[Yzandrl]

The Story:

Well I'd like to put down some first impressions about the upgrade journey I took for a 2006 e90 330i w/sport suspension in Germany. Long article alert. And by no means am I a suspension expert, but I like to think I learned something along the way.

The Goals:

I set out on this adventure to improve the following aspects of my vehicle.

• Remove what I call a “detached feeling” from steering & feedback.
• Improve dampening & rebound on bumps at speed.
• Have the rear settle down quickly after hitting bumps under throttle, such as boarding onramps or going over small imperfections at intersections.
• Have consistent, predictable behavior in all most conditions.
• Reduce body roll.
• Improve confidence in g-force turns due to more vehicle feedback.
• Improve the predictability and consistency of thrust for my rear wheel drive under load.
• Try to maintain as comfortable a commuter ride as possible.
• Obtain a silent aftermarket differential.
• Improve traction in icy or snow conditions.
• Keep the cost down.
• Not harm the original engineering done by the real engineers.

The Background:

I really had to do some long and hard thinking about whether to drop the cash on all this or upgrade to another car. I really considered going for an upgrade, but I wanted it to be a non forced induction and I like my fully loaded commuter car. If I had added another 10-13K I could seek a used e46 M3 and but decided against it because it would be an older base model vehicle with a higher cost of ownership for maintenance, and I’m kind of attached to the vehicle that I bought new.

It was a long journey of research, conversing with others in PM's about their setups, more research, and finally pulling all the details together. In the end I finally figured out a solution that would meet the above needs. I originally looked at replacing all the bushings with aftermarket bushings with Power flex Purples and keeping the OEM e90x parts but they were not available for this model due to factory fire. So, I went with the OEM M3 parts which were more expensive but have their own benefits.

I'd like to give a shout out to thank those people who were very involved with sharing their knowledge, experience, and advice from their experiences (Marcel b, stressdoc, Chowbow, Autobahn335i, Harold, & Alpina_B3_Lux). And I think I read and re-read every post that Orb made in suspension forum.

The Chosen Few:

• Michelin Pilot Sport 2s w/stock wheels (Tire Rack)
• OEM M3 Front Wishbones w/Headlight Rod (HP Autowerks)
• OEM M3 Front Tension Rods (HP Autowerks)
• OEM M3 Front Stabilizer Bar (Local BMW parts)
• OEM M3 Rear Stabilizer Bar (Local BMW parts)
• OEM M3 Complete Sub frame Bushings (Local BMW parts)
• Koni FSD Shocks w/stock springs (**********s, kept good price on it too even when everyone in the USA and Canada was completely out of stock)
• Quaife LSD (HP Autowerks) *NOTE: Eventually had to get Drexler Type 188 1.0 Locking but that story is below.

The Tuners:

I looked for information about local tuners and had difficulty with all of them. I tried to reach nearby German companies such as Schropp, Evotech, G-Power, and Raeder Motorsport. I didn’t try Birds as it was too far for me but is the only dealer near here for Quaife officially

I discovered that German tuning shops really don’t like responding to emails, answering the phone during work hours, answering the phone after work hours, returning phone messages, scheduling install dates, and giving price quotes. They really want to see you in person and won’t really deal with you until you commit the time to go and visit them in person. I couldn’t take time off from work to basically just to take a day trip across country without knowing anyone would actually be there to just visit and check out their garage and prices. I would also have to arrange a rental car and pickup drop off as well so I finally looked into visiting local BMW dealerships and just accepting the higher cost. I had questioned local people about dealerships and went to Netuschil BMW in Stuttgart after some recommendations and I had already purchased parts from them for the install.

As for the installation experience, I worked with Andreas Jass at the dealership and with Patrick Jedrzejczak who was the service adviser. I called them and told them what I wanted to do and stopped by after work. They walked over to my trunk and saw all the parts waiting to be installed and had a price quote to me the next morning breaking down all the work that would need to be performed and gave me a start date. The dealer cost was high, but they agreed to give me a free rental 1-series during the work to be performed and that took some of the pain away. About the same time I finally a verbal quote from an independent tuning shop which was the 30% less, but I decided against it as I didn’t get a good feeling from the one month of nagging it took to get a price quote from them. I think it turned out well that I went with the dealer as they were very accommodating and it turned out beneficial that they sub contracted differential work to Drexler.

The Problem:

So my differential housing finally makes it to Drexler and I get a call from BMW that they found out I had a type 188 and a type 215 part for it.

So, I had to decide to:

A. Pay additional fees/rental costs and wait for another Quaife LSD
B. Just take the Drexler part sitting a few shelves over from my gutted differential and having done with it.
C. Cancel the entire differential upgrade and have it sent back and wait to see.

The Decision:

On the good side, the Drexler differential is a race proven race quality part and is a few kilos lighter than the Quaife. It was more expensive and overkill for my goals. I figured I had already gone in that far, and that I might as well go the rest of the way. Drexler gave me a discount on the part and started installing the part as soon as I notified them I had wired the funds.

During this time at Netuschil there was a lot of scrambling, discussions on what to do, and Mr. Jass was very patient, helpful, and in the end I was very happy I took my business to them. I think they ended up with some difficulty because they didn’t charge me for the delay, the extra miscellaneous parts, nor did they get commission from Drexler as I bought it directly from the manufacturer and they were a dealer for them. They kept the price the same and still covered the rental car as well for the second week it took to get the work performed. Basically they jumped through some hoops for me and I’d recommend them without hesitation.

The Review:

Now, finally down to the upgrade itself. I'd like to break out the different parts and map them to the above goals and add some feedback.


The Michelin PS2s removed the harshness of the Run Flats, improved, feel, and handles well in wet conditions. I don't want to get into the RFT vs. STD debate but I like the feel of these tires much better. I prefer them to the original OEM Bridgestone Potenzas that came on the vehicle. Maybe next time I'll get RFTs as I know they are improving...but not just yet.

The OEM M3 Front Wishbones & Tension rods have improved the front feedback and gives an almost immediate response. I can turn and have better feedback on what the front wheels are doing. I also have better control and feedback at autobahn speeds and when in S-curves in the mountains. The front wishbones have changed the camber a bit and I do notice a little more resistance on the front wheels when turning the wheel side to side at very low speeds compared to before. It should improve my front tire wear at least.

The OEM M3 Stabilizer Bars front and rear were the more difficult decision to make. I didn’t want a stiff gave an uncomfortable ride or to harm the suspension’s mechanics or traction in turns. I would absolutely not go any stiffer than the M3 bars for the goals of my setup. That being said, I am still forming an opinion, but the body lean is controlled, predictable, and has good feedback. I like it much more than the original OEM sport suspension stabilizer bars.

The OEM Sub frame Bushing replacements seem to have completely helped keep the rear stable and gives me improved feedback without being harsh. I have to say the rear doesn’t wiggle around under acceleration nor does it jump around as much when going over bumps under acceleration. Because I replaced so much at the same time I cannot accurately say that the replacement of the bushings improved all of my issues; but it definitely gives me more feedback and seems to allow the shocks to work more while being planted better. Considering it appears on the top of everyone’s list and I had already had the rear pulled apart it seemed a good idea to get it all taken care of. I might consider the other rear components, but the cost was beyond my reach at the time. I decided to take a wait and see approach for that. I think I’m satisfied with the way it is right now.

The Koni’s I am still making a decision about. I think that under rush hour speeds of stop and go is where the Koni shocks are less comfortable, but it is still more comfortable than stock with run flats were so we have a win. Overall the bumps are much softer and the car body does not bounce around when hitting bumps as it did before. I can feel the bumps, but I’m not moving around in the cabin like I did before; the wheels are compensating instead and keeping the car body. Under highway speeds the car feels like it lost a few hundred pounds. It’s like riding on glass almost. I’m pleased with them. I had considered KW V3’s for a while but had read too many issues about noise in addition to cost and harsher ride, and the difficulty in tuning them to be “correct”. I didn’t want adjustable for the handful of times I go to the track as I didn’t want to have to go to the tuner shop each time I wanted to play with them.

The replacement of the LSD was a difficult decision as I didn’t know how much an improvement it would be over my electronically controlled (DSC v3) open diff. Yes, I know it would be an improvement, but would it be enough to be worth the cost? In a simple answer: Yes. I used to have to lay off the throttle as it was easy to get the rear to do a left right bounce under load over bumps or lose traction in turns on s-bends in the mountain roads. The car likes gentle and subtle input from steering, acceleration, and braking allowing the car to work but it wouldn’t take much to trip out the DSC/DTC, and when you had a tire break away; getting it under control again was less predictable where is now I can just control it decisively with throttle input and have the feedback to know what to do and to what extent. It feels completely different and is linear and seems to pull faster under load and keeps traction at all times. It has changed the character of the car and in a manner that I like. I’ll see how it is next winter but it is a silent part and smooth as butter.

The Cautionary Tale:

This is directed to those looking to do a limited slip differential upgrade. Make sure you have the right part ahead of time. It is all fun and games until you have your vehicle pulled apart and find out you have the wrong part and can’t get another because you’re overseas and an angry volcano stops air traffic. I had taken care to make sure I had all the info about assembly date, VIN number, and spoke with different sellers to get the right part. Unfortunately, the book was wrong. There are a lot of references out there that the e90 330i (w/bolt type not welded o-ring) uses a TYPE 215 differential which is the one in the 335i. It turns out I needed a type 188. I had my car torn apart in the garage with a rental car and a volcano that stopped all mail from reaching Europe from the USA. I emailed Harold at HP Autowerks and let him know about the problem, and he offered to immediately next day air the correct part; but due to lack of mail flow; we went with a full refund including shipping instead. They gave me a really good price too so I’d recommend you give them a call first if you need a differential. ;-)

The Conclusion:

After about a week with the new setup I feel that I’ve met all my goals that I set forth. It steers with better control, feedback, and is more predictable and easier to read. The body lean is less in the turns and is easier to gauge how much more I could push it in the turns due to a more linear progression. The replacement of all the bushings and the stabilizer bar makes the car gives me more feedback but the bumps are absorbed much better because of the shocks. When going over multiple street train tracks I hear the noise more but I don’t feel the bumps as the car body stays stable and the suspension does the work. It handles like a far different, much lighter car and I like it a lot.

[Alpina_B3_Lux]

Great review! You clearly invested a lot of time and research into this, and it's fantastic to see you're pleased with the results.

Have loads of fun driving - and I can confirm your experiences with the M3 parts and the LSD. Do some mountain pass driving with that car now, you'll have loads of fun!

And if you find the time, maybe come to the Nürburgring trip planned on 22/23 May, would be great to meet you in person.

Alpina_B3_Lux

[C.D.335xi]

Excellent review! Thanks for taking the time and being so thorough and well organised - makes reading it very easy.

[gizmo335i]

Wow, nice write up.

Man, where I live I've thought about checking out some local shops to do some things. I would DEFINATELY not take mine to any dealerships around here. I had thought about going down to the K-town area. In the end I found a local guy who works for BMW (25 years) and does work at his house. He did a lot for me for a REALLY low price. This guy is really awesome. I live kind of far from you but if you ever want any more work done....you could come up here to this guy.

Anyway, so you didn't want to drop it then? Unless I missed something...or you already have it dropped? Just curious...

I am REALLY happy with my FSD's. Even though I have a VERY slight vibration going on right now...but only on the highways it seems...I know, doesn't make sense....and of course it shouldn't have anything to do with the drop. I got an alignment done finally...and it didn't feel any different. But I have crappy wheels/tires on right now..and my new wheels/tires are in the air on the way....

Sorry I talked about myself so much....lol...I'm intrigued by reading info about going anywhere in Germany to get this kind of work done...so I thought I'd share some of my info as well..

Sounds like it really worked out well for you....can you post some pics?

[TurboBimmer]

Very nice review and interesting read!

Turns out my dealer doesn't want to install the M3 suspension parts on a 335i, so I'm now in contact with Raeder who also installed my Quaife LSD.

[Aridk]

Good review
I´m looking to do something like that myself.
How are the m3 parts priced in Germany compared to the Us?
I would proberly drive down to Flensburg to buy them.

[marcel b]

Originally Posted by Autobahn335i

Very nice review and interesting read!

Turns out my dealer doesn't want to install the M3 suspension parts on a 335i, so I'm now in contact with Raeder who also installed my Quaife LSD.

so it was your car Christoph talked about :-)
They for sure can install that. I already discussed this with them for mine.

[TurboBimmer]

Originally Posted by marcel b

so it was your car Christoph talked about :-)
They for sure can install that. I already discussed this with them for mine.

Jop, that would be me

I mailed Christoph yesterday to enquire about the price for the M3 front suspension conversion.

[Alpina_B3_Lux]

Originally Posted by Autobahn335i

Jop, that would be me

I mailed Christoph yesterday to enquire about the price for the M3 front suspension conversion.

If it's only the front, it should be really easy. Maximum one hour's work, if you go at it slowly.

The rear is where all the work is, actually.

Alpina_B3_Lux

[Yzandrl]

I didn't drop the vehicle as I wanted to keep the stock geometry that the vehicle has, and the FSD's work well with the stock springs. If I could change the level I'd have the rear matched at stock height as the nose down is more visual than functional.

As for week two, I'm pretty pleased with it; it’s a completely new car. I read a review post by Alpina_B3_Lux(and again amazing write up) that described the behavior succinctly and this setup fixed all of it. I'm starting to wonder if I should have done the rear guide rods/bones at the same time but the cost was already very expensive and I didn't know if it was going to have a good cost/benefit ratio.

As for the prices; I found if you could get the parts without the 19% tax they were about mildly lower than stateside and without shipping. I still ordered the kits from Harold because they took the effort to go down that route for trial and error when no one else did and that means something. But for the oversize parts, it was far better to order the sways locally than pay oversize shipping rates. If you really want to know, just click on links at a BMW dealer and call the parts department with the numbers.

Anyway, I wish I didn't wait so long to do this. Its really a different car; and its still comfortable which was a big goal for me.