View Full Version : MRCG FAQ's (Important Update 12/21/08!)

2008.08.04, 01:25 AM
I'll just get this one started with a short list (based on feedback I've gotten from my test drivers) and add on from there. Feel free to ask lots of questions, it'll only make this FAQ better. :)


Q: Do stock Kyosho Autoscales just pop right onto this chassis?
A: Almost. The side clips on the ASC bodies need to be shaved until they slot cleanly and securely into the H-shaped body clips on the chassis. The quickest and easiest way to do this is to just cut off the unnecessary plastic with side cutters. This should be the only modification needed to run ASC bodies on the MRCG.

Q: What electronics can I run in this chassis?
A: Literally anything that fits. The MRCG was designed around the stock Mini-Z board, but because of that it has a generous amount of room on the top plate for even cased modular electronics. As long as you choose something micro-sized (Spektrum Micro, GWS R4PII, Novak Spy, Tekin B1-R, etc.), chances are that it will fit.

Q: What about the servo?
A: Anything that's no wider than 23mm and no taller than 12mm will fit in the front end. We recommend only micro-sized or feather servos such as the Hitec HS-50, JR SM22, or Futaba S3113 (and all other Futaba servos in that family). In the MRCG's 94MM wheelbase configuration, space may get tight, in which case the solution is to shave the back of the front clip and then push the servo forwards to avoid rubbing the battery pack.

Q: Do I have to assemble a battery pack for this car?
A: Not necessarily, but it's preferred -- a pack is much easier to manage in the MRCG. At the moment we don't offer a solution for running individual cells, but if you must run loose cells, you can modify individual AAA holders to make a tray that fits in the MRCG's battery area. The quick-release battery system can be adjusted to account for the extra height of the AAA holders.

Tuning Options

Q: What's with this "center spring" you mention? How do I use it?
A: The center spring is essentially just a supplement to the top spring/oil damper you see on most MR02's. It allows the MRCG to run relatively soft flex plates for lots of traction, while the center spring and top spring together hold up the rear pod and provide a wide range of adjustment. Using it is simple: just jam the spring in there underneath the nut. Preload the spring such that it doesn't fall out when the pod droops. If the spring does come out, however, a small dab of CA glue will secure it without making it impossible to remove later. (Note: While the center spring gives the MRCG its dynamic and responsive handling, if you don't have enough traction you do not absolutely need to run a center spring. You can rely on a top shock alone to hold up the rear pod.)

Q: Do I need a top shock for this car? If so, which one should I choose?
A: A top shock/oil damper is strongly recommended for best performance. There are several on the market but we like the Kyosho MR02 oil damper the best for its weight and smoothness. Others may be able to fit with minor modifications. Just make sure the shock fits comfortably inside the MRCG (~35mm free length is a good guideline to follow).

Q: How do you tune rear steer?
A: Rear steer is tuned by angling the side plates up or down. What this means in practical terms is that you can run more shims on either the chassis side or the rear pod side of the flex plates, and then increase or decrease the preload of the center spring respectively to compensate for the change in rear pod height, and thus angling the flex plates down or up respectively. Angling the flex plates down will give slightly more steering, and vice versa; the effect is most prominent on-throttle when the rear suspension is most heavily loaded. Rear steer is an adjustment that should be used sparingly, as it can really mess up the car's handling if improperly tuned.


Q: My batteries pop out in a hard crash. What to do?
A: The batteries only pop out if the quick-release battery strap is loose or you don't have enough tension on it. Increase the tension on the strap until the problem goes away (don't overtighten, the latches are still plastic after all).

Q: How do I adjust the tension on the quick-release battery strap?
A: The latches are just screwed on, so to adjust the tension, raise or lower the latches by turning them one full turn. If you're really anal you can loosen the screws that the latches are threaded onto, make the tension perfect, and then re-tighten the screws.

Q: My kingpins aren't going smoothly into the front end pieces. What to do?
A: Nothing, the front end pieces are designed to be very tight, for those kingpins that are already worn or have been honed out, and would otherwise fit too loosely in the front end. If you can't get the kingpins in with only moderate force, take a hobby knife and gently scrape away at the sides of the hole until you can get the kingpin through smoothly but snugly. (Avoid jamming the kingpins in at all cost; doing so will scratch the kingpin, hampering the performance of the front suspension.)

Q: The side body mounts in the chassis fit really loosely...?
A: If the side body mounts are loose, you may have worn them enough that the slots are widening. In that case just use a small dab of CA glue to hold them in place.

2008.12.21, 05:41 PM
Important update concerning the steering system of the MRCG!

When you install your servo, please move it as far forward as possible (touching the front clip if you're running a Mini-Z body). When installing the plastic tubing to the servo horn, cut off as little as possible to seat it as deeply as possible into the Delrin tierod adapter. If you do not do this properly the tierod adapter has been reported to break in a hard enough crash.

Your assembly should look like this, to preserve your tierod adapter:


Notice that the servo is pushed up against the front clip, and the plastic tubing goes deep into the tierod adapter, but not far enough to bind it up (this results in poor centering).

Good luck with your builds!

2008.12.22, 01:01 AM
Hi color,

I have one of your kits and all has gone well. My only problem is the tie rod horn. The m2 machine threaded screws go right through the existing hole. Are you using self tapping screws? I could also counter sink the bottom side and use flat head screw and tighten with m2 nut on the top side of the tie rod. What do you suggest?


2008.12.22, 01:40 AM
Hm... in my pieces the hole was the right size for the M2 screws to self-tap into. :confused: But if yours is like you said, then I apologize.

Onto the fix: You can modify the horn/adapter as you said, countersink the bottom, put a screw through it and secure with a nut on top.

Alternatively, you can drill a 1mm deep indentation, large enough in diameter to fit an M2 nut in there. Use CA glue to secure the nut. Then the screw can go in from the top, like in my car. It'll be easier to work with if you have the screw on top, since you can adjust the tierod horn/adapter with the tierod in the car.

Either way works, and while you're working on that let me ask PN regarding offering replacement tierod horns/adapters.

Hope this helps, and thanks for letting me know!

2008.12.23, 02:10 AM
An alternative steering link setup.
JR DS285 Servo with Mini-t servo saver

2008.12.27, 12:47 PM
Hi EMU, Looks great. Can you post a link or give part #'s for the ball links and balls you used on your steering? Thanks.

2008.12.27, 12:59 PM
I wish that I could... I think they are Trinity Blade or IBS parts. I got them from a parts lot that I have had for a while. I will try to track the # down.

2009.01.05, 09:04 PM
Hi EMU, Question: It looks like you are using a GPM servo saver. Is it the small one? Also, what servo are you using? I purchased the GPM SSO5S(SMT) servo saver and it doesn't look like it fits any of my micro servos.

2009.01.06, 03:55 AM
I am using this saver: LOSB1228 Servo Saver, JRP 241/MG: Mini-T (http://www.losipartshouse.com/servlet/the-22181/LOSB1228-Servo-Saver%2C-JRP/Detail)
With this servo: JRPS285 DS285 Digital Hi-Speed Sub-Micro Servo (http://www.losipartshouse.com/servlet/the-26024/JRPS285-DS285-Digital-Hi-dsh-Speed/Detail)

2009.01.06, 01:25 PM
Thanks EMU!