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Stumped. Pad knockback, on 1 wheel, everything replaced

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  • #16
    1.5 mm is about 0.060", and that's quite a bit above runout limits for factory wheels, so I can't imagine that's being very nice to the bearings.

    Why not replace the bent wheel?
    '18 Chevrolet Volt - Electric fun hatch for DD duty!


    DefSport Koni Sleeve and Spring Perch Buy!!!
    http://www.nissanroadracing.com/showthread.php?t=5902

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    • #17
      1.5mm is considerably less than the buildup of track rubber on tires. Ain't no big deal.
      Originally posted by SoSideways
      I don't care what color they are as long as they are LONG AND HARD.
      '04 G35 Sedan 6MT- The DD
      '96 240SX- The Track Toy

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      • #18
        Originally posted by Matt93SE View Post
        1.5mm is considerably less than the buildup of track rubber on tires. Ain't no big deal.
        Itís also probably bent laterally. Itís a lot of cyclical loading on things like bearings.
        '18 Chevrolet Volt - Electric fun hatch for DD duty!


        DefSport Koni Sleeve and Spring Perch Buy!!!
        http://www.nissanroadracing.com/showthread.php?t=5902

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        • #19
          Can you be more specific as to where you actually measured the wheel runout? Are you talking radially or laterally? Both? A flat spotted tire is probably a more extreme variance and I've raced on ones for hours without the bearings getting killed.

          Matt's point reminded me of how much tires actually move on wheels of track cars (in conjunction to probably near what seems like 1 lbs of rubber accumulation randomly deposited inside the barrel in a race for me) with typical tire mounting procedure and wheel/tire interface wheel surface.

          Here's my right rear after only a few practice sessions:


          The line where "RR" is and the line on the wheel were perfectly aligned before the practice session. Every corner had similar movement. The rears were worse than the fronts.

          My point here is that during my long ass races, the car almost always develops vibration in the wheels that we deal with for hours and my wheel bearings are perfectly fine. A lot of guys don't even balance their wheels because of how much movement there is with the tire. I still like to because I like starting a race with a smooth running car for a few laps.
          Core4 Motorsports
          CLICK HERE for Wilwood FSL6R Radial Bracket & Rear Wilwood BBK GROUP BUY
          S14 VQ AER Endurance Racing Team

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          • #20
            Sorry for staying silent so long, had a lot of stuff to do and test.

            The 1.5mm "bend" is on the inner side of the barrel (gills pic shows the outer side of the wheel, the inner i refer is the other side of it). On a straight wheel both inner and outer should turn on a plane. That front wheel turns on a plane on the outer side but not on the inner side. I have no idea if this is clear or not ...

            Anyway I raised the car and tested again with my friend's wheels. It feels like the problem is gone. I'll try driving around a bit more today with it and check again.

            The reason i do not change the wheel is i have a hard time sourcing one. enkei RS-3 17x8, 2 piece. Not exactly easy to find.

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            • #21
              A little update on this.

              It seems the problem is gone, but i cannot say for sure since the weather is cold and wet, so getting the same conditions as before is a problem.

              I thoroughly checked the left wheel. It turns out the "bend" on the inner lip is only visual, and a leftover of the repair. Metal was added (it was welded), and the "bend" is just some material that was not trimmed down.

              And then i checked the wheel part that fit on the brake rotor.

              And it had been painted by the people who repaired my wheels. The bloody idiots painted that, and it did not occur to me that a professionnal, heck even anyone remotely connected to automotive or industrial work, would put paint on the assembly side of a FLANGE.

              So i removed all that crap, and sure enough vibrations and steering wheel shaking are gone...

              Next steps:
              finish the engine rebuild, put the engine in the car, get it corner weighted and aligned, then drive.
              Then blow transmission and replace with this. Is there someone here who ever tried this ?
              https://shop.quaife.co.uk/nissan-sil...quaife-gearkit

              I need to stay H pattern if i ever want to drive in some local historical events, but dog boxes are allowed, so ...

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              • #22
                Quaife and higher power cars don't seem to really work together, especially in retrofit gearsets like this. The folks I've talked to about them say they don't hold up well to higher power use, as the shafts and bearings are still designed to fit a case that was intended for 150whp. The shafts deform slightly under high load causing the gears and bearings to wear faster. etc etc.

                If you're putting down over 300whp and want a dog box, G Force, and Jerico are names you need to learn.
                Originally posted by SoSideways
                I don't care what color they are as long as they are LONG AND HARD.
                '04 G35 Sedan 6MT- The DD
                '96 240SX- The Track Toy

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                • #23
                  You're still using a CA18 right? If you put in an RB25 trans, which should be possible based on my knowledge of late 80's-mid 90's Nissan trans, then it'll hold about anything. Even the stock SR/KA trans can actually take a lot if you're not clutch kicking the **** out of it and running 350+ rwtq on a regular basis.
                  '18 Chevrolet Volt - Electric fun hatch for DD duty!


                  DefSport Koni Sleeve and Spring Perch Buy!!!
                  http://www.nissanroadracing.com/showthread.php?t=5902

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                  • #24
                    I am on a CA, and these engines make around 180hp stock. The gearboxes are known to somewhat accept around 300hp without drifting. My ca is running around 250whp now, with a gt2560r at 1.2bar (20psi ?) , and there is a whine coming from the gearbox anyway, so bearings are on their way out. Not bad for a 160.000 miles gearbox, but it will definitely not hold a g25 550 with 2bar boost (30psi ?) and the ~9000rpm rev limit my new CA is going to run.

                    The idea was to keep the stock casing, so i have nothing else to change, to avoid an adaptation flange, cutting, welding, a new prop shaft, and bashing the firewall and trans tunnel so something else fits, thus keeping costs somewhat down.

                    If i need to change the gearbox casing, i will go with a z33 box, i know they can handle that kind of power ( if it can take 45psi on a CA, it will take 30psi ).
                    Although the gearing is not as good as a race designed gear set, the cost and maintenance is also not the same. Gear change is quite fast and easy, and the CD009/A are impossible to break. I will have to remove / disable 1st gear someway as it is even shorter than the CA, so basically useless, and ... i cannot use a 6 speed gearbox in historical events. Finding an rb25 gearbox is a pain, and the adaptation cost is the same, as a z33, so ...

                    In any case i will take a look at what jerico and gforce do. Thanks

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