Category Archives: bmw stuff

Bmw stuff in here.

Day 8 – 10 Day Build – E21 S54

It’s clear that this will not be a 10 day build. More like 13-15 days. But I’ve done my best and Garagistic has been an excellent proponent. Today, I got the Differential reluctor ring installed. It involved contracting the carrier by freezing it overnight….img_5199

Putting the reluctor ring in the oven at 500 degrees F for 1hr….img_5200

Then immediately, after install it. Within 10 seconds, it will have contracted enough to stay on. Then after 1hr, almost impossible to remove without a press. Very easy way to install!


Got some front subframe work done today. It’s not pretty, but it works, and now the S54 sits on its own weight in the car. Nice an aligned!!img_5203 img_5204 img_5205

For the driver side mount, using the E36 Arms, I found out that I was only able to utilize 2 of the bolts. So I had Garagistic cut me a custom piece that adapted 2 other holes, thereby allowing me the use of at least 3 holes in the assembly. img_5208

Had to shave off the Aluminum arm to make room for the 11ga bracket. img_5209

I might end up utilizing an additional hole. Not sure yet. img_5211

Shortened the shifter mechanism. Just need to weld it up!img_5213

After final alignment of the drivetrain, I couldn’t push the engine back any further. Disappointing because now the driveshaft is just too short to feel comfortable. Therefore, I’m having the rear half lengthened and re balanced professionally.

Stay tuned for tomorrow – no welding work, but alot of ancillary tasks like intake, brakes,

Day 7 – 10 Day Build – E21 S54

It may not look like it, but a lot of progress was made this Satuday, Day 7. I was able to effectively place Garagistic’s M60 80A poly mounts in place on the modified/shortened E36 M50 Arms. The Arms bolted right to the S54 Block. The Driver side mount only has 2 bolts utilized, so I must add an adapter plate to adapt the 2 unused holes to the block’s other holes. Not a big deal. More on that later this week. Here are some of the pics: Final pics will not be posted until later this week:

Passenger Side:


Drive Side:


I also took some time to update the subframe brackets. While Garagistic works hard at creating my custom offset rear subframe bushings, I am working on holdiong those bushings down by virtue of the modified brackets, now holding down on the OUTSIDE of the body as opposed to the inside. The reason for this is because of the wider E30 subframe would make contact with the weld nuts on the existing version E21 subframe bracket. So with some modifications of the bracket, weld bolts, we’ve got a pretty solid setup!


I also had a chance to shorten the shifter lever arm as well as the shift carrier, but I have not welded it yet. More on that this coming week.

Due to the final placement of the drivetrain, I had to modify the placement of the center bearing location and I decided to add rivet nuts as opposed to weld studs. This was actually pretty easy to implement.


Day 8 is Monday. I’m taking off this Sunday, so no work or progress is being made today. I want to accomplish the following:

  1. Weld the entire Front Subframe complete – Paint it.
  2. Side Radiator Clearance – Cut/Weld if necessary
  3. Install rear subframe bushings – Weld Diff Mount to Frame
  4. Measure rear driveshaft length – send out for lengthening
  5. Weld downpipes.

A lot planned – Stay tuned!

Day 6 – 10 Day Build – E21 S54

Today I got a couple hours to work on her, but I did go a long way in establishing engine position. Using E36 Arms, I was able to get very close on both sides using Garagistic’s M60 mounts. I might shave them down to get the right size, but the M20 ones might be more appropriate. I’ll  try it with that tomorrow

Drive side: No interference with Steering shaftimg_5166

Passenger Side – No interference with Headersimg_5164

Got the Transmission mounts in, This is just temporary and will EITHER be welded together and utilize 4 rail bolts, OR I’ll adapt an E30 trans brace and extend the arms to install into the 4 rail bolts.


Again, this is temporary so I can get the proper driveshaft alignment.  img_5171 img_5175


Before I get the engine arms in the final spot, I had to ensure that the radiator AND coolant reservoir fit. Everything fits perfectly. Upper and Lower hoses must be adapted to fit. This is no big deal. The thing that concerns me is that the alternator pulley comes very close to the coolant reservoir. I think I must shift the reservoir a bit to the driver side so that the clearance is adequate, regardless of the polyurethane mounts (which should, by the way, hold the engine very steady with minimal movement).img_5177 img_5178 img_5179

Things are looking grim to get this done in 10 days, but I keep making progress each day. Saturday should be a big day. Stay tuned

Day 2 – 10 Day Build – E21 S54

Today was all cutting and grinding. Turns out I didn’t need to do any E21 fuel tank siphoning. I just needed to bang it back a little. So with a bit of persuasion, it turned out just fine and cleared the subframe.

Installed parking brakes. E30 parking brakes fit just fine, but the crimp does not fit into the tunnel like the E21 does, so I will need to simply tack weld it in place so it stays solid.



You can clearly see the offset. I did have to cut the frame to get it to fit. You’ll see I cut much more later. i will weld more metal in place later. img_4989

Cutting out the rear wheel well. Making room for the exhaust. That’s for tuesday. img_4987

Look at the interference on the E30 subframe to the E21 body. img_4993

img_4999installed the diff housing and got a rear engine position. Very exciting.  img_5002

The E46 driveshaft has more of a nub than the E30 diff will allow, so I had to grind down the driveshaft to get it to fit squarely on the e30 diff input flange.



Much better!img_5015

Installed the driveshaft just to make sure it clears the gas tank hose. It clears!!img_5005


Now that I have the diff in place, I can see where the rear cover ear will mount up. Very close, but still offset. I’ll need Garagistic’s custom offset diff ear mounts to get this mounted!

After the installation of the diff housing,  I just needed to get the input shaft location. Attached the driveshaft and now I am defining my engine position.

I welded the driveshaft center bearing brackets to the body and the front half driveshaft now attaches to the body without the need for the rear half. Effectively separating both halves independently so that I can work on the front or the rear. This is a big convenience factor for the swap.



Did some sizing on the shifter position. I can easily cut and tig this shorter to be the perfect size. This part of the swap is a cinch. img_5032

Some more pics of the extra cut out. There are actually like 3 layers of 14 gauge metal here that make up the subframe. I plan to weld more metal higher in the frame to strengthen it back to stock. img_5030


Some shots of the engine bay where I fit the E46 325i radiator. This has the quick connects to make it easier for installation. Perfect width. thin enough for the swap. Bad part of this is that I need to push the engine further back, if the driveshaft will allow me. Good part is I have coolant temp by going to this route on the lower radiator hose. img_5034


Some pics of the E21 in all its glory. Not bad for a days work.img_5036

Continued to collect parts for the entire swap. Thanks Garagistic for the stainless steel brake lines, clutch line, and Z3 shifter!!


One of the setbacks i can see is a resistance of the subframe from getting pushed up as high as possible and that’s due to the fuel filler. It will hit it. not that big of a deal .

Next is to sort out the fuel filter/pump/regulator area. it’s clearly going to hit the half shaft.



Weld subframe triangle holes in, hang muffler, cut rear skirt, relocate gas filter, put my battery on a charer, rear trailing arm work for the shock mount. Assembly ZF trans to S54! Stay tuned!!


stop shameful shifting – e36 and e46 rear carrier bushing

So the rear carrier piece is a mod that we’ve seen become more popular in the e36 and e 46, and here’s why we think that makes sense.  (This part is available at the garagistic online store here.)

e46 Rear Poly Carrier Shifter Bushing e36 Rear Poly Carrier Shifter Bushing e31 Rear Poly Carrier Shifter Bushing e90 Rear Poly Carrier Shifter Bushing e92 Rear Poly Carrier Shifter Bushing
e36 and e46 rear carrier bushing

Rear Poly Carrier Shifter Bushing for e46 and e36

Let’s for a moment talk about we like e36 and e46 in the first place. It feels good to drive them. The feel solid and comfortable, the ride is predictable when driving at the limit. You can manage driving fast pleasurably. There’s a classic Motor Week video from 1998 where Richard Hammond explains why the E46 is the perfect car. But it get even nittier and grittier.

The tiny qualitative details for for a car this old just make the car feel good. And why do we all like manuals? Because it feels good to shift. Unless of course you have old ratty rear carrier piece holding your shifter.

It is shameful, that’s right shameful, to have a piece of engineering that feels as sappy as a mechanical watch be ruined by a sloppy rough shifter.

e46 Rear Poly Carrier Shifter Bushing e36 Rear Poly Carrier Shifter Bushing e31 Rear Poly Carrier Shifter Bushing e90 Rear Poly Carrier Shifter Bushing e92 Rear Poly Carrier Shifter Bushing
E36 and E46 Rear Poly Carrier Shifter Bushing placement.

Enter garagistic. And we’re here for you e46 and e36 guys with our rear carrier pieces and carrier shiftier bushings. Made of 80a poly, lubricated to make the action smooth – giving that satisfying feel to all our e46 and e36 enthusiasts.

e21 polyurethane front control arm bushings

Being the first official 3 series the e21 is is getting up there in years. This car taught our dads what handling mean but now your average Honda accord probably drives better. This is partially because of the years of cracking and abuse the suspensions bushings take. We’ve seen e21 suspension bushings that are virtually non existent after years of wear.

This not only makes for a lame and sloppy ride but safety becomes an issue as well. replace the worn e21 outer control arm bushing with our polyurethane e bushings. They’re going to last for as long as you have your e21, and this piece is even of a higher caliber than the OEM part. This part is available at the garagistic store.



We have three different levels of rigidity to select from. We carry a 80a poly, a 95a poly, and a delrin bushing. The 80a OCAB bushings are used for an OEM + feel. This means you’d like a subtle upgrade  for a street car without a serious compromise in comfort, designated f or street enthusiasts. The 95a is great for dual purpose aggressive street and track applications providing a happy medium for those taking their daily driver to the track. Finally we have the delrin bushing which we suggest strictly for racing applications.

While most manufacturers outsource their work all of our e21 bushings are made in the U.S.A. for quality assurance. Please beware of low quality bushings that may have air pockets in the material which leads to premature bushing failure.

Please note: garagistic e21 polyurethane front control arm bushings replace OEM part 31121123037, and will only fit 1978 – 1983 models. As with all of our poly bushings the e21 polyurethane front control arm bushings come with a our lifetime warranty. Available at the garagistic store.

Symptoms of Faulty E30 Control Arm Bushings

I once asked my dad, who was driving me to the store one day, “How come I can feel every single bump and crack in the road when we’re driving?” to which he replied, “Maybe you think you feel every bump, but what about the ones that you don’t feel?”

It comes on slow, but when it does, it’s not only annoying, it’s downright dangerous. Some automotive designs are more susceptible than others based on the geometry of the suspension arms. It’s something that we all suffer from at least once in our lives. And if we’re avid automotive enthusiasts, it’s something that we all must deal with, either by reaching into our pockets to have someone else replace, or getting on our backs and fixing it ourselves. That’s right. I’m talking about control arm bushings. All cars have ‘em. All cars need ‘em.

They’re a high wear item on our cars and for good reason. They control the suspension travel and buffer the rough road noise/bumps/potholes so that you don’t have to feel them while driving. Most rubber bushings, durometer 60A from our previous polyurethane bushings post, is very soft. This is great because it’s comfortable, but it’s loose, non-sporty, and wears out fast. Not to mention, you need expensive pullers and or other creative tools to press it out.


What are the symptoms of bad Control Arm Bushings, particularly the front? The symptoms vary quite a bit, but the same general theory is the same. Steering wheel wobble at specific speeds is the most common. But bad control arm bushings can sometimes mask itself through warped rotors. Oftentimes when you brake at a specific highway speed, regardless of steering, the wheel shakes. This is due to bad ball joints on the control arm bushings. There are 2 ball joints on the E30 Front Control Arms.  From Real OEM, see below:


As you can see there is no “upper” and “lower” control arm. There is just the single, triangular control arm, and it’s below.

Unfortunately, the ball joints are not repairable. However, it typically takes much longer for the ball joints to wear out compared to the rubber control arm bushing itself.  So for most shadytree mechanics, the control arm is to be thrown out in the even that the ball joint itself develops play.

You can test for ball joint wear by taking a long pry bar and inserting it in between the control arm and the subframe. This allows you to see at a glance if the control arm ball joint moves, you have play and need to replace the ball joints, aka the entire control arm.

Another symptom of bad front control arm bushings is the fact that everytime you go over a speedbump, onramp/driveway, large crack, or quickly brake the car and hear a clunk, it’s much more likely that the rear control arm bushing, commonly referred to as the “CAB” is worn. If you look at the diagram above, you’ll see that the control arm is a stud going through a rubber control arm bushing. This membrane tends to wear out, and quickly if you drive aggressively.

You can replace these and fix any clunking you’re experiencing relatively easy. Here are the rough steps for replacement. Please note that we highly recommend you have these installed by a professional and if you decide to install any product by yourself that you are proceeding at your own risk:

  1. Remove the 2 M10 bolts that hold the “eyelet” to the frame. Use a 17mm boxwrench and NOT an open ended wrench. You need the leverage to remove. They eyelets contain concentric studs that fit very nicely onto the frame member of the E30. Unscrew them, stick a pry bar in, and pry it loose. Oftentimes, you’ll relieve some stress once you remove it.
  2. If the old bushing is bad, it will simply pull right off. But you’ll need to remove the bushing from the eyelet, so that you can reuse the eyelet. For this you can cut the inner diameter bushing from the eyelet twice, making 2 halves. Break through that wall and it will fall right out. Best way to do this is put it in a vice and use a sawzall to cut. See the figure below.3
  3. Now you can replace the bushing. This is where it gets easy, and rewarding. I recommend Garagistic’s polyurethane bushings, 80A. Soft, but great for occasional track use. Perfect for street, and lasts for a ton of enjoyable spirited driving miles!
  4. Simply take the bushing and push it right in. The fit will be very tight and you will need to use a rubber hammer to get it 100% in as the friction increases during installation, but it will fit, and perfectly at that.
  5. Then, Installation of the eyelet is the reverse of removal. Torque the 17mm bolts (M10-1.5) to 14ft-lb.

Best of all, they come with a lifetime warranty!

For those looking for a sportier ride and more aggressive stance, you can always obtain offset control arm bushings. This allows you to have more caster, more camber, more traction.

When you go to place an order for Garagistic Control Arm Bushings, simply check whether you want the centered version (more factory feel) or offset (more aggressive for occasional track use), and whether you want 80A (more aggressive than factory) or 95A (harder and more connected feel) or even delrin (much harder and more aggressive exclusively for track use).


Thanks for reading and have a safe and happy modding experience with Garagistic!


Install INPA/EDIABAS right here!

I’d like to introduce you to a comprehensive write-up on how to become a BMW specialized hobby-mechanic. It’s funny how seemingly intimidating this can be. As I search through the forums, I see so many people struggle and get confused with what is what, how to install, problems during installation, connectivity issues, driver issues, or simply don’t understand or become overwhelmed by the amount of information. To help the community, I’d like to break this information up into 2 stages.

The first stage is getting your computer setup with the basics, including a virtual machine with Windows XP SP3 which includes the wiring diagrams, technical information, and parts catalogue. All things that do NOT integrate with a car through OBDII.

The second stage is actual code reading through INPA, EDIABAS, WinKFP with a FT232RL cable.



This is nothing more than acquiring wiring diagrams, parts catalogue, which can also be found at, and TIS, which is step-by-step instructions for basic and more complex repairs to yoru BMW. Here’s what you need to get started.

Go on Ebay and buy yourself a BMW service repair workshop manual including TIS/WDS/ETK/EPC/ETM.

TIS – Technical Information Systems. The most detailed, comprehensive step-by-step procedures, explanations, and pictorial diagrams from bumper to bumper you will ever see. All major and minor service and repair instructions included.


WDS – Wiring Diagrams (1982 – 2008). Every wiring diagram for all BMW’s. From components to pins to connectors and much more.  Fully interactive and user-friendly! There’ll be another blog post on how to navigate through these wiring diagrams specifically.WDS

ETK/EPC – “Parts Catalog” (Covers 1982-2013): The most detailed and extensive BMW parts catalog on the Internet. Now includes PRICES as well, something that was not included in earlier versions. Comes with exploded diagrams for a detailed analysis of all parts.


ETM – Electronic Troubleshooting Manuals. These are the old PDF’s for all BMW’s made in the 80’s/90’s & early 00’s. Electronic wiring diagrams and connector view guides that complement the Wiring Diagrams. 


This typically comes in one or two DVD’s and can be found on ebay for anywhere from $10-$15. The DVD comes with a VM (Virtual Machine) application for this to be installed on a Windows XP SP3 tunnel. This is mandatory and complements your stage 2 upgrade of INPA/EDIABAS/WinKFP/NCS…etc.


This is where things become more complicated…and for good reason. I would like to take some time to guide you through the detailed installation. Again, you absolutely need to either have a dedicated Windows XP SP3 computer, or you can have a windows 7, 8, or 10 computer, 32 or 64bit machine is fine, as long as you have a virtual machine set-up as I documented above in stage 1.

What you see below is taken from and is free information online.

However, the download links to the latest software is becoming harder to find. And as a result, I’ve taken the 700MB INPA file and have it on my Dropbox account which is free with the purchase of any M62/S62 Swap write-up upon request. Just go to, purchase the M62/S62 writeup, and send a request to share the INPA file as well!

DOWNLOAD THIS ON YOUR PRIMARY COMPUTER, IF RUNNING WINDOWS 7, 8, or 10, OR IF YOU’RE RUNNING A VIRTUAL MACHINE, YOU MUST BRING ALL OF THESE FILES TO YOUR VIRTUAL MACHINE. It’s a 700MB file, so it takes a while, but all of the installation itself you see below must be done on the Windows XP SP3 machine.

So what is it, and what’s included in the download?

INPA/DIS – The most common version is 5.0.2. This is not an acronym for anything that I’m aware. It’s the portal for which you can connect directly to your car’s computer on all 1996+ OBDII BMW’s. This includes most if not all models from 1996 to TODAY. INPA does diagnostics including read/reset engine codes. It also communicates with your other computers (Transmission, ABS, Instr Cluster, Seats, Cruise Cntrl…..etc).


WinKFP – This program allows you to flash ECU’s and reprogram your module. Unless you know exactly what you’re doing, do not use this program. It takes some specialized knowledge in order to extract the files and reflash the ECU’s. This will be covered in future blog posts.WinKFP

NCSexpert – This is used for coding. You can enable options that are not normally installed on your car. It’s mostly in german, so you have to do a lot of research to ensure that you don’t unintentionally screw up your ECU.


Tool32 – This allows you to conduct specific tests on your engine. You can actuate VANOS, cycle your ABS pump or move your seats if you’d like. It’s mainly used for diagnosis more than what INPA can do. It’s useful if you’re trying to debug a problem on your BMW.


What to purchase? You need a cable. That’s a fact. You need a DCAN + K-Line cable with a FT232RL usb chip inside the cable. The FT232RL chip is your interface from OBDII to your USB computer. There are cheap cables out there with other interface chips (CH340 for example). Do not buy these cables as they are unreliable and have connectivity and driver issues. The FTDI FT232RL Chip is much better for this application. See below for a picture of the cable you should buy. Your best bet is to do this:

  1. Go to ebay or google
  2. Type in the following search criteria: “DCAN cable FT232RL”
  3. Buy a cable no more than the $15-$30 range max.


Again, as long as it has the FT232RL Chip, you’re good.


You might benefit from getting access to your diagnostic through this system as well. For that, I purchased an OBDII to Diagnostic adapter. It connects to your OBDII port of your DCAN Cable and plugs directly into your diagnostic port in your BMW ranging from 1996 to 2005 timeframe. After 2005, they removed the Diagnostic port altogether and now solely rely on the OBDII.

OBDII to Diag Connector

Now that you have the necessary cables, do not plug them in to your computer yet. Set them aside. You must access and download the software. Follow these directions EXACTLY as you see them below. The screenshots are again, from

Unpack INPA and run Programminstallation/setup.exe Application

Choose language:


Click “Next”:


Next step:INSTALL3

Next step:INSTALL4

Next step:INSTALL5

Next step:INSTALL6

Next step:INSTALL7

Next step:INSTALL8

Next step:INSTALL9

Next step:INSTALL10

Next step:INSTALL11

Next step:INSTALL12

Next step: Select “STD:OBD”. Next step is very important. Whatever COM you select will need to match the driver when you install the DCAN Cable. I recommend you use the first available COM.INSTALL13

Next step: INSTALL14

Next step: (just skip 3x)INSTALL15

Next step:INSTALL16

Next step (restart your computer). If you have a Virtual Machine, restart the machine and let it reboot normally.INSTALL17

After restart:

Open :\Referenz.2005\INSTALL\Instprog.exe. It’s the application.

Click OK:


Choose Language for UK:


In next 2 windows click “Continue”.


In next window choose BMW Group Rectification programs UK: Notice the Source drive. This is important that you unzip the INPA files to the correct path or it will not find it. ALL OF THE UNZIPPED FILES NEED TO BE PLACED IN YOUR C:\ DIRECTORY. Adding it as a subfolder will prevent you from moving past this step.

In next windows set 3 checkmarks:


In next 2 windows click “Continue”


After copying click “END”

Now, here’s where your DCAN + K-Line USB Cable come into play. This is where you may need to load your drivers as a one time setup. After that, plug and unplug as much as you’d like. Here is what you need to do.

  1. Open your VMware or equivalent virtual machine for Windows XP SP3.
  2. Plug in your DCAN Cable into your computer, USB 1.0, 2.0, 3.0 – Doesn’t matter.
  3. Depending on your computer or VM, you it might recognize the USB easily and load the FT232RL Drivers automatically. If that’s the case, then follow the steps and complete that driver installation. If that does not work, follow the steps below.

In my dropbox folder I’ve shared with you contains a driver called, “CDM v2.12.06 WHQL Certified”. Follow the instructions below for installation. AGAIN, INSTALL THIS IN YOUR VM OR WINDOWS XP SP 3.

When you plug in the cable, and you have question marks by the drivers, do the following:

Right click on the driver and click on update driver:


Click next:

DCAN Install 1

Click browse: Then open your documents folder, or the folder that you saved all of the INPA files. DCAN Install 2

DCAN Install 3

Find the file “CDM v2.12.06 WHQL Certified”. Double click it and it will load the drivers.

DCAN Install 4 DCAN Install 5

DCAN Install 6

Click finish:DCAN Install 7

Click finish:


DCAN Install 8

There should be no more question marks or exclamation points.

DCAN Install 10

Now go back to your device manager and locate the usb for the DCAN cable. Ensure that the port is the same COM as that you have chosen when you originally set up INPA.  You can change the port by doing the following:

Right click on the Port and click “Properties”.


On the port settings tab, click “advanced”


On the drop down, pick the correct COM port that is not already in use (NEED TO USE COM1). Again, you must have the COM’s match from the initial INPA Installation. Click Ok, Ok, Ok, Ok, until all is good.


Now’s a good time to restart your Windows XP SP3 machine or your VM.

Now is where it all comes together. Start up your VM Windows XP SP3, plug in your cable to the computer and then to your car. Turn the key to ignition and you should see the image at the top of this screen….. That’s success right there!



TOP-10 E30 Performance Mods


There has been an ongoing debate for decades regarding the top bang-for-buck mods for your e30. And even then, there is a subjective criticism on what is cheap and what is expensive. Here is your one-stop shop for the top 10 mods for your e30, including risks, benefit, and yes even persuasion into getting onto the track to give these products a try.


Don’t underestimate the value and importance of getting your E30 stock functions working! There are a wide variety of products available to get your car that modern look/feel, yet maintain that stock feel including ‘is lips, frequently burnt replacement LED OBC lightbars and Odometer gears. Gotta get that E30 working and looking good before doing any modifications!

back to stock

There are many other items that are necessary including proper alignment, suspension refresh, and of course, no oil/coolant/fluid leaks!


A performance chip is probably one of the most impacting upgrades to your E30. Depending on your model, some benefit more than others. Here’s a short list of the gains you can typically see with a chip: These are ranges not specific to any manufacturer


87-92 325i 90-91 318i 85-87 325e 88-91 M3
Engine Type M20B25 M42B18 M20B27 S14B23 / S14B25
Horsepower +15 @ 5,000 RPM +13 @ 5,500 RPM +23 @ 4,500 RPM +25 @ 7,600 RPM
Torque +15 @ 5,000 RPM +15 @ 2,500 RPM +28 @ 4,500 RPM +18 @ 6,000 RPM
Rev Limit 6,900 RPM 6,900 RPM 5,300 RPM 7,800 RPM


Chips typically range from $225-$300. Do Not Buy Ebay. Not only will you see no gains if you install one of these chips, you can also damage your engine.  A small list of vendors that supply chips include MarkD, TurnerMotorsport (Jim Conforti), Bavauto, Dinan…etc.

Installation is a snap with a simple removal of the ECU, dislodging the chip, and inserting the new chip. Easy Peasy!

Note that to really experience these gains, you must install the 2 other important upgrades to your E30: Air Intake and Exhaust, both covered here!


The most popular, easiest to install, and cheapest mod is probably the cold-air free flow intake. And “Cold-Air” is the key word here. Commonly, people throw on a cheap free flow air filter but neglect to realize that it’s sucking in hot air from the engine bay! So if you’re going to do this mod, you want to ensure that you block the air intake from the hot engine air.

air intake

K&N is the most ubiquitous household name when it comes to free flow intakes. And lucky for the e30 enthusiast, they even offer a cold-air version as well!

This mod alone does not increase horsepower. But combined with a chip, and you now have an engine that wants to breathe, and actually, now can breathe!


Next, those old tired rubber bushings got to go! For the avid auto enthusiast, poly bushings are the new norm and dramatically improve handling and responsiveness. The best part? You can easily install this yourself without any special pullers or presses! Choose from 80A (soft), 95A (harder, race), or for the extreme Delrin. More information will be in a future blog, but see below for a sneak preview to choose what’s right for you. Best of all, there’s a lifetime warranty on the bushings!

80A – Perfect for the OEM Feel with a bit of responsiveness. Rest assured that there is no compromise for comfort here, yet your E30 will turn, brake, and accelerate much more precisely and predictively.

95A – Recommended for motor swaps, very aggressive drivers, or otherwise track use. These further increase the responsiveness of all aspects of driving and provide the ability to have a more spirited driving experience.

Delrin – Harder than 95A and one step below solid mounts. These will allow virtually no play between your engine, transmission, and subframes. The feel will be a very sporty feel recommended for race applications.

Garagistic offers Polyurethane Bushings in a wide variety of applications including drivetrain, differential, trailing arm, control arm, and rear subframe bushings.


The options here are endless, including free-flow headers, catalytic converters, removal of resonators, or replacement of the heavy stock muffler with a light aftermarket. No matter what, you’re saving weight, which increases performance.

So let’s keep it simple for now: Replace that heavy rusty muffler with a free flow supersprint, ansa, tri-flo, or MagnaFlow, Remus, Scorpion…etc. You can get a cat-back exhaust system, which includes the pre-bent tubing with fittings, clamps, and hangers. Here is an example of MagnaFlow’s Cat-Back system.

These systems range in the price of $1200 (complete cat-back system) to as little as $140 (just a muffler). The cheaper you go, the more aftermarket modifications and welding you’ll have to do, so if you’re creative and resourceful, you can get better sound and more power for a fraction of the cost of a complete bolt-on system!


Do not get FlowMaster. They do not mate well to the exhaust note of these high-revving engines. The glass-packed (fiberglass) are the way to go for an E30 Mod.

If you decide to go with aftermarket headers, steer clear of the ebay OBX headers. Even though they are cheap, they have had confirmed fitment issues, they use inferior thin walled steel, and have been known to corrode. But most of all, they are not equal length headers and have no testing to back up the claims of increased power. In fact, you will likely decrease your power!

When it comes to headers, stick to the brand names… headers are one part of a tuned system and they do show more power with a chip, because they provide a tuned back-pressure to extract exhaust gasses, creating negative pressure on the exhaust stroke.


This is an incredibly broad topic, and will be discussed in further dedicated blog posts.  But to keep things simple, here are the things you need to know about the E30.

  • 57.1 – This is the centerbore of the E30. If you get aftermarket wheels with a different centerbore, you will need hubcentric spacers
  • 4x100mm – This is the lug pattern for the E30 and is a must-have when fitting new wheels, unless you have a 5 lug.
  • Low Offset – Anything above +20mm is likely too high and you’ll have rubbing issues and/or need spacers.
  • Diameter/Width – 15″ diameter is appropriate for an E30. Many go with 16″ and if you want more extreme, you can go 17″. 18″ and up is not recommended.

Tires is just as broad a topic and there are certainly tradeoffs no matter what you decide to go with. Some questions you must ask yourself before buying tires is:

Will I be racing? I might want a softer rubber compound.

Am I looking for max gas mileage? Then an all-season with a 400AA treadwear is most appropriate.

Remember that no matter what wheel/tire combo you go with, you will be sacrificing one aspect for another. Larger wheel/tire combos rob the car of more energy as they are heavier and have more mass to spin further away from the center of rotation whereas smaller wheel/tire combos have less rotational inertia and can effectively increase the acceleration of the car. 17’s just look cool though!

At the end of the day, it all comes down to your personal agenda for use and your preference.


With more power and stiffened suspension comes an increased need to provide additional bracing. Suspension reinforcements are not only popular, but they’re an indication that you not only care about going fast, but doing so reliably and safely. Garagistic offers a wide array of subframe reinforcement kits for both the front subframe, the rear subframe, both, and strut bars.  You can either weld the kit on your own subframe or send your subframe to get completely welded for you! For those looking for some insane support underneath, check out the X-Brace, race proven reliability and performance.

A new product that just came out to further reinforce the flimsy stock E30 front subframe is the clever front control arm ball joint reinforcements. These are critical for race applications and ensure that your E30 is always on the straight and narrow. Installation is easy and accessible, so give it a try!



There are a couple of upgrades that can help your engine run cooler, especially in those hot summer months waiting in traffic! Stock thermostats close at 99C (or 210F). But you can adapt a plug and play thermostat that opens at a lower temperature to allow the hot coolant to get to the radiator earlier. Here is an example of an 92C, 80C, or even as low as 71C thermostat. These can be found many places in the $20-$30 range.


If that’s not enough, you can always turn those cooling fans on earlier with a lower temp fan switch, mounted conveniently in the radiator itself. It monitors the temperature of the coolant and activates both the low and/or the high speed radiator fans to activate the cooling earlier as well. Again, stock switches open at 99C, so having a switch that opens at 80C/88C (3 prong below), or 82 degree (2 prong for older models) can help immensely in keeping your M10, M20, or M42 cool

Be aware that there is a shortcoming to earlier opening thermostats and switches: The lower degree thermostats open at lower temperatures for better cooling but can reduce heater output when outside temperature is colder.

fan switch



One of the best ways to improve the feel is to upgrade one of the most widely used components on your car: the shifter! Changing the length of rod below the cup actually, allows a shorter shift throw and a notchier feel. As a result is one heck of an improved driving experience with every-single-shift. Driving becomes sportier and more connected with the road than you ever have before. The most popular mod here is the Z3 Shifter, which positions the shifter perfectly in the E30 and provides the sporty feel that all Z3 owners currently enjoy. While you’re at it, you might as well upgrade the bushings for your shifter assembly. More detailed technical information about the dynamics of a short shift kit is in an upcoming blog, so stay tuned!



This will not only be covered in many more detailed blog posts, it will be covered in so much detail that you’ll be considered an expert in the subject yourself! Garagistic specializes in many engine swaps including E30 M30, M60, M62/S62, and LS1. There are many parts supplied by Garagistic to get you started on the right foot!



The list goes ON!

Want to be the ultimate specialist in your community? Purchase the E30 M30, M60 and M62/S62 write-ups with hundreds of annotated pages, tables, diagrams, and wiring schematics showing you how to get your swap done, from start to finish. These can be found at our partner, for your convenience. All swap parts are supported and supplied by Garagistic to get your swap started, moving, and completed so you can move on to the next big project!

Visit the Garagistic Store for all of your favorite BMW E30, E36, E46 Parts and much much more!

E30 Differential How-To for Beginners

BMW E30 differentials are essentially the gearing module that connects the input driveshaft to each of the rear wheels. Some differential are “open” and some are “limited slip” or “posi-traction”. The primary difference being the ability of both wheels to spin in a slip event. An open differential is oftentimes cheaper because it is not designed to maintain traction of both rear wheels. You can most commonly experiment with this in the snow. One wheel spins and the other does nothing. In limited slip, at least 25% of the force will be distributed to the most heavily loaded wheel, or the wheel that normally would not spin, now gets 25% of the torque.

But there are clutch discs inside of the limited slip mechanism, and they do wear out. So a hard driven 25% diff may only have 5% lock. Which is why you should stay tuned for a more detailed blog about changing LSD clutch packs!

From the outside, you can easily denote a limited slip differential by 2 means: The tag on the differential has an S before the ratio. Example: S2.93, S3.73. You will also find an “S” stamped on the top of the differential. Be careful. The tags can always be removed and added to an open differential as a scam. However, the stamps cannot be added, so this is something to definitely check for.

LSD Tags stamps

The “ratio” is that of the number of rotations of the input to the number of rotations of the output. Most BMW E30 Differentials vary from 2.79 and up to 4.45. That means that the input shafts spin 2.79 times for each spin of the output shafts! With the transmission gear and vehicle’s speed being constant, the higher the differential ratio, the higher your engine will rev. A lot of racers experiment with the perfect ratio as to get the most useful horsepower during race day. The good thing is that you are not limited to simply E30 ratios! You can use the E23 7 Series, E24 6 Series, or most commonly, the E28 5 Series.

diff ratios

Just note that there is a bit more work that needs to be done if you are swapping from a different model. You must swap the rear cover and the output shafts, but this is easy. The output shafts remove very easily with a wooden stick, pry them out at the flanges. They should just pop right out!

You have 2 versions: small case and large case. Small case has a ring gear diameter of 168mm and the large case has a diameter of 188mm. The large case differential has been proven to handle upwards of 500ft-lb. See below for a common comparison between small case (left) and large case (right) E30 differentials. You almost never want a small case. The two sizes are 100% interchangeable in the E30 subframe.

small medium case

Do you already have big power and want to provide additional bracing? Or perhaps want a sportier feel – – Something more engaging for the driving experience?

Well, Garagistic has you covered!

Feel free to browse and check out their selection of 80A, 95A, or delrin differential bushings. Installation is easy and can be done with basic hand tools!

diff bushing

If you’re looking for supporting more power, click below for the installation video on the ONE OF A KIND IN THIS INDUSTRY second differential mount. This is a must for any >250bhp upgrade to your E30. Installation is, well….. see for yourself!

youtube diff mount 2

To complement that power, strengthening your subframe is key and can also be sourced right here. Garagistic offers a simple, easy to weld kit to strengthen your subframe to where the differential mounts. 4 holes, all can be strengthened. Examples time and time again on the track have shown this area to be particularly susceptible to weakening during hard acceleration. With additional bracketry, this problem is now dissolved.

differential reinforcement

You can certainly swap your own gearing. But if you do, you must take note on what ratio differential you currently have and what ratio gears you WANT to go to.

The rule for swapping gearsets is that you have 2 ranges. The low gears (3.07 and below) and high gears (anything higher than 3.07). To make this easy, you must have the gearset for the differential that you want to change.

Example: You currently have a 3.25 differential and want to swap to 3.46. You can easily acquire a  3.46 gearset and swap into your 3.25 by exchanging the pinion and the input gears. This is because both are above the 3.07 ratio.

Same goes for the lower gears. Stay within the range.

If you decide to cross the 3.07 threshold with swapping gearsets, you must use 2 extra shims that are necessary to make up for the geometry of the gearset fitment. Without the shims (or removing them), you will certainly have fitment issues and have premature failure, noises, or vibration.


Thanks for reading!