[tetsuo111]

Originally Posted by 8081M

The new hood should help a bit with your weight loss program...

Yes, technically correct - the CF hood is around 17 lbs lighter in weight compared with the steel OEM part. Remove the OEM latches and we'll estimate an even 20 lbs off the front of the car.

Economically, the numbers are questionable IMO. While the cost of the CF hood is what it is, the accoutrements drive marginal costs rapidly. Quik-Latch QL-50 with locks are around $350, vents around $ 400, those silly M3 gas struts cost more than $100 because OE is the sole available option. Add heat protection under-hood and paint to finish it, and you get the gist. For people considering a commercial CF hood, you might instead consider just getting a real, BTCC/WTCC hood. The economics are close enough.

I went ahead with the CF hood because light weight is central to the goal of this project. I expect the laden weight, w/o driver, at around 3,100 lbs when finished. Wagons are ~ 200# heavier than sedans, so it would be roughly the same as a 2,900 lbs E90. The interior, at least the front cockpit, is fully complete and livable.

Why the focus on lightweight?

Easy - let the numbers tell the story. As you can see, a 3,100 lb, N52-powered station wagon has a virtually equivalent weight to power ratio as a stock M235i and Porsche Cayman. Add capable suspension, and the wagon starts looking pretty interesting. Now, one can argue the Cayman is still more fun to pilot given the mid-engine architecture, but the point is the wagon is now running with a mid-engine Porsche.

Pretty cool.

[andreu12qw]

Originally Posted by tetsuo111

The interior is mostly finished after the addition of a M3 6MT kombi. I was accessing hidden menus to monitor coolant temps. The new cluster includes a temperature gauge and aesthetic details. Several miscellaneous bits and pieces are needed to convert the interior.

Turner 60A poly motor mounts were also installed recently. The last car had 034 Motorsports 50A rubber mounts. The 034 mounts were perfect for a dual use car. They're clearly less compliant compared with stock, but have zero NVH penalty. All upside with none of the hassle. In contrast, the 60A poly mounts are less compliant than both the 034 and OEM mounts. But NVH is a challenge when the motor spins less than 750 RPM. Furthermore, the nature of the NVH is different between rubber and poly. Rubber has a more forgiving nature, while poly seems to transmit more undesirable frequencies to the cabin. Even above 1k, the vibrations go away with the 60A polys, but there still seems to be a "hardness" to the NVH character.

More chassis strength and stiffness are ALWAYS welcome. The M3 has many chassis reinforcements, and most of them are invisible unless one knows where to look. The largest brace reinforces the front subframe with a large and strong aluminum panel. Non-M cars don't have this panel and use an "A-frame" truss instead. I was able to install the M3 aluminum reinforcement panel by adding 4 OEM blind rivets to the subframe. There are already holes in the frame for a perfect fit. In addition to this panel, I'm having an aluminum reinforcement bar fab'd to connect the subframe to the unibody.

So, after seeing this and the 328 CSL tackle this mod, I went for it as well. I found an M3 plate on ebay ($80!) but when fitting it, the passenger side of the power steering lines seemed to hang down a little more than compared to the driver side. The passenger side had the hard-lined loop and it would have rubbed against the plate if pushed up into place. Did you experience this at all when installing? I will be revisiting the front plate install again once I get a free weekend but wanted to ask a few people to see if they had any challenges while installing.

[Biginboca]

Originally Posted by andreu12qw

So, after seeing this and the 328 CSL tackle this mod, I went for it as well. I found an M3 plate on ebay ($80!) but when fitting it, the passenger side of the power steering lines seemed to hang down a little more than compared to the driver side. The passenger side had the hard-lined loop and it would have rubbed against the plate if pushed up into place. Did you experience this at all when installing? I will be revisiting the front plate install again once I get a free weekend but wanted to ask a few people to see if they had any challenges while installing.

I didn’t have any issues but I was warned that the hard line might need some bending when I was researching the mod. I’m sure you can make it work!

[andreu12qw]

Originally Posted by Biginboca

I didn’t have any issues but I was warned that the hard line might need some bending when I was researching the mod. I’m sure you can make it work!

Good to know! Once I can get my little one to hold a flashlight stable, or I get a free day, I am going to re-attack this mod.

[tetsuo111]

Originally Posted by andreu12qw

So, after seeing this and the 328 CSL tackle this mod, I went for it as well. I found an M3 plate on ebay ($80!) but when fitting it, the passenger side of the power steering lines seemed to hang down a little more than compared to the driver side. The passenger side had the hard-lined loop and it would have rubbed against the plate if pushed up into place. Did you experience this at all when installing? I will be revisiting the front plate install again once I get a free weekend but wanted to ask a few people to see if they had any challenges while installing.

I don't remember any interference issues when I installed the M3 stiffening plate.

There are several members who have installed the M3 plate, each using slightly different attachment methods. I can only speak to mine. I used the entire M3 plate, unmodified, and attached it to the front subframe using OEM rivnuts in front. This is identical to a factory M3. For the rear, I fabricated two billet Aluminum bars to attach the rear of the plate to the front subframe.

Any opportunity to stiffen the frame results in goodness.

Now, I need to figure a way to repurpose the M3 underbody nose panels to my E91. Unlike non-Ms, the M3 actually has front down force, as measured by a German car magazine. The M3 hood power bulge should actually contribute to lift. The under body panels, with spoiler and oil cooler vent, contribute to downforce.

[tetsuo111]

My Voltphreaks VPH900 finally retired.

1. The 7 lb battery functioned flawlessly, even as a street battery. The car actually turned over with more authority than a traditional wet cell battery. And slashed almost 50 lbs compared with a traditional wet cell.

2. Over the past months, the car began throwing more and more random codes. The sole common thread was over or under voltage issues. This flummoxed me because the car continued to turn over with authority. No wimpy cranks - the battery took charge of the starter and CRANKED. The battery was around 6 years old by this time.

3. I finally took a known-good battery from my wife's vehicle and attached to my wagon. The car fired up immediately. So, time for a new battery.

4. I sent my VPH900 to Voltphreaks for service. The battery was diagnosed as benefitting from replacing a couple of cells with new ones, as well as an updated BMS. The fee was $300.

5. In return, Tony (Voltphreaks) sent me a new VPH1200. This battery has more than sufficient power for our energy-intensive platforms. Sadly (tongue in cheek), the 1200 weighs one pound more than the 900, so I'm up to 8 lbs now, 9 lbs with the custom Al battery box.

6. The wagon has wings again!

[Biginboca]

Originally Posted by tetsuo111

My Voltphreaks VPH900 finally retired.

1. The 7 lb battery functioned flawlessly, even as a street battery. The car actually turned over with more authority than a traditional wet cell battery. And slashed almost 50 lbs compared with a traditional wet cell.

2. Over the past months, the car began throwing more and more random codes. The sole common thread was over or under voltage issues. This flummoxed me because the car continued to turn over with authority. No wimpy cranks - the battery took charge of the starter and CRANKED. The battery was around 6 years old by this time.

3. I finally took a known-good battery from my wife's vehicle and attached to my wagon. The car fired up immediately. So, time for a new battery.

4. I sent my VPH900 to Voltphreaks for service. The battery was diagnosed as benefitting from replacing a couple of cells with new ones, as well as an updated BMS. The fee was $300.

5. In return, Tony (Voltphreaks) sent me a new VPH1200. This battery has more than sufficient power for our energy-intensive platforms. Sadly (tongue in cheek), the 1200 weighs one pound more than the 900, so I'm up to 8 lbs now, 9 lbs with the custom Al battery box.

6. The wagon has wings again!

Wait... this was the issue you were chasing since the end of last year? The car is all good now?

[Phil325i]

I assume you had to discard the black plastic undertray once the M3 stiffening plate was fitted? Any pics of your alu bar/subframe arrangement at the rear?

[tetsuo111]

Originally Posted by Phil325i

I assume you had to discard the black plastic undertray once the M3 stiffening plate was fitted? Any pics of your alu bar/subframe arrangement at the rear?

I made an effort to replicate as much as possible the M3 design goal, within the limits of our different front subframe.

1. The front four fasteners for the reinforcement plate fasten to the non_M front subframe after installing rivnuts into existing holes on the subframe.

2. The rear two fasteners differ because the front subframes are significantly different in design. The M subframe has "wings" that extend diagonally outboard and aft, compared with the non-M subframe. See attached graphics.

3. I had two "wings" fabricated with billet AL bar stock, connecting the rear plate with the subframe per the picture.

I'll try and take pics next time the car's on the lift.

[tetsuo111]

I know - another 'Ring video....

Still, modest power + light weight + suspension = a lot of smiles.

It's been said before, going fast in a slower car is more fun than going slow in a fast car.

Just watch Team Shirmer light it up in a 325i, making all of 218 hp!

[bkwld]

Originally Posted by tetsuo111

3. I had two "wings" fabricated with billet AL bar stock, connecting the rear plate with the subframe per the picture.

I'll try and take pics next time the car's on the lift.

This is great! Can't wait for pic of this. I'm ready to do this mod for my 328i and always wondered about not having the "V" bar would be worth it.

[tcphoto]

The E36 and E46 were determined drivers but the E90 driver has some skills and knows his car. Love it!

[kolasinskir]

what a beautiful set up that was !

[tetsuo111]

For anyone who might benefit down the line...

The DSC trifecta can be caused by any number of things. As with any diagnosis, capture the fault codes, then use your reader or go here: BMW Fault Codes to understand the definition and context behind the code(s).

In my case, symptoms pointed towards an SAS optical disc problem.

Follow the excellent instructions here: My $0.02 Steering Angle Sensor Fix

Carefully disassemble your steering column / clockspring / SZL. Open the SZL to access the optical disc. Carefully clean the disc and reassemble. Calibrate the SAS. No more lights or codes...

Enjoy!

[tetsuo111]

There was oil leaking around the ESS gasket, so I ordered a new gasket and replaced. This is preventative maintenance. The pins aren't soaked yet, and I prefer they stay that way. This also cleans up the oil mess around the valve cover and coils.

[tetsuo111]

I spent time recently optimizing the Nitron damper settings for balanced comfort and handling.

Everyone says their city streets are horrible. Some Seattle streets are truly on par with Kabul, Afghanistan. The Nitron suspension (before tuning) is confidence-inspiring on smooth Interstate surfaces at speed, but inappropriate on poorly-maintained surface streets.

After optimizing for DD comfort, the ride is compliant (enough) on the city streets, while trading a bit of high-speed grip. The grip can easily be dialed-in for track days.

My recollection is the TCKline SA suspension on my old E91 was more compliant for DD while retaining control on the track (this may simply be the result of softer springs on TCK coils, compared with the newer R3s), while the Nitron R3 is vastly more precise, vastly better built, and more adjustable.

IME, damper control and adjustment affects ride and handling significantly more than spring stiffness. The suspension frequency and distribution front / rear differ significantly between the Nitron and TCK SA setups. Nitron ratios align closely with the race cars, TCK SA less so, but slightly more comfortable on street. Street car suspensions typically are tuned to a lower resonant frequency, < 2 hz.

Thought a comparison of the two (Nitron and TCK) is interesting. This isn't to determine which suspension is "better". Rather, the idea is to gain insight on the differing designs and objectives for each. The first table captures spring rates and data for Nitron (track and sport), TCK SA, plus examples of two race cars, M3 GT4 and 320si WTCC. The second table captures damper adjustments and ride height. Using M3 ZCP suspension specs here.

Current spec highlighted in green:

[Phil325i]

Interesting. Are you using NTR R1 or NTR R3? I've had my Ohlins for nearly 100K and was thinking about Nitron. Three things put me off:

1) the price (about $1000 more than Ohlins)
2) concern that the rear damper perch might not cope with the forces of a 'pure' coilover (Ohlins use separate spring and damper at the rear)
3) the service interval of only 15,000 miles (Ohlins is around 40K).

Glad you're happy with them though...

[tetsuo111]

Hi Phil,

Nitron's HQ is somewhat in your neighborhood, I think? What a terrific opportunity to meet the people behind the product.

I have NTR R3 on the car.

I am a happy, satisfied user of the product, and I would buy from Nitron again. I considered Ohlins at the same time I looked at Nitron.

Price - I think Nitron R3 is more comparable with Ohlins TTX. R&T is priced more like TCK SA. I have no idea if one is better than another. I've heard they're both well-regarded, in the top-tier. Caveat - much feedback is sourced from the motorcycle community.

Customer Support - Nitron was superb - tops. There was a problem on my delivery with a part fitment. I reached out to Nitron support via email. They clarified and confirmed the issue with a handful of emails in a day, and overnighted parts from the UK to Seattle, WA!

Build and materials - Industrial art. All billet parts, low-friction coatings and finishes. I have not yet had the dampers serviced.

On the other hand, Nitron lacks the distribution network and vendor support compared with Ohlins, in North America.

Sounds like a great decision you're presented with...

Originally Posted by Phil325i

Interesting. Are you using NTR R1 or NTR R3? I've had my Ohlins for nearly 100K and was thinking about Nitron. Three things put me off:

1) the price (about $1000 more than Ohlins)
2) concern that the rear damper perch might not cope with the forces of a 'pure' coilover (Ohlins use separate spring and damper at the rear)
3) the service interval of only 15,000 miles (Ohlins is around 40K).

Glad you're happy with them though...

[Phil325i]

Phew! NTR R3's are even more expensive than the R1's I costed. Will be interested to see how the rear damper perches hold up over time...or did you have them reinforced before you fitted the Nitrons?

[tetsuo111]

I perseverated on that for awhile. I understand this was a challenge on the E46 platform.

The few comments I found for E90 platforms indicated the rear perches are reinforced compared with the E46. I know this isn't data, so take it with a grain of salt.

Since the car isn't a full-time track car, I proceeded with the rear coilover conversion. If I really felt the need to scratch this itch, I would have the towers reinforced, and definitively put the issue in the rear view mirror.

As it stands, I have had no issues in the 1.5 years the setup is on the car.

I don't want to sound like a shill, but if Nitron was in my backyard, it would be no-brainer. The level of customer support was a best-practice, IMO.

Originally Posted by Phil325i

Phew! NTR R3's are even more expensive than the R1's I costed. Will be interested to see how the rear damper perches hold up over time...or did you have them reinforced before you fitted the Nitrons?

[tetsuo111]

We added a second BMW to the garage. This is my wife's new daily driver.

We lost her old car after an accident (no injuries).

For a replacement daily, I needed something that met a difficult set of requirements:

- budget
- daily appliance duties
- high safety rating for the family
- reliable
- AWD for winter mountain travel w/o needing to install chains
- some ground clearance for winter mountain travel
- compact dimensions for urban errands
- large enough for several sets of skis and mountain gear
- not too 'special'. if / when it gets dinged in the parking lot, I would rather not get too upset (Macan disqualified, sadly).

So, she's happy with her new ride. After a couple weeks of ownership, all's well. We purchased the car from BMW Seattle. The experience was positive, and I would buy there again.

[Biginboca]

Originally Posted by tetsuo111

We added a second BMW to the garage. This is my wife's new daily driver.

We lost her old car after an accident (no injuries).

For a replacement daily, I needed something that met a difficult set of requirements:

- budget
- daily appliance duties
- high safety rating for the family
- reliable
- AWD for winter mountain travel w/o needing to install chains
- some ground clearance for winter mountain travel
- compact dimensions for urban errands
- large enough for several sets of skis and mountain gear
- not too 'special'. if / when it gets dinged in the parking lot, I would rather not get too upset (Macan disqualified, sadly).

So, she's happy with her new ride. After a couple weeks of ownership, all's well. We purchased the car from BMW Seattle. The experience was positive, and I would buy there again.

Congrats… but what year/mode is it? I’m guessing it’s an X3?