achievement unlocked: perfect alignment

[westwest888]

I had Alu Kreuz, solid endlinks, adjustable upper control arms, and lower control arm spherical bearing inserts installed on my car two weeks ago. I took a 1000 mile drive to LA last week and now that everything is settled, I needed to get the car aligned for the track on January 10/11.

I took the car to Custom Alignment in Mountain View. The owner Joe worked with me. He was on the pit crew for the 034 Motorsport Audi TT RS at 25 hours of Thunderhill, so he knows what he's doing when it comes to setting up an Audi for the track:

The driver side lower control arm bearing needed some lithium grease sprayed on it, because it was making a creaking noise. The upper control arms needed some loctite where the caster adjustment thread is. The front swaybar needed some preload removed from it.

They loaded the car up with 270 pounds of weights for a driver and passenger. There was about 10 gallons of gas in the tank, which is 60 pounds. My car weighs 3,812 pounds with no gas and no people. I opted to pay $90 to have them throw the car up on the corner balance scales, to see how well the factory set the car up and to adjust the swaybar preload (to zero). The cross weight is near perfect at 50.7%. I won't need coilovers or adjustable springs. Think of it like a table with 4 legs that wobbles. You can cut down legs opposite each other to get it level. The weight distribution is 56.1% front, 43.9% rear. There's not much you can do about that. The front left/right balance is 49.9%/50.1%. Not much you can do about that either but it's perfect.

Final alignment specs:

-2.6 degrees camber front
-1/8 toe out front (total, so 1/16 each side)
-2.1 degrees camber rear
0 toe rear (total, 0 each side)

I learned some other cool things like how (SAI - Included Angle = camber). Older suspensions used to have one link top and bottom. Now there's 5 links so there's a lot more motion and some of the "secondary angle" numbers are kind of theoretical. The max camber adjustment at the rear is -2.2 from the factory (we tried it).

The car handles like an absolute dream. I'm very happy with it.

http://i48.tinypic.com/2e0i9n6.jpg

http://i50.tinypic.com/1pxnjc.jpg

http://i46.tinypic.com/2dtnh3c.jpg

[ENV²]

Very nice! [wrench]

[PitchS4]

Seems like a ton of negative camber... What am I missing?

[Leor604]

Nice. Look forward to a track report after your next track day. I was VERY happy with the improved handling after AK and full USS. I don't know the relative stiffness of the USS bars vs the factory bars, but with the USS setup soft at front and stiff at rear, car no longer punishes the front tires.

How harsh/noisy are the spherical bearings? Still OK for DD use?

[westwest888]

Seems like a ton of negative camber... What am I missing?

I'm missing the writing that used to be on the sidewall of my tires. It's scrubbed all over turn 11. Not going to happen next time. In this photo the car is practically riding on the rim.

http://i49.tinypic.com/34sidyh.png

[westwest888]

How harsh/noisy are the spherical bearings? Still OK for DD use?

TBD. They got noisy then we greased them and they're quiet again. Let me beat them on the track and see what happens.

At highway speed they're perfect. If they're noisy, it's a low speed thing like 35 mph and under, or coming to a stop. But at the moment they're riding quiet.

[catch]

Great write up!

I dont think -2.1 is overly extreme, im currently running -2.7 camber, dosent look nor feel odd to me

[AQuattro]

needed to get the car aligned for the track on January 10/11.


Thunderhill? Post some video if you can!

[MrFunk]

That's great info man! Thanks for sharing!

[westwest888]

I lied: I think there's something you can do about the front/rear weight distribution. The front suspension is kind of like a bench press. If I were to, for instance, put a 20mm lowering spring like the Eibach pro on the rear of the car only (and retain the factory spring up front), the weight would shift away from the front. To what percent, I'm not sure. I think the best case would be 1.0-1.9%.

BMW is famous for doing this to achieve a 50/50 static weight balance. My 3 series rode very high in the front. Here's an example of a factory BMW:

http://www.toledoblade.com/image/2005/10/16/800x_b1_cCM_z/2006-BMW-M5.jpg

The people who lower the front to get a perfect "wheel gap" are actually shifting weight to the front.

[esz61]

I lied: I think there's something you can do about the front/rear weight distribution. The front suspension is kind of like a bench press. If I were to, for instance, put a 20mm lowering spring like the Eibach pro on the rear of the car only (and retain the factory spring up front), the weight would shift away from the front. To what percent, I'm not sure. I think the best case would be 1.0-1.9%.

BMW is famous for doing this to achieve a 50/50 static weight balance. My 3 series rode very high in the front.

The people who lower the front to get a perfect "wheel gap" are actually shifting weight to the front.

This is absolutely not true. F/R weight distribution has nothing to do with spring rates or ride height. It is exactly what it implies; the percentage of the car's weight that is supported by the front wheels vs. the percentage of the car's weight supported by the rear wheels. If you were able to saw the car in two pieces precisely at the midpoint of the wheelbase, you could weigh each piece to determine how much weight is supported by each set of wheels (as well as determine the % weight distribution). If you want to change the weight distribution, you would have to physically move weight from one piece to the other. Car manufacturers achieve this by locating things (engine, transmission, etc.) in places that will enhance weight distribution or by making components lighter (e.g. aluminum block engines) that would otherwise have a negative effect on weight distribution. Weight distribution is one reason that Audi located your battery in the trunk.

A person could, of course, achieve 50/50 weight distribution in a nose-heavy car by throwing some sandbags in the trunk, but then the car's overall weight would increase and slow it down (among other things).

[AQuattro]

^ word

Grassroots has a good write up on corner balancing and weight distribution.

http://grassrootsmotorsports.com/articles/understanding-corner-weights/

[westwest888]

This is absolutely not true. F/R weight distribution has nothing to do with spring rates or ride height. It is exactly what it implies; the percentage of the car's weight that is supported by the front wheels vs. the percentage of the car's weight supported by the rear wheels. If you were able to saw the car in two pieces precisely at the midpoint of the wheelbase, you could weigh each piece to determine how much weight is supported by each set of wheels (as well as determine the % weight distribution). If you want to change the weight distribution, you would have to physically move weight from one piece to the other. Car manufacturers achieve this by locating things (engine, transmission, etc.) in places that will enhance weight distribution or by making components lighter (e.g. aluminum block engines) that would otherwise have a negative effect on weight distribution. Weight distribution is one reason that Audi located your battery in the trunk.

A person could, of course, achieve 50/50 weight distribution in a nose-heavy car by throwing some sandbags in the trunk, but then the car's overall weight would increase and slow it down (among other things).

In your opinion, what would this read on the corner scales? I still believe raising the car an inch in the front (or lowering it 1" in the rear) would change what those scales say. I also think the M5 V10 case is valid - putting an extremely long heavy engine in front and getting a 50/50 weight balance can only be achieved by setting spring seat height.

EDIT: looks like that old M5 was 53/47.

http://images.publicradio.org/content/2009/04/30/20090430_lowrider_4_33.jpg

[Akatsuki...]

Great write up!

I dont think -2.1 is overly extreme, im currently running -2.7 camber, dosent look nor feel odd to me

catch what suspension are you running? and do you street? -2.7 i am thinking may be too much for a daily driver / occasional track day car for me.

[s4nAri]

[QUOTE=westwest888;8311291 I needed to get the car aligned for the track on January 10/11.
[/QUOTE]

What track event are you going to?

[westwest888]

What track event are you going to?

Audi Golden Gate @ Thunderhill. It was like half price for winter. I guess the track rental is cheap because it's going to be freezing in the desert. It's like 35 degrees there as I write this, with a high near 50.

[AQuattro]

In your opinion, what would this read on the corner scales? I still believe raising the car an inch in the front (or lowering it 1" in the rear) would change what those scales say. I also think the M5 V10 case is valid - putting an extremely long heavy engine in front and getting a 50/50 weight balance can only be achieved by setting spring seat height.
http://images.publicradio.org/content/2009/04/30/20090430_lowrider_4_33.jpg

Since the front wheels aren't touching the ground 100% of weight will be on the rear axle.

Did you read the Grassroots article? The only way to shift the front to rear or left to right balance is to move the center of gravity. This is well documented, Milliken's book is a good read if you want to learn the science behind it.

BMW achieves nearly 50/50 weight through good component location. The light weight V10 engine is mounted far back and they use a heavy rear drive assembly.

[westwest888]

I think we're in violent agreement. If you change the height of the rear of the car, you would lower the cg and move it back ever so slightly. I would expect the scale to read something like 44.4% rear if I changed the rear springs to a shorter spring. Overall this probably isn't worth it.

It's interesting to see what the alignment does when you do various things to the car. When we removed the passenger weight from the front seat, the balance got slightly worse (43.8% rear) and the swaybar took on some preload (50.7% left from 50 even). When we jacked up the front of the car to adjust the caster, the front camber melted away back to -1.5 or something. You could imagine if you were going around a track and the inside wheels was barely touching the tarmac.

[ilspazzaneve]

I'm missing the writing that used to be on the sidewall of my tires. It's scrubbed all over turn 11. Not going to happen next time.

Lol, you and me both brother. Definitely like where your alignment ended up...keep us posted.

[AQuattro]

I think we're in violent agreement. If you change the height of the rear of the car, you would lower the cg and move it back ever so slightly. I would expect the scale to read something like 44.4% rear if I changed the rear springs to a shorter spring. Overall this probably isn't worth it.


I think the height change required to get any meaningful weight shift would create bigger problems which is why its not considered a viable method of changing F/R distribution. My quick math says you'd have to raise one side about 7 inches to get a 1% weight shift to the other.

[CircuitTested]

Wildwest888, alignment settings look good. Might notice a bit more tramlining on the highway but who cares.

Remember, 50/50 distribution is not always ideal. Considering where the mass is located in this car it's also going to be detrimental to the handling characteristics to force it into 50/50 compliance. Just look at the distribution on a 997. Better that it's on the back but still highlights the importance of proper engineering and suspension setup over even distribution.

[westwest888]

Wildwest888, alignment settings look good. Might notice a bit more tramlining on the highway but who cares.

Remember, 50/50 distribution is not always ideal. Considering where the mass is located in this car it's also going to be detrimental to the handling characteristics to force it into 50/50 compliance. Just look at the distribution on a 997. Better that it's on the back but still highlights the importance of proper engineering and suspension setup over even distribution.

I tram lined an actual trolley line. Highway is fine, though. I can still drive the car without my hand on the wheel. I think that's the AK. Keeps it dead center even over joints.

http://www.bridgeandtunnelclub.com/bigmap/outoftown/california/sanfrancisco/muni/10car1050.jpg

[esz61]

In your opinion, what would this read on the corner scales? I still believe raising the car an inch in the front (or lowering it 1" in the rear) would change what those scales say. I also think the M5 V10 case is valid - putting an extremely long heavy engine in front and getting a 50/50 weight balance can only be achieved by setting spring seat height.

EDIT: looks like that old M5 was 53/47.

http://images.publicradio.org/content/2009/04/30/20090430_lowrider_4_33.jpg

westwest888 - Raising or lowering one end of a car with respect to the other end does not effect the static weight distribution. Your statement that "I also think the M5 V10 case is valid - putting an extremely long heavy engine in front and getting a 50/50 weight balance can only be achieved by setting spring seat height" is incorrect. 50/50 weight distribution can only be achieved by putting 50% of the car's weight over the front wheels and 50% of the cars weight over the rear wheels. The effect that gravity has on a stationary object is not a matter of belief or opinion, it's a matter of physics and fact. However, a person may "believe" whatever he or she wants to (but that still doesn't change the facts).

[westwest888]

When you change caster, you effectively change the distance between the contact patches of the front and rear tires (ever so slightly). When you change ride height at one axle, you change center of gravity on two axes.

Your calculations are for dead weight on the ground. Mine are for a sprung car with ADJUSTABLE connection points to the ground. Namely, the 5 links up front the 5 links at the rear. I'm asserting that the spring collar (or spring height) is indeed a 6th connection point. We're not talking about much, but a few tenths can be sent back/forth side/side or cross by pulling on these links.

[well_armed]

Think about it from a two axis scenario, say a dirt bike stripped down to just the frame, wheels, suspension, and engine mounted.

Now change the mounting position of the engine --> more forward in the chassis, towards the front wheel. Now jack up the bike's front end to get it back to 50/50 weight distribution.

Do you think that character of the bike has changed in any way?

[esz61]

When you change caster, you effectively change the distance between the contact patches of the front and rear tires (ever so slightly). When you change ride height at one axle, you change center of gravity on two axes.

Your calculations are for dead weight on the ground. Mine are for a sprung car with ADJUSTABLE connection points to the ground. Namely, the 5 links up front the 5 links at the rear. I'm asserting that the spring collar (or spring height) is indeed a 6th connection point. We're not talking about much, but a few tenths can be sent back/forth side/side or cross by pulling on these links.

OK, this is my last response (and I'm only doing it because it's a little fun and I like the math):
1) When you say a few tenths, you mean a few tenths of what? If all your talking about is a few tenths of a percentage point, that would not be enough to allow BMW to achieve ideal weight distributions as you alluded to earlier.
2) F/R weight distribution is a measure of (as you put it) "dead weight on the ground" where the tire meets the road. It has nothing to do with connection points.
3) Our S4's have a 110.7" wheelbase and you said your weight distribution was 56.1/43.9 (F/R). By my calculations, If you raised the front end of your car (or lowered the rear end) 2", you would move the center of gravity towards the back of the car by 1/4" and change the weight distribution to 55.9/44.1 (F/R).
4) If you wanted to achieve a 50/50 weight distribution in an S4 by changing ride height, you would have to raise the front end (or lower the rear end) 24". I don't think that's how BMW did it with the M5, I'm sure they just engineered it with the weight in the right places.

[Tomasz@Startup]

You write TOE OUT, but your sheet shows TOE IN....

[westwest888]

Negative toe == toe out. The "final" number is the one you want to read.

[s4buckeye]

Audi Golden Gate @ Thunderhill. It was like half price for winter. I guess the track rental is cheap because it's going to be freezing in the desert. It's like 35 degrees there as I write this, with a high near 50.


Lol, Thunderhill is not in the "desert."

[westwest888]

Yes, I did have a goal of maximum caster first. I didn't really have a target. If they could get 7 or 8, awesome. But the cards were going to fall wherever they may.

Any place that is dry, needs tons of irrigation to do farming, has crazy wind, and has a daily temperature swing of 60+ degrees is a desert to me.

[Tomasz@Startup]

You are right regarding toe, and actually your original post is quite valuable. I am seriously considering adjustable control arms as 1.2 degrees of camber up front seems too little. Unfortunately my track day was wet, and my pyrometer was out of batteries to measure tire temps. But by wear I can tell that I need to be closer to your specs, than what I have now.

Tomasz

[westwest888]

I got a pyrometer and finally started playing with tire temps and tire pressures. I was able to get very even outside edge to inside edge temperatures with this camber setting.

[westwest888]

I'm going to get another alignment done for 2014:

-2.7 degrees camber front
-1/16 toe out front (total, so 1/32 each side)
-2.2 degrees camber rear
0 toe rear (total, 0 each side)

The big difference is slightly less toe out in front. It caused slightly premature tire wear on the front left tire - I just noticed some cording. I'm sticking with zero toe in the rear because this is a high horsepower car - applying throttle in a zero toe situation will make the car rotate because the wheel will "toe in" under force.

The negative camber is working great. Adding 1/10 of a degree on each axle if I can. I think the stock rear is good for -2.2 and then I'll add -0.5 for the front (-2.7 total) to create an oversteer bias.

I have the Eurocode sways set to stiff at the front and rear.

[rs4dreams]

Don't you mean that the rear wheel will "toe out" under force? Toe in doesn't promote rotation.

[drob23]

I'm going to get another alignment done for 2014:

-2.7 degrees camber front
-1/16 toe out front (total, so 1/32 each side)
-2.2 degrees camber rear
0 toe rear (total, 0 each side)

The big difference is slightly less toe out in front. It caused slightly premature tire wear on the front left tire - I just noticed some cording. I'm sticking with zero toe in the rear because this is a high horsepower car - applying throttle in a zero toe situation will make the car rotate because the wheel will "toe in" under force.

The negative camber is working great. Adding 1/10 of a degree on each axle if I can. I think the stock rear is good for -2.2 and then I'll add -0.5 for the front (-2.7 total) to create an oversteer bias.

I have the Eurocode sways set to stiff at the front and rear.

Given how much you've tuned your setup and all the tracking, I'm surprised you haven't gone for an adjustable suspension. Maybe some PSS10's or KW V3's with adjustable rebound and compression along with adjustable ride height for proper corner balancing.

[westwest888]

Given how much you've tuned your setup and all the tracking, I'm surprised you haven't gone for an adjustable suspension. Maybe some PSS10's or KW V3's with adjustable rebound and compression along with adjustable ride height for proper corner balancing.

I could. I like to wear a part out before I replace it. In another year or so the dampers will start to show a big performance degradation. Then I'll think about a replacement. The best coilovers out there are the TTX36. http://www.audizine.com/forum/showthread.php/543524-stage-4-coilover-suspension

I like having my ground clearance for now. It's needed on a lot of the steep approaches in SF.

http://www.worldofstock.com/slides/TAC1835.jpg

[westwest888]

It costs a couple hundred bucks, but getting a performance alignment at a motorsports shop is important if you've got aftermarket parts. Some of the bolts on my lower control arms were loose. The spherical bearings take a lot of road vibration and can loosen up bolts even when you torque them. Other shops didn't notice this. I didn't put the car up on scales this time but I suspect it's exactly 3800 pounds with no gas.

I got the car aligned because I put four new pilot super sports on it. The car ending up toeing itself out over the course of the year. The rear went from 0 toe to toe out. The front went from mild toe out to lots of toe out, which corded my inside right tire. An alignment check every 6 months might not be a bad idea for me.

A proper alignment requires that they inflate the tires to 41 PSI, put weight in the driver's seat to simulate you sitting in it, they should set the preload on the swaybars to 0, etc.

Final:

[front]
6.3 caster
-2.6 camber
-1/16 toe (out)

[rear]
-2.2 camber
1/16 toe (in)

http://i39.tinypic.com/23uezja.png

http://i43.tinypic.com/9gisn5.png


Milltek non resonated exhaust, and sport diff:

http://i41.tinypic.com/m9w1u9.png

Eurocode sway and front lower control arm with spherical bearings:

http://i43.tinypic.com/9knrsn.png

My new rear JHM two piece rotors and Pagid RS19 pads:

http://i41.tinypic.com/10wi4w2.png

[raudiace4]

LOL so raising and lowering one end of a car on opposite ends changes static weight distribution. [facepalm]

[westwest888]

LOL so raising and lowering one end of a car on opposite ends changes static weight distribution. [facepalm]

That's the funny thing about a sprung car. The scales read something different if the front is 26" off the ground and the rear arches are 25" off the ground, or vice versa. The spring perch height and spring rates make a difference to how the car "sits" on each "foot" at rest.

You are correct that if you put the car on jack stands under the frame rail the static weight distribution cannot change. Unless you slid the jack down the frame rail and put a scale under it.

[damndante]

So how about an update on increase road noise/livability of the spherical lower control arm bushings?

I'm looking at doing coilovers (still deciding which), eurocode adjustable control arms, and possibly the spherical control arm bushings (already have Eurocode alu Kruez, sways, and control links, MPSS 255/35/19, luv them all).
I can handle some noise but not alot, its still my daily driver with 1:30 round trip commute.

[westwest888]

High mileage and sphericals are probably a bad idea. They use rubber because it easily lasts over 100,000 miles. The sphericals are very streetable but require frequent inspection and tightening of the lower control arm bolts. The metal on metal vibration loosens them. You'd only do this if you're pretty serious about going to the track > 10 days a year.

[jazza08]

Quick question, our cars understeer by nature, wouldn't you prefer a zero toe at the front and a small toe out at the rear? Sure the car will wonder about on the highway a little bit but it'd be much better for our handling characteristics?
Oversteer > Understeer

[F40LM]

Too bad your car still can't do this at 1:50:

http://www.youtube.com/watch?v=q8sVDenpPOE

[rs4dreams]

Too bad your car still can't do this at 1:50:

http://www.youtube.com/watch?v=q8sVDenpPOE

I remember that video... Whatever happened to that?

[F40LM]

I remember that video... Whatever happened to that?

I am not sure but there are existing electromagnetic suspensions I believe the Zr1 has one.

Sent from my SCH-I545 using Tapatalk

[damndante]

High mileage and sphericals are probably a bad idea. They use rubber because it easily lasts over 100,000 miles. The sphericals are very streetable but require frequent inspection and tightening of the lower control arm bolts. The metal on metal vibration loosens them. You'd only do this if you're pretty serious about going to the track > 10 days a year.

Thanks for the feedback westwest

I guess I can always add the spherical joints later (if I feel the need), but was looking for any labor overlap with coilover install.
When you say "very streetable", can you talk about the before road noise vs after road noise.
Also can you talk about before handling vs. after handling.

I understand they won't deform, but do you notice a large difference in handling as a result.
And if I drive 11K a year, how often would I want to do "frequent inspection and tightening of the lower control arm bolts."

[westwest888]

Thanks for the feedback westwest

I guess I can always add the spherical joints later (if I feel the need), but was looking for any labor overlap with coilover install.
When you say "very streetable", can you talk about the before road noise vs after road noise.
Also can you talk about before handling vs. after handling.

I understand they won't deform, but do you notice a large difference in handling as a result.
And if I drive 11K a year, how often would I want to do "frequent inspection and tightening of the lower control arm bolts."

The handling is dead on when the suspension is loaded on one side. You don't really get to corner at 1G on the street, so you'd never know. Normally your alignment deflects as all of that force goes into the rubber pieces in the suspension.

It makes some creaky noise pulling into a parking spot, like slowly opening an old barn door on a hinge or something. It may make some noise while moving but you can't hear it in the cabin or over the tire and engine noise. You can hear it in my GoPro videos when I have the camera mounted near the front wheel.

I get the car inspected 4-5 times a year before each event. Once a year I get the alignment checked and everything is usually loose and needs tightening.

[westwest888]

Quick question, our cars understeer by nature, wouldn't you prefer a zero toe at the front and a small toe out at the rear? Sure the car will wonder about on the highway a little bit but it'd be much better for our handling characteristics?
Oversteer > Understeer

I don't really get the understeer sensation, as long as throttle pressure is being applied. No alignment will fix being gun shy of the throttle in a nose heavy car. You simply have to be positive throttle to coax the car around a turn.

Mild toe out in front helps the car start a turn. Mild toe in at the rear helps with high speed stability (and predictability).