[D.Yooras]

Originally Posted by vrooooom

May I know how this is re-clock? Which bushing? I don’t think the installer did this.

You'd have to ask them if they loosen and torqued all the pivot bushings.

In the front it's easy because it's only one #10 inboard side

F87 Front Suspension

If you take the rear suspension it would be any of the arms that have "rubber bushing" in the name. So that would be #4,5,and inboard side of #3

F87 Rear Suspension

It's not really a safety thing as much as it is a longevity/maintenance aspects. If the bushings remain with residual deflect/twist while the car is stationary or driving with minimal acceleration, they will wear out much faster. That's why any time I install coilovers or lowering springs I re-clock all the rubber bushings. Most shops don't even know you need to do this so it's highly common they miss it. Irony of it is, if the shop doesn't re-clock the bushings, they get sell you control arms far sooner than if the car remained stock.

In other words, if they don't know what re-clocking is, or didn't do, you can't fault them too much. It's rare that it gets done at all but I would insist they do it if they didn't in the near future.

[vrooooom]

In other words, is it like saying the rubber bushing is already set from stocks in an angle (say 4 o’clock) and when the new coilover is installed, it’s now forced to be at 3 o’clock. Which would add some more unnecessary rotational stretch to it? Like a watch’s coil spring.

If so, wouldn’t it be ideally done while the wheels are on level ground position and not hanging down?

[No_curebimmer]

Originally Posted by vrooooom

Finally took the leap and had B16 installed. –12mm on all four. Set at 4F and 2R from the shop. Not sure why but I’ll be trying out diff settings when I get a chance anyways.

Sweet, awesome to hear! Did you get an alignment too or are ya gonna wait till they’d settle?

PS I find that 4 on the soft side, and 2 is almost Lexus-like soft, so if you don’t ‘feel’ much of an improvement vs OEM, clock up the settings to at least 5 all around (higher-firmer), that seems the sweet spot compression/rebound setting for many daily drivers. Basic rule of thumb I found is to have the rear slightly softer than front (helps w/ traction). I’m running 6F and 5R and I love it! Beauty is that you can make these adjustments in a jiffy, the only downside is that your clothes will be dirty as you lie on the ground reaching for the adjustment knob. 💁

[vrooooom]

Yeah I read about the ease of adjustment and boy I was a bit disappointed as you really need to reach in from the back. Short arms. Changed the rear to 4, making it 4 all around and took it on a canyon ride. I probably need to turn the front wheel for easier access right? On one of my turns, the rear kicked out. A little scary but seriously fun. I guess making the rear a little softer than the front should help with those surprises?

[vrooooom]

Yes will wait for it to settle before I bring it for alignment. Myb a month.

[vrooooom]

Originally Posted by D.Yooras

You'd have to ask them if they loosen and torqued all the pivot bushings.

In the front it's easy because it's only one #10 inboard side

If you take the rear suspension it would be any of the arms that have "rubber bushing" in the name. So that would be #4, 5, and inboard side of #3

For the front, do I need to get the Bolt #14 also?

For the rear, what about those joints #11? and #2 (ball joint).

Thanks for mentioning this and no, they didn't do this and I've already driven it a good full tank.

[FaRKle!]

Originally Posted by vrooooom

For the front, do I need to get the Bolt #14 also?

For the rear, what about those joints #11? and #2 (Bushing also).

Thanks for mentioning this and no, they didn't do this and I've already driven it a good full tank.

You only need to reset rubber bushings, some of the items you marked are ball joints that don't need it (14, 11, 2, 6).

[D.Yooras]

Thanks for the assist Farkle, been busy with holiday season and the like. That's correct, it's only the rubber bushings that need to be reset/reclocked so you can disregard the mounting points on the list he made.

[D.Yooras]

Originally Posted by vrooooom

Yeah I read about the ease of adjustment and boy I was a bit disappointed as you really need to reach in from the back. Short arms. Changed the rear to 4, making it 4 all around and took it on a canyon ride. I probably need to turn the front wheel for easier access right? On one of my turns, the rear kicked out. A little scary but seriously fun. I guess making the rear a little softer than the front should help with those surprises?

When it comes to adjustable dampers the thing to remember is that you're adjusting the speed at which the suspension is able to travel using hydraulic fluid dynamics to regulate the movement. In laymans terms, your adjusting the valve on a garden hose, the further you turn up the adjuster the more the flow is restricted (in both directions).

There are two directions of movement and two rates/speeds of travel:

Bump (compression) travel
Rebound (droop) travel

Low speed compression/rebound
High speed compression/rebound

The adjuster on the Bilstein dampers adjusts low speed compression and rebound together in the same direction (more damping=higher number). Technically this isn't the best way to do things because usually a properly tuned car will run significantly more rebound damping than stock (due to super stiff springs) and equal or less compression damping than stock. Also, that adjuster mainly affects low speed movement (setting the car into a corner) but has minimal affect on the way the suspension handles bumps and drop-aways. When the rate of movement becomes high enough there is a bypass section of metal shims that open allow the oil to move through in large volume. At that point, the effect of the adjuster is so minimal it's not worth talking about.

With the baseline aside, the adjuster on Bilstein dampers can greatly affect the handling characteristics of the car (more than most would give them credit for). When you make one axle stiffer than the other using the adjuster, generally speaking, that axle compresses at a slower rate in a corner than the other. That means the weight transfer on that axle will happen faster relative to the other axle and the lateral load transfer will be achieved faster.

For example, that means if you were to take the rear axle, turn the adjuster all the way up, and the front all the way down, you'd have a car had a sloppy feel in the front end on corner entry leading to significant tendency towards oversteer throughout the corner until corner exit. That would leave you with a car that had a moderate oversteer bias.

Reverse this example and the front end would have tremendously tight feeling corner entry but would the rear would be sloppy/unreactive and the overall balance would be pretty significant understeer. Nether of these example would work very well.

Now for the setup that will. On most BMWs slightly to moderately stiffer in the front than the rear is where most people end up for a couple of reasons.

Without writing a long comment, BMW uses strut front suspension which means it doesn't play by the same rules as a double wishbone. So all the information in those tuning books doesn't always work the way it would on a properly designed racing chassis.

You will NEVER have too much front grip because the strut suspension will not be able to out-grip the rear in a neutral cornering situation. BUT because the rear axle is the driven one, you CAN overwhelm rear grip by applying more torque than the rear axle can handle while cornering.

So the goal on these cars is to maximize front grip, then adjust rear grip to match how you want the car to handle and be balanced. This is usually done by running a stiff front axle (both springs and anti-roll bar) to balance body roll vs lateral load transfer. Then the rear grip is adjusted to match the desired balance through springs and damping (generally stock or significantly smaller rear anti-roll bar, springs vary).

My tuning advice is to leave the rear at the recommended setting and tune only the front adjusters until you've found the best front characteristics. Then adjust the rear until you like the way it balances with the front adjustment. Once you've found the balance you like, then you can turn both up/down at the same rate to retain the balance but make the whole car softer/stiffer.

[vrooooom]

I’ve read the above post a few times and all I’m getting is to run the front with more clicks than the rear. But when you consider that first example of extreme setting differences of max stiff in the front and soft in the rear, one would end up with UNDERSTEER. So this 6F /4R would be towards an understeer? Or I should ignore that first 2 examples of extreme settings since that’s more for a double wishbone suspension?

I’m assuming the setting of the front is different for everyone depending on the speed the driver is capable of. So a faster driver would require more clicks to handle the transfer of weight than one that’s a casual driver? Is that a correct assumption?

[No_curebimmer]

Originally Posted by vrooooom

I’ve read the above post a few times and all I’m getting is to run the front with more clicks than the rear. But when you consider that first example of extreme setting differences of max stiff in the front and soft in the rear, one would end up with UNDERSTEER. So this 6F /4R would be towards an understeer? Or I should ignore that first 2 examples of extreme settings since that’s more for a double wishbone suspension?

I’m assuming the setting of the front is different for everyone depending on the speed the driver is capable of. So a faster driver would require more clicks to handle the transfer of weight than one that’s a casual driver? Is that a correct assumption?

As another input: I’m currently running 6F/5R and I’m very happy, but I may drop the rear to 4 since adjusting it is easy-peasy.

I started with 5/5 and found the setting a significant improvement over stock suspension: stiffer with much improved steering feedback yet more compliant over normal daily road bumps like RR tracks or the potholes I have around here in DFW (not as bad as other parts of the country or world, but not the smoothest either). With the OEM suspension, I always cringed, and funnily enough, even found myself jumping off my seat in synchronization when going over regular bumps. However, the last straw was driving on hwy at normal speed (70-75 mph): any road undulations would result in crashes when the car was settling in (was hitting the bump stops). ZERO such issues with B16s at 5/5.

Also, for kicks, I tried out 3/3 and found the ride too floaty and relaxed, decreased steering communication- so went back up to ~5.

For a DD, weekend warrior, with occasional spirited drives, B16s fit the bill perfectly for me.

[D.Yooras]

Originally Posted by vrooooom

I’ve read the above post a few times and all I’m getting is to run the front with more clicks than the rear. But when you consider that first example of extreme setting differences of max stiff in the front and soft in the rear, one would end up with UNDERSTEER. So this 6F /4R would be towards an understeer? Or I should ignore that first 2 examples of extreme settings since that’s more for a double wishbone suspension?

I’m assuming the setting of the front is different for everyone depending on the speed the driver is capable of. So a faster driver would require more clicks to handle the transfer of weight than one that’s a casual driver? Is that a correct assumption?

The extreme examples were more to show things you wouldn't necessarily do but were to demonstrate what would happen if you took things extremely far one direction or the other.

Since the Bilstein's tune low speed damping, it's based primarily on driver preference and chassis set up. General rule of thumb on BMWs would be that the front will always be higher than front all things being equal. What happens with struts (vs double wishbone) is that you don't want much body roll the on the front axle because it leads to lose of negative camber which leads to a loss of grip.

To address what you're asking specifically, the sweet spot for all out performance in the front is likely 6-8F. I don't have PSS10's on my car yet so I haven't had a chance to test/tune them specifically for this chassis, but that is usually the sweet spot on PSS10s on that cars that I have worked with. Most of the tuning on these cars is on the rear axle for turn-in and acceleration out of the corner to keep the rear end planted.

My recommendation would be to try driving the car with your current 6F/4R, then try 8F/4R and see which setting works better for the front. Then try 8F/6R and 6F/2R as a finally test. Write some notes for each different combination which should help you narrow in on what works best.

The good news is Bilstein leaves safety margin for all these adjustments so nothing will ever be TOO far off. Ultimately, you'll want to dial in the front for your driving style, then tune the rear to match.

[vrooooom]

6F / 4R ....will try that first. Thanks.

Reclocking first and the shop has not opened since the holidays.

[ZM2]

Anyone know the spring perch size for this kit? Trying to make sure I order the correct Vorshlag camber plates.

Thanks.

[FaRKle!]

Originally Posted by ZM2

Anyone know the spring perch size for this kit? Trying to make sure I order the correct Vorshlag camber plates.

Thanks.

For the front struts Bilstein uses springs with OE spring ID for the top mount and 60mm ID for the lower spring perch. You'll want Vorshlag's OE/stock spring perch.

[ZM2]

Originally Posted by FaRKle!

For the front struts Bilstein uses springs with OE spring ID for the top mount and 60mm ID for the lower spring perch. You'll want Vorshlag's OE/stock spring perch.

So, when I asked Bilstein this question, they just now sent me this:

Spring OD, top- 119.00 mm
Spring ID, top- 95.00 mm

[FaRKle!]

Originally Posted by ZM2

So, when I asked Bilstein this question, they just now sent me this:

Spring OD, top- 119.00 mm
Spring ID, top- 95.00 mm

Yes, that matches the OE/stock spring.

[ZM2]

Any consensus on what F/R settings to start with for the street and track?

[vrooooom]

8F 4R??

[vrooooom]

I’m at the alignment shop getting it done after the suspension settled. I’m informed that the camber in FRONT can not be adjusted? Only the toe can be adjusted.

Is this correct?

Left camber is –1°41’ (-1.68°) Right is –1°15’ (-1.25°)
Difference of 26’ (0.43°)

[Kattanah]

Originally Posted by vrooooom

I’m at the alignment shop getting it done after the suspension settled. I’m informed that the camber in FRONT can not be adjusted? Only the toe can be adjusted.

Is this correct?

Left camber is –1°41’ Right is –1°15’ Difference of 26’

That is correct as far as I know.

[D.Yooras]

Originally Posted by vrooooom

I’m at the alignment shop getting it done after the suspension settled. I’m informed that the camber in FRONT can not be adjusted? Only the toe can be adjusted.

Is this correct?

Left camber is –1°41’ (-1.68°) Right is –1°15’ (-1.25°)
Difference of 26’ (0.43°)

I saw you're numbers in the other section. It's possible you have that big of a difference in the front, but the rear showed the same thing. If they're alignment rack isn't sitting level on the locks, you'll see the problem show up where camber is shifted. It may piss them the off but I ask when the last time the rack and aligner were calibrated.

That, or you post a picture of the alignment system and rack and that will give me a good idea of what you're working with.