Shelby GT horsepower rating

[wildcat]

Is it just me, or does a mere 25 HP over the base model seem pretty small? Why is the HP only 25 more? I would have assumed Shelby would have wanted to at least get a meaningful bump up in HP for a "specialty" car like this. Is there something I'm missing?

Also, my dealer (don't know if he knows what he's talking about or not) said that the Shelby GT is supposed to have 80 HP more than a stock GT. This doesn't jive with what the articles say about it. Any input?

Having a different ratio and the manual transmission will help performance over the GT, but man I wish they had more HP too.

[MDGT]

Is it just me, or does a mere 25 HP over the base model seem pretty small? Why is the HP only 25 more? I would have assumed Shelby would have wanted to at least get a meaningful bump up in HP for a "specialty" car like this. Is there something I'm missing?

Also, my dealer (don't know if he knows what he's talking about or not) said that the Shelby GT is supposed to have 80 HP more than a stock GT. This doesn't jive with what the articles say about it. Any input?

Having a different ratio and the manual transmission will help performance over the GT, but man I wish they had more HP too.

 

 

I was thinking the same thing about the HP. I think with the upgrades they are doing, they might be underrating it a bit. But I think with the software tuning they are doing it will also "feel" much faster. Hopefully they get the "drive by wire" settings correct on it. From what I hear, that makes all the difference.

 

Also, I wouldn't believe the dealer.

[Fungu5]

my car made 501 at the motor and 468 rwhp with 461 tork i put a metco 2.6 pullie and a jlt cold air kit new flow masters we put it on the dyno and she purrs out 570 rwhp 560 tork shit now new mt street slicks and a 373 gear this car is a rocker i beet my friends new z06 vett by 5 cars so ford did its home work on this car boy toys lol love them fords

[KCMO-GT500]

..I noticed that you did not install an additional idler assembly with the smaller pulley. Have you run into any belt slip yet??

 

John

[Son of GT]

What I want to know is why Motor Trend rated the car at 319 H.P. in their video drive test report that was linked here a few days ago.

[ShelbyPilot]

.....That was the official number from Ford/Shelby after the last test.

[ilmor]

.....That was the official number from Ford/Shelby after the last test.

 

Bear in mind that the way horsepower figures are calculated has changed in the last year or so. This same car may have had a stated HP of more like 330 in the past I imagine.

[mastersmech1]

It sure is fun to drive... :happy feet:

[JosephMCorbett]

It's my understanding that horsepower ratings can change depending on the circumstances/environment during testing. So unless you know these circumstances, etc, and all other cars are tested under the same "parameters", a meaningful number is hard to come by. Horsepower peak at a given RPM is more about bragging rights than anything else, IMO. Most of us will never get the RPM's up high enough to "feel" the horsepower at that peak. Besides, it's torque that moves metal...it's torque that you feel in the seat of your pants when you step on the gas. All that being said, don't get me wrong, it would be nice to have more horsepower.

 

J

[ShelbyDude]

Is it just me, or does a mere 25 HP over the base model seem pretty small? Why is the HP only 25 more? I would have assumed Shelby would have wanted to at least get a meaningful bump up in HP for a "specialty" car like this. Is there something I'm missing?

Also, my dealer (don't know if he knows what he's talking about or not) said that the Shelby GT is supposed to have 80 HP more than a stock GT. This doesn't jive with what the articles say about it. Any input?

Having a different ratio and the manual transmission will help performance over the GT, but man I wish they had more HP too.

 

 

The Shelby GT was initially rated to have 325 HP and then was officially rated to only have 319 HP which is only 19 HP more than the stock GT Mustang.

 

What the actual HP really is I have no idea. But from what I read those that have the car claim it feels like it has a lot more than 319 HP. I assume the 319 HP is probably underated.

 

I also think this is one of the reasons this car has not been selling as well. They are all over the place where you can buy one for MSRP yet no one seems to be knocking the doors down to get one. Where are all the MSRP buyers that were crying for the MSRP deals??? This car is more rare than the GT500 with only 6,000 being made VS 18K - 20K GT500's over two years, yet the GT500 is bringing $10K - $30K over MSRP and the Shelby GT isn't moving near as well and it is much more limited production. Then the GT-H is bringing hude money in comparision and those are used rental cars with miles and who knows how much many of those have been beat to death by people renting them for a day or so.

 

I think if the Shelby GT had come with a super charger included in the package it would be selling much better.

[blueshawk]

The Shelby GT was initially rated to have 325 HP and then was officially rated to only have 319 HP which is only 19 HP more than the stock GT Mustang.

 

What the actual HP really is I have no idea. But from what I read those that have the car claim it feels like it has a lot more than 319 HP. I assume the 319 HP is probably underated.

 

I also think this is one of the reasons this car has not been selling as well. They are all over the place where you can buy one for MSRP yet no one seems to be knocking the doors down to get one. Where are all the MSRP buyers that were crying for the MSRP deals??? This car is more rare than the GT500 with only 6,000 being made VS 18K - 20K GT500's over two years, yet the GT500 is bringing $10K - $30K over MSRP and the Shelby GT isn't moving near as well and it is much more limited production. Then the GT-H is bringing hude money in comparision and those are used rental cars with miles and who knows how much many of those have been beat to death by people renting them for a day or so.

 

I think if the Shelby GT had come with a super charger included in the package it would be selling much better.

 

 

I have a dyno sheet of a Shelby GT stock (not mine) and it shows 281 RWHP and 301 RWTQ. Using the 88% eff rule to calculate the crank values that's 319 HP and 342 Torque. The Shelby manual shows 319 HP and 330 torque. It's a nice flat torque curve and I'll tell you I'm able to lay down two car lengths of rubber when I hit second gear. It's much quicker than my 1970 SS 396 Chevelle.

[ShelbyPilot]

.....I would offer the difference in sales is three parts. First, yes the modest rated horsepower bump is going to make some think why I am paying $10K over a Mustang GT for 19HP. Second, the Shelby GT doesn't have that prominent name. The GT500 has history and people know they are buying history. Even the GT-H and it's connection with Hertz. If the Shelby GT would have been called the GT350 like alot of dealers still try to call it would have sold much much better. Lastly, marketing, marketing, marketing. Ford and SAI have done nothing to market this car. No posters in dealerships, nothing in the brochures. A short pass over the auction block. Although it got a little attention it was quickly over shadowed by the Mr. Shelby's Super Cobra. The GT500 even though sold out is still in commercials during everything from NASCAR to American Idol. Even Hertz marketed the GT-H more than SAI and Ford have marketed the Shelby GT.

 

Ultimately lack of sales is going to benefit me and my fellow Shelby GT owners. 2008 model year and even 6000 units seems doubtful for the Shelby GT at this point.

[mastersmech1]

.....I would offer the difference in sales is three parts. First, yes the modest rated horsepower bump is going to make some think why I am paying $10K over a Mustang GT for 19HP. Second, the Shelby GT doesn't have that prominent name. The GT500 has history and people know they are buying history. Even the GT-H and it's connection with Hertz. If the Shelby GT would have been called the GT350 like alot of dealers still try to call it would have sold much much better. Lastly, marketing, marketing, marketing. Ford and SAI have done nothing to market this car. No posters in dealerships, nothing in the brochures. A short pass over the auction block. Although it got a little attention it was quickly over shadowed by the Mr. Shelby's Super Cobra. The GT500 even though sold out is still in commercials during everything from NASCAR to American Idol. Even Hertz marketed the GT-H more than SAI and Ford have marketed the Shelby GT.

 

Ultimately lack of sales is going to benefit me and my fellow Shelby GT owners. 2008 model year and even 6000 units seems doubtful for the Shelby GT at this point.

I would have to agree with you.

[North Shelby]

Well said, Shelby Pilot. I believe you are dead-on.

[blueshawk]

.....I would offer the difference in sales is three parts. First, yes the modest rated horsepower bump is going to make some think why I am paying $10K over a Mustang GT for 19HP. Second, the Shelby GT doesn't have that prominent name. The GT500 has history and people know they are buying history. Even the GT-H and it's connection with Hertz. If the Shelby GT would have been called the GT350 like alot of dealers still try to call it would have sold much much better. Lastly, marketing, marketing, marketing. Ford and SAI have done nothing to market this car. No posters in dealerships, nothing in the brochures. A short pass over the auction block. Although it got a little attention it was quickly over shadowed by the Mr. Shelby's Super Cobra. The GT500 even though sold out is still in commercials during everything from NASCAR to American Idol. Even Hertz marketed the GT-H more than SAI and Ford have marketed the Shelby GT.

 

Ultimately lack of sales is going to benefit me and my fellow Shelby GT owners. 2008 model year and even 6000 units seems doubtful for the Shelby GT at this point.

 

 

I wonder where they are with the numbers produced? The dealer in town got his 3 weeks ago and sold it within a week and its S/N was in the 1400s. That has me also wondering if they'll produce as much as 6000.

[ShelbyPilot]

....a couple of days ago there was a car in the 2000's posted on ebay.

[Alloy Dave]

Bear in mind that the way horsepower figures are calculated has changed in the last year or so. This same car may have had a stated HP of more like 330 in the past I imagine.

Please elaborate on this and provide a source.

[ilmor]

Please elaborate on this and provide a source.

 

Here is one article that talks about the recent revisions; there are more if you Google. The ratings change began longer ago than I thought, though (2004).

 

Horsepower Ratings

[Alloy Dave]

Here is one article that talks about the recent revisions; there are more if you Google. The ratings change began longer ago than I thought, though (2004).

 

Horsepower Ratings

I see nothing in this article that supports your claim that the car would have had a higher power rating. Of course you did say you "imagine" it would have had a higher power rating...but I don't know where you would have come up with that idea reading this article.

[ShelbyPilot]

....then the question is why does the 2006 Shelby GT-H pull a 325HP rating and the 2007 Shelby GT with the same modifications pulls a 319HP rating.........not to mention the couple of dyno sheets that show the Shelby GT pulling 328 HP (adjusted from RWHP rating of 288).

[ilmor]

I see nothing in this article that supports your claim that the car would have had a higher power rating. Of course you did say you "imagine" it would have had a higher power rating...but I don't know where you would have come up with that idea reading this article.

 

I tried to find an article for you to support what I've read about over the last couple of years - sorry you don't interpret it like I do. Apparently you're not aware that horsepower ratings and the way they are measured have changed during that time. Do your own research and let us know what you find.

[Alloy Dave]

I tried to find an article for you to support what I've read about over the last couple of years - sorry you don't interpret it like I do. Apparently you're not aware that horsepower ratings and the way they are measured have changed during that time. Do your own research and let us know what you find.

You're right, I'm not aware that they've changed...and the article you posted doesn't say that either. All I ask is that when people post information it's backed by something factual or stated that it's their opinion....as people rely on it. We have enough speculation on this site already. I don't need to do any research, I'm not the one making any claims.

 

Dave

[Five Oh B]

What the actual HP really is I have no idea. But from what I read those that have the car claim it feels like it has a lot more than 319 HP. I assume the 319 HP is probably underated.

 

With the extra rear end gearing, the Shelby GT would feel snappier off the line even if it didn't have the "extra" 19 horsepower. My 07 GT with 4.10 gears and DiabloSport tuning for 93 octane gas feels like it picked up 50 hp over stock, but I know it really only picked up about 20 hp. Gears are a "torque-multiplier" and torque is what gives you the seat-of-the-pants feeling of power, so that's why the Shelby GT feels like more than 319hp. I got to drive Shelby GT #340 (white) a couple days ago (thanks, James!). It felt just as strong as the 2007 Saleen Parnelli Jones Mustang I drove last month (no offense, John) with its 400hp. I think the PJ's torque curve is much higher up in the revs than the Shelby GT, giving the impression that the SGT is just as quick. Once up to speed, though, the PJ's extra displacement (5.0L vs 4.6L) and 81 extra horsepower should give it a clear advantage.

 

As to underating the Shelby GT? Could be, but I think not. Ford's Power Pack is set for premium fuel to get the extra fuel/spark curve for more power, but it is still more conservative than an aftermarket tune (i.e. DiabloSport, SCT, etc.) and those guys are only claiming 18-27hp gains in just the tune alone.

[ShelbyPilot]

Below is a link I posted in the technical forum but seems appropriate to repost. An owner took a baseline before having a supercharger installed. Accoring to the poster bothpulls were right around 280 RWHP and 300 ft/lbs of torque. I am not a dyno expert. Some have told me you lose 15% from the crank, others say 12%. If it is 12% then the below link shows the Shelby GT making the advertised 319Hp. If it is 15% then the dyno shows the car making 330Hp.

 

I am going to post to see if he put the supercharger on and what happened because I am sure that will be the next question.

 

 

http://forum.shelbyautos.com/index.php?showtopic=986

[ilmor]

You're right, I'm not aware that they've changed...and the article you posted doesn't say that either. All I ask is that when people post information it's backed by something factual or stated that it's their opinion....as people rely on it. We have enough speculation on this site already. I don't need to do any research, I'm not the one making any claims.

 

Dave

 

The article states "Some engines will have a decrease in horsepower ratings because of the revised test procedures." - To me its clear from this and other articles I have read over the last year or so that the ratings have changed. Obviously your interpretation differs from mine. This is really two minor an issue for me to be concerned with, so I'm done posting on this one, but if you research it further you'll find that I am correct.

[Five Oh B]

I would presume that 319hp is a number that Ford feels is repeatable often enough by the vast majority of SGT's. There are always minor differences in tolerances when mass-producing anything, including engines, so there will be some that make a little less than 319hp and those that make over 319hp. So again, I would think 319hp is a number that Ford feels comfortable with as a minimum number for most of the SGT's out there.

 

I've been told that intial timing in modular motors (as built at the factory) can vary as much as 5 degrees either direction of the specified advance, giving a difference of as much as 10 degrees between two "identical" cars. Anyone who has ever used a timing light (in the good ol' days before computers) and set initial timing knows how big a difference this will make in the way a car feels.