[Chowbow]

This is pretty lengthy, so take a seat. Cliff notes: This setup is great for daily drivers that see a few track events a year.

Here is a write up on my first impressions with my new Bilstein PSS10 setup with Dinan camber plates. My previous setup was Eibach Pro-kit springs mated with Bilstein HD shocks. I ran this setup for about 25k miles with lots of daily street driving and a few track events and a good amount of autocrosses. About 200 miles before I installed the PSS10s, I purchased Dinan camber plates and installed those on the shocks/springs. The reason I went with the Dinan setup - after much thought and back and forth - is that I wanted something completely noise free and doesn't wear out. The Dinan plates only give you another -0.5 degrees of camber by offsetting the mounting point of the top of the strut in towards the chassis a bit. The plate is about 1/4" thick, and it goes above the stock top hat so it increases the stack height - which means it will raise your ride height a tiny bit (about 1/4", I thought it'd be more due to the geometry of things, but it only raised it 1/4" or so). I was scrubbing off the outside of the front tires a lot at the autocross and canyon runs, so I wanted something to help with the tire wear and contact patch. Don't expect a revelation, but it is a subtle difference in turn-in. I was at -0.9* with the alignment pins drilled out and lowered 1" with the Eibach prokit springs, prior to the plates. After installing the plates and getting aligned, I got -1.4* camber on both sides and 7.1* caster, so about a -0.5* improvement over stock top hats with pins drilled out, and 0.2* more caster.

2/23/11 update on alignment: I brought the car in for a more aggressive alignment and they were able to get -1.9* camber on the front, with 0.15" toe out.

Dinan camber plates:


Even though my E90 is pretty much a weekend and autocross / track car now, I still wanted something completely streetable. I did not want a track car on the street. I wanted a street car on the track. This was the decision process on my suspension purchases. I looked at the Ground Control coilovers. They are custom valved Koni single adjustables with Eibach linear springs and in-house camber plates. Very capable, and a great review here by dieguito37: http://www.e90post.com/forums/showthread.php?t=304521. I nearly bought the GCs, but after reading a lot across other forums, I was worried about noisy camber plates down the line, and adjusting the shocks requires disassembling the whole shock/spring assembly - same as the Koni yellows available for the E9x now. I'm also really biased towards the feel of high pressure monotube shocks, so I really wanted a Bilstein setup as the Konis and KWs all used twin tube shocks. This is simply a preference, and while some can argue the consistency and performance of one damper / shock over another, I made my decision based on feel and bias. With the Dinan plates selected, I wanted a set of coilovers I could adjust easily. Something that I can drive to the track, turn a few knobs to get dialed in, and then soften it up again to go back home in comfort. It must be my old age, but even for a weekend car I wanted something comfortable and complaint.

After much research, reading, and riding in other people's cars, I decided on the PSS10s. I wrote off KWs because they are not really easy to adjust (and the V3s get pretty pricey), and I was really looking to buy something with a high pressure monotube gas shock. I checked out AST setups from Vorshlag, but it is not within my price range so I wrote that off regardless of adjustability. If I got something that high end, it would be beyond my driving abilities. I looked at the PSS9s as they were a lot cheaper than PSS10s, but they are difficult to adjust, and I decided the few hundred extra dollars for the PSS10s would be worth it. I also considered the H&Rs and Eibach, but could not find much info on them.

I was then torn between the Bilstein PSS10s and the B16 electronic ride control setup. It would have been awesome to be able to press a button in the cabin and change from soft to stiff damper settings, but the fact that I cannot choose the presets, and I cannot adjust the fronts and rears individually for under/oversteer tuning was a deal breaker. The final variable that put the nail in the coffin for the PSS10s is that I can send the shocks into Bilstein and have them revalved and sent back to me in less than a week. Shocks will have to be revalved as they get worn out and Bilstein's revalving services are somewhat reasonable (although the PSS10s are the most expensive at $150 per shock, vs $65 per shock for my Bilstein HDs), and have a fast turnover rate. At least I know I can go directly to the manufacturer to have them revalved. Try finding a place to revalve your KWs... As a side note, there are numerous places which can revalve Konis, a few places local to me too where I can drop them off and pick them up in a few days.

Onto the install. I did it myself with the help of a friend. Not too difficult but set aside some time and be patient. The PSS10 install is pretty much like any other E9x coilover install. Pretty straightforward except that the rear shocks are a little tricky with the adjusters. You have to remove the adjustment knob and the adjustment base, and there are only a few OEM parts that you reuse. The instructions were honestly not that helpful but after looking at the parts supplied and the parts from the OEM setup, it becomes obvious what OEM parts need to be re-used. Of special note is that the rear shocks come preset at "10" and when you re-install the adjust knob and adjustment base, you want to ensure that the rear shocks are set to 10 first, because as you soften the rear shocks, the adjustment pin threads downwards. If you do not install the adjustment knobs while the shocks are set to 10, then the knob will "bottom out" and you will not have the full range of adjustment. This may sound a little wacky on here, but if you are installing this, I think that the last sentence will assist you. This was the only little issue I ran into throughout the install. Everything else was pretty plug and play if you've done coilovers on the E9x in the past.

The Dinan camber plates came with no instructions at all, but it should be obvious what needs to be done. The "alignment pin" that comes on the stock top hat must be removed. I had drilled mine out a long time ago. You will also need to have the 3 studs in the stock top hat pressed out. I used a C-clamp and a 12mm box end wrench to push the studs out:



The arrow on the camber plate points towards the front of the car, and you just bolt the camber plate to the top hat once you press the studs out. If you look carefully at the stock top hats and strut mount, the strut does not actually come up through the middle of the mount. It is offset a tiny little bit. I mounted it to the Dinan camber plate in a way that it gave me the maximum amount of caster (I gained 0.2* caster). It fits well, no noises and it's solid. It was a rip off though at $299.

In terms of height adjustment, this is where the PSS10 sucks. In the front, I have the coilovers set to the highest setting, and this still lowered the front 1" from stock ZSP. I would have preferred to be able to lower the car just a 1/2" or so to maintain the factory suspension geometry as close as possible. It looks quite nice sitting as it does, but having the option to lower the car less, or to not lower the car at all, would have been optimal. For the rears, I adjusted them so that they are also approximately 1" lower than stock. This way I keep the weight distribution close to stock, and in stock form the E90 is pretty well corner balanced. With the rear lowered 1" from factory height, the rear perches are set to about "2/3rds low," meaning I do have some room to go lower, and lots of room to go higher. I am still happy with the height, it is very close to the ride height I had with the Eibach Prokit springs, but the ability to go higher would surely be welcome. At this ride height, I have not had any issues with bottoming out at all. I cannot speak to a lower ride height and I will not be going any lower than the car already sits so I can't comment on that. There seems to be plenty of shock travel both in the front and rear. Particularly in the front shocks, there is more shock travel than my Bilstein HDs. There is a particular bump on this section of freeway which caused my car to bottom out on the Bilstein HD's internal bump stops, which the PSS10s did not bottom out on, even on the softest setting.

Pic of front PSS10. Highest setting available, and threads taped off to keep debris / rocks out:


Pic of rear PSS10 to match front ride height. About "2/3rds low":


The PSS10s have single adjustable dampers with progressive rate springs. Per Mr. 5's post, the spring rates are around 385lb/in F and 615lb/in R: http://www.e90post.com/forums/showthread.php?t=235797. Setting 1 is the softest and 10 is the stiffest, and the knob only controls rebound. It is VERY easy to adjust the dampers, and this is where this kit excels. In the rear, the adjusters are at the top of the shock, and I have cut out holes in the trunk carpeting to reach the adjusters. The PSS10s come with a plug to cover the access hole and gives you measurements on where to cut. The numbers are easily legible on the adjustment knobs. On the front, the adjustment knobs are at the bottom of the shock. On the E9x, this is somewhat easy to access since the bottom of the shock sits between the wheel hub and chassis. With the car on the ground, it is too low to see the adjusters, but you can reach in and adjust it without jacking up the car, or putting it up on ramps. It takes me about 1 minute to adjust all 4 corners of the car, but I do have to get on the ground and get my hands dirty to adjust the fronts. The limitation is that these are only single adjustables. You can get DAs from the KW, TCKs, and AST (triple adjustables available from AST as well) if that is something you need. But I don't track enough to consider double adjustable shocks on my car. I kept reminding myself... street car on the track, not race car on the street.

You've read this far, might as well finish. Simply put, this system has incredible dampers / shocks. At "1" front and rear, the softest setting, the car rides exceptionally well. However, it feels a tad floaty and large bumps mid corner are not that well controlled - feels a bit disconnected and has some body roll, but manageable. I haven't driven a stock ZSP car in a long time but I would say setting "1" has about the same feel. Not bad, and great ride but at the cost of some stability and rebound through the corners. If I were driving my 84 year old grandma around, I would set it to this. At setting 5 F/R, it is actually a little disappointing. It's neither here nor there IMO. It's not that complaint and comfortable, and the dampers have not stiffened up so significantly that it handles like a dream. Car rolls a little still, nothing spectacular. I think you might as well either have it setup stiffer for a tauter feel, or softer for more compliance. This middle of the road compromise sucks, I would equate it to an unattractive partner who isn't that great in bed. At "7" F/R, some magic starts to happen. This would be about as stiff as I would go on a daily driver where the driver is pretty tolerable of bad roads. Things tighten up and the car feels really controlled through the corners with much reduced body roll. Exudes confidence on smooth roads but mid-corner bumps can upset the car a bit. On a smooth onramp it feels fantastic though, if I were 18 years old again I'd set it to this and leave it. I never got to setting "10" but at "9" it was jarring, way too stiff and beyond my DD needs.

So 1 is too soft, 9 is too stiff, 5 sucks, where do we stand? On a day to day basis, I will be running 4F/3R. What I noticed is that when the fronts and rears were on the same number setting, the car was pretty neutral but had just a hint of oversteer. It might be the slight improvement in traction I get from the camber plates up front too. Regardless, something that I am not willing to live with on the street. I don't consider myself a n00b driver with nearly 10 years of autocrossing, but I think i would prefer a mild understeering street car. Softening the rear just 1 click takes care of this condition. The car understeers just a bit, and at 4F/3R, the car still handles well enough for the street but is also quite comfortable even on mildly bumpy roads. I went through a tough canyon road with lots of mid corner bumps and the car was NOT skipping all over the place on this setting. A softer setup car works better on these roads as you're not skipping across the bumpy road. On a road course I would imagine myself in the 6F/6R or 7F/7R area, but will have to get on track to see. At autocross, I can deal with some more oversteer and rotation and may start at 6F/7R or 7F/8R. Track impressions to follow later.

Update 2/23/11: I can provide some input on the car after I've done a number of autocrosses now. Simply put, from a competitive autocross standpoint, this won't be your kit. It is too softly sprung as you can see from the spring rates listed above. I don't run competitively and as I mentioned before, this isn't a race car. It does OK and is plenty of fun, but don't expect to trophy in STU or BSP with this setup. The car leans quite a bit still but it does handle transitions pretty well on stiffer shock settings. I ran 9F, 10R with RE01Rs and it felt pretty good. I took advice from user "The HACK" (page 2 of this thread) and ran a stiffer rear which worked out quite well actually. I used tire pressures and an alignment to help steady out some twitch in the rear. If I ran a drastically different setting like 5F and 9R, then the car would snap oversteer on me on really quick left right transitions. It was great to be able to get to the site, adjust the shocks in 1 minute and run. Then at the end of the day dial it back down and drive back in a soft and good riding car.

A picture of how much the car is leaning at the local autocross. A pretty flat section here, on street tires. Hint of understeer as I was going in too hot, but you can see how much the car pushes over.


In conclusion, I am very happy with my purchase. The ability to adjust the shocks so easily was really the key selling point for me. I was already happy with my Bilstein HDs with Eibach springs. But I wanted something more comfy on the streets and can be adjusted in minutes on track. All the components were of high quality, and the install went without a hitch. No clunking, no "making things fit" and most importantly it feels great to me. There's something to be had just from the "feel" of things. There are definitely better performing options out there, and other COs which can be dialed in much more precisely. But my original goal was to have a good street car on the track and I am confident this setup fits the bill for me.

Picture after all height adjustments done and car settled:


Update 2/23/11: I put the car on some scales to check the corner balancing, as it sits in the picture above. The car was never actually corner balanced, but what I did was I measured the distance from centercap to fender at each corner when the car was stock, and adjusted the height until each corner was 1" lower than stock. On the fronts I had no choice since the highest setting lowered the car 1" already, so really it was just adjusting the rears to match. Incredible result IMO - 50.2% cross weight with me in the car and 1/2 tank of fuel (this pic is without me in the car - 50.4% cross weight). Note how heavy the car is too - 3687lbs. Pretty much stock except for the coilovers, 6MT, most options, stock wheels.



EDIT: Updated some driving impressions, and shortened the whole thing a bit.
EDIT2: Added alignment numbers from camber plates.
EDIT3: Updated new alignment numbers, corner weight information, and autocross impressions.

[Hedges]

Jesus, not even a smiley face in there!

Joking aside, that was a good read! Something I will consider If i go coil-overs! How much did this setup cost if you dont mind me asking?

[Chowbow]

Originally Posted by Hedges

Jesus, not even a smiley face in there!

Joking aside, that was a good read! Something I will consider If i go coil-overs! How much did this setup cost if you dont mind me asking?

I got a killer deal on them. I got a few quotes from some vendors and they were all quite competitive with each other. However, I came across a site in my google search that was over $100 lower than everyone's quote. And then they had another $100 off coupon plus free shipping. And then they took another $60 off when I ordered it through their live chat system. Total was under $1600 with around 8% CA tax. While I want to support my local vendors and speed shops, the price difference was pretty big and in this economy I gotta save where I can.

[Gen_E92]

Awesome review! I would suggest upgrading those springs to linear springs from Swift or Hypercoil if you want stock ride height and even better performance.

I would do a review of my set up (FK Silverline X with M3 rear camber link and TCK M3 rear dampers), but I'm not experienced enough as a driver so I'm not very sensitive to suspension changes when I change damper settings

[bavarian19]

nice review

[E90RYANJB]

lot of infos there and

nice ride man.love that drop!

[Mahhvinn]

great review brian! your car looks good too!

[Chowbow]

Originally Posted by Gen_E92

Awesome review! I would suggest upgrading those springs to linear springs from Swift or Hypercoil if you want stock ride height and even better performance.

I would do a review of my set up (FK Silverline X with M3 rear camber link and TCK M3 rear dampers), but I'm not experienced enough as a driver so I'm not very sensitive to suspension changes when I change damper settings

I'm not looking to swap the springs. I would need to get new top hats since the PSS10s use the stock ones with a tapered spring. If I swapped springs I could go with Vorshlag or GC camber plates that match up with the coilover springs, but I would be worried about noise from the plates. I can actually get Vorshlag plates right now since they make a fitment with stock style springs, but I passed on that and picked the Dinan ones.

[I335]

Excellent review and it's great to read someone with great writing skills!

[joec500]

Originally Posted by Chowbow

I got a killer deal on them. I got a few quotes from some vendors and they were all quite competitive with each other. However, I came across a site in my google search that was over $100 lower than everyone's quote. And then they had another $100 off coupon plus free shipping. And then they took another $60 off when I ordered it through their live chat system. Total was under $1600 with around 8% CA tax. While I want to support my local vendors and speed shops, the price difference was pretty big and in this economy I gotta save where I can.

Regardless of the economy....it's not wise to just give away $250

Nice Writeup.

[Chowbow]

Updated the post with a few pics and some new driving impressions after a few hundred more miles.

[BMW1983]

Would you please equate what settings on the PSS10's would correspond to your Bilstein HD's? In other words, to which setting on your PSS10's would you describe the HDs?

[stressdoc]

Nice job. I wanted the PSS10s, but the BMW Perf kit was a lot less $ at the time. It would be great if several of you E90 posters in CA would get together and do a suspension comparo.

[Minefield]

Originally Posted by I335

Excellent review and it's great to read someone with great writing skills!

[Chowbow]

Originally Posted by BMW1983

Would you please equate what settings on the PSS10's would correspond to your Bilstein HD's? In other words, to which setting on your PSS10's would you describe the HDs?

About a 6 or so. Something to consider is that the Bilstein HDs had 25k miles on it already so if I had both brand new, impressions might change just a bit. But definitely in that 6/7 area. My day to day setup is softer right now than my old Bilstein HDs.

Originally Posted by stressdoc

Nice job. I wanted the PSS10s, but the BMW Perf kit was a lot less $ at the time. It would be great if several of you E90 posters in CA would get together and do a suspension comparo.

Hmm... we should, there are lots of guys here with different suspension setups but I don't know anyone with the BMWP kit close by.

Originally Posted by I335

Excellent review and it's great to read someone with great writing skills!

Originally Posted by AiyahPK

Thanks all.

[Chowbow]

Measured the ride heights again today and made small adjustments after the springs settled. About a 1/4" lower on all sides. I took the driver's side front and rear down a tiny bit so the car sits a bit more even, and went out for a quick pic. First post updated.

[turpiwa]

nice info - done any track work with the new setup?

[Chowbow]

Originally Posted by turpiwa

nice info - done any track work with the new setup?

Unfortunately no. I was out at the autoX and found out I had a small brake fluid leak from my front caliper so I didn't run. And with the rainy season upon Norcal, I won't be doing any road racing until next year. I may still fit in an autocross or something and I'll post impressions then.

[DaFish]

I was wondering how much the camber plates made a difference. If you didn't have the camber plates, what difference would that make - I am assuming turn in wouldn't be as sharp, and it would understeer a bit more - but I would love to hear your description of what the car would be like.

Thanks a ton for the great write up !

[DaFish]

Originally Posted by Gen_E92

Awesome review! I would suggest upgrading those springs to linear springs from Swift or Hypercoil if you want stock ride height and even better performance.

Fantastic write up!! Thanks a ton.

Gen_E92 (also a great poster), I didn't know you can get coil overs that keep/maintain the stock ZSP ride height. Is that true? I'll look into swift or hypercoil.

Question 2: Do you still need to do the M3 sway bars if you got the coil overs? From this fantastic post, it seems you can control body roll with the COs (if you don't have to change the swaybars - especially the rear - you can save a lot of money)

Chowbow, did you change your sways? Great job !

[Chowbow]

Originally Posted by DaFish

I was wondering how much the camber plates made a difference. If you didn't have the camber plates, what difference would that make - I am assuming turn in wouldn't be as sharp, and it would understeer a bit more - but I would love to hear your description of what the car would be like.

Thanks a ton for the great write up !

I was on my old setup for quite a while without camber plates. And then added the plates onto my old setup, before putting in the PSS10s. The camber plates do help and they are noticeable but it's not a dramatic difference. I do know that I was not getting enough negative camber as I was just killing the outside of the front tires at the autoX. Even right now with about -1.4*, it's not a whole lot of negative camber but it's a good compromise for a street car I think. I'd prefer to be around -2* or so all around, but I didn't want to run camber plates with moving parts due to noise concerns.

Originally Posted by DaFish

Fantastic write up!! Thanks a ton.

Gen_E92 (also a great poster), I didn't know you can get coil overs that keep/maintain the stock ZSP ride height. Is that true? I'll look into swift or hypercoil.

Question 2: Do you still need to do the M3 sway bars if you got the coil overs? From this fantastic post, it seems you can control body roll with the COs (if you don't have to change the swaybars - especially the rear - you can save a lot of money)

Chowbow, did you change your sways? Great job !

I am on stock sway bars. You should change your sway bars as a final step to tune your suspension. Get the correct shocks and springs and alignment, and utilize sway bars to fine tune everything. You'll even find some race cars not running any rear sway bars at all.

I may end up changing out the sway bar bushings with the M3 ones. It won't really make a difference in terms of absolute handling limits, but the M3 bushings are not hollow like the factory 335i ones and they would make the car "feel" more reactive and faster to respond. But this would not be an actual performance upgrade per se.

[Malek@MRF]

How much are the Dinan Camber plates?