Aby@MIL.SPEC

iTrader: (161)

I recently discovered how the handling went to s**t during the time my lower cross bar was off to make spacers up after a DP install.

So it got me thinking, which would be a better handling upgrade without making the ride any worse than it is.

Cusco lower cross bars, version 1 & 2 or a works rear sway bar?

Any RMR lower cross bar input would be nice too.

My evo came with the front & rear strut tower bars & everything handling wise is stock. I just hustle my car to & from work.

Thanks.

IzenGreyEvo7

iTrader: (3)

Suspension braces will stiffen the chassis allowing the suspension to work more effectively and reducing deflection under load and stress. How much of a difference it makes has more to do with your driving style. You may or may not notice more responsive steering, less bump steer, and more linearity. IT WILL NOT AFFECT HANDLING.

A rear sway bar WILL AFFECT HANDLING. You can tune it to control the amount of rotation. A stiffer rear sway bar will cause the rear to rotate more on exit from a turn and a tad on turn-in.

So it just depends on whether you want to stiffen up the chassis or change the handling dynamics of the car.

Aby@MIL.SPEC

iTrader: (161)

So a flexing chassis wont affect handling? I thought loss of grip = reduced handling?

Somebodybody better tell The Mcclaren F1 team they are heading up the wrong tree. I guess the complete redesign of the BAR chassis & gearbox that significantly reduced flex is a mere coincidence to their leap in on track performance as well!

Thanks for your insight.

slt

iTrader: (2)

I doubt that more bracing will make the same difference as the sway bar. I put one on last week and the difference is quite substantial.

IzenGreyEvo7

iTrader: (3)

You're partially correct. A stiffer chassis makes for a more effective suspension (which short of powertrain layout and weight makes the biggest difference in handling) which does help handling. You have to detach grip from handling. They're interdependent but not the extent you think.

The braces don't make as much of difference as you would expect. Handling is not defined by grip. You can have a high grip car with terrible handling and vice versa. The miata has fantastic handling with less than amazing levels of grip.

If you want to use an F1 example. Mechanical grip can actually be increased by loading the tires with more weight through the use of heavier components. This however decreases handling and response.

In F1 cars the gearbox and engine are stressed members of the rear suspension. Increasing rigidity in the BAR chassis (according to team principles interviewed in Racecar Engineering) is an effort to provide a more stable platform for the suspension and to solve
a tendency for their gear box casings to crack under race conditions.

If you think you can change handling behavior such as oversteer or understeer by stiffening up your chassis by using bolt on braces all the power to you. You're wrong but
best of luck. If you want to significantly improve chassis strength you have to seam weld, add spot welds, or add a cage.

The stock suspension of the EVO has enough compliance and flex that increased rigidity from a bolt on brace will have no discernable effect on linearity, travel displacement, contact patch, etc.. It will affect a host of subjective criteria as I mentioned before.

I have done a rear sway bar and both Cusco Ver 1 and 2 bars. I took off the rear sway bar as it's best exploited on the race track and I found better improvements for street driving by adjusting the alignment. The Cusco bars actually make a nice difference in turn-in response and steering response. No difference in handling what so ever. The car still has the same driving character in terms of oversteer and understeer, weight shift, response from the chassis to steering inputs, etc. I also added the cusco rear strut bar with V-bar. Did it increase oversteer?? No. Don't misinterpret what I am saying. I fully support adding additional chassis bracing. Every little bit helps short of additional welds. However, it will not change the handling.

Aby@MIL.SPEC

iTrader: (161)

So what bars & braces do you have on your evo? stock or not?

IzenGreyEvo7

iTrader: (3)

Just to clear things up a stock miata on a skidpad will post a lower cornering force measure in "g's" than one with 1,000 lbs of ballast. Weight increases cornering grip. That's exactly what downforce does. It increases weight on the wheels for more grip, yet it doesn't add mass which hurts polar inertia and other factors involved in handling.

Aby@MIL.SPEC

iTrader: (161)

Let's try this again!

value

iTrader: (1)

If you use bars with the stock springs/shocks you aren't going to be able to take full advantage of them because of the soft springs. Get them with coilovers and you will feel the increase from bars.

Ludikraut

iTrader: (17)

... and what about something like the Worx Croxx plate (skid plate/cross brace). I'm very interested to see what people think of it vs. standard and upgraded cross braces.

l8r)

BatEvo

iTrader: (1)

We experimented with several braces and what not, RMR lower control arm brace included and the WORKS CroxxPlate gave us the best results. We use the upgraded Mitsu aluminum strut tower brace in front.

Out back, Hotchkis hollow rear sway bar and a BR strut tower brace up top. A little bit from everyone is what ended up working for us.

Aby@MIL.SPEC

iTrader: (161)

Thanks for the insight BatEvo.

This is the type of info I was looking for!

'ringmeister

iTrader: (25)

-This is not correct, it is an age old misconception. The coefficient of grip between the tires and the road surface will increase if you add a 1000 lbs of ballast. that is true. BUT, and this is a big but, the inertia, or force that is pushing the car off the skidpad (for example) increases at a MUCH faster rates so cornering abiility actually decreases. basically, double the weight of the car and the coefficient of friction double, but the cornering forces QUADRUPLE. this issue can be muddied slightly depending on where you add the weight: improving weight distribution, or lowering the center of gravity.

mayhem

iTrader: (9)

I don't believe that the CofF increases between two materials by just adding weight. Net resisting force of the tire may increase but not the CofF. Graph the weight (vertical force) and grip and as you increase weight (vertical) the improvements slowly taper off until they become cumbersom. There is a small range everyone should be aiming for where both grip and horizontal forces are happy. Too much weight and you'll quickly have to much horizontal force. Too little weight and you'll quickly have to little grip. (The last two sentences do not apply to aero forces) This is why some race cars run so much aero down force. Aero does not give horizontal loads through turns. Just drag.

BatEvo

iTrader: (1)

The idea of adding weight to increase grip is known as “Tracktive Effort” (sp?). Works great for things like locomotives, tractor and truck pullers, but sucks when it comes to road racing. Sure you increased the grip level, but for the wrong reasons in the wrong application, your not trying to pull 10 times your own weight.

Think about it, weight is added in various forms of road racing as a penalty, not to improve your cornering ability over the opponents you’ve already beaten.