First track day shakedown

Arrvaxx

Great post! Thanks!

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wstar

It can sometimes, counter-intuitively. I won't argue the point with you, since it's a ridiculously complicated topic and I'm not a suspension engineer (I don't even play one on TV!), and it's not like I've gone and attempted adding removing every possible combination of settings and stock/aftermarket suspension bits either But there are all kinds of complicated interactions going on even with a simple item like a swaybar.

In the net, I do think a stiffer front bar + adding both caster and camber in the front (I'm at approx -2.5 and 6 now on the SPL camber arms) is the magic ticket on this car for trackday stuff (assuming reasonably-upgraded coilovers and grippy tires), and I don't get any understeer issues to speak of (nor, for that matter, do I get out-of-control twitchy oversteer - I get a nice neutral feeling that's easy to push into controlled oversteer). I think the stiff front bar is part of the equation.

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synolimit

Man how nice would it be to lower the car and achieve -2.5?! I'm -1.5 now with swift specRs in the front. My coils will be here soon and I might lower a hair more. To bad I can't go lower and get a number I want. $800 SPL arms suck for only needing a few degrees.

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13 370z-

DR_

Then just get the Kinetix arms (I'm selling mine BTW). They are only a little heavier than stock and a lot lighter than the SPL arms.

GSS138

The initial reduction in understeer is most likely due to just reducing the body roll up front. The body roll, especially on softer springs, will induce understeer by throwing the CG towards the outside front wheel. But there should be a point where "too much" bar will yes, cause the outside to again push. But the first problem you are trying to solve with the stiffer bar is killing some body roll.

If the car was close to being balanced then a sway bar is sort of like the trim on an airplane. But when the front is bouncing around like a pogo stick as it does on the OEM suspension, you are dealing with a problem situation, not a fine tuning situation.

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Current Mods: Vorpal Weapon +5.

Zauskycop

Now I'm agreeing. Too much roll will overwhelm the outside tire, and by reducing that roll, you are correct that it will balance the car more. Ideally, you want as little swaybar as possible up front, with the work being done by the springs. For lack of springs, the swaybar is the poor man's substitute.

Years ago I was at a little speaking engagement by Carrol Smith and it really enlightened me to the "common sense" portion of setting up cars. His quote was "Swaybars do all the right things for all the wrong reasons". Basically, the front swaybar is balancing the car by putting load on the inside spring. But the load isn't into the ground, but actually LIFTING the tire, thus reducing the grip on the inside tire...hence the push. Luckily the Z, with its immense front weight, is still able to keep a load on the inside and keep its balance. I used to autocross a MR2 Spyder...and if you have ever seen one of those (or some Porsche vehicles for that matter) with big front bars, seeing them three wheel out of corners is a very common occurence!

Tracy Ramsey

Rusty

I'm running the Hotchkis sway bars (biggest bars out there).The rear on the softest setting. Front camber -2, caster +6, toe zero. Rear camber -1.75, and toe zero. With 275/35-19 front and 325/30-19 rear tires. Fo me, it feels pretty much balanced for my driving level.

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synolimit

No caster though. A modded SPC so the nut won't slip might be ok.

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13 370z-

wstar

Yeah so that basically mirrors my setup, except I'm on square 275/35-18s or 285/645-18's and half a degree more front camber. I expect mine's a little more oversteer-happy than yours, but it's comfy and controllable to me. That and I'm running those nice JRZ dampers, but with fairly weak spring rates on them.

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GSS138

Pretty much use the same train of thought, I am also a big Carroll Smith fan.

It always bothers me when I see those damn 3 wheeling pictures lol.

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Drew M

So after a couple months of use, would you recommend the car for a fellow instructor?

Zauskycop

I instruct at the Chicago Region PDX program, and I know *I* would! I am still learning some finer points of the car but so far I love it in the 4 track days I have done.

My latest "aha" moment came when I was understeering a bit (Whiteline front sway, stock rear) in steady state corners. Normally it would mean too much speed, or too much steering angle, and I tried both with limited success. So I tried to give more throttle and it worked! Basically I think you are using the on power oversteer that is inherent in the car to balance out the off throttle understeer?

Still have stock suspension underneath, and this may all change when I go to a square setup and put SPL arms on the car, but it was rather enlightening to me using power in the car...quite a change from a 125 hp Spec Miata!!!

Tracy Ramsey

Drew M

Thanks Tracy! Do you feel you can drive the hell out of it like you can the Miata?

It's hard for anything to compare to an SM car. They're phenomenal through the turns and will reward you with a little more straight line speed. I just don't want to drive one everyday. I'm making the change from an ITS RX7. Less power than the Nissan and decent (at best) through the turns. I'm just trying to consolidate everything into 1 car.

wstar

Yes! The answer to every problem in the Z is more throttle, basically. Unless you're in a hard braking zone, or about to go flying off the edge of the track. Then maybe less throttle, I guess

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GSS138

Completely agree. More gas. It's one of the most un-natural instincts you have to overcome with this car. I am still pretty much a beginner driver myself, but my instructors this summer have been showing me how to really get this car to rotate using throttle, and even when appropriate at lower speeds trail braking.

It is not something instinctive that someone like myself that only has about 1.5yrs of experience doing would do. But once the light bulb goes off and you see it work. The car starts to make a lot more sense.

Of course then you need to buy a new diff.

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Current Mods: Vorpal Weapon +5.