Lower your car, make sure to get an alignment

[I<3flippyheadlights]

So I lowered my car a few months ago and finally decided to get that pesky alignment done. I thought when you lowered a car the only thing affected was the camber. Oh how I was wrong. Well I went to our friendly mazdaroadster admins place on July Fourth for his alignment special and the car feels fantastic. Well there is a reason why, check out my numbers!


BEFORE
Front Camber: -2.5 / -2.5
Front Caster: +5.6 / +6.2
Front Toe: 1" IN (yes, one full inch)
Rear Camber: -3.0 / -3.8
Rear Toe: 1/16" IN

AFTER
Front Camber: -2.5 / -2.5
Front Caster: +5.6 / +6.2
Front Toe: 3/16" OUT
Rear Camber: -2.7/-2.7
Rear Toe: 1/8" IN

So maybe I should of done it sooner? :teehee:

[kung fu jesus]

Just curious but why did you select those settings?

Those still don't seem good. What is your ride height?

[I<3flippyheadlights]

I have about a inch of suspension travel. So I set my camber to make up for the lack of of travel.

[kung fu jesus]

OK, that really doesn't answer the question. I'm not flaming, either.

How is negative camber making up for lack of suspension travel?

[I<3flippyheadlights]

Well Loren explained to me that when you turn and your suspension compresses, you camber becomes more negative. So when you can predict how much camber you gain for every inch that travels you can set it so your tire is flat, or as flat as possible, when turning. After driving his car I understand it more. He is at stock height running about -1 camber because he has 3 inches of travel. So when we looked at my car we considered (he considered) what my camber would need to be like his car in a turn. I'm trying to do my best to explain as I'm not to understanding of everything that goes into an alignment. But when he explained it, it made sense and I trust his opinion.

and I know you aren't flaming, you aren't that type of guy :P

[kung fu jesus]

OK, just trying to get the mindset.

Generally, that is a bit too much toe out in the front. The wheels will also toe out even more when the suspension is compressed. I am guessing the car is pretty sensitive to bumpsteer.

More camber in the rear than the front isn't too stable, especially with that much difference between the toe angles front and rear. I don't know Loren's numbers, so I can't compare his to yours, but if you have only an inch of suspension travel, you're defeating the mechanical grip of the suspension design.

Trying to match your static settings to his dynamic settings, I get that, but it is the wrong idea. Look at this site that shows you the camber curves at different heights:

http://www.virkki.com/jyri/miata/camber/

[I<3flippyheadlights]

Well we are guessing around an inch. I have koni adjustable shocks with Tien-S springs. its not like I'm using crappy stuff and slamming the car. He also explained that the back doesn't create as much camber as it travels. My car also sits a bit higher in the rear due to the springs.

[kung fu jesus]

What is your ride height, F/R?

[I<3flippyheadlights]

I'm so lazy to go out and measure... but I will.

Ok from the center of my wheel to fender
Front:11 1/2 inches
Rear: 12 1/2 inches

[jux]

That's a pretty fair amount of rake. Used to seeing no more than .5" from front to back. ...but if it works for you and rides/handles the way you like, good on you. :)

[I<3flippyheadlights]

Its not that noticeable and that's how the springs come. Personally, I love how my car handles. I do bottom out in the rear sometimes, but ill just turn my konis a little.

[Tekel]

That's not very low. I'm about 12" front and 12.5 rear and still have full travel

[I<3flippyheadlights]

If you have lowered your car, how do you have full suspension travel? if you drop your car an inch, you lose an inch. At least thats my logic.

[Tekel]

Oh, I see you have konis. I'm on ez streets with adjustable body.

[I<3flippyheadlights]

Is that how coilovers work? They can lower the car without eliminating the travel? That is pretty badass

And I would of went with coil overs but I got my koni's for 100 bucks and my springs for 60.

[kung fu jesus]

That is how a lot of the upper level coilovers work. On mine, the bodies thread into the lower mounts for height adjustment without detracting from the stroke. The fronts have an extra inch of adjustability because the lower mounts have an adjustable heim joint. The lowest I have taken my car was 10.75" in the front. I figured I had another 1.5" left. I measure off the pinch welds now and the car is higher that that now.

You would do your rear suspension a huge favor to run taller tophats in the rear with your current setup. slamming the shock bodies into the bumstops when they bottom out can damage them and cause them to leak.

[blenderblast]

This thread is surprisingly informative.

[I<3flippyheadlights]

This thread is surprisingly informative.

I KNOW!

And KFJ, I don't bottom out often... actually not at all. But it feels more "bouncy" in the back and I guess that could mean I'm hitting my bump stops. Its not that bouncy (like cut springs on a honda) but it is slightly noticeable when going over a few bumps.

[MazRoadAdmin]

OK, just trying to get the mindset.

Generally, that is a bit too much toe out in the front. The wheels will also toe out even more when the suspension is compressed. I am guessing the car is pretty sensitive to bumpsteer.

More camber in the rear than the front isn't too stable, especially with that much difference between the toe angles front and rear. I don't know Loren's numbers, so I can't compare his to yours, but if you have only an inch of suspension travel, you're defeating the mechanical grip of the suspension design.

Trying to match your static settings to his dynamic settings, I get that, but it is the wrong idea. Look at this site that shows you the camber curves at different heights:

http://www.virkki.com/jyri/miata/camber/
His front toe is a little aggressive, but still streetable. I'd have set it closer to 1/16-1/8 but our first test run was with it at 1/4 out and Gavin LOVED the way it felt, so I didn't want to take it all away. We're only talking 3/32" per side, which my trig calculator tells me is about 0.23 degrees.

More camber rear vs. front is a fairly typical Miata setup, and often more than 2/10ths. When someone comes to me with no idea what they want, and I know that they don't have a lot of performance driving experience, I generally set their car up to NOT oversteer. Hence a little bit more camber in the rear, and adequate toe-in. After he's had time to live with that for a while and can tell me whether or not it over or understeers, we can fine-tune it to his liking.

The graph you linked to doesn't make your point. The camber curve doesn't change with ride height. The CAMBER changes with ride height, that is by definition, the camber curve and it is determined by the geometry of the control arms.

That graph actually explains WHY I set his camber as aggressively as I did. Look at their default numbers. at 13.5" ride height (stock), if you have 1.5 degrees negative camber, at full compression (10"... I'd be surprised if you get that far with a bump stop, but we'll use that number) you'd have about -5.5 degrees of camber. (a little more in the rear than the front)

Now, if you change your starting ride height to 12", but kept the static alignment at -1.5, you only reach -4 degrees at full compression! To maintain a stock level of dynamic camber, you have to dial in more static camber BECAUSE the camber curve doesn't change.

At a 12" ride height with -2.5 static camber (as demonstrated by the nifty tool you linked to), you get -5.0 degrees at full compression. Still a little less than stock, but I don't recommend running much more than -2.5 degrees of camber on the street.

But, hey... suspension tuning is a mysterious black art... there's more than one way to tune a suspension. Feel free to do something else. :)

If you want to change the actual camber curve, you have to start monkeying with the lengths or mounting points of your control arms.

[bokehmon]

^... mind explaining the differences in caster?

I gotta agree with KFJ on this one - it seems a little off. Your alignment will differ to your suspension setup.

Saying that you don't lose travel when lowering could be mis-interpreted. You can only have as much "travel" (stroke) as you have room to the metal of the tub, otherwise your tire will bottom before the suspension.

[MazRoadAdmin]

Because I didn't need to adjust the front camber, I just checked the front caster and it wasn't too far out so I left it alone. If I had made adjustments to the front alignment eccentric bolts, I'd have tried to get the caster more even.

And it's true, your setup will determine your alignment requirements. In this case, his springs are actually not THAT stiff and he's on stock swaybars. So, body will roll pretty readily until it hits the stops (which is only about an inch of travel maximum). His dynamic camber requirements should be the same as that of a stock suspension.

Anyway, those are the choices that I made. You don't have to agree with them.

THE POINT of this thread was that when you lower your car, the FRONT TOE changes drastically. Gavin lowered the front of his car by about 2 inches, gained a bunch of static negative camber in the front, and as a result, his alignment was TOED IN massively in the front. That's why he posted this thread, to be sure people were aware of that. It happens every time, and anyone who lowers a Miata needs to know it... he didn't know, and he wanted to share that fact.

[kung fu jesus]

Thanks, Loren! I like to hear the reasoning. I'm not here to dispute it. Your explanation is very good!

The graphs show what the camber angles are at static and what they will go through travelling though their arc.
I am no means a suspension guru, but a lot has rubbed off on me through osmosis over the years. :)

The camber settings are very close to each other front to rear, so I don't really see a big deal. The toe settings are a bit odd, but now that I see you were trying to make the car understeer prone, I undertand. More in the rear, more than flippy's settings, have really bizarre characteristics at higher speeds. I am still trying to imagine what the toe settings set as they are will go through durning their travel

The danger, for the user, comes in when the rear shocks start getting into the bumpstops and bottoming out. That effectively overrides the springs and rates go from whatever the s-techs are to ∞. At that point, the alignment settings in the rear stop factoring and become static (they can't change anymore because the suspension isn't moving anymore).

There are others out there that are FAR more knowledgeable than I am in this stuff and would take everyone here to the wood shed on this stuff until our brains implode. :)

[I<3flippyheadlights]

This thread is now beyond the scope of my knowledge. I will sit back and watch. Thanks for chiming in Loren, I tried my best to explain what we did but, I didn't know all of it. :P

[VagaXt]

If you want to change the actual camber curve, you have to start monkeying with the lengths or mounting points of your control arms.

Actually, you effectively change the lower arm length by moving the eccentric bolts (the bolts holding the lower control arms to the subframes). Effectively, you change the camber curve that way.

[VagaXt]

And to the OP, at 11.5" fender-to-hub ride height in the front on your NA (based on your car info in your profile), I can see what you and Loren are trying to do with having your front toed out since he know that your car will have toe-in-induced change when you eat though your front damper (shock) travel whenever you load up your front suspension dynamically (under braking/cornering). However, I don't think it is necessary.

My concern is that Loren's assumption is purely contingent on you having sufficient bump travel in the front end. With you on Konis (spring preload adjustable ride height only), I assume you are losing some front bump travel lowering your car to 11.5".

Through personal experience at that front end ride height and using various Miata coilover setups, you will either be limited by damper bump travel (hit bumpstop) or the chassis itself (tire/wheel hitting the top of the wheel well). I am betting you will have the former situation. This will limit the amount of toe in you will have under load in the front end.

In regards to your front toe settings, I see anything other than 0 toe unnecessary for a performance street-going HPDE (track) car since I suspect the front tires your car will spend more time rolling with toe out. With 3/32th toe out per side (which is 3/16th total on the axle), it is acually a great auto-x setting since you get that quick darty steering feel, but at the cost of accelerated tire wear and a bit of rolling drag.

[MazRoadAdmin]

Actually, you effectively change the lower arm length by moving the eccentric bolts (the bolts holding the lower control arms to the subframes). Effectively, you change the camber curve that way.

You do, it's true. But, not very damned much.

[kung fu jesus]

Not much at the mounting point, a lot more out at the wheel.

[MazRoadAdmin]

Not much at the mounting point, a lot more out at the wheel.

I'm all for learning something. Please explain how much the camber changes due to adjustments at the eccentric bolts and how you came to the conclusion that it's a lot more at the wheel.

[kung fu jesus]

Are you being facetious? :P

[MazRoadAdmin]

Not really. You're stating facts as if you know something. Spill it!

(meanwhile, I'm searching around trying to find answers for myself, it's an interesting topic... and not a simple one)

[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/forum/grm/looking-for-a-good-base-camber-gain-curve-for-rear-irs/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. :lol:

[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 :blaugh2:

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.

[kung fu jesus]

Ooops! thanks!***checked it, its around 5 degrees of castor***

[MazRoadAdmin]

Ooops! thanks!***checked it, its around 5 degrees of castor***

On the rear suspension?

[kung fu jesus]

Gotta stop editing from my phone. :p

The rear doesn't have adjustable camber. Thank you, Loren!

[NAautoxer]

my car:
front: -2 camber, max caster (somewhere 4-5) 1/16 toe out
rear: -2.5 camber, 1/16 toe in.

wheel specs: depends.. 15x7 for track, 15x6 for street
ride height: higher than most.. i know, that doesn't help. hahahaa. FM springs and swaybars. nothing fancy, but it gets the job done.