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Doing Away With ABS and PAS.

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  • Doing Away With ABS and PAS.

    Right, for once I'm going to start a project with one of the most important things first....Brake's

    My B3 Saloon project is going to be super light weight and I wish to do away with the ABS System and PAS, to save weight and make more room in the engine bay. Has anyone on here who races a B3 based model be it a Coupe (S2 or otherwise), 80 or 90 done this?

    I know to do away with ABS one has to remove all trace of it ever being there, so no senders on the hub's, ABS module, brake bomb ect, ect, etc.

    A non PAS rack can be acquired from eBay as a Brazilian model uses a such a thing.

    I'm retaining the stock rear calipers as they're in good working order for once and I'm going to add a grease nipple to help lubricate the actuation arms shaft.

    Problems I can foresee, rear brake Bias, the car is going to be totally stripped with addition of a cage and I won't be carrying luggage or passengers so the only variation at the rear is going to be fuel at approx 50 kg being the difference between a totally full and empty. Can I add a pair of bias valve's?
    1992 C4 100 2.8 Avant quattro, daily driver.
    1989 B3 2.0 (for now) quattro.
    1996 C4 2.8 30V quattro.
    1990 3B Offically dead.
    1995 RS2, MTM K26/7, 340 BHP conversion. Wrapped in cotton wool.

  • #2
    Opp's pressed post too early, I guess I'm going to have to have a look underneath and see how things are set up now and go from there, I can't recall seeing one of those alloy bias valves as seen on FWD cars so bias must be either be preset or somehow built into the ABS module.
    1992 C4 100 2.8 Avant quattro, daily driver.
    1989 B3 2.0 (for now) quattro.
    1996 C4 2.8 30V quattro.
    1990 3B Offically dead.
    1995 RS2, MTM K26/7, 340 BHP conversion. Wrapped in cotton wool.

    Comment


    • #3
      I'm pretty sure 2wd versions would have had a bias/pressure relief valve attached to rear axle via heavy duty spring.. They used to seize up. I don't pretend to be an expert but what about the wilwood brake bias set ups?

      Comment


      • #4
        Yeah, I'm confident quattros don't have one of those alloy blocks, yet one would have thought that they do have some sort of active bias control...

        There's various aftermarket options but I'm on a serious budget at the moment.
        1992 C4 100 2.8 Avant quattro, daily driver.
        1989 B3 2.0 (for now) quattro.
        1996 C4 2.8 30V quattro.
        1990 3B Offically dead.
        1995 RS2, MTM K26/7, 340 BHP conversion. Wrapped in cotton wool.

        Comment


        • #5
          Qs have a bias control for rear axle, it is underneath the master.

          Greg W.
          They can have my car when they pry my cold dead fingers from the steering wheel.

          Comment


          • #6
            My understanding of brake bias on quattro is that it is sat under the master cylinder. There is definitely nothing around the rear axle that could do the job. Look for something like this pic, it doesn't look particularly active but, what else is it?

            Comment


            • #7
              Originally posted by steve briance View Post
              My understanding of brake bias on quattro is that it is sat under the master cylinder. There is definitely nothing around the rear axle that could do the job. Look for something like this pic, it doesn't look particularly active but, what else is it?
              Yep, checked it put today, there is no active bias on a quattro B3 just the valve's on the master cylinder which I guess are preset.
              1992 C4 100 2.8 Avant quattro, daily driver.
              1989 B3 2.0 (for now) quattro.
              1996 C4 2.8 30V quattro.
              1990 3B Offically dead.
              1995 RS2, MTM K26/7, 340 BHP conversion. Wrapped in cotton wool.

              Comment


              • #8
                Non PAS racks were used in europe also, but they are slow. About ~4 turns from lock to lock. Regular rack is 3.1 turns and ABY rack is 2.6 turns.
                1989 Audi 80 Quattro
                1994 Audi 80 Quattro Competition

                Comment


                • #9
                  European racks arnt much use to me being LHD... I think I've found an alternative a B2 Audi 80 sport rack.. Thanks anyway.
                  1992 C4 100 2.8 Avant quattro, daily driver.
                  1989 B3 2.0 (for now) quattro.
                  1996 C4 2.8 30V quattro.
                  1990 3B Offically dead.
                  1995 RS2, MTM K26/7, 340 BHP conversion. Wrapped in cotton wool.

                  Comment


                  • #10
                    If you are stripping it Kit, don’t discount a LHD rack as LHD actually makes a lot of sense for packaging reasons and also corner weights with driver mass taken into consideration.
                    The quattro brake bias is set via that regulator valve as pictured above. It’s essentially just a flow control valve.
                    You would be best with either a twin F/R cylinder pedal box with a bias bar, or using stock pedal box with an inline bias valve.
                    In my experience there is nothing wrong with the B3 ABS system in fact it is the least intrusive system of any car I’ve driven properly, it leaves you to it until you actually need it. The weight saving is pretty minimal and you can always move the pump to help with packaging / weight distribution.
                    Panthero Coupé quattro 20vt
                    Indigo ABY coupé
                    Imola B6 S4 Avant

                    Comment


                    • #11
                      Originally posted by K Simmonds View Post
                      European racks arnt much use to me being LHD... I think I've found an alternative a B2 Audi 80 sport rack.. Thanks anyway.
                      Brazil is also LHD.
                      UK also had racks without power steering. 894419063E

                      1989 Audi 80 Quattro
                      1994 Audi 80 Quattro Competition

                      Comment


                      • #12
                        Originally posted by Error404 View Post
                        If you are stripping it Kit, don’t discount a LHD rack as LHD actually makes a lot of sense for packaging reasons and also corner weights with driver mass taken into consideration.
                        The quattro brake bias is set via that regulator valve as pictured above. It’s essentially just a flow control valve.
                        You would be best with either a twin F/R cylinder pedal box with a bias bar, or using stock pedal box with an inline bias valve.
                        In my experience there is nothing wrong with the B3 ABS system in fact it is the least intrusive system of any car I’ve driven properly, it leaves you to it until you actually need it. The weight saving is pretty minimal and you can always move the pump to help with packaging / weight distribution.
                        Hmmm, you've made a very good point alex, though I've just purchased a RHD non PAS Rack, still it was very cheap so it's not the end of the world having to buy another rack and I actually prefer LHD cars.

                        Part of the reason I want to do away with the ABS is the control unit is shagged, but I do agree that the system on B3 cars is about as non intrusive as possible.
                        1992 C4 100 2.8 Avant quattro, daily driver.
                        1989 B3 2.0 (for now) quattro.
                        1996 C4 2.8 30V quattro.
                        1990 3B Offically dead.
                        1995 RS2, MTM K26/7, 340 BHP conversion. Wrapped in cotton wool.

                        Comment

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