To get the M6x family of v8s to fit your e30s engine bay, the brake booster needs to be relocated. Being that the v8 is wider, the booster setup cannot go in the stock location and must be relocated further forward like the e34 setups. This is arguably the hardest part of the swap. However, it can be done.
There are two ways to go about doing this:
The first route is the e30 booster delete. Everything is located under the dash and almost no fabrication is needed. We will explain this process first.
The second route is to use the e34 setup to mount everything behind the driver side headlight. This takes a lot of work / fabrication / effort / time etc etc etc.
Although, this is the easier route to take, it ends up costing around the same (depending on how much you can fabricate yourself), but swap time is cut in half, performance is better and there is less clutter in the engine bay, etc etc. We are talking about the e30 brake booster delete. That means no fabrication, no donor brake booster, no relocation of everything, none of that. Simply use the garagistic booster delete bracket with Wilwood or Tilton pedals, match correct master cylinders, rebend lines to a new location, and you're there.
Our boosterless brake bracket allows you to use Wilwood or Tilton pedals/master cylinders. Everything is relocated tightly and neatly under the dash in the factory pedal area. When the conversion is done, it's all hidden! Simply mount the reservoirs in your engine bay and thats the only give away.
When paired with correct master cylinders (read:smaller) the effort is not as much as it would be if you unplug your brake booster, and can be manageable.
General rule of thumb: Bigger bores: Minimal pedal travel/stiffer pedal/higher pedal effort. Smaller bores: Long pedal travel/softer pedal/less pedal effort. All grade 8 hardware included. Pedals/master cylinders/brake switch are not included and must be bought. This is for the conversion bracket and hardware only.
We recommend using masters with 5/8" bore front and rear. These are the most compact masters and the smaller bore means that effort will be bearable (especially if you plan to run these on the street).
Click here to read more about it and how to purchase.
-Complete brake booster set up from a 540i or 740i (e34/e32)
-Some minor fab skills
Nothing from the factory brake booster will be needed. Drain the master cylinder. Try not to get brake fluid on anything. It's abrasive and will damage paint along with any rubber it touches.
Undo the clip that holds the the brake booster to the brake pedal. There will be four bolts that hold the booster to the firewall,remove them. Undo the lines that go to the master cylinder. Label the lines so you know where they go. This will assist you when you need to identify where the extended lines need to go to the relocated abs (we have put the factory e30 plumbing here just in case you forget to label the lines!). The wires going to the abs will also need to be extended to reach its new location.
The best place to relocate the ABS is in the passenger side engine bay. Simply rebend your old lines or make them completely new. (some delete the abs all together).
To mount your new setup you will need to use the existing mount from your e34 or e32 donor car. This piece is cast aluminum and is actually too tall to use as is. Some people actually remove part of the frame making it "channel" looking and use this cast aluminum piece as is with part of it sitting where the frame used to be. You will need to drill out the spot welds and little cups that held onto the abs. If you do it right, you can use these cups to mount the abs once again in its new location. Pic below shows what to remove.
Another way (the way our very own lela was done) is to cut this piece shorter. This has worked for us and survived track days and daily driving with no signs of giving up. You can use one of the existing holes to mount the inside wheel well, drill another to also be put into the wheel well. The top bolt is what requires a bit more work, but is needed to give this mounted the strength it needs. The top two holes do not reach anything. This is why a piece must be bolted, or welded in place. On Lela, we chose a piece to bend (see pictures). Other have done a cleaner job and actually made a "boxed unit" with bolts welded on the inside. This is a great way to make your relocation look factory. It is also a good idea to grab as much as the factory mounting equipment and modify it to work in an e30. As you can see in the pictures below, this is what we did.
Note: On manual cars, it is best to also grab the clutch reservoir from the donor car because unlike the e30, it does not take fluid from the same reservoir as the brakes. It takes from its own reservoir. See Below (#27). Also, the actual clutch cylinder seems to have no difference to an e30 unit.
Once your brake booster is mounted firmly, it's time to make the connection to the pedal. It's best to leave the factory return springs on the aluminum housing in place to help return the rod as well as make any binding minimal or eliminated. You will need to pick a size rod that is stronger and thicker then the factory e34 rod. Some people add gussets to the bends (not a bad idea). We didn't on Lela. The ends of this rod will need to be tapped and the factory ends can be reused. The side on the booster will need to be widened to be able to be mounted on the top portion. Some have tried to eliminate most of the bends in the rod by drilling though the shock tower housing gusset and ran the rod right though.
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