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    #1

    General R-Comp Questions

    Not being able to afford new rubber for my 15" wheels, I bought some used R3S04's in 225/45/14, hoping to mount them on a 6" bottlecap. The previous owner of the tires said he used them on 6" and it is a stretch, but will work (He raced a CRX).
    -Will the bubbling sidewall be a problem?

    Next concern:
    A 225 tire on a bottlecap might just rub the inner fenderwell on an E30. This didn't come to mind until this morning, does anyone have experience with using 225's on b-caps? I have some 8mm spacers that I can use if necessary. Height is no problem, the car isn't totally "slammed" in the rear.


    Tire Pressures?
    I've only run 225/50/15 ES100's at the track, I got them way too hot and tore up the treads. I know R-comps can handle more abuse, but do I set the pressures similar to street tires? (32/34 cold)

    Any other general tips for a first-time on a hoosier? If any racers can throw in some input from their transfer from street tires to R-comps at drivers schools, that would be just what I'd like to hear.

    Thanks,
    Stu
    Tags: None
    #2
    Rob Case should be able to tell you about cramming big Hoosiers onto a small rim.

    Beyond that info, I am useless. ;-)
    Current Cars
    2014 M235i
    2009 R56 Cooper S
    1998 M3
    1997 M3

    Comment

      #3
      I would use somewhat higher pressures than stock rubber, especially since the tires are stretched over a 6. How much camber are you running? If less than 2.5*, you may need to increase even further the front pressure to save the tires from folding over. I have run almost 50 lbs in a camber challenged MINI to try to get the tire to stay off the sidewall.

      I would try 45/40...front camber dependent, and more in the rear if you need rotation.

      Ed
      1988 E30/S50...now with S52; Track
      1994 Miata R; ES Solo2
      1998 Lexus LX470; Wife (Slee'd anyway)
      2002 BMW 530i; A+ Commuter
      2002 BMW 325iT; Sport/Premium 5-speed
      2011 21' EconoTrailer

      Comment

        #4
        C'mon Dave, you have track tires. Drop the knowledge bombs

        Comment

          #5
          As far as 225s on bottlecaps go, I'll let you know in about two weeks.

          Dad just ordered a set of 225/50-14 R3S05s for el track.

          "See, we're adding a little something to this month's sales contest. As you all know, first prize is a Cadillac Eldorado. Anyone wanna see second prize? Second prize is a set of steak knives. Third prize is you're fired."

          Comment

            #6
            Originally posted by e30Matt
            As far as 225s on bottlecaps go, I'll let you know in about two weeks.

            Dad just ordered a set of 225/50-14 R3S05s for el track.
            I'll know in 5 days, I need to know if anyone has tried this before.

            Comment

              #7
              They will fit. You can make just about any size fit, you just have to know the procedures. We ran a ~285 on a 8 inch rim until we moved to 18's on the DM car.
              Take it easy the first lap or so. You shouldnt have any rubbing problems as far as width goes, but you might have to experiment with spacers.
              Oh, and watch your wear closely. (Tire pressures etc)
              Life is much simpler on street tires ;)

              NASA MidSouth TT Director / GTS2 #018
              Mods: Coastal PS Fluid, 10w40 Oil
              Future Mods: Bosch Micro-Edge Wiper Blades, Painter's Tape, Spark Plugs, Freezer for Nutty Buddys, Adam Nitti CD's

              Comment

                #8
                Concering R compounds, my instructor at this last event seemed to think I should try R compounds, but i've repeatedly heard that it's smart to run street tires for the first 4-5 schools simply because of the feedback, and the fact that you won't be going near as fast when they finally break loose.

                Up to you, you've definitely got a little more power to deal with.
                Trevor Ely
                '95 M Sport 540i - '00 A4 1.8TQMS - '85 190E 2.3-16
                '88 535is - '87 325e - '89 325is - '91 318is - '90 325is - '96 328is

                Comment

                  #9
                  You will definitely want to run high pressures in the front unless you have a lot of negative camber. The s04's have a relatively soft sidewall and you will wear out the outer edge. I would start at 48f and 43r and go from there, take it easy the first few laps and check the marks on the tires for your wear.

                  Comment

                    #10
                    Whoa, you guys are freaking me out. The Hoosier with a soft sidewall... and running higher pressure than a street tire.
                    For saftey sake you do as the tire manufacturer says with the rim width. You can go a bit over it but your still taking your chances. I would not run a 225 on a 6" tire. That ones on you.
                    The nice thing about racing tires is the sidewall is very very stiff so it allows you to run lower pressures.
                    Your signature picture has been removed since it contained the Photobucket "upgrade your account" image.

                    "I cannot undertake to lay my finger on that article of the Constitution which granted a right to Congress of expending, on objects of benevolence, the money of their constituents. Charity is no part of the legislative duty of the [federal] government." ~ James Madison

                    ‎"If you've got a business, you didn't build that. Somebody else made that happen" Barack Obama

                    Comment

                      #11
                      If that's the correct size, it will be smaller than the stock tire so rubbing will most likely not happen. A 225 45 14 would be around 22" in diameter as opposed to 24 stock.
                      I don't remember seeing that size in the Hoosier though.
                      Your signature picture has been removed since it contained the Photobucket "upgrade your account" image.

                      "I cannot undertake to lay my finger on that article of the Constitution which granted a right to Congress of expending, on objects of benevolence, the money of their constituents. Charity is no part of the legislative duty of the [federal] government." ~ James Madison

                      ‎"If you've got a business, you didn't build that. Somebody else made that happen" Barack Obama

                      Comment

                        #12
                        Originally posted by joshh
                        If that's the correct size, it will be smaller than the stock tire so rubbing will most likely not happen. A 225 45 14 would be around 22" in diameter as opposed to 24 stock.
                        I don't remember seeing that size in the Hoosier though.

                        He's not worried about diameter, he's worried about width.

                        Comment

                          #13
                          Originally posted by Rigmaster
                          He's not worried about diameter, he's worried about width.

                          Right, but if the diameter is that much smaller...is it even going to touch the lip of the fender? That's my point.
                          He's gaining 1" from the fender to the tire if he uses that size tire. So the width might be a moot point.
                          Your signature picture has been removed since it contained the Photobucket "upgrade your account" image.

                          "I cannot undertake to lay my finger on that article of the Constitution which granted a right to Congress of expending, on objects of benevolence, the money of their constituents. Charity is no part of the legislative duty of the [federal] government." ~ James Madison

                          ‎"If you've got a business, you didn't build that. Somebody else made that happen" Barack Obama

                          Comment

                            #14
                            Stu get some 7s or 8s....

                            Comment

                              #15
                              Jet H runs 225-50-14s on his basketweaves...

                              Comment

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