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My Big Brake Upgrade

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    My Big Brake Upgrade

    Disclaimer: Do not copy my designs or methods without first doing the calculations yourself. I will not take responsibility for your actions if you drive on public roadways and hurt yourself or someone else.

    The turbo M20 has been running great for the past few years, but I was really feeling the need to get involved with another project for this poor old E30. I was just running the stock brakes, and felt like they were the current weak link with the car. Then last year one of the calipers seized up, so I used that as an excuse to myself to finally pull the trigger and get started on my own Big Brake upgrade.

    I enjoy the engineering and development of these sorts of projects, so I wasn't prepared to just buy an off-the-shelf kit from one of the vendors out there.

    My goals were:
    - Improve the braking power and thermal capacity over the stock system
    - Use standard parts for my consumables (pads & rotors) and not require them to be heavily modified (or require specials tools - mills, lathes, etc)
    - Fit the largest components I can under my 16" wheels (ie. 300 mm rotors)
    - Retain some sort of hand-brake
    - Budget friendly?
    - Keep with a 4-lug system (goes back to the "Budget" point...)

    I initially purchased a set of front and rear calipers from an E36 M3 with hopes that I'd be able to easily implement them. The M3 front calipers are very large and bulky and I decided that it would be wise to set them aside and find something a bit slimmer and lighter. I frequented the Wilwood site going through all of their calipers and finally decided on the Dynapro 6-piston lug mount. It gave me the mounting flexibility I needed with in a fairly slim package for a "decent" price of ~$260 each (yes, more than the M3 calipers, but I felt the price point was acceptable).



    The next step was finding appropriate stock rotors from ANY vehicle that met my fitment needs (diameter, thickness, offset, center bore). I went through many, many vehicles to look up these specs in hopes that I would find one. I also didn't want to end up with something obscure and expensive like some 1980's Ferrari or similar... I stuck to major production vehicles as they will likely have decent aftermarket support and a good supply of reasonably priced parts.

    The rears were straight-forward, as the E36 M3 rear rotors would be simple to integrate and obviously work with the M3 rear calipers that I already bought. This would also make the hand-brake system easier to work with (more on that later). These are 312 mm x 20 mm rotors, with a center bore of 75.0 mm (E30 rear is 62.0 mm).

    The front rotors took a lot more digging, but I eventually found that the 2008-14 Dodge Caravan front rotors would work very nicely (302 mm x 28 mm x 72.5 mm bore). Nothing stops like a caravan :)

    Now that I had the rotors, they just needed to be drilled out to 4x100 and I had to make some centering rings to center the rotor on the E30 hub.

    Dodge caravan rotors drilled to 4x100 (similar for the M3 rears):



    Some measurements, CAD, and a bit of beer later, and I have the brackets completed to mount the Wilwoods to the E30 front spindle.

    Test fitment of front calipers (you may also be able to see the steel centering ring used for the rotor):









    All finished with wheel studs, braided line, and some paint:






    Now that the easy part was out of the way, it was time to move onto the rears...

    I really wanted to have some sort of hand-brake as I find it very handy to be able to leave the car running and hop out to inspect something without fear of it rolling away..... And I suppose having an emergency brake is also useful :)

    The E36 hand brake is identical in overall design and function as the E30 - it's just a bit bigger.

    E36 M3 hand brake shoes on left, E30 on right:





    I eventually figured out that I could just weld some small adapter "ears" onto the M3 shoes to put the actuator mechanism in the same spot as it is on the E30. Here are those ears tacked into place:



    And fully welded with the other hardware in position:



    Then all installed with the E36 M3 dust shields to hold the hand brake hardware in place (the shields did require a bit of cutting to make them fit):



    Then finally with the caliper and rotor installed:








    You may, by now, be wondering about the front/rear bias and how that was handled. I decided to go with the stock master cylinder for my car, which was a 20.64 mm bore (both front and rear). Since the rear calipers were "fixed" in their size, I chose the Wilwood bore sizes which gave me a 66% front bias. I then installed a Wilwood adjustable valve on the rear circuit which gives me up to a 57% reduction in pressure, therefore allowing up to an 82% front bias. Somewhere in this range I will find the sweet spot to maximize overall brake force but also suppress rear lockup before front lockup. I am expecting it to be in the ~70% range or so.

    This new caliper and rotor combo results in an 80% increase in brake torque over the stock system. I knew that this would be far too sensitive to keep the stock brake booster, so I decided to go booster-less. I have kept the stock pedal ratio for now, but may change it in the future if the brakes require too much leg force....

    I made an adapter plate and new clevis for the master cylinder and push rod:







    Finally, everything assembled and the car is on its own 4 wheels again:








    The car is out driving now, and the brakes work quite well without any funny sounds or vibrations. Whew.....

    The pedal effort is fairly high (at least compared to the stock booster-ed setup), but I can still lock the brakes with my undersized legs. I'll likely drive it like this for the season and then consider changing the pedal ratio (or finding a smaller MC) over the winter.

    Cheers!

    #2
    I like your big brake kit you made!!!!
    Projects Hartge,Alpina & AC Schnitzer Builds.http://www.r3vlimited.com/board/showthread.php?t=280601
    http://www.r3vlimited.com/board/showthread.php?t=227993
    http://www.r3vlimited.com/board/showthread.php?t=289362

    DSC04926 by Raul Salinas, on FlickrDSC03413 by Raul Salinas, on Flickr

    Comment


      #3
      wow impressive stuff, wish I had skills like that
      Worlds 1st LS powered e30 cabby.
      Cab
      billac: 92 LagunengrĂ¼n cabriolet + cadillac LQ9 + Nitrous + rotiform SJC

      Raphael: 88 LagunengrĂ¼n IX + Hella 500's + Red ACS type 1's

      Shaggin Wagon
      : 01 325xiT 5 speed


      91 MR2 GT3076TS + E85 = 505whp + antilag = wheelies
      88 CRX OEM+ 42mpg DD.

      Comment


        #4
        This is a GREAT reference for finding rotors:

        http://www.bremboaftermarket.com/En/...ue_Search.aspx

        You can search by size, so it's very easy to find what you need.

        Comment


          #5
          Originally posted by AndrewBird View Post
          This is a GREAT reference for finding rotors:

          http://www.bremboaftermarket.com/En/...ue_Search.aspx

          You can search by size, so it's very easy to find what you need.
          I did use that site a bit, but I found it took too long to look through the endless possibilities.... Now, if I could set the search criteria such that I can browse sizes in between X and Y, then that would be more useful!

          Comment


            #6
            Great work! This is not the first time Caravan rotors have been used on E30s. There was a guy named Ernie Bello 15 or so years ago who sold BBKs that used 11" caravan rotors and a relocated stock caliper.

            I like your setup much better :)

            Comment


              #7
              Thanks for the kind comments everyone.

              With the nicer weather finally here I can drive this a bit more often. It's been a few weeks now and I'm pretty much used to the firm pedal. I still think it would be nicer to be a bit lighter, though....

              Does anyone happen to know of any master cylinders with a smaller bore (ideally the same size front & rear) that are "similar" in mounting style to the E30s? A bit of fab work is not a problem to make an adapter plate, but I don't want this to be another large project... I feel like changing the MC is a more desirable solution than changing the pedal ratio.

              Cheers

              Comment


                #8
                Porsche 914 m/c comes in 17 and 19 mm bores and fits with no fab work. Mine was intended for a remote reservoir which is a bit of a pain, though.

                Comment


                  #9
                  This is awesome. I've priced out wilwood components to make something like this(although with the wilwood generic front rotors/hat) vs buying IE or one of massive's kits.

                  I'm going to have to revisit this thread again for ideas once the car is running.
                  Originally posted by priapism
                  My girl don't know shit, but she bakes a mean cupcake.
                  Originally posted by shameson
                  Usually it's best not to know how much money you have into your e30

                  Comment


                    #10
                    Well I know what I'm doing for a bbk


                    1989 325is l 1984 euro 320i l 1970 2002 Racecar
                    1991 318i 4dr slick top


                    Euro spec 320i/Alpina B6 3.5 project(the never ending saga)
                    Vintage race car revival (2002 content)
                    Mtech 2 turbo restoration
                    Brilliantrot slick top "build"

                    Comment


                      #11
                      How terrible of an idea would it be to take an early/solid front disc, turn off the excess, and drill 8x7.00" PCD holes through the old rotor surface to try to mount one of these or these depending on what size you want.

                      I guess there are four ways you could try to mount the rotor to the hat, one of them has to at least be close to fitting.
                      Originally posted by priapism
                      My girl don't know shit, but she bakes a mean cupcake.
                      Originally posted by shameson
                      Usually it's best not to know how much money you have into your e30

                      Comment


                        #12
                        Originally posted by Northern View Post
                        How terrible of an idea would it be to take an early/solid front disc, turn off the excess, and drill 8x7.00" PCD holes through the old rotor surface to try to mount one of these or these depending on what size you want.

                        I guess there are four ways you could try to mount the rotor to the hat, one of them has to at least be close to fitting.
                        I thought about that same thing. I say do it.

                        But, Ultimately I ended up going to an E36 M3 rotor. they are $50ea and I didnt have to spend a lot of time machining the rotor hats.

                        If you are staying 4 lug, I liked my corrado swap. I still have 4 rotors machined to fit the e30 and a set of brackets to put the dynalite caliper on the e30 strut. Just sayin.

                        Comment


                          #13
                          OP,
                          Well done. I like it.

                          Lets talk brake pads. What are you using?

                          what do you use your car for?


                          I am currently running E36 front rotors with wilwood 4pots and Z4 rear with wilwood 4 pots.

                          I have PFC 01 front and HP+ rear pads. Stops like crazy.

                          Comment


                            #14
                            The car is mostly a "fun" street toy that I drive on nice days. It may see one or two track days a year.

                            The pads I'm using are Wilwood BP-10 in the front and Stoptech Street Performance in the rear.

                            Comment


                              #15
                              That rust on the gas lid

                              Comment

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