2019 GT500 Mustang New Spy Video, Pics, Info

[BmacIL]

How similar are the other platforms you quoted, the fusion, escape (which is c chassis right?) etc. For example will parts from one work in the other?

I find it weird that they platform share suspension but keep those chassis heavily front wheel biased. That doesn't seem like a great idea.


And then the majority of the alpha chassis being developed for the base cts is really that much more efficient ?

The alpha has the similar separate spring and damper like the S550, but has a much smaller knuckle, and lighter control arms all around. There are a few other things too.

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[Hack]

The alpha has the similar separate spring and damper like the S550, but has a much smaller knuckle, and lighter control arms all around. There are a few other things too.

Are these smaller and lighter components just as strong as the Mustang components? If so, then that would be a good example.

 

[Darkane]

As you well know, every single design ever done is a compromise. I mostly objected to your use of "much less compromised" when describing the Camaro. I think the Camaro suspension just might be slightly better, but judging based on performance data they are very similar in capability. If you can tell me the wheel rates are X better the chassis is X stiffer I can't dispute that. However, I sure can dispute "much less compromised".

I understand what unibodies and subframes are. I'm not into them at your depth, but I am a mechanical engineer. As you well know, a subframe does nothing alone in space, it must be supported by the rest of the car's body.



Funny how you quoted a post where I pasted a definition when saying everything I say and talk about is based on emotion...

I have asked for data and facts. All I've been given from you is a statement with nothing to back it up. If I were to compare the Mustang to the Camaro, about all I have is lap times. I think they are probably within 1% of each other on most tracks, assuming similar tires and power.

So can you provide me with some evidence to support your statement (really BmacIL's statement) that the Camaro's underpinnings are better?

Or are you saying the Camaro's underpinnings are 1% better than the Mustang's? I could probably see my way through to agree with that.

These technical bits are highly confidential and not easily accessible to the public.

I can tell you, the alpha platform is 28% stiffer than the Zeta, which allowed use of much lighter suspension components.

The S550 came in at 50-100 lbs heavier than the S197, while trying to reduce unsprung weight in the rear. I don’t they they hit their target with that one.

Also the Alpha has around 3” longer wheel Base than the S550 and reduced overhangs, which decreases the pendulum effect. Think the rear of the 911 and it’s previous “widow maker” nickname.

Don’t get me wrong man, I love cars and I own ford. But I’m not blind to other competition, and I’m not saying you are either. You’re passionate about the mustang. I get it.

 

[BmacIL]

Are these smaller and lighter components just as strong as the Mustang components? If so, then that would be a good example.

Outside of a crash situation, in which either will be bent/broken, the Camaro's lower control arms appear to have plenty enough section to be just as, if not more rigid and will be far less susceptible to fatigue being steel. The upper arms (camber control) are more dainty but can be as they're distributing the load vs taking it all in one member. One person I almost know has the mass comparison is @BMR Tech

 

[Hack]

These technical bits are highly confidential and not easily accessible to the public.

I can tell you, the alpha platform is 28% stiffer than the Zeta, which allowed use of much lighter suspension components.

The S550 came in at 50-100 lbs heavier than the S197, while trying to reduce unsprung weight in the rear. I don’t they they hit their target with that one.

Also the Alpha has around 3” longer wheel Base than the S550 and reduced overhangs, which decreases the pendulum effect. Think the rear of the 911 and it’s previous “widow maker” nickname.

Don’t get me wrong man, I love cars and I own ford. But I’m not blind to other competition, and I’m not saying you are either. You’re passionate about the mustang. I get it.

I am passionate and I definitely get emotional. Especially when I believe statements being made are unsubstantiated or misleading.

If someone has data that proves something I will listen. However, claiming that one design is MUCH better than the other when they obviously perform very similarly is going to raise my ire when there's no objective evidence.

You have written some true things about both platforms, painting the Chevy in a positive light while painting the Ford in a negative light. None of that information tells me that the Camaro chassis is MUCH better than the Mustang's. Was it a failure for the S550 to gain 50-100 lbs when converting from SRA to IRS and upgrading whatever safety equipment was required by regulations? The 2002 Camaro SS weighed 3,300 lbs whereas the 2018 Camaro weighs 3,700 or so. I guess a little more than 50 lbs, even after a second generation redesign of the IRS to reduce weight.

Greater chassis stiffness allows much lighter suspension components? Can you explain that?

 

[Darkane]

Greater chassis stiffness allows much lighter suspension components

Without getting super technical (because admittedly I won’t be able to) but if the chassis flexes it will put more stress on the corners of suspension and wheel contact. That causes deflection in the suspension components and they need to be beefed up to counter the forces.

So if a soft chassis had softer suspension components, it would handle like hell. Tires would have different contact angles during hard cornering and every time the engine would load up it would transfer to the chassis making it twist axially.

But with a super stiff (and light!!) chassis it won’t flex as much and reduce the requirement for ultra strong suspension pieces to counter the other forces like deflection.

Bmac would be better suited to an explanation. I can picture what’s happening in my head but it’s hard to articulate. I found some technical studies and one written as a thesis on the Volvo S60, but I was getting lost in it and it was way to technical to explain much.

 

[Hack]

I found some technical studies and one written as a thesis on the Volvo S60, but I was getting lost in it and it was way to technical to explain much.

Link?

 

[Darkane]

Link?

Have fun. Bring a lunch.

http://publications.lib.chalmers.se/records/fulltext/219391/219391.pdf

EDIT:

The more rigid body allowed engineers to more precisely calibrate the steering and suspension without being forced to accommodate for chassis flex. It also allows lighter suspension pieces.

https://autoweek.com/article/car-news/new-2016-camaro-stronger-ever-says-chevy

 

[BmacIL]

Without getting super technical (because admittedly I won’t be able to) but if the chassis flexes it will put more stress on the corners of suspension and wheel contact. That causes deflection in the suspension components and they need to be beefed up to counter the forces.

So if a soft chassis had softer suspension components, it would handle like hell. Tires would have different contact angles during hard cornering and every time the engine would load up it would transfer to the chassis making it twist axially.

But with a super stiff (and light!!) chassis it won’t flex as much and reduce the requirement for ultra strong suspension pieces to counter the other forces like deflection.

Bmac would be better suited to an explanation. I can picture what’s happening in my head but it’s hard to articulate. I found some technical studies and one written as a thesis on the Volvo S60, but I was getting lost in it and it was way to technical to explain much.

Well, a rigid chassis is inherently much more tunable and keeps the car's geometry more consistent. Chassis torsional rigidity becomes important when you have significant differences in front to rear roll stiffness, as the difference between them must be resolved in the chassis. A good rule of thumb from racecar chassis and suspension design is to have a chassis that is at least 10x stiffer torsionally than the difference between your front and rear roll stiffness. This allows for a tunable car.

As far as having lightweight components, well that is a function of many things, but chassis stiffness is very low on the totem pole. Cornering, and accel/decel loads, as well as fatigue strength from potholes and such are the primary. There is a correlation between roll center and the loads from chassis roll that go directly into the suspension members (lower RC = lower arm forces, higher RC = higher arm forces). There's a balance to strike there, as lower RC means higher suspension stiffness is required to limit roll, which means worse ride.

 

[Stuntman]

Roll stiffness from high roll centers negatively affects ride quality in addition to reducing the tractive capacity of a pair of tires when cornering (grip).

 

[BmacIL]

Roll stiffness from high roll centers negatively affects ride quality in addition to reducing the tractive capacity of a pair of tires when cornering (grip).

Not exactly accurate, particularly with Macpherson strut front end.

 

[Stuntman]

Not exactly accurate, particularly with Macpherson strut front end.

Kinda is. Re: jacking effect.

If there was a free lunch, then all cars would have high roll centers to achieve said (inaccurate) claim of good ride quality and roll resistsnce. It's far more complicated than that.

 

[BmacIL]

Kinda is. Re: jacking effect.

If there was a free lunch, then all cars would have high roll centers to achieve said (inaccurate) claim of good ride quality and roll resistsnce. It's far more complicated than that.

Yes jacking is a thing with high roll centers. It has to be much closer to the CG than most cars typically are for that to come into play, though.

I didn't make the claim you're stating, but am merely saying that it's a balance and moving one way or the other can have benefits. Each extreme has issues, too. Quite low roll centers typically, but not strictly also come with poor camber gain, which means a lot more static camber is required to achieve the desired camber in roll.

Onto topic: the S550 has an overall pretty good IRS. Could it be better? Sure.

 

[Stuntman]

Yes jacking is a thing with high roll centers. It has to be much closer to the CG than most cars typically are for that to come into play, though.

I didn't make the claim you're stating, but am merely saying that it's a balance and moving one way or the other can have benefits. Each extreme has issues, too. Quite low roll centers typically, but not strictly also come with poor camber gain, which means a lot more static camber is required to achieve the desired camber in roll.

Onto topic: the S550 has an overall pretty good IRS. Could it be better? Sure.

If you are still referring to McPherson struts, then yes a lower RC can cause poor camber gain. This is why it's possible to improve front grip by increasing front roll stiffness via a higher front RC or stiffer front swaybar, which is the opposite if the classic textbook understanding of reducing the tractive grip of the pair of tires because the increase in grip from the loaded tire outweighs the grip lost from the unloaded tire.

I agree there is a balance between a ton of different factors when it comes to suspension. My point is that high roll centers can also negatively affect ride quality even without being "extremely high".

The irs has a lot of RC migration. It could be a lot better.

 

[BmacIL]

If you are still referring to McPherson struts, then yes a lower RC can cause poor camber gain. This is why it's possible to improve front grip by increasing front roll stiffness via a higher front RC or stiffer front swaybar, which is the opposite if the classic textbook understanding of reducing the tractive grip of the pair of tires because the increase in grip from the loaded tire outweighs the grip lost from the unloaded tire.

I agree there is a balance between a ton of different factors when it comes to suspension. My point is that high roll centers can also negatively affect ride quality even without being "extremely high".

The irs has a lot of RC migration. It could be a lot better.

That it does.

Even in a double wishbone suspension, lowering the roll center (by making the upper and lower arms more parallel or making them convergent to the outboard direction) results in less camber gain, it's just nowhere near as bad as a strut front end.

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