darylcha

Last time I was on scales I was a little off, by probably >5-10% and I thought it wasn't worth the time and money to get it perfect. Went to track and it felt fine, couldn't feel the difference...until I had a passenger and I guess it offset the improper balance. I could take certain right handers on average 2-4mph faster than with just me in it. I can only conclude that the imperfect corner balance is what's causing this, driver error aside...

rob.ok

That is more than likely the case.


Think about this though too
Sometimes extra load can help in generating additional grip. Enter aero....we usually do this through the use of aids that deliver additional load to the tires without weight penalties, but it can be done by adding ballast too. We usually only ever hear about weight penalties imposed on race cars but many teams use them for load to produce additional grip (make the car lighter than regulation and then use ballast to deliver better performance for it's weight class). The harder you push the tires down through any load (mechanical, weight, or aero) the tires will achieve higher grip levels. As long as you got the power to continue to accelerate you will be faster than a similar car that is not producing as much G load. It's a thin line when you consider weight distribution, CG, and RC. Ideally, you want to be as light as possible and balance the car out through rearranging its parts or their orientation to achieve the lowest and most central CG and weight distribution, but even then some times ballast are used and depending on the track configuration they may make it an advantage over a car that is equally set up but slightly lighter. What you have to worry about is tire wear and straight line acceleration. Generally though, faster through the corners nets faster overall lap times.

In fact I know a few Miata drivers that like to take passengers simply for the additional load. Doesn't equal faster laps but faster mid corner speeds for sure.


-Rob

darylcha

Interesting and never thought about that. But why does this matter, when we can pretty much corner balance the effects out? Maybe my understanding of what corner balance does is wrong?

And that is indeed weird following the logic. So the additional load will net better mid corner speed, but still slows you down in general through acceleration etc. So why bother trying to get that faster mid corner speed when ultimately what you're trying to do is minimize the lap time?

rob.ok

Ha Ha! Yeah it's a funny thing. The Miata guys I know like it cause they can really get the car hooked up in the corners. I guess it's just a different feeling for them. Shoot I'm not even sure if Miatas were made to carry more than one person

The 034Motorsports Audi A4 runs something like a 100-125lb ballast in the rear of the car just above the rear diffuser (really, really heavy). I talked to these guys for a while about it and they tried pretty much everything before adding weight to the car. Once they started adding weight, it rotated better and held a higher cornering G. They kept adding weight till they felt like it was starting to become a penalty with no positive effects. In that particular car it has everything to do with the way the VW engine is mounted, but it's still proof positive that sometimes adding a little extra load through what ever means can benefit the cars over all performance. Oh yeah...that car also has more than enough power....unlike a miata.

-Rob

macr88

Sup Derek, hope I got the spelling right, it's been a while
Hope everything is going well for you
How's the S?

macr88

ZDan

Adding normal force to the tires by adding WEIGHT will in general reduce performance, because the load/grip curve isn't linear. Add 10% more weight and you don't quite get 10% more grip. I.e., you should be slower in a straight line *and* slower in corners (less lateral grip per weight = less cornering g's).

The only reasons I can think of that adding ballast should make a car faster is if it either improves the balance of the car, improves the ratio of sprung to unsprung mass, or better suits the spring/damping of the car.

It would definitely NOT be due to the added weight increasing grip, because grip per lb. will be reduced.

Downforce is totally different, adding grip without adding weight/mass.

macr88

I think the stiffer you go spring rate wise then the more you may actually get out of it.
I see why it can be very useful but at the same time I see so many people getting caught up in thinking they have to have it to go at an ok pace and it's just not true.

I heard that Charles Ng did a 2:04 in a stock S
was it corner balanced? I doubt it it.

Voodoo_S2K

This statement isn't relevant, except to prove something we know already, that Charles is a fast driver.

Does the S2000 come from the factory with corner balance messed up? Not really. Is it easily possible for someone to take the wrong measurements when installing coilovers which could result in serious "pogoing"? More likely.

I'm not necessarily of the opinion that the corner balance needs to be spot on, but I think it should be somewhat close and something that should be check after doing a new install.

macr88

Corner balancing in that situation can actually make things worse unless it's someone that actually knows what they're doing. The chances of that is so very slim because that person that measured incorrectly will not be willing to pay the person that does corner balancing correctly.