'17 Toyota 86 vs '17 Maza MX-5

[nikitopo]

Yes, in a stock car the tires are basic the limitation and not the suspension. There is already the triangulated strut brace.

If you go with stickier tires, then there is more flex and you need a beefed up strut brace or an extra tower bar.

[Gforce]

Originally Posted by nikitopo

Yes, in a stock car the tires are basic the limitation and not the suspension. There is already the triangulated strut brace.

If you go with stickier tires, then there is more flex and you need a beefed up strut brace or an extra tower bar.

Sadly, my Supercharger presents an insuperable barrier to doing so. TRD has some interesting looking beefed up and damped triangulation strut bars that fit the stock locations but, again, they don't fit around my Supercharger.

Just by the way, upper wishbones stress the "strut towers" in exactly the same way as the McPherson strut.

While full double wishbone suspension is definitely what you would use for a low slung racing chassis, they are completely unnecessary if you have a tall road car to fit everything under. If you are designing a sportscar the struts work even better because of the more limited wheel travel you normally design in.

[wparsons]

Originally Posted by nikitopo

McPherson struts have been used for decades in racing with success. The key point is to have a good strut tower brace. I've a discussion in the past here and not many understand how this brace works or saying that there is no tower/chassis flexing in our cars.

It's not just flex... mac struts have very little (or no) camber gain on compression, which means more static camber on a car that doesn't ride like a dump truck.

Race cars are fine because they run really high spring rates and a lot more static negative camber. Less compression under cornering loads means less camber loss from compression on a mac strut, and higher static camber puts the contact patch flat under lateral load.

Double wishbones or multilink can run softer springs and have more compression travel in corners and still keep the contact patch flat under lateral load.

Originally Posted by Gforce

BRZ McPherson struts are fairly vertical which addresses the minor difference in camber curves.

Vertical in which axis? What makes you think that improves the camber curve? Adding caster can give some negative camber with the wheels turned, but under compression it's still going to lose camber because of how macpherson struts work. The only way to have anything approaching a curve is to ensure that the LCA would be flat to the underbody under full compression, but even then it's a very slight curve.

Our rear suspension gains 1.5*+ in a 1" compression, the front stays nearly identical to normal resting.

Camber gain is a VERY good thing on cars that have bump travel in a corner (or body roll).

Originally Posted by Gforce

I think the point I'm trying to make is that the MX5 supposed advantage comes from Bridgestone PP S001 tires as compared to the Primacy.

I'm not comparing lap times in what I'm talking about...

[ame="https://www.youtube.com/watch?v=DsEmK1M87VQ"]Double Wishbone Suspension - Explained - YouTube[/ame]

[nikitopo]

Originally Posted by Gforce

Sadly, my Supercharger presents an insuperable barrier to doing so. TRD has some interesting looking beefed up and damped triangulation strut bars that fit the stock locations but, again, they don't fit around my Supercharger.

There are strut bars that can fit even above of intercoolers. If they wanted, they could create something like that:

[Yoshoobaroo]

Originally Posted by nikitopo

There are strut bars that can fit even above of intercoolers. If they wanted, they could create something like that:

The WRX motor sits waay further forward than ours though. I don't think there's a way to run an effective strut brace over or around the edelbrock manifold.


Sent from my iPhone using Tapatalk

[Scrappydoo]

Originally Posted by Gforce

Sadly, my Supercharger presents an insuperable barrier to doing so. TRD has some interesting looking beefed up and damped triangulation strut bars that fit the stock locations but, again, they don't fit around my Supercharger.

Just by the way, upper wishbones stress the "strut towers" in exactly the same way as the McPherson strut.

While full double wishbone suspension is definitely what you would use for a low slung racing chassis, they are completely unnecessary if you have a tall road car to fit everything under. If you are designing a sportscar the struts work even better because of the more limited wheel travel you normally design in.

What is an insuperable? I'd love one.

[guybo]

If you want to know what sort of suspension is best on a road car, learn from those who know- the WRC suspension uses a MacPherson front and rear. MacPherson struts is another name for coil overs- http://www.volkswagen-motorsport.com...php?id=339&L=1

WRC cars have some of the most advanced suspensions in ANY race cars in the world.

[wparsons]

Originally Posted by guybo

If you want to know what sort of suspension is best on a road car, learn from those who know- the WRC suspension uses a MacPherson front and rear. MacPherson struts is another name for coil overs- http://www.volkswagen-motorsport.com...php?id=339&L=1

WRC cars have some of the most advanced suspensions in ANY race cars in the world.

Close, but not quite.

First, WRC cars use the same suspension design as the homologated road car. That means not swapping out the stock struts for double wishbones. Plus, most WRC cars use boxer or transverse engines which takes up a lot of width and severely limits the space available for UCA's the length desired for travel and desired camber curve.

Second, macpherson struts aren't another name for coilovers, but they are a type of coilover. All macpherson struts use coil springs over the shock, but not all coilovers are macpherson struts.

Third, again... I'm not saying macpherson struts can't handle well, but they're a compromise on a street car that sees track duty. You're either not running enough camber on the track, or too much camber on the street. Gaining negative camber under compression is a very good thing, and struts just don't do that.

http://mechanicalmania.blogspot.ca/2...on-double.html

[nikitopo]

Originally Posted by wparsons

It's not just flex... mac struts have very little (or no) camber gain on compression, which means more static camber on a car that doesn't ride like a dump truck.

Race cars are fine because they run really high spring rates and a lot more static negative camber. Less compression under cornering loads means less camber loss from compression on a mac strut, and higher static camber puts the contact patch flat under lateral load.

Double wishbones or multilink can run softer springs and have more compression travel in corners and still keep the contact patch flat under lateral load.

Yes, this is the theory. However, as you said in racing they are fine because you have higher spring rates and more static camber. Additionally, MacPhersons have advantages in long travel applications ie rally.

Originally Posted by wparsons

I'm not comparing lap times in what I'm talking about...

This guy is very good in theory, but has much less practical knowledge.

Originally Posted by guybo

If you want to know what sort of suspension is best on a road car, learn from those who know- the WRC suspension uses a MacPherson front and rear. MacPherson struts is another name for coil overs- http://www.volkswagen-motorsport.com...php?id=339&L=1

WRC cars have some of the most advanced suspensions in ANY race cars in the world.

Exactly. Subaru also used MacPhersons front and rear and after they changed the rear to gain basically luggage space. At that time, many said it was mainly a marketing decision ...

[totopo]

Originally Posted by nikitopo

Yes, this is the theory. However, as you said in racing they are fine because you have higher spring rates and more static camber. Additionally, MacPhersons have advantages in long travel applications ie rally.

This guy is very good in theory, but has much less practical knowledge.


Exactly. Subaru also used MacPhersons front and rear and after they changed the rear to gain basically luggage space. At that time, many said it was mainly a marketing decision ...

Originally Posted by guybo

If you want to know what sort of suspension is best on a road car, learn from those who know- the WRC suspension uses a MacPherson front and rear. MacPherson struts is another name for coil overs- http://www.volkswagen-motorsport.com...php?id=339&L=1

WRC cars have some of the most advanced suspensions in ANY race cars in the world.

Originally Posted by nikitopo

Yes, in a stock car the tires are basic the limitation and not the suspension. There is already the triangulated strut brace.

If you go with stickier tires, then there is more flex and you need a beefed up strut brace or an extra tower bar.

What the heck are you trying to say? with the stock tires a better suspension design wouldn't help the car? That's completely wrong, suspension works in concert with tires.

Are you guys seriously saying macphearson are EQUAL to uneven length double wishbone? Like seriously truly believe that and not just because the 86 uses it?

Can you make macphearson work? sure. Are there things in a race car more important than macphearson vs real suspension? sure. But which is better is unequivocally double wishbone. With the double wishbone you have huge freedom in defining your camber and toe curves on compression and rebound. Not to mention the anti-dive and anti-squat control you can have. Multi-link is almost as good as uneven length double a-arms and give you a nice trunk.

If you want to learn about suspension, a good place to start can be the famous "tune to win" by Carroll Smith.

And if you want to argue with examples, what do all the no-holds-barred race cars use?

https://www.subaru-msm.com/global/SU...e/detail/8.jpg

http://www.tune86.com/sites/default/...spension_0.jpg

https://www.jamesallenonf1.com/wp-co...t-13.42.44.png

https://www.formula1.com/content/fom...024.medium.jpg

[guybo]

Tune to Win is from the 1978- things have come a long way. MacPherson are best for a road car for lots of reasons- not the least is durability. It's very easy to throw out a double wishbone's alignment. On a road car, durability is one of the most important things and that's one of the reasons rally cars use them because of the rough nature of the sport. DD is more analogous to rally than track racing. A purebred race car only goes a few hundred miles between alignments.

Also, modern race cars don't use double wishbone, they use push or pull rod. Outboard brakes and aerodynamics make them very advantageous.

[totopo]

Originally Posted by guybo

Tune to Win is from the 1978- things have come a long way. MacPherson are best for a road car for lots of reasons- not the least is durability. It's very easy to throw out a double wishbone's alignment. On a road car, durability is one of the most important things and that's one of the reasons rally cars use them because of the rough nature of the sport. DD is more analogous to rally than track racing. A purebred race car only goes a few hundred miles between alignments.

Also, modern race cars don't use double wishbone, they use push or pull rod. Outboard brakes and aerodynamics make them very advantageous.

So I guess the LaFerrari, the mclaren P1, and porsche 918, Nissan Gt-R, Corvette z06, Viper ACR, and the radical sr8 are sub-par hack jobs with their front double wishbones. If only they went with the superior macphearson am i right????

I'm not saying the macphearson are terrible, it's just that the uneven double wishbone is superior in terms of road holding. It's not like a car is terrible because it has macphearsons... but you can't honestly say it is better than double wishbones in terms of track performance (don't bring up gt examples with homologation and balance of power rules, they balance power).

the pull and push rods on F1 ARE double wishbone suspensions. They refer to the way the spring/shock is connected.

edit: So then do you agree that the miata has a better suspension setup than an 86 for the track? What on the track do you think can possibly make a macphearson strut outperform an uneven length double a

edir #2: also, point out to me what in tune to win about suspension design is outdated.

[Gforce]

Originally Posted by Scrappydoo

What is an insuperable? I'd love one.

Nissan model. Designed to take on Toyota.

[Gforce]

Originally Posted by nikitopo

There are strut bars that can fit even above of intercoolers. If they wanted, they could create something like that

It's the hood clearance. The underhood insulation even has to go.