Build Log: M57 X5


Nov 7, 2016
San Diego
And a 200 shot of nos or whatever. Upgraded turbos do not even make that much.

That sounds bad ass. What would you say 25% louder?

This what you used?
Correct, 3" QTP but I added the turn-down tip and replaced the HUGE momentary switch with a much sleeker and easier to operate switch.

Hard to say about the audible change since from my perspective the turn-down under the car (when open) makes it seem much louder in the cabin than it would be as a rear exiting exhaust. Conversely in the video behind the X5 the exhaust through the muffler may seem louder as it's pointed reward and the turndown in pointed down. I like having the option with the valve but in an ideal world both open and closed would exit the rear of the X5 but the added time/labor/expense to do this isn't worth it IMO.


Nov 7, 2016
San Diego
I had a chance to execute the 3.15 rear end swap, I will be making a separate thread on this but will add some cliff notes here. For those who have done diff swaps, the change from 3.64 to 3.15 doesn't offer any surprises. Install was straight forward. The downside is acceleration from a dig isn't as dramatic but normal daily driving benefits from the gearing as the X5 has a lot of torque and has no issue moving itself along. The real benefit of this comes at highway speeds, I did some stretches at 60-65mph and it was returning ~35mpg which is what the 3.64 mustered. 65-80mph is where the 3.64 would fall apart and MPGs would drop down to the low-mid 20s, with the 3.15 at 70mph the X5 was still returning 35mpg. I still need to do some testing at higher highway speeds, 80+mph, but the X5 is definitely not as affected by the added speed. I will be swapping in the front diff to complete the gearing conversion and recommend this mod to others who value highway MPG and a less dramatic driving experience overall.

I was able to get a drive from San Diego up to Orange County, just under a 200 mile round trip, mainly flat with some rolling hills. On the drive up I was able to get 32.2mpg and this included 10 miles of urban driving to a shop. On the way home I got 35.1mpg highway only. Unfortunately I wasn't able to hand calculate the figures, this is based off cluster read-out and mine is usually 0-1mpg optimistic so take it for what it's worth.



Big Ass Wrench

If you recall I was playing around with running the shorter rear-air struts with the taller (2" taller) upper strut mounts from a non-air X5 and the goal was to get proper strut actuation while lowered. the air strut with the air mount was too compressed and the air strut with the non-air mount was too extended so I made some 1/2" and 3/4" spacers out of plastic cutting boards which are used to space the taller non-air mount down bring the strut into normal operating range.

To accommodate the spacers I needed to replace the OEM M10 studs with longer versions, after some research I found that ATVs run M10 wheels studs and with all the crazy modding that is going on in that industry, some companies make extended wheel studs to accommodate spacers. I found some that gave me an extra ~20mm of usable thread length.

Old studs out

Extended studs

Building spacers

I made 2 sets of 1/2" and a pair of 3/4" so I can space the mounts as needed between 1/2-1"

What's interesting is how little stanchion travel BMW allows before the bump stops come into play on the rear struts. There are 3 OEM bump stop options: short, medium, and long with the short being sport, long being for 3rd row, and medium for X5s spec's in the middle.
Looking at the meidum bump stop install you can see there is only about 10mm of travel before the bump stop is activated, this is why most X5s ride so poorly when lowered, most are riding on the bump stops, literally.

Here is the medium BS in the back and the sport (short) bump stop installed.

Here is a sport trimmed.

I installed the medium bump stop and paired with a 1/2" spacer which positions the strut in an acceptable operating range but closer to the "extended" side of the spectrum as opposed to "compressed." I know I am still mis-matching the dampening characteristics of the strut with squished air bags but this is a step in the right direction, more testing to do.

I got around to installing the switch for my QTP exhaust valve. I ditched the huge/ugly/hard-to-operate switch QTP supplies for a sleeker momentary switch I bought off eBay, I wanted a more OEM look and easier operation. The goal was to mount the switch in an easy to access location that was also a bit out of sight, and I wanted to mount the switch into a panel or piece of trim that could be easily replaced if I wanted to revert back to stock. Very happy with how everything came together.


With the dark theme of the X5 the taillights and their bright red bothered me a bit so I got some Lamin-X smoked film. This is the lightest they make and offers the "dark-cherry" look I was going for. I also used some knifeless tape to cut the film so that it was only on the red and the white/clear sections have no film.

As a lighting nerd this is a step in the wrong direction in terms of illumination and safety so I had to offset that. I upgraded the rear turn signal and brake light bulbs to Diode Dynamics LED bulbs, I also coded the light module to do a double hazard flash. The bulbs are significantly brighter and combined with the instant-on flash of LEDs the turn signal more effective now than it was in the OEM configuration, even with the tint.



Nov 7, 2016
San Diego
I was able to get the X5 on some dynos, both a Mustang Dyno and a Dynojet.

Mustang was 317whp 504wtq
Dynojet was 370whp 520wtq

For those that don't know Mustang dynos use load and typically read lower. In general Mustang dynos should be more accurate but it's hard to say since it all comes down to proper calibration. Dynojets are more common for "big stick" comparisons amongst enthusiasts as dynojets are simply and measure power based off how quickly the vehicle can spin a drum, less variables to manipulate the numbers.

The dynojet operator was starting the pulls at way higher RPMs then he should have, shame on me for not picking up on this but he was going WOT between 2,500 and 3,000 rpm (seriously) and the M57 makes peak TQ around 2,950 so for my observant BMW diesel enthusiasts you may notice the Dynojet TQ numbers seem low, this is why, with a clean pull TQ #s would likely be ~550wtq.

On the Mustang dyno I was able to compare my custom inlet to the OEM airbox and although the data isn't perfect since the engine was getting a little heat soaked, it looks like the intake does flow better and offered more power, roughly +10hp +10tq. I am patiently waiting for the shop to email me the overlaid graphs.

On the Dynojet I did 2 pulls with my custom intake and 2 with just a 3.5" velocity stack mounted on the MAF. The pulls are so chaotic and the data so sloppy it's hard to discern what's going on but there was no measurable difference between the two.

Mustang session

Dynojet session

Custom Intake

Velocity stack
  • 2Like
Reactions: derekgates and Torgus


Feb 23, 2018
Your motivation and creative work-arounds to problems continues to amaze me.

I knew I wanted an E91 but never knew I wanted an X5 until seeing your posts. I'm loving the diff changes and observations of mpg; I am about to do the reverse with my 335is (2.56->3.15) :D


Nov 7, 2016
San Diego
ZL1 wheels repaired and powder coated Prismatic "Graphite Black" it's essentially a black with a fine metallic flake and a satin finish. I liked the way the OEM GM satin black finish looked so I used that as a base and I figured the slight metallic finish of the graphite black would compliment the Platinum Grey Metallic on the body. The powder coat turned out to be slightly different than I was envisioning but overall I am very happy.

With my front left sidewall damaged and the other tires on lower tread it was time to replace the tires. I jumped from a 295/40/20 square setup of Pirelli Scorpion Verde to a slightly taller set of Hankook Ventus ST RH06 in 295/45/20. I knew they would be tight and after much research, measuring, and guesstimating I still wasn't confident they would fit. I was relieved to find out the fit perfectly.

I was going between these Hankook RH06s in 295/45 or doing the Michelin Pilot 4 SUV in 305/40. I run Hankook Evos on all my other cars and appreciate the value the tires offer; good grip, quiet ride, adequate tread life, and a fair price. My personal experience combined with the reviews I read were enough for me to give the tires a shot. The Hankooks are about 1/3 the price as the Michelins too.

For the way I use my X5 this 295/45 20x11 square setup is perfect. Given the limitations of the vehicle, tire options, DXC, etc. I can't think of anything I would change. Jumping back up to a taller and heavier tire does zap some of the acceleration performance but the added comfort of the beefy tires is welcomed and worth the trade off.

I am glad the X5 is back from my wheel guy but it was REAL fun dailying the E61 again, never a dull moment.

Garage space was taken by my e39 touring which is getting engine work and a manual swap so I had to get creative in the drive way with 2 jack stands and removing 2 wheels at a time to swap tires. lol





No rubbing except at full-lock to the right. I will heat, melt, mold this vent further forward. It eats up a lot of space but I can work with it.

I love tight fitment. Looking at the X5 from afar it looks fairly normal but poke your head in the wheel well and you can see where all the research, calculations ....and luck paid off! lol


A look at the tread pattern.


Nov 7, 2016
San Diego
It has been about a month since the last update and the X5 hasn't received any fancy upgrades or major maintenance, instead it has been put to work.

Here are some updated thoughts on a few items. The Brembo BBK is but the Ceramic Hawk pads I purchased squeal like crazy with a little bit of heat in them, upon further research this seems to be fairly common. The temporary solution others use is to put a TON of grease on the back of the pad which will only work for a short amount of time. No thanks. I will be replacing the pads when I have free time.

The Hankook tires are great, especially for the price. Cornering grip isn't the best but considering how I usually drive the X5 they are well suited for cruising + occasional spirited driving. In general they roll smooth and quiet but do pick up some textures and small undulations in the road periodically. It's a bit odd because I am used to a tire either being very communicative to what it's rolling over of it's a mushy/smooth ride, it's usually one or the other. The Hankooks are quiet 95% of the time but do transmit some vibrations/hums depending on the surface. It's not a big deal or a major annoyance, I just find it peculiar since it is selective on the what the tire transmits.

Cargo Box. This thing was installed for a trip out to AZ in which I also had 2 bikes on a hitch rack. I am a large human and ride a large bike so my handlebars, seat, and tires protrude over and around the perimeter of the X5 and add a bit of drag, much more than what "normal" people experience with their average sized bikes. I was a bit disappointed to see such underwhelming mileage, I was seeing 22-23mpg where I was expecting closer to 30mpg.

During this past winter trip I achieved 30mpg for a tank, driving in snow, with the cargo box, on snow tires, and bouncing around between 3,000 and 8,500ft. So I always thought the cargo box wasn't adding too much drag. Since this winter trip I have added the BBK and taller/heavier Hankook tires which both add some unsprung weight so I was kicking myself that I ruined the fuel efficiency of the X5 with the brake and tires (still worth it!).

The last couple weeks I have been moving into a new house and once the main move was over I took the cargo box off and while running some errands doing an out and back on the freeway 65-75mph, soly highway driving I was able to hit 31mpg one way and 36mpg on the return. Nice. My cluster mpg read out is usually within .5mpg of actual mileage so I use it as a fairly accurate reference. There are many variables which can impact fuel efficiency so this isn't a hard science but my guesstimate for mpg loss due to cargo box (at highway speeds) has gone from 1-2mpg up to 5-6mpg.

Anyway, here are some pics of the recent adventures.

Riding San Juan Trail in Southern Orange County


Always using HPR when I can.

In the mountains for sunrise. Noble Canyon Trail, Mount Laguna.

My buddies bike matched the brake calipers!



Scoured a deal on some lightly used SwissTrax Ribtrax!




Fun Fact: The tiles were previously installed in a hanger which was featured on the Swisstrax website.

Working on the new house, replacing a warped 20ft 2x4. Aka Activate Joust Mode. lol

Just a pic!

The last items to be moved from my old house was my E39 Touring project, "DAS VADR" The goal was to get it running before the move buuuuuuuuuuut that didn't happen so in the engine and trans went with the essential components so I could roll and trailer the chassis. If anyone wants more info on the build you can Google "Das Vadr E39 Touring" and links should show in the results.

This was 3 days before the move :)


It wasn't easy loading the wagon myself and with $50 worth of Harbor Freight tools but it worked (barely).

PSA: Air Suspension is awesome


Unloading at the new house



Reunited at last! time to finish the garage remodel so I can pull the E39 in and finish it up!


Nov 7, 2016
San Diego
The X5D has been fulfilling it's role as the diesel workhorse running errands, hauling stuff, and dropping the hammer on unsuspecting "sporty" vehicles around town.

Here is a collection of random pics sprinkled in with some meaningful updates in chronological order.

Random pic 1

Tailgate FTW

20' 2x4s to reinforce my attic

Propane! This high-noon lighting shows the (sorta) flush fitment.


I have decided that my next project will be a M57 powered, RWD, AT, E61 Touring. In addition to the E61 I will probably buy a e90 335D donor for the engine, trans, and misc parts. There will be a shipment of 535d specific parts from Europe like wiring harnesses, proprietary cooling, ducting, etc.

The dream was to make a BEAST AWD diesel wagon that could handle repeated launches. Unfortunately the front drivetrain on the 530xD is shared with the E61 535xi which doesn't like high loads especially at lower ride heights so it would be a ticking timebomb with the M57. I explored retrofitting the AWD from the E70 X5 which is much stronger but the larger ACT500 TC won't fit the E61 which is paired with an ATC300; a custom transmission tunnel would allow it to work but I am not interested in tackling that at this point. Although not as dreamy as an AWD diesel wagon the RWD configuration is the easier, simpler, and more reliable option -this is why I converted my 535xi to RWD.

Of course with RWD the issue becomes traction and the wagon will make somewhere between 600-700tq to the wheels, I also wanted a STRONG drivetrain which for me means OEM M5 drivetrain with a 210mm BMW LSD. Installing an LSD into a stock 188mm E60 open diff works but 210mm diffs are better :) Fitting M5 drivetrain to an E61 is easy, it all bolts up with the exception of the driveshaft which needs to be modified. The tricky part is getting a 210mm LSD with a diesel friendly final drive. E60 M5 comes with a 3.62 and a 535d comes with 2.56 lol. BMW 210mm diffs are now only found on M cars and certain older heavy-duty vehicles like V12 7 series, etc. and with all the gasoline cars in the US it's rare to find a ring and pinion that isn't in the 3.00-4.00:1 range. AFAIK BMW never fitted a 210mm diff on a diesel vehicle, ever, they all had the smaller 188 cases.

Through furious research and some luck I was able to track down a 2.65 210mm ring/pinion. Originally equipped on an E31 850i, V12, with a manual trans. This was a US-only import and after looking up the production numbers there are only about 300 in existence and through luck/fate I was talking with an eBay seller who had a 2.91 R/P and I mentioned the E31 and he said he had one not listed!!!! Sick. This was the missing link that allows me to build an essentially bulletproof differential, that has an OEM LSD, and near-perfect ratio for a diesel wagon. It also means I can run the complimentary M5 drivetrain which means more durability and peace of mind!

Anyway, the 3.62 I currently have in my white N54-E61 makes for very short gears and I have been meaning to "upgrade" to something taller. The E92 M3 has a 3.84 in the manuals and a 3.15 if equipped with the DCT. 3.15 is just about perfect for my intended use SOOOOOOOOOO I picked up a 3.15 LSD from a M3 w/ 43,000 miles. This will go into the N54 wagon and the M5 LSD will come out, be rebuilt with the 2.65 R/P, and wait patiently for the diesel E61 project.

The M3 LSD was located 90 miles north of me and it was a nice opportunity to do some highway cruising and check out MPG numbers. Normally my impressive fuel economy just gets decimated while driving around town since I drive hard. This highway testing got extended as the dismantler gave me the wrong diff at first so I did the drive x2 so about 350 miles when it's all said and done. The first leg I got 32mpg and return was 34mpg, highway only. On the following 2 trips averages were right around 33mpg and this is driving smoothly in the 60-70mph range. With some hard city driving the X5 was sitting with 1/2 a tank of fuel left, ~370 miles covered, and an 31mpg average, not bad!

A celebratory pic bringing the M3 LSD home, little did I know it was the WRONG one. lol

Better look at the beefy boys

I will do my best to break it

Enjoying the highway MPG before it's destroyed by spirited driving.

I had 2 oil leaks that were destroying my driveway. One was from o-rings that were failing on the vacuum pump, the other was my connection between my oil catch can outlet that connected to my dip stick via a T-fitting. The connection was leaking and it was due to Evan-error. Although an actual dipstick > electronic oil level, the X5 has both so for the sake of a clean and secure install I deleted my dipstick and plumbed the OCC output directly into the oil pan via the dipstick. I cut down the remaining dipstick, bored out the top, and pressed in a barbed joiner fitting. I have a 1-way check valve and it's working very well so far.




Due to the leaking vacuum pump the front of the block got saturated which assisted the AC belt in shredding itself. After the leak was fixed I cleaned everything with a power washer.


Meyle HD thrust arms fitting with monoball bushings. A bit of a bugger to remove, you need to turn the steering about 30 degrees towards the side you are working on and gently push the arm reward, upward, and inward to get them out.



My buddy picked up a nicely modded F10 M5. He replaced his manual single turbo 600awhp E90 with a 600whp F10 M5. Cool car but honestly I thought it was going to be faster. lol. I thought it would destroy my 550whp E61 but after driving it, I think it would be a really close race!
  • 2Like
Reactions: Torgus and KAIZZER


Nov 7, 2016
San Diego
Things are looking up for the X5. With a winter trip on the horizon it's finally time to install the 3.15 differential, to match my rear and complete the 3.64 to 3.15 conversion. I have been running the rear 3.15 for about 9 months in RWD mode and it's great, now time to finalize and flash back to AWD. There are some other parts which will be installed in addition:

- Upgraded Level 10/Sutphin Tuning Torque Converter
- 3.15 front diff (to match rear 3.15 and reactivate 4WD)
- Brake pads
- All new suspension F/R to compliment the just-installed monoball thrust arms.
- Mayle HD wishbones w/ adjustable camber
- Replacement AC belt
- Replacement pano roof surround
- Diesel Extreme injector cleaner
- Oil change

Items not pictured:
- Replacement exterior driver door handle
- Repair pano roof partitions
- Repair Vacuum pump seal (still leaking)

I am excited to observe the difference going from RWD with the sloppy and bullied stock torque converter back to AWD with the upgraded converter. My Dragy data shows about .5g during a launch with my current setup and that is with the tires hooking up well, not absolute grip but not bad all things considered. The Dragy data from another tuned diesel X5 with similar mods shows 1.1g from a dig which is awesome. With my 3.15 gearing and larger tires I am assuming my performance won't be as ferocious but it will still be a hoot. Response/driveability around town should also be much more pleasant.

Finally put the ZL1/Hankook combo on a scale. The tall tires have a very obvious weight penalty and offset the light ~27lb 20x11 ZL1 wheels.

Hike in the rain with the doggos.



Major General
Staff member
Aug 11, 2017
Great thread. Couple questions on the suspension, as I'm looking to undertake mine. What's your observation on steering feedback with the tension strut monoball? Have you given thought to using ball joint in any of the other suspension components you are replacing? For example the lower front control arm? The two replacement arms in the rear? I'm not sure what the upper wishbone in the front does, load deflection wise.

@[email protected] and I plan to do an Öhlins damper setup for the X5. I just got in junkyard parts so he can start working on the setup. We'll be using AC Schnitzer springs.

This is probably one of my favorite builds around. Please keep posting. Superb!

BTW who milled out your wheel hub centers? I need a buddy close by with a Bridgeport. No one I know at the moment has a mill big enough.