Anyone has Bilsten PSS9 installed?

[Phantom]

Yes, there is air under the inside front tire. Next mod is adjustable anti-roll bars.

[xeler8]

On further examination this looks like it is the M3 setup as pictured on Turners website and doesnt look like it uses the same linear rated spring or tender spring on older PSS9 setups? Looks like a single progressive spring. Maybe this reduces the need for a wheel spacer?

Jason

[Phantom]

Good point. It looks like the design has been updated and improved from the version on my car.

OFF-TOPIC: xeler8, are you regular air force? Buddy of mine flies ANG C-130s, Greg Caldwell.

I bet you're right about the new design eliminating the need for wheel spacers.

[xeler8]

Marine Corps actually, right now I am stationed in Cherry Point NC but I have a lot of Airforce and ANG buddies.


Jason

[Phantom]

Cool. My bud is with the Charlotte ANG.

I just called Turner Motorsports and asked them a bunch of questions about the PSS9s and the differences between the new version and the kit installed on my car back in 2003:

New Kit
NO Hub Spacers required.
NO Anti-Roll Bar strut links required. ARBs use OEM connection.
Similar spring and damping rates compared to the previous kit.

Looks like a good improvement on the older design.

Hope this helps.

[xeler8]

Great info, I really appreciate you posting it. I plan on pulling the trigger on this kit next month!

Jason

[wayne325]

I had PSS9s on a '94 325is. I didn't like it. It was too hard for the street.
Also, in order to set the ride height, you have to preload (compress) the
spring. This is a BAD idea. The correct way to do it is have the height
adjustment not directly linked to the amount of spring preload. Maybe
mine was "too hard" because I had it preloaded about 1.25" on the 325.
Oh ya, I ran it full soft on the street; #4 on the rear and #3 on the front
on the track.

I've now have a 99 M3 with the TC Kline setup (came on the car when I
bought it) and I like it much better. It has a lot of control but not as
harsh on the street.

I also had severl rides in a 99 M3 on JRZ 4-way adjustable dampers with
some Eibach springs. Much much better, but mucho $$$$ also.

I'd stay away from PSS9 unless they have solved the ride issue.

There's always H&R - but I think those may just be a better setup that
uses Bilstein dampers.

What about the "Cross" setup - I see ads in the Porsche "Excellence"
magazine - they have them for Porsche and say there are models for
BMW on the way...

[Colicious]

I had PSS9s on a '94 325is. I didn't like it. It was too hard for the street.
Also, in order to set the ride height, you have to preload (compress) the
spring. This is a BAD idea. The correct way to do it is have the height
adjustment not directly linked to the amount of spring preload. Maybe
mine was "too hard" because I had it preloaded about 1.25" on the 325.
Oh ya, I ran it full soft on the street; #4 on the rear and #3 on the front
on the track.

you said it was too hard on the street, but how did it perform on the track?

im wonderin how this kit performs against the top GC kit aswell as the TC Kline kit.

[95///M3]

I had them, I liked them, but only adjusted the shocks. I never adjusted the ride heght after I had that dialed in.

Jimmy

[Phantom]

I had PSS9s on a '94 325is. I didn't like it. It was too hard for the street.
Also, in order to set the ride height, you have to preload (compress) the
spring. This is a BAD idea. The correct way to do it is have the height
adjustment not directly linked to the amount of spring preload. Maybe
mine was "too hard" because I had it preloaded about 1.25" on the 325.
Oh ya, I ran it full soft on the street; #4 on the rear and #3 on the front
on the track.

Some things to consider:

Change in Ride Quality

Going from a stock 325/328 ride quality to the PSS9 is a much larger leap than going from a stock M3 ride quality to the PSS9.

To illustrate this point, simply go for back-to-back rides in a stock 325/328, and a stock M3. The 325/328 ride quality is relatively plush compared to the M3. For this reason a person may find the PSS9 too large a leap in ride stiffness coming from a stock 325/328.

Ride Height Adjustment

Ride Height adjustment does not involve spring preload on the PSS9.

In its assembled state, the front coilover spring must be compressed before attaching the strut hat/camber plate because the shock's finite length is shorter than the spring's uncompressed length. In other words, the coilover spring must be compressed to fit onto the shock for assembly before installation on the vehicle. This "preload" is fixed and is independent of ride height. Furthermore, this "preload" is non-existent and negated after installation on the vehicle because the weight of the vehicle compresses the spring much further than that required for strut assembly.

To prove this point, raise the vehicle so that the front wheel is off of the pavement. In this state the coilover is fully extended, limited by the finite length of the shock. However, the spring is still compressed between the strut hat/camber plate at the top of the spring and the ride height adjuster at the bottom. If this weren't the case then there would be slack in the spring and the ride height adjusters would turn freely on their threads.

Next, lower the vehicle. Note how the spring is further compressed by the weight of the vehicle. This negates the "preload" required for assembly or ride height adjustment.

This spring compression constantly pushes on the ride height adjusters, much more so when the vehicle is lowered. For this reason it is difficult to turn the ride height adjusters on their threads against the friction from the compressed spring. One may relieve this friction by compressing the spring through external means by using a spring compressor, perhaps about 1.25" as in the above case, prior to adjusting the ride height. Do not confuse this with applying a permanent or varying "preload" to the spring.

[Colicious]

<snip>

how exactly do you adjust the hight? just turn the "ride height adjusters" on the threads? do you have to compress the springs at all?

[5speed300]

Kind of a stupid newb question but Im gonna ask anyway...
How do you adjust the rear ride height without having to change springs? I see on the front that the shock and spring are mounted together and that you can turn the knob underneath the spring to adjust how high the car rides, but on the back the shock and spring are separate, so how does that work?

[Phantom]

how exactly do you adjust the hight? just turn the "ride height adjusters" on the threads? do you have to compress the springs at all?

Yes, just turn the ride height adjusters on the threads using the supplied spanner wrenches. Note how the spanner wrenches interface with the notches in the ride height adjusters. This task is easier IF the friction on the threads is relieved by using a spring compressor to compress the springs or by lifting that corner of the vehicle under adjustment.

[Phantom]

How do you adjust the rear ride height without having to change springs? I see on the front that the shock and spring are mounted together and that you can turn the knob underneath the spring to adjust how high the car rides, but on the back the shock and spring are separate, so how does that work?

The kit comes with a perch and shaft for each rear spring that is installed in the spring seat on the main rear suspension arm.

In the picture below look at the "bowl" inside of which the bottom of the rear spring rests. Although it is not visible behind the dustplate in this photo, the bottom of the rear spring rests on a threaded perch which is installed on a short shaft bolted into the bottom of the bowl. The threaded perched is raised and lowered on the shaft by turning it on its threads, thereby adjusting the rear ride height.

*EDIT*
At the top of this page the perch, shaft, and lock ring hardware are pictured in the upper left hand corner of the TMS photo in xeler8's post. The shaft is the D-cell battery-shaped cylinder in the upper left portion of the photo. It is pictured next to the threaded black perch, the threaded black lock ring (note the notches in both), and the blue plastic perch washer, along with the bolt that attaches the shaft inside the bowl of the rear main suspension arm. The blue plastic perch washer rests on the shelf of the spring perch, between it and the bottom of the spring. It reduces friction where the spring meets the perch to prevent rotational binding of the spring during suspension motion and ride height adjustment.
*EDIT*

[Phantom]

If there are any vendors or other knowledgeable personnel reading this thread, please confirm or correct my info.

[fivefreshfish]

Phantom, thanks sharing your insight and experience with the PSS9s.

[xeler8]

After having a C/O's on my previous car I can say that one advantage of a preloaded spring is that you dont have to worry about hitting a big bump and the spring clunking around or worse, becoming unseated.

Obviously ride quality is subjective since we have several people in this thread saying they love the ride and several saying it is too hard...

Jason

[Gofast]

In its assembled state, the front coilover spring must be compressed before attaching the strut hat/camber plate because the shock's finite length is shorter than the spring's uncompressed length. In other words, the coilover spring must be compressed to fit onto the shock for assembly before installation on the vehicle. This "preload" is fixed and is independent of ride height. Furthermore, this "preload" is non-existent and negated after installation on the vehicle because the weight of the vehicle compresses the spring much further than that required for strut assembly.

This isn't entirely true.
At least on the first generation PSS kit, the actual spring is shorter than the shock's max extension. Because of this there's a small "helper" spring with a very low rate that's in there entirely to keep the main spring under at least a small load at all times. (the helper is on the bottom in your picture in post 21). The helper spring is easily compressed, so it doesn't interfere significantly with adjusting ride height.
The new kit seems to have eliminated the helper spring, so this may not be the case any more. Although the new spring appears to have a section at the end of the main spring that may have a lower rate, essentially doing the job of the helper with one part.

[Phantom]

Agreed.

When the static vehicle weight loads the coilover it settles at an equilibrium point where the compression of the spring matches the portion of vehicle weight placed upon it.

This balancing point occurs at a corresponding location within the allowable travel of the coilover's extension, somewhere between fully compressed and fully extended. By raising and lowering the threaded spring perch up and down the length of the strut you are adjusting the point along the strut's travel at which the balancing point occurs, thereby adjusting the ride height.

Therefore, adjusting ride height will not affect the suspension behavior as long as the spring rate and damping characteristics are uniform along the allowable range of ride height adjustment and do not vary throughout the range of suspension travel.

It's true (and wayne325 is correct) that at full extension (when that corner of the vehicle is unloaded, or when the coilover is first assembled with the strut hat/camber plate) the spring perch adjustment varies the amount of static spring compression at the finite full extension of the suspension. We could call this the spring preload at full extension. But with proper design that spring preload at full extension and the corresponding ride height adjustment (balancing point) will not significantly affect the spring and damping characteristics of the front coilover or rear spring/damper combination. According to the TMS rep, Kevin, who was extremely helpful and patient with my questions, this is the case with the PSS9, both the new design and the previous design.

One way to have true ride height adjustment on our chassis without affecting spring preload at full extension would be to have the entire coilover assembly attach to a threaded shaft extending from the top of the strut hat/camber plate. This threaded shaft (I'll call it a "strut shaft") would feed thru a threaded collar fixed within the top of the shock tower. In this way the top of the assembly would not be located at a fixed attachment point by installation of the strut hat/camber plate within the shock tower. Rather, the top of the entire assembly would feed thru the shock tower and it would be adjusted up and down by turning the threaded shock tower collar.

Such a design would have to allow the strut shaft to protrude from the top of the shock tower at varying lengths, maybe requiring a bulge or hole in the hood above the shock tower for the strut shaft to poke into when the vehicle is set at it's lowest ride height

For a good idea of what I'm talking about, look at the telescoping forks of a motorcycle and how the front of the bike can be raised and lowered on the fork tubes to directly affect ride height independent of spring preload. The fork tubes feed thru the triple clamps and are clamped in place. Loosen the clamps and the tubes can be fed up or down thru the triple clamps, effectively lowering or raising the front ride height:

[Phantom]

Loosen the upper and lower clamps at the green arrows, and slide the forks up or down along the blue arrow.

[wayne325]

Quote:Change in Ride Quality

Going from a stock 325/328 ride quality to the PSS9 is a much larger leap than going from a stock M3 ride quality to the PSS9.

To illustrate this point, simply go for back-to-back rides in a stock 325/328, and a stock M3. The 325/328 ride quality is relatively plush compared to the M3. For this reason a person may find the PSS9 too large a leap in ride stiffness coming from a stock 325/328.

Endquote:

I have mucho experience with E36 BMWs. I drove a 94 325is for 100,000 miles,
I've had several rides in a '98 328 sedan, I've have a 99 M3 with the TC Kline
setup that I've driven since the spring, I've driven on the street and on track
a 99 M3 that has as many goodies as you possibly can put etc etc etc.
So I know about ride on E36s. I don't know if this "new" PSS9 for M3 is
softer than the one I had for my 325, but the one I had was HARD. Trust me
you don't want it on the street. I live in Dallas and the streets here are
very good compared to parts of the country where it gets cold and the
roads get broken up. I can't imagine driving that car in NY for example.
You would take the PSS9 off. It was nasty.

Someone asked what it was like on the track - now that is where that car
really shone. I had a full M3 front geometry but with -2 degrees or maybe
it was -3 degrees of camber (it was a Dinan camber plate). It had the PSS9,
SwayBarbarians, new bushings all round, steel brake lines, EBC Green pads,
and I ran with Hoosiers. It had a strut tower bar and the X bar underneath
also. Since it was a 325, it's what we affectionately
call a "momentum" car - meaning you have to carry a lot of speed thru
the corners in order to go fast. It would handle as well as anything else
on track. The only car that could get any speed on me thru corners was a
Kremer K3 look-alike. Nothing else had speed on me in the corners. Straights
of course were another matter. I could walk all over Boxsters on street
tires for example - the extra speed thru corners and deep braking more
than offset the advantage the Boxsters had in torque, power, and polar
moment (or lack thereof). The E36 platform is very very good.

On the preload thing - the front height adjustment was done by adding
preload on the PSS9 I had. If you wanted the car lower, you compressed
the spring more. On the back, the perch is adjusted as an earlier
poster showed.

If you want to see how it "should" be done, go to a newsstand, pick up a
copy of "Excellence" magazine, and look for an advert by "Cross". Study it and
you will see that there is a tube height adjustment and a separate spring
preload adjustment.

Ask yourself this - if there's only one adjustment, how can you adjust the
spring preload and the height separately ? The PSS9 I had, had only one
adjustment.... Look at the Cross, there are 2 adjustments.

OK, so another BAD thing about the PSS9 since I'm thinking about it - and
this had to do with the back.... The back compression was so low, that
if you went over basically any small break downwards in the pavement,
even 1 inch, you'd get a load BANG out of the ass end. I don't get this
out of the TC Kline setup either. Meaning - the spring constant was too high
on the back spring. You'd drop the car off a jack and it would go down
maybe an inch at the back.

Discalimer - I have nothing against Bilstein and I have no interest in TC Kline.
I'm just reporting things I have first hand experience with.

[xeler8]

Yeah but you are talking about your setup like everyone has had the same issues you have had and obviously this is not the case. There are several happy customers on this page as well as other across the board. You are the first real negative post that I have seen about PSS9's ( I am sure there are more though).

Jason

[kfoote]

RE: PSS9 ride quality

The ride comfort of the PSS9 kit will not be as good as a stock package. Any time you more than double the spring rates of a car, the ride comfort will go down. As far as not being able to be used on the rough roads as a daily driver kit, though it's not a BMW, I have had a PSS9 kit on my DD for the last 2 years and have no plans to change it, and I'm in the Boston area, with quite possibly the worst roads in the country.

On the preload thing - the front height adjustment was done by adding
preload on the PSS9 I had. If you wanted the car lower, you compressed
the spring more. On the back, the perch is adjusted as an earlier
poster showed.

If you want to see how it "should" be done, go to a newsstand, pick up a
copy of "Excellence" magazine, and look for an advert by "Cross". Study it and
you will see that there is a tube height adjustment and a separate spring
preload adjustment.

Ideally, yes, this is correct that for optimum performance the ride height and preload should be able to be adjusted seperately. In the real world, what does it gain you? In a progressive rate spring, as the current PSS9 kit, if you raise the front ride height 1", it requires about an additional 150 lbs of force of preload. At the point where the car is sitting on level ground, due to the height change, the net result is an increase in instantaneous spring rate of about 40 lbs/in, and that number decreases the more the spring is compressed. Basically, by raising the ride height and increasing the preload you are making the spring rate less progressive. Keep in mind that 1" ride height change is very drastic and will cause other issues, such as changes in suspension geometry, that will play a much bigger role in the handling characteristics of the car than a 8-10% increase in spring rate.

The advantage of a tender spring setup is that the softer spring takes up all of the preload, and the increase in effective spring rate due to preload is virtually none. Properly set up, there should be no increase in spring rate once the tender spring is compressed, and though there is an increase in spring rate in the tender when it is not fully compressed, the change is much less than a progressive rate spring because the tender spring is softer (most tender springs are in the 150 lbs/in range).

Does it make a change? Yes. Does it make a that anyone other than a mid-level Pro driver will be able to feel if they're testing for it? No.

Ask yourself this - if there's only one adjustment, how can you adjust the
spring preload and the height separately ? The PSS9 I had, had only one
adjustment.... Look at the Cross, there are 2 adjustments.

If you can feel the difference in adjusting the preload 50% without a change in ride height, and it shows up as a faster lap time with less preload, I'll admit that you are a far more sensitive driver than I am, and that the extra $$$ and complexity is worth it for you for a street car (brief driving resume: 150+ HPDE days, HPDE instructor, 25+ SCCA races over the last 10 years).

In the real world for a street oriented kit as the PSS9 is, the preload adjustment is not worth the added expense and complexity.

[scottst]

RE: PSS9 ride quality

The ride comfort of the PSS9 kit will not be as good as a stock package. Any time you more than double the spring rates of a car, the ride comfort will go down. As far as not being able to be used on the rough roads as a daily driver kit, though it's not a BMW, I have had a PSS9 kit on my DD for the last 2 years and have no plans to change it, and I'm in the Boston area, with quite possibly the worst roads in the country.



Ideally, yes, this is correct that for optimum performance the ride height and preload should be able to be adjusted seperately. In the real world, what does it gain you? In a progressive rate spring, as the current PSS9 kit, if you raise the front ride height 1", it requires about an additional 150 lbs of force of preload. At the point where the car is sitting on level ground, due to the height change, the net result is an increase in instantaneous spring rate of about 40 lbs/in, and that number decreases the more the spring is compressed. Basically, by raising the ride height and increasing the preload you are making the spring rate less progressive. Keep in mind that 1" ride height change is very drastic and will cause other issues, such as changes in suspension geometry, that will play a much bigger role in the handling characteristics of the car than a 8-10% increase in spring rate.

The advantage of a tender spring setup is that the softer spring takes up all of the preload, and the increase in effective spring rate due to preload is virtually none. Properly set up, there should be no increase in spring rate once the tender spring is compressed, and though there is an increase in spring rate in the tender when it is not fully compressed, the change is much less than a progressive rate spring because the tender spring is softer (most tender springs are in the 150 lbs/in range).

Does it make a change? Yes. Does it make a that anyone other than a mid-level Pro driver will be able to feel if they're testing for it? No.



If you can feel the difference in adjusting the preload 50% without a change in ride height, and it shows up as a faster lap time with less preload, I'll admit that you are a far more sensitive driver than I am, and that the extra $$$ and complexity is worth it for you for a street car (brief driving resume: 150+ HPDE days, HPDE instructor, 25+ SCCA races over the last 10 years).

In the real world for a street oriented kit as the PSS9 is, the preload adjustment is not worth the added expense and complexity.

OK, you guys need to help me understand something. On a coilover setup w/a single adjustment (height of the perch), my understanding has always been that as long as you're not adjusting against the limit of the shock's travel (preloading), adjusting height does not adjust the spring rate.

Assume the car is sitting on the ground at a specific ride height. If I adjust the collars 1/2" "upward" (raising the spring perch 1/2"), assuming the shock moves freely (e.g. doesn't hit the limit of its travel), how can the spring rate possibly change? It's still "freely" supporting the car without any unnatural compression being applied to the spring.

Oh, and back to the thread; I'd love to hear more first hand experience w/the new kit on street+track driven *M3s*

[Gofast]

OK, you guys need to help me understand something. On a coilover setup w/a single adjustment (height of the perch), my understanding has always been that as long as you're not adjusting against the limit of the shock's travel (preloading), adjusting height does not adjust the spring rate.

I'm wondering about this as well.