GT500 dyno test on TG

Hidden_Hunter

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we could just simplyfy it and say it's a shit car for how much it costs in the UK
 

slowfiveoh

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Wow that was a lot to read. I will add my 2c now because I am bored haha

I am more inclined to believe that the 447hp that came up is an engine number rather than a wheel number. If it was a wheel number that would give the GT500 almost 550hp (going by the 20% loss figure which is pretty reasonable) which is one hell of a fit Mustang.

And you would be dead wrong in that assumption. Many examples of the GT500, like the Terminator forebearer, factually dyno rwhp numbers indicitive of a factory underrating. Terminators for instance dyno inbetween 345-370rwhp. With a factory power rating of 390/390, I will let you do the math when considering driveline loss. Especially spinning a power sapping but strong T56.

The GT500 is the same way. Being a derivative of the notably underrated GT supercar, it is clear that the power ratings could very easilly be skewed. If you would like a listing of technical similarities, I would be happy to oblige.


Why would it be so low?? Any number of reasons, production tolerances are still quite large these days so it could have been a lesser example. The car might not have been fully run in yet and was still yet to reach full power. Also depends what system they used for calculating horsepower. If Ford used ECE (which they do in Australia) while TG used DIN then that accounts for another whack of grunt.

"Run-In" is certainly a factor to consider when determining power deficiencies. Everything from bearing tolerance to ring seat could affect horsepower. It is not overly likely however that the "Run-Hard" test mule GT500 was still in its break-in phase during the Top Gear whimsical bashing attempt.

Claimed bhp 500
less lesser example 20
less not run in 10
less DIN/ECE diff. 10
final bhp 460

Add to that the inaccuracy of measuring BHP from the wheels and I can see why they only got 447BHP.

Your "math" seems to leave a lot desired, as you are literally throwing in more equations than really need to be considered. Realistically the number is not far off from the bhp number promised and stated by the factory.

Not in consideration is the type of drivetrain. Because many euro/japanese cars lack the wide arcing torque curve and powerband that your typical American/Aussie V8 makes, they are equipped with lighter, less reinforced, and generally weaker drivelines. They can get away with it because of a lack of low end grunt, and lack of sheer forceful twist being sent through the driveline. While being the defining characteristic of Domestic/Aussie iron, I am never surprised to see a recent import-turned-domestic-driver complain about his rear suspension because the powerband is simply far more meaty than he is used to. Power induced oversteer here we come.

This meaty driveline saps more power, but is of the strength required to give longtime reliability behind such a voracious powerplant.

For Everyone,

Just an FYI, beyond even the VIR racetrack comparo, the FR500C has been literally eating and crapping out M3's and Porsche 996's for 2 years now in Rolex Grand-Am. Passing them in the corners even, solid axle and all. For comparison, the Fbody GM cars have not been able to do that in 10+ years of competition.

Until you understand the mechanics/application of a technology, it isn't really safe to hide behind the false and ignorant statements you hear from, I don't know, a pompous British Auto Journalist for example. Just a friendly recommendation. :mrgreen:
 

thedguy

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Wow that was a lot to read. I will add my 2c now because I am bored haha. I can see why they only got 447BHP.

It's a pretty well accepted amongst the Mustang crowd that a gt500 will gain 30hp once it's broken in.

Also the GT500 engine has the latest SAE certification (j2723), which is totally optional and done by a 3rd party. It's the same system that has forced several motors to drop their hp ratings by rougly 15hp (honda). Though GM picked up hp on several motors (LS7 went from 500 to 505) due to this stricter rating system.

Horse Power and Torque SAE Certified Power = A new voluntary power and torque certification procedure developed by the SAE Engine Test Code committee was approved March 31, 2005. This procedure (J2723) ensures fair, accurate ratings for horsepower and torque by allowing manufacturers to certify their engines through third-party witness testing.
Every performance GM motor is rated under this (and are constantly adding more), only 4 Ford engines and 1 chrysler ('08 srt10).

Easy way to tell if they have this certification is you'll see "SAE certified" either in an article or next to the hp/torque figures on spec sheets.

Enough with this arguing about the engine, it puts out what it's supposed to, it's certified by the Society of Automotive Engineers to produce 500hp and 480 lbs-ft of torque.

/f-ing thread.
 

Necx0

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Seeking clarification from slowfiveoh. You are arguing that 447rwhp not 447bhp is the true figure due to the fact that the GT500 badge is actually conservative.

Interesting they now have a power certification body. They should introduce that in Australia, as the performance disparities between supposedly identical cars is disgraceful.
 

slowfiveoh

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Seeking clarification from slowfiveoh. You are arguing that 447rwhp not 447bhp is the true figure due to the fact that the GT500 badge is actually conservative.

Interesting they now have a power certification body. They should introduce that in Australia, as the performance disparities between supposedly identical cars is disgraceful.

I am stating very simply that when you measure power from the rear wheels (Which is EXACTLY what Hammond did) you cannot determine bhp figures precisely, but by utilization of drivetrain loss percentages you can come close. 447hp at the rear wheels is easilly within the 500 rated crank horsepower. Making Hammonds statement about as laughable as they come.

Mustangs in general, ever since the power debacle with the Cobra, are typically ever so slightly underrated. Keeps FoMoCo safe.

The 03/04 Cobras were affectionately known as "Terminators", and are a prime example of the GT500's predecessor. They came with 4 bolt mains, forged steel crank, and Manley rods pushin and pullin steel pistons. They were also topped off with an Eaton M112 blower, and as I have stated before, push off 345-370rwhp in bone stock condition. I have personally witnessed no less than ten of these cars doing this easilly.

The GT500 is the exact same way only with a hair more boost, and obviously a lot more displacement. Based on the GT supercars shortblock, you can throw horrendous amounts of boost at it as well, and still retain a nice wide, meaty powerband.

03/04 Cobras make 425+rwhp with a reflash and pulley swapped from a lightning pickup.

GT500's have the same available kits. For comparison it took less than a year for a GT500 swinging stock parts to eclipse the 9 second mark in street trim.

Here is a video of the car:

Here
 

bigsweezey

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Dyno's suck. It's a tunning tool, and shouldn't be used like that. Anyone know what kinda dyno that is? That can make a difference as well. Dynojet's tend to show higher numbers, and mustang dyno's(not a dyno for a mustand but the actual name of the dyno) tend to show lower numbers. Were the numbers corrected? There are all types of variables to consider. Heat for one can play a factor, and make a big difference. Hell, you can dyno a car, turn around and dyno 2 hours later and get a difference of 10hp...maybe more but I've seen a 10hp difference over a couple hours. Hell on my 03 cobra I had a 8 hp difference over 3 runs back to back to back.

oh yeah, the 03/04 cobra's are rated at 390. With a intake I put down 388hp. So 2 things, the car was hella underrated or the dyno overrated my numbers.
 

merp

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Mustangs in general, ever since the power debacle with the Cobra, are typically ever so slightly underrated. Keeps FoMoCo safe.

The 03/04 Cobras were affectionately known as "Terminators", and are a prime example of the GT500's predecessor. They came with 4 bolt mains, forged steel crank, and Manley rods pushin and pullin steel pistons. They were also topped off with an Eaton M112 blower, and as I have stated before, push off 345-370rwhp in bone stock condition. I have personally witnessed no less than ten of these cars doing this easilly.

It's worse than that; the average is 370, with the lowest ever recorded @ 344rwhp. The highest was a whopping 395rwhp, bone stock, paper filter to exhaust tips. Given that's some 60hp above and beyond the advertised power, yeah, I have no problem believing the GT500 makes 447 at the wheel. The GT supercar put down 550 or so, right?

There's a huge weak point in the GT500's motor, though. While the Terminator and GT have Manley forged H-beam connecting rods, the GT500 uses the standard Ford Corporate sinter-forging process. It produces parts that are significantly stronger than cast, but not quite as tough as a real 4340 forged part. So, they tend to let go around the 550rwhp level, unlike the Terminator and GT motors, which are good for 800 and 1000 rwhp, respectively.
 

Necx0

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Like I said, I could believe that a supposed 500bhp car could only record 447bhp......

HOWEVER given the evidence on hand that Ford historically underrate their motors, I can also happily believe that it would record 447rwhp.
 

JCE

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Came back to see what all the fuss is about and its exploded in here with flames. :lol:

Also the GT500 engine has the latest SAE certification (j2723), which is totally optional and done by a 3rd party. It's the same system that has forced several motors to drop their hp ratings by rougly 15hp (honda). Though GM picked up hp on several motors (LS7 went from 500 to 505) due to this stricter rating system.

/thread right there as far as I'm concerned. Why don't the GT500 haters get it? It. Is. SAE. Certified. Period.

*edit*Oh and don't forget Toyota had to lower their numbers as well.*edit*

/f-ing thread.

+1 Agreed.

The 03/04 Cobras were affectionately known as "Terminators", and are a prime example of the GT500's predecessor. They came with 4 bolt mains, forged steel crank, and Manley rods pushin and pullin steel pistons. They were also topped off with an Eaton M112 blower, and as I have stated before, push off 345-370rwhp in bone stock condition. I have personally witnessed no less than ten of these cars doing this easilly.

My former co-worker bought a 2004 Cobra w/25k miles and promptly took it to a dyno and with 93 octane pump gas it spit out 388rwhp. This is a-typical, but I've seen 350-380rwhp numbers from stock 2003/2004 Cobras on more than one occasion.

03/04 Cobras make 425+rwhp with a reflash and pulley swapped from a lightning pickup.

That and a good full exhaust and CAI can give you even more power. ~480rwhp with everything you and I mentioned. That's what my former co-worker did with his...and that's the number he got on the dyno (480rwhp).


Great video, the noise is brilliant. :D
 

slowfiveoh

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Good to see some well informed posters here. Then we can certainly see, and agree that the test for the GT500 was clearly botched, and possibly intentionally. This is why, bar none, if I called out that British twit, I could expose him for the extreme imbecile that he is. It appears however, that at this point, that is not necessary. I think most reasonable people get the jist of what I am pointing out, without further elaboration. ;)
 

BlaRo

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Well, I'm glad we can all agree on something. :lock:

Cute cat merp! :happy:
 

bigsweezey

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That and a good full exhaust and CAI can give you even more power. ~480rwhp with everything you and I mentioned. That's what my former co-worker did with his...and that's the number he got on the dyno (480rwhp).
That's a high number....sure he didn't have a ported blower? I put down 450'ish, then had the blower ported and put down 496hp/512tq.

slowfiveoh said:
Good to see some well informed posters here. Then we can certainly see, and agree that the test for the GT500 was clearly botched, and possibly intentionally. This is why, bar none, if I called out that British twit, I could expose him for the extreme imbecile that he is. It appears however, that at this point, that is not necessary. I think most reasonable people get the jist of what I am pointing out, without further elaboration.

Not so much the test being botched. I think the numbers are correct, but they never bothered to explain why it had those numbers, or anything like that.
 

JCE

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That's a high number....sure he didn't have a ported blower? I put down 450'ish, then had the blower ported and put down 496hp/512tq.

He could have and just forgot to tell me. Either way, those mods still get you some seriously good potent power. :mrgreen:
 

Roberto

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Really can't be bothered to read all of this nonsense, quite frankly I don't care whether Americans think Top Gear did it wrong because I still don't see that they did!! They let the viewer know it didn't have 500 "something power" at the wheels. Now people also know this is true of other cars who have numbers in their name to insinuate or suggest that. So bragging rights at the pub, where people say "my VXR500 has 500 horses at the wheels" are now deemed incorrect, and we can thank Top Gear for that.
 

the Interceptor

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They let the viewer know it didn't have 500 "something power" at the wheels. Now people also know this is true of other cars who have numbers in their name to insinuate or suggest that. So bragging rights at the pub, where people say "my VXR500 has 500 horses at the wheels" are now deemed incorrect, and we can thank Top Gear for that.
I don't see things like that. The fact that the Top Gear guys pointed the lack of WHP out for this very car will mostly be understood in the way that this very car has less than the advertised horses, which kind of destroys it really. It'd only be one sentence for Hammond to state that the majority of cars won't deliver the hp numbers at the wheels which the manufacturer advertises. But he didn't say that, which made this demonstration kind of unfair to this GT500 in my eyes. I don't like the car very much I must say (just my personal taste), but still, what's the point in pointing out a problem on one specific car when any car will have that problem?
 

thedguy

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Really can't be bothered to read all of this nonsense, quite frankly I don't care whether Americans think Top Gear did it wrong because I still don't see that they did!! They let the viewer know it didn't have 500 "something power" at the wheels. Now people also know this is true of other cars who have numbers in their name to insinuate or suggest that. So bragging rights at the pub, where people say "my VXR500 has 500 horses at the wheels" are now deemed incorrect, and we can thank Top Gear for that.

:idiot: Read the damn thread before you post. At least my posts. BTW, GM doesn't underrate their engines, if they say it makes 500hp, it's likely to make a few extra ponies.

Can we get this thing locked before another n00b makes a stupid comment? :lock:
 
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Roberto

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:idiot: Read the damn thread before you post. At least my posts. BTW, GM doesn't underrate their engines, if they say it makes 500hp, it's likely to make a few extra ponies.

Can we get this thing locked before another n00b makes a stupid comment? :lock:


I read the damn thread.. I have written several posts in it :lol: Maybe it is you that needs the eyes :bangin:;)

Top Gear did nothing wrong! Yes perhaps Hammond should have said "all car manufactures do this blah blah" but quite frankly, would people notice?? I think not!
 

TC

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Top Gear did nothing wrong! Yes perhaps Hammond should have said "all car manufactures do this blah blah" but quite frankly, would people notice?? I think not!

I don't really care if people think the GT500 makes less then 500hp, because they're wrong.

The GT500 dyno portion was an insult to the intelligence of gear heads everywhere.
If you know anything about cars, you would know that.
 
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