2019 GT500 Mustang New Spy Video, Pics, Info

[Tomster]

Unsubscribed. This sucks

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[Stuntman]

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.

I'm not sure where to start on this. The variations in angle, relative angle, and arm lengths will GREATLY affect camber gain changes with RC changes. Many SLA suspensions (espefislly those with short and angles upper control arms) will have significant increases in camber gain with lower roll centers.

 

[BmacIL]

I'm not sure where to start on this. The variations in angle, relative angle, and arm lengths will GREATLY affect camber gain changes with RC changes. Many SLA suspensions (espefislly those with short and angles upper control arms) will have significant increases in camber gain with lower roll centers.

Yes, more angle (wider at outer points) increases camber gain. You can have high camber gain with a low roll center, but further lowering the roll center will reduce it (by either lowering the entire lca, lowering the inner lca point, or by making the arms more parallel), even if the change is just slight. It's just geometry. I've done this countless times on paper and iterated and plotted it in OptimumG software. I assure you that it does what I'm saying.

You're clearly not dumb so I expect a little bit of thought before you instantly retort. Perhaps we're saying the same thing differently.

 

[stanglife]

Thanks for all of the new spy pics.

 

[Stuntman]

Yes, more angle (wider at outer points) increases camber gain. You can have high camber gain with a low roll center, but further lowering the roll center will reduce it (by either lowering the entire lca, lowering the inner lca point, or by making the arms more parallel), even if the change is just slight. It's just geometry. I've done this countless times on paper and iterated and plotted it in OptimumG software. I assure you that it does what I'm saying.

You're clearly not dumb so I expect a little bit of thought before you instantly retort. Perhaps we're saying the same thing differently.

I guess it depends on how you lower the RC and the geometry of the suspension since it's all relative to where the baseline is and what changes to the in or outboard UCA or LCA. Because of this you can't really generalize that lowering the RC will always reduce camber gain.

 

[sumfoo1]

Now that it’s transitioned to an actual conversation about suspension it’s pretty cool.

 

[65Terdlingua]

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.

BmacIL, how much caster gain is utilized in the strut suspension of the Mustang? With SLA suspension, you can get a bigger portion of the camber needed in roll via caster gain, and require less static camber or camber gain (with a benefit of more available traction in braking), but is that utilized in the McPherson strut design? Of course this requires higher travel suspension, but just curious.

 

[BmacIL]

BmacIL, how much caster gain is utilized in the strut suspension of the Mustang? With SLA suspension, you can get a bigger portion of the camber needed in roll via caster gain, and require less static camber or camber gain (with a benefit of more available traction in braking), but is that utilized in the McPherson strut design? Of course this requires higher travel suspension, but just curious.

That still applies with a Mac strut. What I don't understand as well with this particular front suspension is dynamic caster via the double joint. The swing arm lengths are different and it should add more through roll via the way the tension link swings.

 

[65Terdlingua]

That still applies with a Mac strut. What I don't understand as well with this particular front suspension is dynamic caster via the double joint. The swing arm lengths are different and it should add more through roll via the way the tension link swings.

I forget about the double joints. Would be interesting to see the results of that, especially compared to the previous single joint design. Any idea if the GT350 knuckle design shares geometry with the standard GT and is just aluminum vs. steel, or if there were further geometry improvements.

 

[BmacIL]

I forget about the double joints. Would be interesting to see the results of that, especially compared to the previous single joint design. Any idea if the GT350 knuckle design shares geometry with the standard GT and is just aluminum vs. steel, or if there were further geometry improvements.

The GT350 has extended ball joints which raise the roll center vs the standard GT. Generally the same otherwise.

 

[Stuntman]

BmacIL, how much caster gain is utilized in the strut suspension of the Mustang? With SLA suspension, you can get a bigger portion of the camber needed in roll via caster gain, and require less static camber or camber gain (with a benefit of more available traction in braking), but is that utilized in the McPherson strut design? Of course this requires higher travel suspension, but just curious.

Tilt the top of the strut rearward for more caster. More caster does not require more suspension travel.

 

[65Terdlingua]

Tilt the top of the strut rearward for more caster. More caster does not require more suspension travel.

Yes, that is static caster. However even more caster can be added dynamically in dive by changing the angle of an upper control arm relative to a lower control arm in a SLA suspension, or by having multiple lower balljoints/lower arms in a strut suspension like the Mustang. This provides the benefit of lower static caster for easier turning (parking lots), but also provides an increase of caster dynamically when entering a turn under braking/compression, which means greater dynamic negative camber on the outside tire, and greater dynamic positive camber on the inside tire in a turn. With greater travel, you can achieve more caster gain to get the dynamic camber you need. With less travel, you need more static camber. An additional benefit is with less static camber needed to achieve the same amount of camber in dive and turning, there is more grip available on the front tires during braking. So better braking performance and stability. Of course there is a lot more to it, but thats how caster gain can be a benefit.

 

[Epiphany]

Problem is, Ford won't ditch the Mac struts and move up to an SLA.

 

[Stuntman]

I misread the "caster gain" in your question.

 

[65Terdlingua]

Problem is, Ford won't ditch the Mac struts and move up to an SLA.

No they won’t. My question was just how much caster gain this system has.

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