Common handling myths.

Wider is always fasterer

Midlana doesn't have bars and I haven't noticed handling issues, so maybe I'm missing something.

Looks like I did pick a good one

Barring edge cases like the suspension running out of travel...
Sway bars adjust the handling balance by affecting the proportion of roll stiffness across each axle. More roll stiffness on a particular axle means that axle gets a higher percentage of the total weight transfer. And as we know, that means lower grip on that axle and thus you get more slip angle on that axle. IOW, the stiff bar makes that end slide more.

Note that it's not lifting the wheel up. The effect is the same whether you increase the roll stiffness via bars or via springs.

The incorrect tl;dr way of looking at that is that sway bars cost you traction. So thus you'll get more grip overall with softer bars.

But what that misses is that it's a proportion of the total. You're not affecting the total weight transfer. So if you decrease the roll stiffness at both axles by the same percentage, you don't change the distribution of the weight transfer and your handling balance doesn't change. Sure, the car will roll more, but the oversteer/understeer balance will be the same. Again, assuming no edge cases like slamming into bumpstops or lifting wheels due to a lack of travel.

Sway bars allow you to separate roll stiffness from ride. They're an excellent tool. And yes, there are some setups that use very little or no bar at one end or the other for various reasons. The amount of bar vs the amount of spring is almost a tuning philosophy and goes through fashions. Go with too much of one or the other and you'll have problems.

Another myth, mostly from Hollywood: the fastest way to stop is to lock up the wheels.

Keith Tanner wrote: Another myth, mostly from Hollywood: the fastest way to stop is to lock up the wheels.

Oh! Like laying down your motorcycle to "avoid a crash." No, you just crashed to avoid stopping. If you have time and distance to lay it down, you have time to stop if you used your brakes right.

It's entirely the cruiser crowd, half of whom think the front brake is dangerous to use.

kb58 wrote: That 50/50 weight distribution = beat handling.

I agree with you. I do not think 50/50 is optimal.

Keith Tanner wrote: But what everyone misses is that it's a proportion of the total. You're not affecting the total weight transfer. So if you decrease the roll stiffness at both axles by the same percentage, you don't change the distribution of the weight transfer and your handling balance doesn't change. Sure, the car will roll more, but the oversteer/understeer balance will be the same. Again, assuming no edge cases like slamming into bumpstops or lifting wheels due to a lack of travel.

Or suspensions that do strange things at one end or another with respect to their camber curves, roll center height/migration, or toe change. Or outliers like 1st-gen RX-7s that get into a progressively worse bind with body roll because the upper links and lower links want the axle to move in two contradictory planes. (I disconnected an upper link and articulated the axle once. The pivot would be 1-2" out of place depending on where I moved it! And people wonder why the cars like to rip the mounts off the shell)

The little niggling details that make the difference between a good theoretical construct and a cussed layout that works only if you stiffen the bugger up so the suspension can't do anything bad because it can't do anything at all.

I like the saying, any suspension can work if you don't let it.

...and that is where the idea "stiffer = better" probably comes from Softer suspension that moves correctly is better, but that isn't as easy a concept to get across. Besides, the big name racers (who are locked in to sometimes crappy street-car geometry) run super stiff...

dculberson wrote:

Keith Tanner wrote: Another myth, mostly from Hollywood: the fastest way to stop is to lock up the wheels.

Oh! Like laying down your motorcycle to "avoid a crash." No, you just crashed to avoid stopping. If you have time and distance to lay it down, you have time to stop if you used your brakes right. It's entirely the cruiser crowd, half of whom think the front brake is dangerous to use.

I'd plus one a few more times if I could. You will also hear this from just about any proud motorcyclist who laid down their bike while trying to stop. "I laid it down because there wasn't anything else I could do..."

Then you will have people like my parents, who listen to those proud motorcyclists tell their stories, then subsequently believe that the fastest way to stop a bike is to lay it down.

In reply to flatlander937:

You might find this article about the 1996 Dodge Stratus NATCC car interesting, most notably about FWD balance on different course types.

http://forums.vwvortex.com/showthread.php?3968406-The-Archive-Dodge-Stratus-Touring-Car

Knurled wrote: ... that get into a progressively worse bind with body roll because the upper links and lower links want the axle to move in two contradictory planes. (I disconnected an upper link and articulated the axle once. The pivot would be 1-2" out of place depending on where I moved it! And people wonder why the cars like to rip the mounts off the shell)..

Glad you mentioned this! I used to try and explain why 4-bar links on Locosts have to be designed just so in order to avoid binding. Everyone always disagreed so I eventually gave up trying.

FWIW, my brother one time replaced the rubber bushings in his 4-bar straight axle setup to "make it better." We learned otherwise after we put a floor jack under one tire and could only jack it up about 2" before the entire rear of the car would lift. The suspension was trying to use the entire axle tube as an anti-roll bar...

4-links are hard to get right. There's a reason I put a three-link on my MG I figured it would be easier to play with various settings, and almost no chance of bind.

I think the only way to make a 4 link not bind is if all the links are equal in length and parallel, and the lateral device's center is halfway between the two.

It won't do anything very useful, but it won't bind, either.

That's the trick, making all four links the same length. If one's even 0.030" different, that end of the axle will rotate at a different rate than the other end and attempt to twist the axle tube. It'll either bind or something will bend or break, like the aforementioned brackets getting ripped out of the frame.

Another myth: "Power to weight ratio dictates laptime." Only to a degree, as tires, driver skill, and aerodynamic drag can have far greater effect.

dculberson wrote:

Keith Tanner wrote: Another myth, mostly from Hollywood: the fastest way to stop is to lock up the wheels.

Oh! Like laying down your motorcycle to "avoid a crash." No, you just crashed to avoid stopping. If you have time and distance to lay it down, you have time to stop if you used your brakes right. It's entirely the cruiser crowd, half of whom think the front brake is dangerous to use.

I always found the fastest way to stop is to hit the large stationary object head on. I never go further than the thickness of the bike.

kb58 wrote: Another myth: "Power to weight ratio dictates laptime." Only to a degree, as tires, driver skill, and aerodynamic drag can have far greater effect.

Drag is only a factor as top track speed increases. 0-60 it has almost no effect.

We did instrumented quarter mile testing on my Locost a while back. The car hit an aerodynamic wall at 80 mph and basically stopped accelerating. Granted, that's quite a bit more drag than 60 mph, but I'll bet even pulling the windshield off would have cut the 0-60 by a notable amount. That's a car that makes about 150 hp at the wheels.

Yeah a buddy's Locost has 500 hp and can beat anything to about 100 mph, but above that he said he gets beat badly due to its poor aerodynamics.

FWIW, Dennis Palatov ("DPcars.net") found much the same when he ran a 1500-lb 300 hp Arial Atom against a 4000-lb 500 hp BMW M5 back-to-back. Most people would put their money on the superior power-to-weight of the Atom, yet it lost due entirely to its poor aero.

As an aside, to increase a car's top speed by X% requires an X^3% increase in power.

We had a 466 hp Miata and a 250 hp Exocet at MRLS recently. Quite similar power/weight ratios. Around Laguna Seca, the high HP car is the winner as it just shrugs off the drag. Around our kart track, the Exocet has the edge.

In reply to racerfink:

Thanks for the link!

kb58 wrote: That 50/50 weight distribution = best handling.

"perfect weight distribution"

DaewooOfDeath wrote:

Keith Tanner wrote: A stiff sway bar means less traction at that end, so no sway bars gives you the most traction!

You have customers who run no bars? That's some super spotty logic, but I've seen some pretty interesting evidence that swaybars do lower the total mechanical grip of a system.

lots of rally/rallycross guys run no bars and/or one bar removed at whichever end, depending on the car.

wbjones wrote:

trucke wrote: More decals = better handling

I thought that more decals = more hp ... didn't realize that they helped with handling also

They also = more scantily-clad car show girls...

Myth: there is any "right" setup on any given car. Setup has a lot to do with the driver's driving style, and the fastest setup for one driver may not be the fastest for another driver.