THSCC Forums

Page 90 of the 2007 rules item 14.8 makes it look like something I could legally do.

http://www.scca.org/_FileLibrary/File/2007SoloRules.pdf

I assume that this is the rule that you are talking about...




Maybe I'm wrong, but that seems to be talking about adjustable camber plates not modifying stock plates.

What do you think Aaron??

_________________
Todd Breakey
STS 42 - 1992 Sunburst Miata
Dammit!
"You souldn't play leap frog with a porcupine. You might get hurt." - Eliza

"and
the original upper mounting holes may be slotted."

_________________
Silver Honda
Green Ford
Blue/White Suzuki
Red Triumph
Grey BMW

"Never let life be shaped by fear of its end"

No, you're a towel!

DOH!! Reading is hard!!!

Thanks Marcus.

_________________
Todd Breakey
STS 42 - 1992 Sunburst Miata
Dammit!
"You souldn't play leap frog with a porcupine. You might get hurt." - Eliza

It's early , you're excused.

_________________
Silver Honda
Green Ford
Blue/White Suzuki
Red Triumph
Grey BMW

"Never let life be shaped by fear of its end"

No, you're a towel!

Interesting! I thought that was a no-no. At least I had been operating under that assumption for years that it was illegal in *SP.

But it's always a good idea to check

Jeb, I din't want to help you do an illegal modification

_________________
Mike Whitney
whit32@gmail.com, 919-454-5445
V10, V8, V8t, I6, I6, V6, F4t, I4, I4, I4, I4, I2, 1, 1

You can slot the upper mounting holes, but NOT the center hole.

I may not know what the hell I'm talking about, if thats true, just ignore me, but I kinda think your problem is the rear sway bar being too big if its oversteering on you. A 27 mm rear bar (Racing Beat) is pretty stiff. The racing beat bars might be designed to be run with a less agressive set of springs (compared to your H-Techs, the RB springs drop it .5" less and have a slightly lower spring rate). Also, you're running a lot smaller front bar than the RB bar (Whiteline=22mm, RB=28.5).

For reference, the stock bars are 21mmF/20mmR, so you've taken the balance consideraby in the oversteer direction, at 22mmF/27mmR.

this from the guy who bought your old 22mm rear sway bar

_________________
2012 MX-5 Sport SUV

Keep in mind that sway bar stiffness is a fourth order of it's diameter. All other factors being constant, you've gone from 22^4 to 27^4.

_________________
Has no responsibility whatsoever.

right, so (assuming the length of the lever arm on the bars is the same) he's increased front sway bar stiffness by 20%, and rear sway bar stiffness by 232%

as opposed to the set (front and rear) which is designed to give a 239% increase in front and a 232% increase in the rear. The RB springs aren't as drastic of a drop, probably b/c they rely on their sway bars to provide most of the roll stiffness.

As a reference point, I'm running a 22mm rear bar with the stock 21 mm front bar (a 46% increase in rear). I've certainly spun my car once or twice, but it feels quite well balanced (I spun due to driver error).

Wouldn't it be better (or just as good, without the "tire eating" effect) to just get the RB front bar (or a less stiff rear bar) to take the oversteer out, rather than 3 degrees of rear negative camber?

_________________
2012 MX-5 Sport SUV

Well, a bigger front bar could make it harder to get power down coming out of corners (it unloads the inside front tire), so there's a minus for you.

Also, how do you know that the oversteer is caused by a camber issue? Too much camber can make a car looser than not enough, and it will be looser on turn in, etc.

In a front dive car I'd avoid a bigger front bar unless the car is *way* underpowered AND has springs that are way too soft.

Scott

I was suggesting an either or. Either, get the matched set of bars, or go with a smaller rear bar. My main point is that I think its the huge rear bar causing the oversteer, probably not a camber issue. The unfortunate thing is that nobody makes an "in between" rear bar. Its either the 22mm bar I have or the huge 27 mm RB bar.

_________________
2012 MX-5 Sport SUV

And Mark and I spent some time discussing this as well. Given the car's tendancies and my level, he felt the -3 would be a nice fit for what I was experiencing.

Now the rear has been adjusted and I am coming back for the front. Based on what I feel right now with zero toe F/R -1 in the front and -3 in the back, in harder city driving the rear seems to be planted a lot more. There is a particular exit ramp that I will push the car through rather hard and the back has often felt like not much would unsettle it. As it is now, is seems to bite a little more, while still rotating (not wanting to push as much).

I know that this sensation may totally change in an autocross situation, but a lot of the same sensations that I felt on this ramp I have felt during an autocross as well. I guess the nice thing about adjustablity, is that I can do this and see how it works/feels and still have room to change back to a smaller bar in the rear or a bigger front bar. IIRC, H&R has a 25mm rear bar, that may be a good in between. At the same time I don't really want to keep pumping $$ into rear bars. The bigger front bar from Racing Beat may calm things down as well, but like was stated above make some of the power transfer sketchy.

So Mike, now that it is a legal mod, are you up to help a brotha out?

Truer words have never been spoken. As I've said, my old Integra, by the time I got fast in it, was *impossibly* loose (and, not as loose as some out there). I'm convinced that this experience made adapting to a number of cars - a loose FWD ITC car, a neutral ITA Miata, and a "somewhat wild" AS S2000, much easier. The S2000 seems loose to some folks who drive it. For me, it just sort of drives itself.

As always, YMMV.

_________________
Karl S.
2014 Baby, 2014 House, 2013 Ford Focus ST, 2013 BMW 328i, 1994 Mercedes E320
(Insert passive aggressive signature line here)

Loose is fast, "tight" is confidence inspiring.

My rear bar is currently disconnected, call me a puss.

_________________
Has no responsibility whatsoever.