Jump to content
TEAM SHELBY FORUM

2013 GT500 on the Dyno


Recommended Posts

So that's in 700 hp territory given a std 15% loss factor unless there is much less loss in this new drivetrain.

 

Jamel Hameedi said the new published SAE numbers were I think @ 661 hp which would only allow for a 7.5% loss factor to arrive at this figure and I've never seen loss factors calculated this low on any dyno.

 

So either Ford is not releasing the true HP numbers or something else does not add up with this equation.

 

Anyone else have any insight ?

Edited by SHELBYCS6
Link to comment
Share on other sites

So that's in 700 hp territory given a std 15% loss factor unless there is much less loss in this new drivetrain.

 

Jamel Hameedi said the new published SAI numbers were I think @ 661 hp which would only allow for a 7.5% loss factor to arrive at this figure and I've never seen loss factors calculated this low on any dyno.

 

So either Ford is not releasing the true HP numbers or something else does not add up with this equation.

 

Anyone else have any insight ?

 

15% is apparently out the door now days. They are at 10% parasitic loss from all of the dyno numbers I've been seeing lately.

 

Also, a chassis dyno is giving you PEAK HP @ PEAK (7,000) RPM where Ford is giving you SUSTAINED HP @ 6,250 RPM. They're not giving you *peak* HP numbers, they're giving you a number at less than peak RPM. And since HP = Torque X RPM (over 5250) the higher the RPM, the higher the HP number providing your Tq. isn't falling like a rock.

 

 

Phill

Link to comment
Share on other sites

15% is apparently out the door now days. They are at 10% parasitic loss from all of the dyno numbers I've been seeing lately.

 

Also, a chassis dyno is giving you PEAK HP @ PEAK (7,000) RPM where Ford is giving you SUSTAINED HP @ 6,250 RPM. They're not giving you *peak* HP numbers, they're giving you a number at less than peak RPM. And since HP = Torque X RPM (over 5250) the higher the RPM, the higher the HP number providing your Tq. isn't falling like a rock.

 

 

Phill

 

Thanks..

 

Makes sense..... but I thought the rev limiter was set less than 7000 rpm ??

 

I never let them run higher than 6000 rpm on the dyno so I guess my 568 rwhp number is pretty good considering.

 

(just had to pull one of the sheets to check and they actually ran it at 6263 rpm ..close enough..)

Edited by SHELBYCS6
Link to comment
Share on other sites

 

but I thought the rev limiter was set less than 7000 rpm ??

 

 

 

It was 6,250 on previous models but not on the 13's. They raised it to 7,000 on the 2013 models.

 

Apparantly the PCM has a period of time (something like 3 or 5 seconds) where it allows the engine to rev to 7K RPM then kicks it back to 6,250 after the time is hit so you can't just hold the revs to 7K and blow the motor. You can still take it to 7K on shifs, you just can't sustain it there.

 

And that's where your peak HP will occur so the HP at 6,250 isn't peak HP. As Hot Rod magazine discovered.

 

 

Phill

Link to comment
Share on other sites

On the 2013's its called an over-rev feature. Its meant to climb higher in the rpm range for limited time in order to get the most out of the acceleration. The time is 8 seconds. once you hit 8 seconds at 7K rpm, it will kick you down and not be available again until the car has driven under 6K rpms for a period of time. ( the over rev is indicated on the tachometer as a seperate light up bar past the redline, car will let you know when its available to use) so it would be a cool down. Its a cool feature for drag racing and stuff...other than that the normal rpm limit is 6250

 

 

evolution performance currently has a car on their dyno today too, but wont release numbers until the article comes out for 5.0 magazine

Link to comment
Share on other sites

It was 6,250 on previous models but not on the 13's. They raised it to 7,000 on the 2013 models.

 

Apparantly the PCM has a period of time (something like 3 or 5 seconds) where it allows the engine to rev to 7K RPM then kicks it back to 6,250 after the time is hit so you can't just hold the revs to 7K and blow the motor. You can still take it to 7K on shifs, you just can't sustain it there.

 

And that's where your peak HP will occur so the HP at 6,250 isn't peak HP. As Hot Rod magazine discovered.

 

 

Phill

 

 

Ahhhh got it....

Link to comment
Share on other sites

On the 2013's its called an over-rev feature. Its meant to climb higher in the rpm range for limited time in order to get the most out of the acceleration. The time is 8 seconds. once you hit 8 seconds at 7K rpm, it will kick you down and not be available again until the car has driven under 6K rpms for a period of time. ( the over rev is indicated on the tachometer as a seperate light up bar past the redline, car will let you know when its available to use) so it would be a cool down. Its a cool feature for drag racing and stuff...other than that the normal rpm limit is 6250

 

 

evolution performance currently has a car on their dyno today too, but wont release numbers until the article comes out for 5.0 magazine

 

 

 

 

Good information....

 

Not very practical I agree but looks good on paper though....

 

I'd like to see the numbers at 6250

Link to comment
Share on other sites

Good information....

 

Not very practical I agree but looks good on paper though....

 

I'd like to see the numbers at 6250

 

 

Not very practical? How do you figure? Do you drive your car around at 6,250 RPM? Engines spend very little time at the top of the RPM ranges, so 8 seconds is an eternity from a practicality standpoint. 8 seconds at that RPM in just about any gear above second would put you north of 130 mph....

 

From the GT500 Source Book:

 

 

Engine Over-rev Indicator

• HelpsincreasetheperformancerangeofShelbyGT500

  • Over-revisindicatedonthetachometerbyraisingthe redline from (6250 to 7000 rpm)

    – When conditions permit, over-rev is indicated by a 7000 rpm redline

    – If conditions limit over-rev accessibility, the tachometer redline is illuminated at 6250 rpm

  • Enginetorqueandmaximumrpmarelimiteduntil coolant temperature reaches 170 degrees F

  • Warm-upisindicatedwhentheilluminated tachometer redline changes from 6250 rpm to 7000 rpm

  • Oncetheengineiswarm,theover-revfeatureallows 8 seconds above 6250 rpm up to 7000 rpm

  • Ifthe8-secondtimelimitisexceeded,maximum engine rpm is reduced to 6250 until both of the following occur:

    – Engine is operated for at least 15 seconds below 6000 rpm

    – Engine rpm falls below 5000

 

Link to comment
Share on other sites

 

From the GT500 Source Book:

 

Engine Over-rev Indicator

• Helps increase the performance range of Shelby GT500

  • Over-rev is indicated on the tachometer by raising the redline from (6250 to 7000 rpm)
    – When conditions permit, over-rev is indicated by a 7000 rpm redline
    – If conditions limit over-rev accessibility, the tachometer redline is illuminated at 6250 rpm
  • Engine torque and maximum rpm are limited until coolant temperature reaches 170 degrees F
  • Warm-up is indicated when the illuminated tachometer redline changes from 6250 rpm to 7000 rpm
  • Once the engine is warm, the over-rev feature allows 8 seconds above 6250 rpm up to 7000 rpm
  • If the 8-second time limit is exceeded, maximum engine rpm is reduced to 6250 until both of the following occur:
    – Engine is operated for at least 15 seconds below 6000 rpm
    – Engine rpm falls below 5000

 

The font was too small to read so I enlarged it.

 

 

Apparently all you need to do is drop your engine RPM below 5,000 RPM and your 7,000 redline reappears. Most shifts would do that so you should be able to hold 7K, shift and hold it again...IF you so pleased.

 

But like someone said, 8 seconds at 7,000 rpm redline is a freakin' ETERNITY. Unless you were racing at Daytona/Taladega, that'd never happen.

 

And a Dyno run only needs a fraction of a second @ redline.

 

VERY cool feature, IMO and VERY far from impractical.

 

 

Phill

Edited by 2010KonaBlueGT
Link to comment
Share on other sites

The font was too small to read so I enlarged it.

 

 

Apparently all you need to do is drop your engine RPM below 5,000 RPM and your 7,000 redline reappears. Most shifts would do that so you should be able to hold 7K, shift and hold it again...IF you so pleased.

 

But like someone said, 8 seconds at 7,000 rpm redline is a freakin' ETERNITY. Unless you were racing at Daytona/Taladega, that'd never happen.

 

And a Dyno run only needs a fraction of a second @ redline.

 

VERY cool feature, IMO and VERY far from impractical.

 

 

Phill

 

 

I agree, anyone going up to 7K rpm should be a split second to shift....hanging out there isnt necessary. I think Ford did this on purpose as a safety precaution for enthusiasts....sounds like good engineering to me!

Link to comment
Share on other sites

Not very practical? How do you figure? Do you drive your car around at 6,250 RPM? Engines spend very little time at the top of the RPM ranges, so 8 seconds is an eternity from a practicality standpoint. 8 seconds at that RPM in just about any gear above second would put you north of 130 mph....

 

From the GT500 Source Book:

 

 

Engine Over-rev Indicator

• HelpsincreasetheperformancerangeofShelbyGT500

  • Over-revisindicatedonthetachometerbyraisingthe redline from (6250 to 7000 rpm)

    – When conditions permit, over-rev is indicated by a 7000 rpm redline

    – If conditions limit over-rev accessibility, the tachometer redline is illuminated at 6250 rpm

  • Enginetorqueandmaximumrpmarelimiteduntil coolant temperature reaches 170 degrees F

  • Warm-upisindicatedwhentheilluminated tachometer redline changes from 6250 rpm to 7000 rpm

  • Oncetheengineiswarm,theover-revfeatureallows 8 seconds above 6250 rpm up to 7000 rpm

  • Ifthe8-secondtimelimitisexceeded,maximum engine rpm is reduced to 6250 until both of the following occur:

    – Engine is operated for at least 15 seconds below 6000 rpm

    – Engine rpm falls below 5000

 

 

 

My point was there are engines built world wide that can run in the 7000 rpm range all day long (Lotus for one ..actually I think they have a 10k redline) and that's what they base their power curves on.

 

To allow and engine to hit it for an 8 second blip before you can't exceed 5000 again is perfect for squeezing some extra juice on a dyno and making numbers look good but to me if you make a performance claim for rwhp based on this squeeze it isn't realistic...unless the repeatability is endless...

 

What is the next claim.. it will hit 200 mph but you can only do it for 8 seconds and only twice over the life of the vehicle ??..would you consider that a realistic claim based on todays super cars.

 

It's like running all out then a quick shot of NOS just to bump the power curve...sure it's on paper but do you strip your car and remove body panels to run 10 flat at the track..probably not...but reducing weight helps your 1/4 times and I'm sure someone has gone to some sort of extreme to have the bigger yard stick...

 

They have done some amazing things with this car but if they are making claims based on the absolute far end of the spectrum they will be shorted lived.

 

I design hydraulic systems and if you want something to last you give the customer 40% - 50% more than they require for performance and longevity.

 

Your absolutely right...I don't drive or shift at 6250 but If I wanted to...I could do it over and over and over and over...without having to reset the program first..that's how it was designed.....

 

Now... ask some members that tried to push the high end of the performance scale that blew apart better than stock engines ....there are limits to everything

 

I'm not knocking the 2013...don't get me wrong...I love his car and I'm on the fence about maybe moving up......but this just seems like a real push to be king of the hill with this new info that is being released.....

Link to comment
Share on other sites

 

My point was there are engines built world wide that can run in the 7000 rpm range all day long (Lotus for one ..actually I think they have a 10k redline) and that's what they base their power curves on.

 

To allow and engine to hit it for an 8 second blip before you can't exceed 5000 again is perfect for squeezing some extra juice on a dyno and making numbers look good but to me if you make a performance claim for rwhp based on this squeeze it isn't realistic...unless the repeatability is endless...

 

What is the next claim.. it will hit 200 mph but you can only do it for 8 seconds and only twice over the life of the vehicle ??..would you consider that a realistic claim based on todays super cars.

 

It's like running all out then a quick shot of NOS just to bump the power curve...sure it's on paper but do you strip your car and remove body panels to run 10 flat at the track..probably not...but reducing weight helps your 1/4 times and I'm sure someone has gone to some sort of extreme to have the bigger yard stick...

 

They have done some amazing things with this car but if they are making claims based on the absolute far end of the spectrum they will be shorted lived.

 

I design hydraulic systems and if you want something to last you give the customer 40% - 50% more than they require for performance and longevity.

 

Your absolutely right...I don't drive or shift at 6250 but If I wanted to...I could do it over and over and over and over...without having to reset the program first..that's how it was designed.....

 

Now... ask some members that tried to push the high end of the performance scale that blew apart better than stock engines ....there are limits to everything

 

I'm not knocking the 2013...don't get me wrong...I love his car and I'm on the fence about maybe moving up......but this just seems like a real push to be king of the hill with this new info that is being released.....

 

 

 

You're not making any sense. The Over Rev feature isn't some type of gimmick or "squeeze" to increase dyno numbers. There is no "program" to reset.

 

The 2013 can be shifted at 7000 RPM over and over and over and over ....as you put it. In a drag race scenario, each time you push the clutch and and shift the next gear, the RPM would naturally drop below 5000 RPM.

 

I'm very comfortable with Ford's Engineering of this feature given the 5yr 60,000 mile powertrain warranty they are providing.

Link to comment
Share on other sites

You're not making any sense. The Over Rev feature isn't some type of gimmick or "squeeze" to increase dyno numbers. There is no "program" to reset.

 

The 2013 can be shifted at 7000 RPM over and over and over and over ....as you put it. In a drag race scenario, each time you push the clutch and and shift the next gear, the RPM would naturally drop below 5000 RPM.

 

I'm very comfortable with Ford's Engineering of this feature given the 5yr 60,000 mile powertrain warranty they are providing.

 

 

Your probably right...I'll admit....I was drinking wine when I wrote this..so it may come across clear as mud....lol

 

Let me try again...and all of you please correct me if I'm wrong as I'm sure you all will...lol

 

IMO....If Ford...as you say, wanted you to run in this 7000 rpm range over and over and over...you would think they would post the redline at 7000 rpm as they do with any other vehicle.....does that make sense ?

 

But from what I understand and maybe this is where I'm lost...they are posting the redline at 6250 rpm with the capacity to go 7000 rpm intermittently which is an 11% increase in rpm.

 

By not posting a 7000 rpm redline, that 11% to me is just part of the original safety factor built into the product that they are just allowing you to tap into and that could lead to premature failure if it's abused.

 

Again...I'm not knocking the product or the engineering I love Ford (I own four) and everything they have done especially with the new Boss and GT500 vehicles, I'm just curious why they wouldn't post a 7000 rpm redline if it was engineered into the car is all.

Link to comment
Share on other sites

Anyone else notice the dyno sheet in the above video looked like it reved to 6700rpm ? Here's another video, says it made 609rwhp..

.

 

 

 

It looks to me like it CROSSED the 7,000 RPM redline. I see the 7 on the tach and as the needle approaches it, the redline appears, STARTING at 7,000 rpm, ENDING at 8,000 and I can clearly see the needle get into the red portion of the tach.

 

Looks like about 7,200 *indicated* RPM but that could be needle swing too. I'd have to see the dyno sheet with the RPM printed out on it to verify the peak HP@RPM.

 

 

Phill

Link to comment
Share on other sites

This car really makes me think my old 2010 was a pile of crap =) So awesome.

 

 

LOL, thats emotion talking... still i'm glad i sold my 2010 last fall before ford announced the specs on the '13. am saving up for a '13 or '14...

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
 Share

×
×
  • Create New...
...