2015 mustang vs Challenge Hellcat

[Fulcrum]

707hp

vs

450 mustang,

go.

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[DHG1078]

http://www.mustang6g.com/forums/showthread.php/challenger-srt-hellcat-1833.html

 

[Fulcrum]

http://www.mustang6g.com/forums/showthread.php/challenger-srt-hellcat-1833.html

/golfclap

this is a VS thread

 

[BONESTOCK]

Um...what's this thread about anyways?

 

[5.0GT]

707hp

vs

450 mustang,

go.

Supercharge the 15 and lets talk then. a 650 hp 15 should easily take the fatcat.

 

[jaja6009]

Yeah a 707hp car is going to embarrass and annihilate a 450hp car. But, the SRT 8 is not meant to compare to the GT. It is aimed at the GT500. The RT is aimed at the GT.
And the GT500 is going to have a very similar power to weight. So it is still TBD with a race between a GT500 and the new SRT 8.

My blown 05 GT will get killed by this new Dodge. But, my S550 will be ready with a Whipple or Roush blower by next summer.

 

[scottpe]

Yeah a 707hp car is going to embarrass and annihilate a 450hp car. But, the SRT 8 is not meant to compare to the GT. It is aimed at the GT500. The RT is aimed at the GT.

^^This

A stock GT is not going to compete with this thing in a straight line (which is the goal for the Hellcat obviously). Though when it comes time to turn the corner or stop, well, things will be a bit different.

But if we have to compare the GT, well, as previously alluded to, we can drop $6-8K on a blower, outperform the Dodge in every possible way, and still save a bundle of money in the process... :ford:

 

[c3po]

^^This

A stock GT is not going to compete with this thing in a straight line (which is the goal for the Hellcat obviously). Though when it comes time to turn the corner or stop, well, things will be a bit different.

But if we have to compare the GT, well, as previously alluded to, we can drop $6-8K on a blower, outperform the Dodge in every possible way, and still save a bundle of money in the process... :ford:

Put the factory Whipple we've been hearing about in the 2015 GT (rated for about 700 HP, correct?) and it'll destroy the Dodge in every performance measure.

 

[Fulcrum]

I wonder if stock 15' gt diff / tranny can handle 700hp

 

[Grimace427]

Everything will eventually break when racing.

 

[EXP Jawa]

I wonder if stock 15' gt diff / tranny can handle 700hp

From a drivetrain point of view, its never about engine HP. Torque is key. You might argue that torque and HP are mathematically related, and you'd be right, but that doesn't account for gearing. When I tell people what a differential is rated for in terms of torque (and I have this conversation often), they think I'm crazy and these things are wickedly overbuilt, but that's not the case (the crazy part might be debatable). Its the gearing aspect that most people fail to consider.

When designing driveline components, we look at the worst case torque loading, which involves gearing. In theoretical land, you take the flywheel torque, multiply that by low gear ratio, then again by axle ratio. Then, you would consider a factor for driveline impact - during a drag start, for example - which puts an instantaneous torque spike on everything during that moment of launch. For a torque converter car, this would be between 1.5 and 2:1. For a plate clutch it could be 3:1 or higher. So, real quick you find out that you're dealing with the potential for many 1000's of lb-ft of torque on the axle, not merely 100s. And that's all well and good - in theory.

But ultimately, there's a cap on this number that's dictated by the tires. If the car's tires cannot support that torque load and break free at a much lower level, then the actual available torque is lower. For all its worth, under these circumstances, 700 HP is only a bragging rights number.

My long-winded point was only that 700HP is meaningless without a value for available torque, as far as the diff and transmission are concerned. And even, that will vary with tires. I think we'll find that the new axle is pretty stout. I'm more curious as to how well the Hellcat's axle holds up. Unless they've upgraded it over the SRT's rear end, that thing is way undersized for the potential torque load...

 

[Fulcrum]

From a drivetrain point of view, its never about engine HP. Torque is key. You might argue that torque and HP are mathematically related, and you'd be right, but that doesn't account for gearing. When I tell people what a differential is rated for in terms of torque (and I have this conversation often), they think I'm crazy and these things are wickedly overbuilt, but that's not the case (the crazy part might be debatable). Its the gearing aspect that most people fail to consider.

When designing driveline components, we look at the worst case torque loading, which involves gearing. In theoretical land, you take the flywheel torque, multiply that by low gear ratio, then again by axle ratio. Then, you would consider a factor for driveline impact - during a drag start, for example - which puts an instantaneous torque spike on everything during that moment of launch. For a torque converter car, this would be between 1.5 and 2:1. For a plate clutch it could be 3:1 or higher. So, real quick you find out that you're dealing with the potential for many 1000's of lb-ft of torque on the axle, not merely 100s. And that's all well and good - in theory.

But ultimately, there's a cap on this number that's dictated by the tires. If the car's tires cannot support that torque load and break free at a much lower level, then the actual available torque is lower. For all its worth, under these circumstances, 700 HP is only a bragging rights number.

My long-winded point was only that 700HP is meaningless without a value for available torque, as far as the diff and transmission are concerned. And even, that will vary with tires. I think we'll find that the new axle is pretty stout. I'm more curious as to how well the Hellcat's axle holds up. Unless they've upgraded it over the SRT's rear end, that thing is way undersized for the potential torque load...

that was a good read,

what kind of torque load does a 14' GT diff is designed to handle?

what about the gt500?

Also if diffs are designed to withstand the torque spike of 2-3x the engine output, that's one beefy diff!

 

[S550Boss]

Simple: an 800 pound difference, and no traction from it's skinny tires. It's called posing.

 

[EXP Jawa]

that was a good read,

what kind of torque load does a 14' GT diff is designed to handle?

what about the gt500?

Also if diffs are designed to withstand the torque spike of 2-3x the engine output, that's one beefy diff!

Well, its not necessarily 3X. As I eluded to, this is usually well-limited by traction. These days, the common practice is for an OEM to put a torque meter on the prop shaft and measure the worst case load scenario that the car actually generates - on the OEM tires - and bases their impact torque requirement around that data.

I'd have to look in my old notes to find out what that number was for S197, but something around 2300 lb-ft axle drive torque comes to mind. Multiply by the 3.73:1 R&P, and you get close to 8800 lb-ft on the actual differential, going to the tires, in a max-load condition. To pass impact requirements, it has to suffer having that load slammed on it something like 500 times (different OEMs have different requirements) and still function. That really is a lot of torque for the 8.8" axle to absorb...

Like I said, the torque number is higher than most people expect, partly because they're used to discussing dyno pull results "at the wheels". Those numbers are, of course, measurements of horsepower, and the torque curve given is calculated from that. If the curve actually showed wheel torque, the values would be an order of magnitude higher since they'd be the flywheel torque, minus losses, through whatever gear ratio the pull was made in (probably something about 1:1), then multiplied by the final drive ratio. So, if the peak torque on the dyno plot is shown as 350 lb-ft, the likelihood is that the actual wheel torque is that X 3.73 (in the case of a GT PP or Boss302). So, during that hypothetical pull, the actual torque at the wheels would be about 1300 lb-ft peak. But during a first gear launch, it would be much higher still.

 

[Fulcrum]

learn something new everyday, I always knew oem components have built in 'room' but that is some interesting tech info, I always had a soft spot for engineering - ended up going to med school.

Used to gawk over my roomates engineering & mechanics hw.

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