Lower your car, make sure to get an alignment

[MazRoadAdmin]

Okay, a person would really have to study a bunch of books, learn and understand some formulae and do some examples to prove this. But, I found a good reference (it's on a forum, so it must be true!) from someone who has that knowledge and experience that essentially states that even EXTREME changes to the ratio of upper/lower control arm length only cause 10% change in camber curve over 2" of suspension travel. Since our example was seeing -2.5 (at 12") turn into -5 (at 10"), if we made the lower control arm fully twice as long as the upper one (rather than just moving it the 1/4" or so that we have available for adjustment), the most we could do would be to change that 2.5 degrees of change into 2.75 degrees.

Reference:
http://grassrootsmotorsports.com/for...s/25771/page1/

Once you chose your VSAL, and know your desired RC position, you simply start at the lower ball joint and your suspension designs it self. If you have a fixed upper ball joint, you just need to pick A-arm lengths. The relative lengths will impact your camber curve somewhat, however if I remember right even a 2:1 lower arm to upper arm length difference only caused ~10% change in camber curve over 2" of suspension travel, but tended to impact the RC migration greatly.

(above VSAL = "Virtual Swing Axle Length", sort of the calculated theoretical length of a swing arm that would move the wheel in the same arc as your suspension; RC = Roll Couple)

So, I'm going to conclude that the minimal amount of camber adjustment that we have on our lower control arm is not enough to significantly change the overall camber curve. As I stated earlier: "The camber curve is the camber curve."

And as I also stated, the simple purpose for THIS thread was to inform people that lowering the front of their Miata jacks up their front toe, so that they need to readjust the front toe (at a minimum) any time ride height is changed. That's all this thread was about. Y'all can continue to debate other stuff without me.

[— kung fu jesus —]

Yeah, I was trying to find stuff, too. This thread is meant to be informative, not a debate. At risk of being incorrect, I don't remember if the the suspension geometry creates parallelograms or trapezoids. I seem to recall they are trapezoids and the camber curves are non-linear. I think Sonny hit on what I didn't; those settings are very good for autocross. I would be concerned about higher-speed maneuvers where the handling characteristics of the car would be a bit unstable or surprising. Again, I am no expert by any means. I worry about the Flippy's solution of stiffening the rear shocks to keep the car off the bump stops creates a large difference in roll stiffness between front and rear. This could contribute to unexpected oversteer at higher speeds that aren't as apparent at lower speeds he might not be expecting. Believe me, I try to keep away from these conversations because my understanding of suspension dynamics is not that deep compared to a lot of Miata enthusiasts. I'm not here to browbeat with my e-peen.

[I<3flippyheadlights]

1. Even with the little debate, it was informative
2. I'm going to adjust the front and back equally
3. I GOT LOREN TO POST!
4. Had fun with the new alignment today in some corners

[— kung fu jesus —]

Drive it a while and see how it feels. Taller top hats will help more in the rear than cranking up the compression/rebound. ISC Racing makes them, so does FM, maybe a few others.

[I<3flippyheadlights]

i would if I was more motivated right now. I'm feeling a little lazy and other parts of the car could use attention. Not stuff like new gauges and center console, but sway bars, bushings, brakes, etc.

[— kung fu jesus —]

No, really. Go drive it.

[I<3flippyheadlights]

Lol alright, ILL DRIVE IT! But due to me being a novice I can't tell when certain things are happening or not. I just feel the car (if that makes any damn sense). After that I adapt and drive. Actually had some fun today. A friend recently acquired a 2nd gen mr2 with a 3rd gen turbo'd engine. The thing is quick. Like 10 power to weight ratio quick. We went through a few corners and guess who was right behind him

It was fun, but I made sure not to push the car too far or myself. Felt much more solid then before making me take advantage of my suspension. I think I had more grip also, but I'm not expert.

[— kung fu jesus —]

A stock Miata makes an average driver look like a great one. Just give it time to learn the car, sharpen your skills then decide which mods will benefit you. Sonny (vaga xt) has shamed a lot of pretty heavily modified Miatas with a stock version that was down on power.

[I<3flippyheadlights]

Today I got to enjoy the calmness and predictably of NA power. My friend with his monster had to be careful on the throttle, especially through the corners, but in a Miata you can just feel it and really use all 100 horsepower. Do i want boost in my life? Of course. But the grass is always greener on the other side.

[NAautoxer]

way kinda off topic now, but my camber is -2 front, -2.5 rear.. just fyi. and i love it like that.. very informative thread, too.

[I<3flippyheadlights]

way kinda off topic now, but my camber is -2 front, -2.5 rear.. just fyi. and i love it like that.. very informative thread, too.

Its a suspension thread now. What is your ride height and wheel specs?

[friday]

0 toe in the front is the way to go with a street driven car like this. I think you are going to see quite a bit of tire wear with that alignment. I would also agree with KFJ that you want less camber in the rear than the front(I think thats what he said).

[I<3flippyheadlights]

No he said make them even, not less than the front. After listening to people I don't see any reason to have less camber in the rear than the front. Also 1 inch of toe in was much worse then the slight bit of toe out I now have.

[— kung fu jesus —]

No, there isn't a right or wrong here.

I was trying to get a mindset for the settings. When you move into custom settings, you ride a fine line of characteristics based on the geometry of the suspension. Loren set Flippy's car to mimic his car, by Flippy's request.

Low speed and high speed characteristics vary. Track and autocross settings differ to induce desired characteristics to suit the driving style and conditions.

My concerns for Flippy are primarily with the rear suspension travel, which is pretty well known to have a short stroke exacerbated by lowering the car. Regardless of principle, his alignment is better than it was!

Personally, I don't like more camber in the rear, but the difference between the front and rear in Flippy's isn't that much to get all twisted about.

FWIW, my specs are, as I remember:

F : -2.1˚ camber, -1/16˝ total toe, about 4-5˚ of caster
R : -1.8˚ camber, 0 toe

I ride at 4.75" F at the pinch, 5.25" R.

504# F, 350 # R on DA monotubes, RB solid front bar, OEM NB rear

15x8 +20 wheels with 205/50-15 tires

It is more of a track setup. It can feel a little odd at lower speeds but better at higher speeds.

[MazRoadAdmin]

You have 4-5 degrees of Caster on the rear of your car? Interesting indeed.