Adjusting the adjustable suspension

[Tdave]

Has anybody done adjustments to the suspension in the Sport model, or the regular model for that matter? This is something I've been very interested in doing. I was going to have a race shop tune it, but have just started doing it myself by experimenting...

Coilover shocks: Set them all to the most firm. This is how I had Tesla set them from the factory, so I haven't compared this to any other setting. Car does feel nice and firm, and reminds me of the feel of my former 3rd gen Mazda RX-7. I'm happy with the firm setting. I'm just assuming this makes a worthwhile difference in handling.

Sway Bar: Loosened the front. Adjustable sway bar has three settings. Car comes from the factory using the middle setting front and rear. I changed the front sway bar to the loose setting and left the rear in the middle. Goal was to reduce the extreme understeer that the car has. I'm quite happy with the result. Car is more balanced, understeer lessened but still present (for safety). The extreme understeer seems to be gone.

I need to gain more experience driving with the sway bar change. The rear weight bias will mean the rear will be twitchy near the limit. I'm guessing that's why Tesla ships with some rather extreme understeer. Frankly, I found the understeer as it comes from the factory so extreme that I actually consider it unsafe, at least for the way I drive the car. I have enough track experience to be able to balance the oversteer if it starts to come on. At least I think so. I've been told by a Tesla rep that the extreme torque of the electric drive, if driven with TC turned off, can induce sudden rear wheel spin and near instant oversteer (spin out). With the sway bar change, this danger will be increased. I'll play with this in a safe place to see what I experience.

Anyone else?

[James]

My Tesla Sport is current getting serviced, so I just sent an email asking the local Tesla server manager to do exactly the same with mine.

I am not sure what setting it had from the factory. I will ask and report back on the changes.

[Tdave]

Just took it out for another drive to gauge the sway bar change. Nice! Really nice! Traffic circles make for good makeshift skid pads. I'd say about half (maybe more) of the understeer is removed by loosening the front sway bar. Now it handles much more like how a sports car should handle. And the gobs of power available coming out of the turn is far more useful when it's applied starting with a more neutral balanced car.

I definitely recommend the sway bar adjustment.

You could probably remove the rest of the understeer by tightening the rear sway bar. That may be useful for autocrossing, but probably too much for safe street driving. Sometime later I may try it to see its effect.

[Roger Reid]

Tdave

What is your definition of loosening the sway bar? Moving the link to the outer hole of the bar?

Thanks, Roger

[Tdave]

Yes, moving the link to the outer, rear-most, hole of the bar. When I say rear-most, that applies to the sway bar for the front tires. The front sway bar is much easier to access than the one for the rear. You can easily see the link and the holes by looking through the front wheels and just under the brake rotor.

[doug]

This thread could use some photos.

[Roger Reid]

I will take some pictures when I adjust my sway bar. But in the meantime here are a couple of links, one with a diagram.

LotusTalk - The Lotus Cars Community - View Single Post - Caster alignment (http://www.lotustalk.com/forums/1318767-post5.html)

LotusTalk - The Lotus Cars Community - View Single Post - Understeer reduction. (http://www.lotustalk.com/forums/1382666-post3.html)

I might add that camber adjustments should be for track use only because of tire wear for normal driving

Roger

[DaveF]

I have a couple of photos of the front bar being re-adjusted. The first is of the Driver's side front bar after the link has been disconnected - showing the 3 adjustment holes. The second is shot from the Driver's side showing the passenger side. The nut to be removed and the washer behind it are in the center of the photo.

Changing the front was easy without removing the wheels or jacking the car up. Turn the steering wheel to the right to do the driver's side and vice versa.
You will need 2 17mm wrenches or one wrench (open end) and a 17mm socket and ratchet. One wrench (or the ratchet) loosens the nut, the other wrench goes between the rubber boot and the sway bar to fit over the flats on the stud that is part of the swaybar link.

The rear is tougher to get to. I backed up onto 2 homemade ramps made of 2 2x6 boards stacked on top of each other. One is 2 feet long the other 1 foot. The ends are beveled to allow the car to drive up on them. It ends up with the rear raised about 3 1/2 inches (due to undersizing of US lumber). Otherwise the same as the front. Jacking up the car will not work, unless perhaps you have 2 floor jacks to jack up both sides at once. This is because you will put the bar in a bind if you jack one side up and then you cannot get the link out of the bar (trust me on this!).

Results follow from track testing at the MotorSport Ranch 1.7 mile track. First I did a baseline with the stock middle bar settings F/R. Best lap 1:32.7. Then I set the front bar to soft - using the hole at the end of the bar. Huge improvement with a best lap of 1:29.8. Then I stiffened the rear bar by moving the link in the opposite direction - further away from the end of the bar. The change was less dramatic than softening the front bar. Some bonehead pulled out of the pits in front of the Porsche I was following and ruined my planned hot lap. Since it was late in my track day I was only able to run a 2 to 3 laps before getting into reduced power mode and other traffic made a clean lap impossible - 1:30.8 best time. The next time I can run the 1.7 mile track CCW is next weekend. I'll try a couple of sessions then and decide whether to leave it as-is or soften the rear. The car felt much better after the first adjustment and some better after the second - but I want hard data before deciding. I'll also get tire temps and decide on the best tire pressures for the track and likely dial in a bit of camber depending on the temp readings - probably a street/track compromise. Then play with the shocks... Then some Hoosiers... Then figure out how to keep this baby cool for a 30 minute session.

[Tdave]

Thanks for the detailed writeup, DaveF. Please update us if you have more insight on settings, including the coilover settings. What were shock settings during the lap tests you did?

[DaveF]

Thanks for the detailed writeup, DaveF. Please update us if you have more insight on settings, including the coilover settings. What were shock settings during the lap tests you did?

Stock settings - 5 on all corners for my car. 40 psi rear/30 front. I did check tire temps this weekend and on a track run in the CCW direction, the cold pressures to give a flat temp profile across the tread looked to be about 30RF, 30.5LF, 31RR and 31 LR. I think the rear pressures were too low at that level given the rear weight and want to do some more testing to decide. The RF tire was badly in need of more camber with a 50 degree F hotter outside temp than inside.

I have not duplicated my 1:29s lap time and plan to put the rear bar back to the middle position with 40 psi rear/30 front to see if I improve from the 1:30s or if the variability is just my inconsistency. I have several hundred laps at this track mostly in a Viper but also in a Spec Racer Ford so I'd like to think I can run within less than a second per lap but I could be wrong - a pro I am not.

After the above test, I'll put the car on our alignment system and see where stock settings are on my car. I'll then fiddle with shock settings but my hunch is there will be more benefit in softer front springs.

Your original change to a softer front sway bar has been the single most positive change so far.

Regardless of the results, this is really fun! I have some cooling ideas to give me more than 3 hot laps before reduced power mode kicks in. With colder weather here, that issue may improve without intervention.

[doug]

DaveF, could you repost your photos? I have no idea why they're so tiny.

[DaveF]

DaveF, could you repost your photos? I have no idea why they're so tiny.

I will but I am (obviously) photo challanged. They are on my iPhone. What do I do to post them?

[DrTaras]

Totally a novice here, but I am greatly interested in understeer as I have been the victim of it in the past. When you buy the Roadster Sport they told me the suspension settings were set to "5" out of "10" and that you were entitled to one FREE change. When they change the settings do you know what they are referring to as it applies to the original post? Just shocks, or sway bar, etc? :frown:

[Tdave]

When you buy the Roadster Sport they told me the suspension settings were set to "5" out of "10" and that you were entitled to one FREE change.

That's just the adjustable coilover shocks setting. That's not the only part of the adjustable suspension. They should realize there's more to the suspension than just the shocks. I'm sure they'd adjust the sway bar as well for you. For you, and anyone really, the adjustment of loosening the front sway bar is a safe and worthwhile change. I highly recommend it. Just be more careful if you turn off traction control, as it's easier to induce oversteer with power when driving near the limit.

DaveF is still yet to play with his shock settings. I'm anxiously awaiting his findings. Right now his are all set to 5. And mine are all set to 1 (as I requested from the factory). Neither one of us have tried settings other than those.

[DrTaras]

Shock setting 1 is stiffer or softer? It obviously affects ride comfort, but does it affect over/under steer?

[Tdave]

Shock setting 1 is stiffer or softer? It obviously affects ride comfort, but does it affect over/under steer?

Tesla set mine at 1 when I told them to deliver my car with the stiffest setting. I questioned whether that was right when it didn't feel as stiff as my 3rd gen RX-7 R1. I couldn't find anything online to verify. I'd love someone to verify this for me or confirm. Right now I'm just trusting that Tesla was right and 1 is the stiffest setting.

[James]

My Tesla Sport came with the factory setting of 5.
When it was recently in the Seattle service center, I asked Carl to dial it into the firmest setting possible.

WOW !!!

The car feels so damn good driving compared to before. It was a nice sports car before, but now I feel like I am driving a fighter jet. This car is so damn tight driving through turns and around other cars in traffic.

Anyone with a Tesla Sport should do this.

I don't have enough experience with performance sports cars to describe what is actually happening with any technical details. All I do know is that my Tesla Sport feels amazing. I drove 4,400 miles with the factory setting before the adjustment. So I really can tell something different with the car now. And is a MUCH better feel on the road.

[Tdave]

So James, can you check what settings your shocks now have? Did they change the setting to 1?

And have you loosened the front sway bar yet?

[DaveF]

Correction to my earlier post: my shocks were factory set to 1 front and 10 rear. I thought they were all at 5 because the number facing out at each corner was 5. However, the shocks are read at the inboard side of the shock on my car. I say my car because they can easily have the bottom shock eye rotated 180 degrees. How to tell? On the fronts there is a very small red dot on the side of the mounting eye where the reading is taken - I have not had the rears off and can see no dot when they are mounted on the car. Another way to tell is to cycle the adjusting ring through the full cycle. That is a bit tricky if each shock is full against one of the stops as mine was delivered.

Second: 1 is the softest, not firmest setting. 10 is the firmest. I felt this was true through internet research (our shocks appear to be the PSS10 model) and verified it on my shock dyno (high quality Roehrig).

Third and most disturbing was that there was a post on another forum regarding a PSS9 Bilstein (9 position instead of 10) about a dyno test that showed the adjuster was close to useless with 8 settings the same for all practical purposes and only the firmest setting of 9 having any significant effect. I also saw a similar post on a PSS10 Porsche shock that showed complete and proper adjuster response. Unfortunately my dyno results were similar to the former PSS9 test . Settings 1 through 8 were virtually indistiguishable (tested at 4, 6 and 9 inches/second). Setting 9 increased rebound slightly and setting 10 made what I would consider a proper amount of change in rebound. Compression was changed very slightly but insignificantly at setting 10.

The shock force seemed quite high overall (which is why high speed bumps like traffic lane markers, potholes and other abrupt pavement irregularities are so harsh). I did not take the time to rate the spring but will in due time.

[Webbie]

Just got finished with the suspension settings. Front shocks now at 6 (were at 4), rears at 7 (were at 5). Both sway bars have been set to 3 (were at 2). Ride is a little harsh which doesn't bother me. Dramatic difference. Turn in is much smoother and more predictable. Balance is much better. Feels very flat and settled.
I recommend this if handling is more important to you than ride.

[James]

I switched my Roadster Sport back to the factory settings when I got new tires. I like the more quiet and softer ride.

My rear Sport tires were bald at 6,000 miles. So I replaced them with the standard Tesla tires. The tire roll noise is much more quiet now.

I left my two front Sport tires at the Seattle store in case someone needs replacements. They still have plenty of life in them.

[Tdave]

I left my two front Sport tires at the Seattle store in case someone needs replacements. They still have plenty of life in them.
Ooo, I'll take them. Seattle, eh? That's far away.

[Tdave]

Just got finished with the suspension settings. Front shocks now at 6 (were at 4), rears at 7 (were at 5). Both sway bars have been set to 3 (were at 2). Ride is a little harsh which doesn't bother me. Dramatic difference. Turn in is much smoother and more predictable. Balance is much better. Feels very flat and settled.
I recommend this if handling is more important to you than ride.
What's the sway bar 3 setting? Is that looser (outside hole) for both front and rear? Or something different?

Also, do we yet have confirmation whether the a setting of 1 or 10 is the firmest setting?

[Webbie]

What are the two tires you mentioned?
I have the shocks cranked on all my cars, and set the tires a few pounds above normal, too. I just like a harder ride, no sway, better steering and handling,and I figure most roads are pretty smooth anyway. I doubt this makes any difference in tire wear. You are not likely to get more than 10-15K on Yokohama AD07s, especially if you autocross as I do. They sure are sticky, though.

[Webbie]

Sway bar setting three is wider, but I wouldn't call it looser. Shock settings go from soft at 1 to hard at 10. I confirmed that with the Tech here, and I can certainly feel that it's true, too.

:-)

[Tdave]

While I have my car in for repair, I'm having the following settings done:

1) Shocks all on 10, as they currently are.
2) Front sway bar loose (outside hole), as it currently is.
3) Rear sway bar back to middle position, was on outside hole.
4) One full degree negative camber front, half degree in rear.

I considered increasing positive caster, but without power steering, I really don't want to increase steering effort.

[Webbie]

I'm seeing even tire wear for now, so I elected not to change camber.
May do it later after a coupe of autocross competitions.
Let us know how you like it, now or after trying it awhile.
We are lucky to have such an adjustable car with such a
simple power and drive train, eh?

[Webbie]

And, why did you move the rear bar back to the middle notch?

[Tdave]

And, why did you move the rear bar back to the middle notch?
I'm scared of oversteer. That's what caused my accident. Granted, the rear tires were brand new with only 10 miles on them when it happened, so they were slick, but still. That scared the hell out of me.

[Webbie]

OK, I will watch out for it. Felt some understeer and front tire scrubbing before the change. Driving on too much dirt and snow so far to push hard and be sure. Will definitely test it in autocross in April --better there than on the road anyway ( Ooooops! .... No problem). ;-)

[Roger Reid]

Well it it is finally warm enough to get my Sport out of the garage.

I attended the local SCCA autocross driving school yesterday. I am new to the sport, having only one event (last October) under my belt. Last October I reported understear and weak brakes.

Since last October there were three things I changed.

First I didn't charge the system to full performance mode. This allowed room in the battery for regenerative braking. At the end of the event I still showed 130 miles remaining.

Second I switched to Hawk H4 brake pads from Sector 111. A good change but still need heavy pressure to activate the ABS Chatter. The brake squeal of the stock pads is now gone.

Third I changed the front sway bar to the outer (soft) hole setting. The rear sway bar to the Inner (firm) setting. The shocks were set to position 9 (I only counted 9).

The results were great. There is still understeer in the skid pad (with traction control on) and by turning off the traction control I can finally induce some oversteer at full throttle. A welcome change (for track conditions).

I had a blast. Everyone there was amazed at the quickness and response between the cones. It was still the second time ever driving 4 wheels on a track (cones). My times were respectable and should get better.

I concentrated on smooth throttle input and had no power interuptions.

Autocross will teach you things that you can not (re: should not) do on the street. The if someone pulls out in front of you you have a better chance of staying out of an accident.

Roger

[TEG]

Thanks for that report! Sounds like great fun.


...I concentrated on smooth throttle input...

You might want to experiment with more dramatic inputs and try pushing your limits.
Someone once told me that you aren't trying hard enough unless you spinout once and a while.
In autocross you have nothing but cones to run into so you can take chances you wouldn't want to do on the track or street.

[Webbie]

"aren't trying hard enough unless you spinout"
True enough. But smooth curves and smooth inputs are still the rule -- you just push them further.
Some good rules: Slow hands make fast times. You have to know where to go slow to go fast. The fastest way around any corner that's more than 120 degrees is the shortest way. Brake before you turn.

With the kind of torque these cars have, you need to roll on the power when you are coming out of a turn, not floor it.

Here's a rule for clutch cars that we would have to modify: In a spin, both feet in. ;-)

Anyone with a roadster-- if you haven't been to an autocross, find one. It's the most fun you can have in a car safely. And that includes ... well ... never mind.

Question for y'all. What about charging in standard mode, then switching to performance mode just when you are running the autocross course? Maybe get the best of both?

[Webbie]

tdave got me thinking about oversteer spinouts.
Obviously, making an abrupt turn while on full acceleration is likely to cause a spin (that's not a criticism of you in any way, tdave -- just fact - you did well to steer around the idiot). Not so obviously, especially with our severe regenerative braking, abrupt steering while quickly lifting the foot from the accelerator can also cause a spin. the regen acts like a brake on the rear wheels only, like pulling the emergency brake. I learned that first hand at 90 mph in my m-coupe at the very top of third gear and wound up going backwards through the infield. Something for us all to remember, perhaps.

[Tdave]

Anyone use left foot braking during an autocross? Allows quick brake input without having to totally lift the accelerator, or for so long. That's standard in kart racing, which our Roadsters sort of ar .. nevermind, not going to say it. :-)

[Webbie]

Left foot braking in autocross.
We have a married couple in our area that have 27 National Championships between them.
She left-foot brakes. He does not. I think it is generally considered more useful for cars that have to keep their engine spinning in order to keep the torque up. Like karts. ;-)

[Roger Reid]

...smooth curves and smooth inputs are still the rule -- you just push them further.
Some good rules: Slow hands make fast times. You have to know where to go slow to go fast. The fastest way around any corner that's more than 120 degrees is the shortest way. Brake before you turn.

With the kind of torque these cars have, you need to roll on the power when you are coming out of a turn, not floor it....

Question for y'all. What about charging in standard mode, then switching to performance mode just when you are running the autocross course? Maybe get the best of both?

Agreed 100%. I did charge in standard mode and ran in performance mode. The only way for me to induce oversteer or spinout was full throttle without traction control. At no time did the car oversteer without my input and I could back out anytime.

It was great fun
Roger

[Webbie]

Seventeen days until my first autox with the Roadster. Gee, that's a long time.

A

[Tdave]

Got my car back yesterday, with some new suspension adjustments. So of course I had to go out during the evening for a 1+ hour drive. Wow, another great improvement. The car is just getting better and better with each tweak I do.

This latest big change was with camber. To adjust the camber you need to use shims, which is a bit more of a pain than just switching a bolt on the sway bar, or turning a ring on the adjustable shocks.

Stock spec camber settings from Tesla are:

Front: 0.0 degrees
Rear: -1.8 degrees

The spec range is:

Front: +0.01 to -0.03
Rear: -1.6 to -2.0

I wanted to dial in quite a bit more negative camber in the front, to improve cornering grip and get rid of more of the understeer without sacrificing rear grip with a tighter sway bar setting in the rear. To that end I moved the rear sway bar back to the middle hole, put more negative camber in the rear, and quite a bit of negative camber in the front. I was more confident with this change given the tire temperature readings that was posted above by DaveF, which proved the front definitely needed negative camber.

So this is where I'm at now with all my settings.

Adjustable Shocks: 7 in the front, 10 in the rear
Sway Bars: outside (loose) hole in the front, middle (stock setting) hole in the rear
Camber: -1.0 degrees in the front, -2.0 degrees in the rear

This was another significant improvement over only the front sway bar setting change, which was the previous big win. So this is big win #2, in my opinion. There's still some understeer, especially at very low speeds. And if I used the car only for performance driving, it could probably use 1.5 or 2.0 degrees of negative camber in the front. For now I'm happy with the -1.0 I have dialed in now.

I'm looking forward to more data and tire temp readings from autocrossers, especially if you also add as much or more negative camber in the front as I did.

[Tdave]

Drove over 100 miles today just for fun. More experience with my recently changed settings...

I don't know. I think it may have been a mistake to return the rear sway bar back to the middle hole. Leaving it tight, on the inside hole, may be better. I'm still not entirely sure though. The thing is that the understeer is still too much at low speeds (20-30), but not so much at 40-50. At those medium speeds the car corners pretty damn good. That's why I'm uncertain. Where I have it now may be a good choice, as higher speed handling is more important for safety.

[Webbie]

"understeer is still too much at low speeds (20-30)"

What tires are you wearing?

And,what the heck are you doing to induce understeer at 25? Donuts? ;-)

[Tdave]

"understeer is still too much at low speeds (20-30)"

What tires are you wearing?

And,what the heck are you doing to induce understeer at 25? Donuts? ;-)

Still the stock 60 wear rating Sport tires in front. Some new 180 wear rating tires in the rear.

25-30 mph on some relatively tight traffic circles (with no traffic in sight at the time). There's a medium sized one and small one close to each other that's good for this. Here's a satellite map (http://maps.google.com/?ie=UTF8&hq=&hnear=8727+Lake+Edge+Dr,+Savage,+Howard,+Maryland+20763&ll=39.146412,-76.905584&spn=0.004843,0.006877&t=k&z=17).

[kgb]

When you adjust these shocks, do you have to take the weight off the wheels, or can this be done with the car on the ground?

Same question for the sway bar.

[Webbie]

When you adjust these shocks, do you have to take the weight off the wheels, or can this be done with the car on the ground?

Same question for the sway bar.

My local Tesla tech says," When I did your adjustments I did jack the car up, but that was more for ease of access than anything else. You definitely don’t have to take the weight off the wheels when adjusting the shocks, and I don’t think it’s necessary for the sway bars either."

Webbie

[kgb]

Cool. I'll take a flashlight and try and report back.

[n8te]

My local Tesla tech says,"You definitely don’t have to take the weight off the wheels when adjusting the shocks, and I don’t think it’s necessary for the sway bars either."

Webbie

I can confirm this. I made both adjustments on my Roadster today. Shocks are 7F/10R and anti-roll bars are now front outer-most (loose) and rear middle. I'd say that 80% of the understeer is gone but there is still an understeer bias. Testing the new setup, I had to work hard to create oversteer (previously impossible) but the car was FAR better balanced.

The adjustment was very simple. I did it in my garage with a 17 mm socket and a 17 mm open wrench. No jack or lift. To adjust, turn the steering wheel fully to one side and hold the inside bolt still with the open wrench while you remove the outside bolt with the socket wrench.

The shocks are adjusted with a simple dial you can reach easily in the front and with the aide of a hand mirror for the rear shocks. Look for the orange dot below the dial. You might need to clean the base of the shocks and under the dial with a rag to see it.

[kgb]

@N8te, thanks that is a good explanation. I just checked the other day, and due to the low clearance, I couldn't even stick my fat head under the car to look. I'll try the wheel turning experiment (and mirror).

Also, I need directions to the front and rear stabilizer/sway/anti-roll bars. I popped the hood & trunk and for the life of me, couldn't see anything that looked like an "anti-roll bar." How much of the car needs to be disassembled before I'll see it?

[n8te]

Can't get my fat head under the car either, but that's ok because you won't need to. You'll take the entire car apart if you start from the hood and the trunk, so don't do that. You don't need to remove/dismantle anything to reach these parts and adjust them.

For the front anti-roll / sway bars (the only ones I adjusted), lie down next to the aft side of your driver's side front wheel and look across the bottom of your car at your passenger side front wheel. On the other side of your car, you will see a black metal bar that comes down from the body of the car just medial to the passenger side front wheel (you are looking at it from the other side of the car just so you know where it is). It will curve so it runs parallel to the side of the car, just a few inches inside of the wheel and just below the flat underside of the car. It will have three holes at the end of the bar and a bolt attaching it to the wheel that goes through the center hole. This is the anti-roll bar. When you see the three holes, you will know it is the correct bar (sorry if this sounds like some bizzare sexual reference, it is completely unintended). It connects the two front wheels. They are the same on both sides. I turned the wheel all the way to one direction to better access the bolt. I found it easiest to reach the bolt on the driver side with the steering wheel turned all the way to the left (working from the front of the wheel).

Using the 17mm socket wrench and another 17mm open wrench, remove the outer nut. The open wrench is needed to keep the inner nut from turning on the other side of the bar, right next to the rubber piece. When the outside nut is off, the bolt should be moved to the end hole and the nut tightened securely after the bolt is moved. I had to play with one side to set it to come loose from the hole, but the other popped out immediately.

You need the hand mirror only for the rear shock adjustment. Just look for the blue dial with numbers 1-10 of it at the base of the coiled metal springs. The stiffness setting corresponds to the number aligned with the orange dot BELOW the dial. If you are like me, you will turn it the wrong way the first time thanks to the reversed image in the mirror. The dial turns very easily. You don't have to force it at all. The difficult part is finding the blue dial and a path for your hand to reach it. The shock adjustment is much easier if you take off the wheels, but who wants to do all that?

The front shock adjustment dial is much easier to reach. Just turn the steering wheel fully to one side.

I hope this is helpful.

[Alan]

Hi Guys,

A diagram of the adjustable suspension is attached. For the front anti-roll bar could someone please confirm whether the setting to reduce the understeer (softer) means moving the bolt to the left hand side of the diagram or the right?

1154

Just want to be 100% sure before adjusting!

Thanks
Alan

[kgb]

Hi Guys,

A diagram of the adjustable suspension is attached. For the front anti-roll bar could someone please confirm whether the setting to reduce the understeer (softer) means moving the bolt to the left hand side of the diagram or the right?

1154

Just want to be 100% sure before adjusting!

Thanks
Alan

Great Diagram. Thanks for posting.

[Doug_G]

Hi Guys,

A diagram of the adjustable suspension is attached.



Hmmm... I wonder why my car didn't come with (a North American version of) that document? It's not a Sport but it does have the adjustable suspension...

[dwegmull]

Hmmm... I wonder why my car didn't come with (a North American version of) that document? It's not a Sport but it does have the adjustable suspension...
Same here. I wonder if that diagram is an initiative of the London store or a diference in policy / law from country to country...

[n8te]

On your diagram, to reduce understeer, move the front anti-roll bar bolt to the furthest left position. That is the "softest".

[kgb]

@n8te's post was very helpful. Early in this thread, most people wrote about stiffening the shocks and adjusting the front anti-roll bar 1st and then possibly the rear. Interesting to note that the semi-official position of Tesla is to leave the front alone and to only adjust the rear. That said, I thought I'd write a little something about adjusting the rear anti-roll bar.

The rear ant-roll bar has the same nut configuration. 17mm. Use socket on the outer nut, and stabilize the inner nut with an open wrench (I used a narrow vice grip). For the right rear wheel, lie down with your feet facing the front and your head just behind the tire. When you lift up your head to peer over the splash shield (undercarriage cover), you'll see the anti-roll bar, but sadly the nut will be facing away from you. With your left hand, slip the socket wrench over the nut (socket facing you). Although you can see, some of the work is done by "feel." Left rear was easier, since I'm righty and get to use my right hand.

I chose to follow the Tesla recommendations and left the front alone. I'll let you know how it feels later.

[kgb]

UPDATE:

First let me give you a little background to put this opinion into perspective... I don't consider myself a "gear head." First I found myself playing Grand Tourismo... then I went to the track a few times... the Tesla is my second sports car, the previous was a Mercedes SL55 AMG (my track car is a 1988 Toyota MR2 Supercharged).

I have a 2.5 Sport with the performance tires and it came as indicated in the EU spec sheet. All four corners set to 2 and the anti-roll bars in the center holes. I just finished setting the car to their settings: Front 7 anti-roll still middle hole, Rear 10 anti-roll in hole "3." I didn't take the car to the track yet... I will soon. However, just driving aggressively on some cloverleafs with TC off I found that I was able to do some throttle turns, but with TC on there was still some under-steer. I am satisfied with these settings and have no desire to play with the fronts. That being said, this car is also my everyday car. The shocks are too stiff for everyday driving. Now that I see how easy it is to change the setting on the shocks, I'm going to try out 1 in the front and 2 in the rear and see how that is...

This makes me wonder about all the reviewers who complained about the Tesla's handling. Did they drive the car with the comfort settings or the "sport" settings. I think they might change their opinion.

[kgb]

Another UPDATE:

When I adjusted the suspension to the stiffer settings, like some of the earlier posts in this thread, I wasn't sure I felt much of a difference. But now that I set the springs to 1 in the front and 2 in the rear, the car is so smooooooth. Much nicer for getting around town. So, if you use your car for everyday driving I can recommend these settings (leaving the rear anti-roll in the sport "3" position). Then, whenever I want to have fun, it is super-easy to just stiffen the springs.

[Roger Reid]

KGB, this is what I did to my Tesla Sport.

I softened up the front sway bar (outside hole).
Stiffened up the rear bar (inside hole).
This is easiest done by putting a jack under the lift point under the frame close to the rear of the door. This will lift both tires. Removing the tires makes it easier. see post 46 for other details.

Front shock set to mid (5).
Rear shock set to firm (10).

I also removed the abs sensor bracket and any shims on each front wheel hub and band clamped it to the a arm. This maximizes the negative camber. The bracket and shims are found by removing the 2 screws near the upper ball joint (use a breaker bar, they are tight). It still needs more negative camber but would require a machine shop to get it. Keep in mind that certain racing class rules (SCCA Super Stock class) prevent this bracket from being removed. Check your local regs. Removing this bracket or adding or removing shims (front only) will not affect toe in.

I installed Hoosier A6 205 wide front tires (20 psi). Stock front is a 195. No clearance issues. Stock size Hoosier A6 rear tires (22 psi). The car will need to be set up for the new tire size (it works with this tire combo). Iis on the touch screen menu and is explained very well on screen.

With all these modifications the car turns much better. I can now modulate the balance of the car mid turn with the throttle. The car is not biased towards oversteer yet.

One thing I have not tried yet is to remove the linkage to the front sway bar (allowed by SCCA rules). Removing just one link will keep the bar attached to one wheel so it won't flop around.

My son Blair has had great results at autocross so far and wants to take a national event in the spring. I'm getting set up with an enclosed trailer and portible generator. See you at the races.

Roger

[kgb]

I have additional input to this thread. I do not claim to have nearly the experience of Roger Reid, but I thought I'd add my experience.

Up until now, I've only driven my car around town. The best cornering we have here in Houston are the freeway ramps. I finally had the chance to do some autocross. I used the "official" Tesla sport settings. Front anti-roll bar is still in the stock middle hole, and the rear is in the 3rd (inner) hole. I set the front to 8 and the rear to 10. Front tires were stock Yokohama A048 at 32 psi and rear were Toyo Proxes R888 at 38 psi. (Now that I re-read Roger's post, I'm thinking I had the tire pressures too high... but the higher pressure in the back did help a lot with the understeer)

In any case, those settings were an EXCELLENT starting point. Problem was, it was my first autocross, and I only had 4 runs, so I didn't really get a chance to play with the settings. I would like to say there was absolutely NO understeer with these settings, nor was there any oversteer. Of all the cars I have ever driven, this was the best handling car I have ever driven. It was so surefooted. I have never felt so solid. I really liked the fact that I could do throttle steering with such precision. This was a really great car to autocross with. I wasn't planning on doing it again, but now that I did, I will definitely do it again.

Here's a video of my fastest (4th of 4) run.

http://www.youtube.com/watch?v=Nq_RIq02-Lo

[vfx]

That sure does look like fun! With that lens and speed those cones just look like little chocolate chips!

You might think about one frame from this vid as a new avatar for you.

[Mitrovic]

VERY nice!
How did you compare with the other cars?

[kgb]

Some guys there were running with racing slicks. My tires were street legal. I think the fastest time was 65 seconds. I fell in the middle of the pack. But the important thing is: I was invited by my brother-in-law who does this ALL THE TIME. The dance at the end of my lap was because I beat his best time by .06 seconds. :wink::biggrin:

June 5, 2011 Autocross Results (http://www.houston-bmwcca.com/portal/attachments/article/100/ax-results_110605.txt)

[Webbie]

Looks to me like you did pretty well. You brought your times down in every run, and wound up with a respectable time for street tires.
We could check with Roger, but I don't think your tire pressures are high for street tires. He may set low because he's running R tires.
If you are still getting some understeer, you could try more pressure in front. Often, the understeer is because the front tires are rolling
over onto their edges. You can mark them with chalk to check that. If the chalk is wearing off, you need more pressure.

I campaigned a Tesla Sport last year with shocks set at 6 front 8 rear and stock tires pressures at 30 and 40. Later I set the fronts higher and had less understeer.
I won my class with a 4th (on snow tires!) a third, two seconds and a first, and finished about middle of the pack overall -- maybe 30th out of 70, mostly BMWs.
We compare with PAX numbers, and the Tesla is heavily penalized by having a Super Stock PAX.

[S-2000 Roadster]

What are the torque settings when tightening all of these adjustable suspension nuts and bolts?

[richkae]

Have you had a wheel alignment done?
I'm going to be taking my car to an autocross sized track next week, I've been there 4 or 5 times before, but next week will be the first time since getting my alignment done.
( It will also be my first time on R compound tires and with better brake pads, I'm hoping for a huge improvement in my lap times )
The old ( factory ) alignment had massive amounts of toe-in and not enough negative camber in the front.
I'm not an expert, but my new alignment makes the car feel much more ready to turn - but it also feels a little less stable on the highway, the bad pavement and ruts make it drift around a little more, requiring more tiny corrections.
It seems likely that all the drag caused by the toe-in was designed to keep the car going straight.

[S-2000 Roadster]

Good question, richkae.

Could someone post alignment specs, both OEM and 'track'?

For my S-2000, I learned that Honda UK took the car around the track until they dialed in the alignment - to reduce bump steer among other things - and those alignment specs were published online. After a year or so with the default Honda US default alignment, I switched to the UK alignment and really enjoyed the car even more.

Sorry for the long story, but I am hoping that we can get similar public sharing of knowledge here. With the adjustable sport suspension, there are obviously more figures to track than mere alignment. So far, we seem to be accumulating great information on the adjustable suspension, so I'm hoping we can add alignment specs as well.

[richkae]

My car before the wheel alignment was done ( as it came from the factory plus almost 2 years of driving wiggling things ):

Left Front:
Camber:-0.55 deg
Caster: 4.58 deg
Toe: -2.6mm

Right Front:
Camber: 0.09 deg
Caster: 3.78 deg
To: 6.1mm

Left Rear:
Camber: -2.03 deg
Toe: 3.9mm

Right Rear:
Camber: -1.61 deg
Toe: 6.1mm


New specs ( I told him I wanted to make it perform on the track and still be good on the street, and that I weigh 180 pounds - its a left hand drive car ):

Left Front:
Camber: -0.85 deg
Caster: 4.52 deg
Toe: 0.1mm

Right Front:
Camber: -0.85 deg
Caster: 4.36 deg
Toe: 0.2mm

Left Rear:
Camber: -2.19 deg
Toe: 1.9mm

Right Rear:
Camber: -2.19 deg
Toe: 2.1mm

I don't yet have feedback to give on how it performs when pushed hard, and since I changed two other variables ( tires and brake pads ) it will be difficult to isolate improvements.

[Roger Reid]

Well, we took the adjustible suspension to the next level. I sent the shocks off to Bilstein for revalving. Blair just finished testing the new setup in the Winnemucca autocross (the other thread). So now the shocks are stiffer and slow the roll rate a little. We are still rinning the rear sway bar at full stiff and the front at full soft to balance the understeer. With modified shocks we are running the rear at setting 10 and the front at 6. Blair wants to try 8 on the front but my opinion is it will bring back some understeer.
If anyone is interested in the address of Bilstein in SoCal, let me know.

[Lloyd]

Sounds like a bigger bar on the rear would help, and possibly allow a better ballance of the front. Likely cheaper than custom bilstein's.

[Roger Reid]

Sounds like a bigger bar on the rear would help, and possibly allow a better ballance of the front. Likely cheaper than custom bilstein's.

Not within the SCCA rules for the SS class. Also the stock springs must be retained.

[Lloyd]

ah, yes, but would this be a better performance option for the 'street speedster' ?

[Doug_G]

My Tesla Ranger recommended shocks 7 front, 8 rear, roll bar outer (loose) front and middle rear. It looks like the factory setting for my car was 4/4/4/4 and middle/middle.

I just dialed in his recommended settings and took the car for a spin. Wow, it's quite a difference. Should have done this a year ago.

One thing I wasn't expecting - the steering feels lighter, especially at low speeds. Should I have expected that?

[speedy99]

Now my turn to play with settings. I am using the EU spec sheet as a guide (Thanks!). My 2.5 settings from the factory were as specified on the sheet (for AD07 tires - which I have) - Shocks 4-Front, 5-Rear, Anti-roll bar in center on front and rear. The shocks are TRIVIAL to adjust, once you know what to look/feel for. I had the benefit of looking at a Tesla on a rack a week ago at the Menlo Park store - so I could see the orientation of the shocks. You can peek through the ends of the car to see what setting they are on, then reach around and "click click" to adjust, and double-check the numbers when done. All I needed was a flashlight and about 10 minutes.

I have dialed in the "Factory Sport settings for AD07 tires" as a first step - cause I am lazy. This means no change to sways (slightly harder to adjust), but Front/Rear shocks at 7/8 instead of 4/5. I plan to do a bit of driving today (got the day off), to see the difference.

My second test will be to adjust the anti-roll bars. I'll look at loosening the front (move to hole on the "outside edge" of the bar), instead of stiffening the rear (per the spec sheet), since this mod seems easy, and is getting good reviews here.

For full disclosure, I am using the Tesla as a "daily driver", and I've done several dozen open track days in other cars, but fewer autocrosses, so I am looking for more mid-high speed stability, excellent turn-in, but with some comfort. As a "comfort" benchmark, I've had a few M3s (stock and modified suspensions) and a 911 with PSS9 setup, so "comfort" to me is relative. I like my suspension "confident", but not "rock hard". I could certainly stand for better turn-in and less understeer, and a bit more "confidence" on the shocks.

[Jaff]

I had Mark emulate your settings on my car...noticed a big difference right away...the car corners much better now!


My Tesla Ranger recommended shocks 7 front, 8 rear, roll bar outer (loose) front and middle rear. It looks like the factory setting for my car was 4/4/4/4 and middle/middle.

I just dialed in his recommended settings and took the car for a spin. Wow, it's quite a difference. Should have done this a year ago.

One thing I wasn't expecting - the steering feels lighter, especially at low speeds. Should I have expected that?

[speedy99]

This means no change to sways (slightly harder to adjust), but Front/Rear shocks at 7/8 instead of 4/5. I plan to do a bit of driving today (got the day off), to see the difference.

My second test will be to adjust the anti-roll bars. I'll look at loosening the front (move to hole on the "outside edge" of the bar), instead of stiffening the rear (per the spec sheet), since this mod seems easy, and is getting good reviews here.



The shock setting change had very little impact - as could be guessed based on previous posts. If anything, it is a bit smoother (ironic). This is because on freeways, the front end can get a bit bouncy over old expansion joints. The slightly stiffer settings seemed to have settled down the car a bit. I suspect this is because the springs are a bit stiff, so the suspension is a better match on the sport setting.

The tips on anti-roll bar (17MM (deep) socket and wrench) are spot-on. Really easy to crank the wheels over, and adjust the front sways from the rear side of the wheel. I just changed to loose setting for front (keeping middle for rear), and it is time for another test drive. I suspect this will make a bigger difference in handling.

As an aside, making the front bar looser, or making the rear bar tighter technically should have a similar effect. Since I am not worried about the car leaning when cornering, the front-loose option is a better/easier one for me...

I'll update again after the second test drive! Fun!

[Doug_G]

The shock setting change had very little impact - as could be guessed based on previous posts.

Yes, the effect of dialing the shocks is fairly subtle.


The tips on anti-roll bar (17MM (deep) socket and wrench) are spot-on. Really easy to crank the wheels over, and adjust the front sways from the rear side of the wheel. I just changed to loose setting for front (keeping middle for rear), and it is time for another test drive. I suspect this will make a bigger difference in handling.

Unless you are willing to jack the car up and remove the wheel, it is far easier to adjust the front. I can't comment on the relative effects of the front and back sway bars, but adjusting the front has a very noticeable effect.

Has anyone here tried adjusting both the back and front sway bars?

[Roger Reid]

My suggestions for the 2.0 or 2.5 with adjustible suspension is to start out with the front sway bar set at loose (outside holes).

The rear sway bar set to firm (inside holes).

Set the shocks up at 5 front and rear.

Set the tire pressure at the recommended street pressures (example 35 psi all 4 tires).

In general whatever you do to the left front, do also to the right front. The same goes for the rear.

In general whichever end you stiffen up, it will push more.

Stiffining up the rear will shift the balance of the car towards more oversteer whether done with the sway bar, shock, or tire pressure. Softening the rear has the opposite effect.

Stiffining up the front will shift the balance of the car towards understeer. Softening the front has the opposite effect.

Now go out and mark out a 60 foot radius skid pad in a safe empty parking lot where you won't get anybody mad at you. Enter the skid pad and start increasing your speed until you reach the maximum speed you can maintain. Either you will find out that the front end pushes (understeer) or the rear wants to spin out (oversteer). Go both directions to even out the tire wear and temperatures of the tires.

If in the case of understeer (most likely) you will want to stiffen the rear shocks 2 clicks at a time (remember both left and right) then test on the skid pad again. If you reach full stiff on the rear shocks, next soften the front shocks 2 clicks at a time then hit the skid pad again. If you still have understeer after changing front and rear shock settings, increase the rear tire pressure 2-3 psi then skidpad test again (6 psi max difference front to rear). Something to remember is that the heat generated by working the tires on the skid pad will increase the pressure in all tires until the tires cool off. If it still pushes, decrease the front tire pressure 2-3 psi.

If in the case of oversteer (not likely), do the opposite by adjusting the shocks first, tire pressure second (6psi max difference front to rear psi), then sway bar adjustments.

I hope this helps.

[speedy99]

I just changed to loose setting for front (keeping middle for rear), and it is time for another test drive. I suspect this will make a bigger difference in handling.

OK, front bar adjust is the "fix" that makes the most sense. Hard to believe what a difference such a small adjustment makes, but WOW!! Just got back from a nice "Skyline" drive. A few low speed (20-30) corners, and lots of sweeping mid-speed (40-60) twisties. The car is MUCH more neutral than before. I can get it to "set" in corners, and adjust with the throttle (I left TC on). Still a (slight) tendency to understeer, but not nearly as much as before. For me, this is a good thing. If I was doing competition/autox, I might be more extreme, but for my daily driver with occasional detours into the local hills driving at 8/10, I'd say this setup is just about perfect. It feels just as "comfortable" as before (tested on those pesky freeway expansion joints), but the handling is MUCH MUCH better.

To complete the picture/recap, I am also running the "sport" tire pressures (30F/40R), and have the AD07 Tires. Front shocks at 7, Rear shocks at 8. Anti-roll bar front at full soft (outer-most hole), and rear anti-roll bar at the middle setting. This is a 2.5 sport model with less than 1000 miles on it. Now that I've upped the fun factor, I am sure I'll be hanging out on the tire thread sooner than I expected...

Enjoy!

[Doug_G]

I hope this helps.

Indeed, very useful information. I'll have to see if I can find a place to use as a skid pad.

I did find by trial-and-error that I had to reduce the pressure in my fronts by a few psi. Otherwise the car would really plow in the corners. That was after the loose/middle and 7/8 adjustment. It made a huge difference.

Do you readjust your sway bars back to mild understeer when you aren't autocrossing? I've seen a comment elsewhere that balanced settings might make a car a little twitchy for street driving. After all it's one thing to mow down cones...

[SByer]

Darn! Now I really have to get the suspension upgrade!

And, if you 'Skyline' Sunday mornings at all, watch out for me so you don't wreck me and my other carbon fiber beauty. I'll be in the Chrome kit, so you'll know it's me. ;-)

[Roger Reid]

Doug

I dont change the sway bar settings between autocross and street driving. If anything I just soften the shocks.

Roger

[frequencydip]

Is the only adjustable suspension available the Sport suspension directly from Tesla? Can aftermarket Bilsteins either PSS10 or ASN be used as upgrades?

[Robert.Boston]

Is the only adjustable suspension available the Sport suspension directly from Tesla? Can aftermarket Bilsteins either PSS10 or ASN be used as upgrades?
Tesla built the suspension from scratch, so I would strongly doubt that any non-Tesla suspension currently available can be added. Of course, some aftermarket guys might come with an offering in the future.

[DrTaras]

I know its been over a year since this thread has been touched so I hope there are those who are still 'following' it...
There is no Performance Discussion (http://www.teslamotorsclub.com/forumdisplay.php/66-Performance-Discussion) for the Model S (maybe there should be), so I figured that guys who frequent this Performance Discussion (http://www.teslamotorsclub.com/forumdisplay.php/66-Performance-Discussion) may know a thing or two about DIY tweaking of cars in general. I know next to nothing! I have a Model S-Performance and know that through the user interface you can push a button for suspension to be soft, standard or performance. "Problem" is that on performance, I'd consider the suspension "soft" which, I know, is the intent of Tesla because those who want a car that insulates them from the road far out number those who want to feel it. BUT there are different strokes for different folks so I'll get to my question
... is there a Tesla-approved or non Tesla-considered (that would not invalidate the warranty) way to adjust the suspension to make it stiffer for the twisties? :confused:

I just cross posted this question in the Model S forum as well (here)
http://www.teslamotorsclub.com/showthread.php/12400-Further-(beyond-the-UI)-way-to-adjust-the-Model-S-Suspension-to-make-it-stiffer?p=244918#post244918