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    Best setup for manual braking

    Looking to do something about my not so responsive manual brake setup with my M60 swap. Right now I'm on some crappy Autozone pads, stock rotors, and some rusty 28 year old calipers. I've been looking at some slotted rotors, braided steel lines, ceramic pads, and new seals to rebuild my current rotors... but I'm not sure if it'd enough. With my Wilwood pedal assembly and two compact master cylinders, you really gotta get on it to get the car to stop. Anyone else on here not running a brake booster in their E30?

    #2
    What size master cylinders are you running?
    My M20 Frankenbuild(s)
    4 Sale - Fully Built TurnKey Megasquirt Plug and Play EMS

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      #3
      I am also running manual brakes. I'm running slightly larger E30 M3 calipers and rotors, which have slightly larger diameter discs and also larger caliper bores. The larger discs offer slightly more brake torque, but the larger caliper bores offer less of a hydraulic advantage when considering the ratio between master and wheel cylinders.

      I have a brake calculation spreadsheet. The filename is BremsbalancekaklulationTIiM.xls
      I took it from http://www.gt40s.com/forum/gt40-tech...ood-setup.html

      I've run some numbers in the spreadsheet. The numbers for a stock E30 braking system, which consists of:

      Diameter of:
      Front brake pistons: 48 mm
      Front brake rotors: 260 mm
      Rear brake pistons: 33 mm
      Rear brake rotors: 258 mm

      Effective braking radius, front = (260-48 )/2 = 106 mm = 4.173"
      Effective braking radius, rear= (258-33)/2 = 112.5 mm = 4.429"

      A reasonable pedal effort is between 75 - 100 lbs. To get that, you must combine sticky tires and pads with good friction coefficient, mu, and of course, 5/8" front and rear MCs. I know that Autozone/Duralast Gold pads are awful even with a boosted setup. Pads with good friction coefficient can easily reduce your pedal effort by 30+ pounds.

      My suggestion to you is to run inexpensive, normal, stock rotors, but upgrade to more aggressive pads. You could run something like Hawk HP+. If I were in your shoes, I'd spend an extra $30 and get PFC 11s. Bimmerworld has them for $225, front and rear sets. You just need to scrape them leaving your driveway and they're good to go. HP+, of course, would be a safer bet as they have better torque when stone cold.

      Rebuilding your calipers and running some new lines, rubber or SS, and a fresh bleed will also do wonders.

      Originally posted by whysimon
      WTF is hello Kitty (I'm 28 with no kids and I don't have cable)

      Comment


        #4
        Originally posted by whodwho View Post
        What size master cylinders are you running?
        Two 5/8".

        Originally posted by FredK View Post
        I am also running manual brakes. I'm running slightly larger E30 M3 calipers and rotors, which have slightly larger diameter discs and also larger caliper bores. The larger discs offer slightly more brake torque, but the larger caliper bores offer less of a hydraulic advantage when considering the ratio between master and wheel cylinders.

        I have a brake calculation spreadsheet. The filename is BremsbalancekaklulationTIiM.xls
        I took it from http://www.gt40s.com/forum/gt40-tech...ood-setup.html

        I've run some numbers in the spreadsheet. The numbers for a stock E30 braking system, which consists of:

        Diameter of:
        Front brake pistons: 48 mm
        Front brake rotors: 260 mm
        Rear brake pistons: 33 mm
        Rear brake rotors: 258 mm

        Effective braking radius, front = (260-48 )/2 = 106 mm = 4.173"
        Effective braking radius, rear= (258-33)/2 = 112.5 mm = 4.429"

        A reasonable pedal effort is between 75 - 100 lbs. To get that, you must combine sticky tires and pads with good friction coefficient, mu, and of course, 5/8" front and rear MCs. I know that Autozone/Duralast Gold pads are awful even with a boosted setup. Pads with good friction coefficient can easily reduce your pedal effort by 30+ pounds.

        My suggestion to you is to run inexpensive, normal, stock rotors, but upgrade to more aggressive pads. You could run something like Hawk HP+. If I were in your shoes, I'd spend an extra $30 and get PFC 11s. Bimmerworld has them for $225, front and rear sets. You just need to scrape them leaving your driveway and they're good to go. HP+, of course, would be a safer bet as they have better torque when stone cold.

        Rebuilding your calipers and running some new lines, rubber or SS, and a fresh bleed will also do wonders.
        Thanks so much FredK, I'll definitely be going the stock route with sticky pads first. A BBK would be awesome, but I'm trying to save some cash since I'm getting new suspension at the same time. I'm sure a full refresh of my brakes will do wonders.

        Comment


          #5
          Skip the slotted rotors, blanks work fine. After all, all the Pro3 and SpecE30 guys run blanks, seems to work for them.

          Comment


            #6
            If you're not completely opposed to doing a 5lug swap while doing the suspension bits to do a budget BBK then there's that.

            Here's what I've got:

            *Massive booster delete
            *Wilwood 3/4" master
            *E46 330i front brakes
            *E46 330i rear brakes
            *Econo blank rotors on all 4 corners
            *Hawk HPS on all 4

            Brakes feel amazing. And by amazing I mean they feel like stock, boosted brakes again (though definitely more stopping power) which I'm sure you can appreciate what that means

            Comment


              #7
              Originally posted by jalopi View Post
              If you're not completely opposed to doing a 5lug swap while doing the suspension bits to do a budget BBK then there's that.

              Here's what I've got:

              *Massive booster delete
              *Wilwood 3/4" master
              *E46 330i front brakes
              *E46 330i rear brakes
              *Econo blank rotors on all 4 corners
              *Hawk HPS on all 4

              Brakes feel amazing. And by amazing I mean they feel like stock, boosted brakes again (though definitely more stopping power) which I'm sure you can appreciate what that means
              I'm running two 5/8" master cylinders. Was considering maybe going up to 3/4" but I don't want the pedals feeling stationary in terms of stepping down on it. I actually found out that CATuned makes this bolt on BBK for decently cheap.

              How much you spend all together to go 5 lug? I've read varying numbers in terms of cost.

              I barely drive my car as it is though, let alone hard. Mostly just to school or work sometimes, or cruises on windy backroads. For like ~$400, I can do all new rotors, good pads, caliper rebuild kits, and all SS lines. If that doesn't make a noticeable difference, then I'm going 5 lug or BBK for sure haha.

              Comment


                #8
                Unless you have excessive pedal travel going to 3/4 would only make for more effort to stop
                My M20 Frankenbuild(s)
                4 Sale - Fully Built TurnKey Megasquirt Plug and Play EMS

                Comment


                  #9
                  Right, forgot you've got two of em, should be pushing enough fluid with two (I only have one master, wouldn't push enough fluid for all four calipers with a 5/8")

                  I also find it odd that CAtuned doesn't list how big their rotors are... would be good to know

                  As far as the swap cost goes... I spent about $1000-1200 for the BBK setup and 5lug. Used Lithuanian hub adapters up front, Z3 non-m 6cyl hubs in the rear. If you factor in the mandatory cost of wheels and tires (unless you've got a set of 5x120s that'll fit laying around) it was more like $2k. Which IMO is pretty goddamn reasonable for a BBK AND a new set of wheels & tires for both axles.

                  Use this calculator to figure out what kind of stopping power you have now vs what you'll have post swap

                  http://www.jakelatham.com/radical/in...culators.shtml

                  Comment


                    #10
                    Originally posted by whodwho View Post
                    Unless you have excessive pedal travel going to 3/4 would only make for more effort to stop
                    True, except the MC Jalopi and I both use is a single channel (or bore, whatever the term is) master cylinder, which is basically like using a 3/8" dual bore MC. The pedal feel is great- I used a 1" dual bore and the pedal effort was too high (like had a hard time locking the wheels on gravel), tried a single bore 5/8" and that was too low and vague feeling. The 3/4" is just the right mix of pedal stroke, effort, and feedback. I could probably stand going to a single 7/8" but I'm tired of buying master cylinders.

                    My setup:

                    UUC front BBK with Raybestos ST-43 pads
                    Stock rear calipers/rotors with Hawk Blue pads
                    Massive Booster Delete, 6.4:1 ratio pedal
                    Wilwood 3/4" single outlet master
                    Adjustable rear proportioning valve
                    Last edited by e30_302; 07-25-2014, 08:26 AM.
                    sigpic

                    Comment


                      #11
                      Your using a single master cylinder for both front and rear circuits? Not sure I would be comfortable with that

                      "With my Wilwood pedal assembly and two compact master cylinders" this had me thinking you were running a dual setup with a bias bar

                      I have several compact masters if you want to borrow and experiment without having to buy them(.625, .700, .750, .812, .875)
                      My M20 Frankenbuild(s)
                      4 Sale - Fully Built TurnKey Megasquirt Plug and Play EMS

                      Comment


                        #12
                        Yeah sometimes I worry about what would happen if I sprung a leak.... but yolo, or whatever it is the cool kids say these days.

                        Comment


                          #13
                          Originally posted by jalopi View Post
                          Yeah sometimes I worry about what would happen if I sprung a leak.... but yolo, or whatever it is the cool kids say these days.
                          Yeah, basically.

                          At some point I would definitely like to go to two masters with a balance bar.
                          sigpic

                          Comment


                            #14
                            Originally posted by jalopi View Post
                            Right, forgot you've got two of em, should be pushing enough fluid with two (I only have one master, wouldn't push enough fluid for all four calipers with a 5/8")

                            I also find it odd that CAtuned doesn't list how big their rotors are... would be good to know

                            As far as the swap cost goes... I spent about $1000-1200 for the BBK setup and 5lug. Used Lithuanian hub adapters up front, Z3 non-m 6cyl hubs in the rear. If you factor in the mandatory cost of wheels and tires (unless you've got a set of 5x120s that'll fit laying around) it was more like $2k. Which IMO is pretty goddamn reasonable for a BBK AND a new set of wheels & tires for both axles.

                            Use this calculator to figure out what kind of stopping power you have now vs what you'll have post swap

                            http://www.jakelatham.com/radical/in...culators.shtml
                            They look like they're 295mm, which are the smaller size rotors Wilwood makes. I doubt they'd be 310mm for that price too. I was playing around with that site last night actually, I really need to get my car weighed so I can see my weight bias with the M60. I'm curious where guys get their cars weighed anyway? Highway truck weigh station? Having the 5 lug hubs is nice though, no need for annoying adapters.

                            Comment


                              #15
                              Easiest way to get your car weighed is pretty much any race shop, most of them will have a set of scales. While some truck stops will weigh your car, I don't think they can only measure the total weight of a vehicle.

                              Either that or you can do it the real oldschool/probably wildly inaccurate way and measure your contact patch + tire pressure to figure out the weight on each corner

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