My rear motor B5 started out with the latest "team" setups, but I quickly learned that most of my B4 experience at our local track was directly applicable to the B5 and applied past lessons learned to dial in this car VERY quickly.

Platform Notes

• Shocks
  • Based on feedback from others who had run the B5 at our local track, I knew that the car shared the same behavior regarding springs and oils as the B4 did. Long story short, our track can go from slippery to quite tacky depending on watering, and usually develops bumps in the surface. This requires us to run reasonably light damping to absorb the bumps and grab traction when it is dry and slippery. The down side to this is that it leaves the car under damped when using the standard green fronts/white rear spring combo, which is not a huge issue until traction comes in, and then the car can be a twitchy mess. The answer to this is to run black/green instead--one step lighter. I have found that with these springs, the car tends to "seesaw" (i.e. transfer weight front/rear) too eagerly, and a little less droop all around is the answer. This adds a bit of on power steering, but removes some mid corner, but the mid corner steering that was lost was a little bit non-linear and a bit of a handful, so that's not a horrible loss, plus we can get mid corner steering via other things besides front droop.
  • Piston Notes
    • 2x1.6: These pistons were the "go to" piston before, but I rarely use them now as they offer much larger steps for damping tuning than I can utilize. While they pack up nicely with light oil, the damping is very light in the corners, but if you go up in oil, the damping goes up dramatically. Basically, they do not offer fine grain damping tuning. I think the 3x1.4 pistons should almost always be used in preference to the 2x1.6 on the 2wd at this point.
    • 3x1.4: These pistons are great. They offer good fine grain damping tuning with various oils and pack up nicely. These are what I started with, but unfortunately, they were still a hair heavier at 27.5 in the rear than I wanted on our bumpy track with washboard section. If the track was smoother, these are by far the best pistons for the 2wd.
    • 2x1.7: These pistons used to not be my favorite at all, but on the b5, for some reason, they're wonderful. They offer damping significantly lighter than the 3x1.4 and 2x1.6, but still pack up "just enough" to land well but not be destroyed by bumps. These are officially my bumpy track pistons. On the b4, my experience was that they did not pack up at all, but for whatever reason, on my b5, the story is different!
• Battery forward vs back: forward makes the car more stable in general in my testing.
• Trailing axle, caster block spacing, and ackerman
  • I hate the fact that I list these all together, since the idea with the whole front axle cam system was to be able to isolate the trailing axle change. Here's the skinny: If you're unconcerned about a wheelbase change (i.e. your front tires moving forward of backwards 1-2mm), then you can adjust trailing axle with just the cams. On the other hand, if you want to maintain the same front wheelbase setting, then you have to counter the trailing axle setting change with a caster block spacing change to move the wheel back to the prior location. Following that, you have to adjust your ackerman washers to account for the spindle moving. Uggh. That's a lot to remember, but it's really a beautiful system once you understand it.
  • To counter the loss of mid corner steering from removing front droop, I went to 2mm trailing axle. This dictated that I move my caster blocks back 2mm, and my ackerman back 2mm as well. This opened up a can of steering and poured it all over the car--it was awesome.