Atacama Yellow 35is build thread

[Daniels34]

I loved reading your 51 pages of 35si tuning and improvements Peter (tried direct message but that failed)

I admire your perseverance and that you list all the stuff that went wrong

Just bought a 35i myself which is mildly tuned (decat and light tune)
My new 35i has 60,000km of FSH and some 29,000km of mostly oil and spark plugs

The DCT oil was changed 20,000km ago but I think only the oil and external filter
Guess it needs the full BMW DCT filter kit now? (Some gbp 350)

I do see cheaper aftermarket DCT filter kits but which are any good?
After the many reported leaks following changes of the gearbox sump, I have become hesitant….

Another job I listed was replacement of the rear diff oil. BMW advised me both jobs are not needed but surely a good idea?

Also wanted apple carplay and also looked at the mr Volt system
Noted the many issues you had with that conversation
Worth it or simply put the iPhone on a MagSafe phone holder?

Thanks so much for your valuable work and willingness to share
It’s inspirational

Sander Daniëls

 

[B21]

I loved reading your 51 pages of 35si tuning and improvements Peter (tried direct message but that failed)

I admire your perseverance and that you list all the stuff that went wrong

Just bought a 35i myself which is mildly tuned (decat and light tune)
My new 35i has 60,000km of FSH and some 29,000km of mostly oil and spark plugs

The DCT oil was changed 20,000km ago but I think only the oil and external filter
Guess it needs the full BMW DCT filter kit now? (Some gbp 350)

I do see cheaper aftermarket DCT filter kits but which are any good?
After the many reported leaks following changes of the gearbox sump, I have become hesitant….

Another job I listed was replacement of the rear diff oil. BMW advised me both jobs are not needed but surely a good idea?

Also wanted apple carplay and also looked at the mr Volt system
Noted the many issues you had with that conversation
Worth it or simply put the iPhone on a MagSafe phone holder?

Thanks so much for your valuable work and willingness to share
It’s inspirational

Sander Daniëls

If you’ve changed the oil then frankly that’s enough ..assuming it was correctly filled..many garages don’t fill them correctly as they confuse the fill procedure with the ZF8HP one which is simpler..

I detest loose wires in the cabin and ‘bits’ tacked on in the cabin so very much a fan of the mmi boxes especially mr 12 volt…

Rear diff I’d revisit when you do the LSD.

 

[B21]

Great book…very in depth…sadly I’ve already done most of the mods he suggests.ll

 

[B21]

Another one of those in theory short jobs…

Remove the standard rear anti-roll bar drop links that are fixed in length to suit the standard ride heights and standard ARB with adjustable versions.

Theory dictates that the ARB should be set with zero preload on the links front and rear with the car sat on the ground in the intended loaded position.

I suspect very few are..if for no other reason that it’s not very easy to do with the wheel fitted and that means you need axle supports or some other method to preload the suspension to the correct ride height.

Since I’ve now custom tweaked my Ohlins Road Track shocks with uprated springs and different ride heights ..and with H&R ARBs it should be done ‘properly’…

However trying to get the old droplinks off was a job over 3 days…

There is NO room to get sockets in on the top ones..and precious little room on the bottom ones..many hours trying to fabricate something that had enough leverage with access…I should have bitten the bullet and removed the springs and shocks..not that it would have helped much..

The extension tension on the ARB with the suspension of full droop was one thing..

Then I discovered that my local garage guy who fitted the H&R ARBs way back in 2022 had ‘mullered’ the threads on the bottom drop link shouldered bolt.

You can see the thread is twisted and damaged…took over 180nm on the torque wrench to move the critter..and the nut fought me all the way to the end.

I was crying by my metaphorical quiet river as these bolts are custom made by H&R and are not available as spares…

But loh..through the joys of Christmas ..I found a bag in my store with a number of new bolts including two of the offending type…a Christmas miracle!

How, why, when they appeared I can’t think off…I can only assume that the other H&R ARB fitted to my 20i MSport never used them..?

Anyway 3 days and about 6 hours of labour / head scratching and I’m ready to start the reassembler process

 

[B21]

Steadily worked at fitting the uprated ARB links to the H&R ARB..

Squared the circle of preloading the ride height with no wheels by using these very fetching very tall Draper axle stands…

For the uprated ARBs these drop links are soooo much better than the stock ones…

I’ve set the rear ARB on its hardest setting ..previously on this car and my 20i MSport used the medium setting..

Everything seems to now line up well with no clearance issues on either the drive shaft or the rear lower camber arm which folks report are major issues with stock drop links…/lowered cars..

Interestingly either the ARB is bent / the suspension is slightly different on each side but needed quite a few turns on the RHS shorter to get the bar to fit without preload both across the axles and with the overall preload..

Suspect that’s why the previous gorilla mullered the bolts trying to get them in with attendant preload / distortion..

 

[B21]

Moving to the front…pre loaded the front axle parts on my new taller axle mounts..

Adjusted the front ARB..no adjustment holes , I suspect for safety reasons…don’t want front oversteer..

Lined up bar , fresh washers and nuts..very easy with the axle stands…

Whilst loaded tightened up the subframe to steering knuckle strut..as advised in TIS..

 

[B21]

New Year’s Eve saw the fitment of the production version of my design for a rear BBK for E89s.

I’d fitted a prototype version early in 2025 and there were a couple of issues with it…one was that the initial design required a couple of spacer washers on certain parts of the adapter bracket to get the caliper cradle (BMW M5/F10) to be fully centralised on the disc..345mm BMW E60, 370mm BMW F01.

Each version different combination of washers. I’d plagiarised the caliper cradle bracket design from other similar BBKs for other cars.

However all these designs used 1mm wider hole spacing than bolt size ..the combination causes a fair degree of ‘slop’ in the total structure prior to torque-ing up the bolts.

This version 7 production bracket uses 0.1mm tolerances instead and has fully rebated machining so no spacers are required.

Interesting the left hand version that used TRW caliper cradle (BMW OE) mated perfectly with the M5 caliper and the bracket…the right hand cradle is a NTY copy and just wasn’t as good at mating up with the OE caliper..did it in the end but more faff.

So the production version now installed in a fetching Phoenix Gold with Ferodo DS2500 pads to match the front…just need to apply the brakes a couple of times from a cold start ..otherwise you don’t stop!

 

[B21]

Something nice n geeky for those whose previous technical forays were agonising over which colour to paint their alloys…

Here is the CIC computer which powers the idrive screen and system.

Used for the E89 for it whole run and first released in 2008..its a product of the very early 21st century..

Still useful as its plugged into many sub systems on the E89 and with a MMI box does a great CarPlay rendition.

The map data and the cd track info and possibly some stored audio resides on a 80gb ruggedised hard drive similar to an old laptop drive.

It’s held in a cradle and can be easier swapped out.

There are a number of failure modes on these units, one is the failure of this drive.

A geeky dodge is to clone the contents of the drive before it fails and transfer it to a solid state drive..

Apart from better reliability the SSD has much much faster I/O…over 10 times faster at 50m/bytes per sec

So…your menus won’t operate faster but any map function will be a lot quicker…

There's a chicken and egg issue..you have to copy the image of the hard drive BEFORE it fails..then its too late.

The drive was formatted and used in a Unix system (QNX) that idrive on E89/90 uses.

So any normal PC file utilility will fail.

As you can see there's not that much actually stored on the drive.

Pointless storing audio as its crap quality!

You need a whole image file manager and an adapter cable to be able to read the old hard drive and then write that to a USB stick..then read the USB stick to write to the new SSD.

Fof those who asked the old hard drive is held to its carrier with just 4 small screws..remove them and fit the now copied SSD and you are good to go!

 

[B21]

Meanwhile back on the car I decided to repurpose my penis enlarger as a pressurised brake bleeder unit.

Modern brake systems are very complex with their ABS/stability control modules.

BMW calls for a two stage brake bleed once the system has been drained as in the removal of calipers and left to drain out.

First stage is a normal bleed on all four wheels..with the rears needing potentially being taken off their mounts and inverted whilst attached to get the air out of the electronic parking brake area.

I was amazed at how long and how much air was in the system with over alitre required to get the first stage done.

Second stage requires ISTA activation of each brake channel on each corner with brake pedal pressed 5 times per chanel to purge air caught inside the DSC unit!

Using 5.1 brake fluid as its now preferred for more complex DSC/ESP units.

 

[Reamesy]

Did you know if you engage the brake pedal and hold it there with a piece of wood for example, it stops the fluid draining out. That limits how much air enters the system?

 

[B21]

Did you know if you engage the brake pedal and hold it there with a piece of wood for example, it stops the fluid draining out. That limits how much air enters the system?

I was aware of it ..but…I decided that I was going to do a full purge anyway as last time I did not and wasn’t sure whether there was a need / benefit of a full purge..

If I was going to get everything back together in a few hours a good idea but with 5-6 weeks down time decided just to let it bleed out..

A few folks who have done caliper changes / updates complain about mushy pedal…

 

[Reamesy]

It’s always best to carry out a full flush and bleed but it limits the mess and air locks

 

[B21]

It’s always best to carry out a full flush and bleed but it limits the mess and air locks

Yup for sure plenty of mess…good job I’m not precious about the floor…

 

[B21]

So moved on to the various media related items today..

Boot was stripped out..but required lots of heat in the garage as those plastics get VERY brittle when they get cold..

The easy ‘bug’ was ‘ticked’..I’d wired up the radar units for the blind spot system to the ID4 digital cluster ‘correctly’ AFAIK. But ..the pin outs must have been transposed into the cluster itself…net result was when I was overtaken on a motorway (rare event) the left hand side warning went off…

Anyway swapped over the two connectors in the rear boot area to sort that out..

Lost quite a few plastic clips as they ping’d off…I’ll find them shortly..

Onto other matters..

 

[B21]

Another geeky and tedious post for those with low boredom thresholds...

My E89 came with the 677 'Top Fi' 14 speakers DSP/amp setup..

IMHO pretty crap by my Volvo XC70 reference..or even the F56 Mini basic system..

Moving on..

I replaced it with the Audiotec Fischer Match 10 DSP

The 677 was rated at around 420 watts 'music power' at 10% distortion..

The Match 10 is rated at 850 watts RMS at less thab 0.03% distortion !

RMS = 'music power'/ 2 ish maybe 4 ish

So that Match 10 is a much more powerful affair.

It also a Class D amp (digital) rather than the 677 Class A/B..so much more efficient

Finally the Digital Signal Processor is many orders of magnitude more powerful than the 2007 ish DSP in the 677

Unfortunately the E89 with 677 runs a MOST 25 digital data bus for audio around the car..

Almost all aftermarket amps can't cope with a MOST data stream (its far more complex than a simple TOS link digital optical link as seen on the back of your TV)

So you need a bridge that takes MOST 25 data streams and convert them into 'simple' TOS link / digital optical / coax digital.

That's the AF Helix SDM125 box..a very expensive box for somthing so small with not much in it.

I mounted both on the old DSP/amp frame that the old amp came with to keep the installation simpler..

With this winter's refresh I decided (cause I can) to add an onboard interface to allow if needed /useful the iphone to play directly to the DSP/amp speakers without having to go to through the factory head unit...don't ask me why..that would ruin the post..

I did buy a USB interface card ..but..this then requires a USB cable from the amp to the phone in the cabin..

I then saw for 'peanuts' the HD bluetooth version..perfect I thought..use that..no need for any extra wires..sell the unused USB card!

However..

I got the DSP/amp out..unscrewed the back plate that is standard and reached for the new back plate for the HD Bluetooth..

Of course over time AF has made many variants of its amps....and yes..this back plate doesn't fit my Match 10!

So I'll go with the USB card as I still need to route my second rear camera feed to the front cabin..so I'll do both at the same time..

Another set of first world problems..

 

[B21]

So various tasks..

Fitted a few shelves in the garage to act as 'scratch' areas to rest tools / bits of car rather than all lying on the floor!

Reassembled the Match 10 DSP/amp with its new USB direct input card back on to the old 677 frame with the Helix MOST 25 to digital optical box.

Bolted that back in..had a minor heart failure with no sound..however helps if you connect the MOST 25 bridge box to the Match 10 with the optical cable..strange no sound without that baby in place.

Need to get the USB cable from the rear bulkhead to the centre armrest cubby hole..thought I might have to strip the whole back out.

However my new toy a flexible picker upper helped me route the cable (and the remaining reverse camera cable) through the gap in the bulkkhead into the cabin..

I think by just lifting the bottom of the csrpet trim up from the bottom I'll be able to get the cables through!

 

[B21]

Folks struggle to visualise the layout, connections and concepts when you start to add yet more 3rd party parts to what is aleady a complicated topology.

Even I get confused as to which bit does what where..

So here's a nice schematic of how all the media systems hang together on the car..

Enjoy..

So yes you could use upto 7 smart phones /media players in this set up simultaneously!

 

[B21]

Today used my very expensive (£300) official BMW special tool to help remove the two roof mechanism gas struts in the boot with new ones.

On the first strut a bit of a learning curve but then second one was a breeze..

God only knows how / what damage you’d do to yourself or the car trying to get these suckers off without it.

The struts are still under a lot of pressure irrespective of the roof position.

I was surprised the old ones still offered very substantial resistance so a simple push test is not going to reveal much..

However..the one and only roof in the boot move so far was less dramatic with no impression that the roof was ‘falling’ into the boot.

A cordless power driver is a big asset as the thread screw requires many turns to off load the old strut and the preload on the new strut…

Used a marker pen to highlight the preload required for the new one.

Best bet is to clip the bottom in first and then you can visually see how much you need to adjust the top one.

 

[B21]

Full system test of all the media parts worked perfectly…Thanks to AnubisZed for the final s/w config tweak in the Mr 12 Volt box..




See if you can spot which fu cation in which subsystem is doing what…

 

[Pondy]

What's the deal with the anti-clockwise rev counter?
A few rev counters have gone 'the wrong way' over the years. It would make my head spin and make me (even more) angry, as 'clocks' are supposed to go clockwise. Otherwise they wouldn't be called 'clocks'.