knows. My only issue is with those who say that under-rating is impossible under the new system as I personally am not inclined to take the SAE's word for it regarding the unchallenged accuracy of their new system.

Gotcha.

[SamSS]

Umm, how did they get 435 hp on the dyno? Plus, the dyno gives you the rwhp, not at the crank. So wth?

I wonder how much power our Camaro's put out on the dyno the way these guys do it.

[Black5thgen]

Originally Posted by THE EVIL TW1N

ford had a 305 hp V8 in their mustang about 15 years ago, when did the camaro go over 300 from the factory?

Uhhhhh, 15 years ago. The 1996 SS was rated at 305hp.

[syr74]

Originally Posted by SamSS

Umm, how did they get 435 hp on the dyno? Plus, the dyno gives you the rwhp, not at the crank. So wth?

I wonder how much power our Camaro's put out on the dyno the way these guys do it.

They corrected for crank horsepower, and to be fair their correction factor was high IMO which does explain away some of the excess power.

[syr74]

Originally Posted by mrray13

Awww, but that's not the whole story. The constant 5250 is indeed based upon a guess, by James Watt. He estimated the force it took for the horse to turn the mill wheel. He didn't/couldn't measure it.

The latter part of your post backs me up. The engine dyno measures torque, then computes horsepower. Which is my argument, even in chassis dyno form. Torque can be measured, horsepower has to be computed. I made that part bold in your quote.




1: Completely agree with you here. No argument from me.

2: Good point. I don't know the difference between the standards, so I'm at a loss.

I'm not blindly ruling out under-rated, just saying that is probably not going to happen. Based upon your comments above, I'll await judgement on the SAE until one can determine if it's the old, or new, standard used.

I do find it hard they would under-rate in a time when paper numbers mean more then anything. If they advertised the car at 425hp, vs the 412hp they are advertising, which is closer to what the dyno says it is making,the 425, it would garner even greater attention then it is. Or are they after they paid for, by both sides, ewww, awwww from magazine puppets when the track numbers show impressive performance for a 412hp car, vs okay performance for a 425hp car?

I'm honestly not trying to argue that the car is under-rated, my issue was more with the notion that it absolutely cannot be under-rated because of the new ratings system. In fact, as I mention in another thread the correction factor they use to get the 435hp rating is, IMO, too large. Using a correction factor I feel is more realistic I came up with between 420-425hp at the crank based on their rwhp numbers which is obviously a good bit closer to the factory rating. And of course, other variables could be leading to inflated numbers even with that more realistic correction factor.

Is it under-rated? I don't know.

[SamSS]

Originally Posted by syr74

They corrected for crank horsepower, and to be fair their correction factor was high IMO which does explain away some of the excess power.

How do they correct it? I mean you'l get different numbers for the rwhp first of all, and also how would you know how much power you lost exactly?

[syr74]

Originally Posted by SamSS

How do they correct it? I mean you'l get different numbers for the rwhp first of all, and also how would you know how much power you lost exactly?

They estimate what percentage of loss the car experiences through the drive-line, and it is an estimate. In this case MT used a 15% correction factor which, for a modern manual transmission car, is arguably much too high. 10-11% is probably more like it which puts the car closer to 420-425hp at the crank according to their rwhp numbers.

Here is who you would do it. If a car makes 385rwhp on the dyno and I think there is 10% loss through the drivetrain I divide 385 by .90 and come up with ~428hp.