Salt Lake Mini-Z Club Forum

Well here is my long awaited (ha, ha) MR-03 build from my completely stock MR-03 to a full race ready one.

here it is in completely stock form. weighing in at 87.9 grams.  Without batteries or body.
(http://www.saltlakemini-z.com/forum/gallery/2/thumb_1_08_11_09_2_37_28_0.JPG)

First thing I did was build my new diff,  now rather than go though the whole process I'm just going to link you to the reflex racing build of the same diff I'm using.  I've also posted 3 pictures of the 3 different diffs for comparison.  The stock gear diff, the Kyosho Ball diff, and my light weight QteQ Diff w/ PN Ultra Light Weight Shaft.

Reflex Racing Diff Build (http://www.reflexracing.net/MR02_build_part_1.asp)

stock gear diff, weight is 5.9 grams.
(http://www.saltlakemini-z.com/forum/gallery/2/thumb_1_08_11_09_2_37_28_9.JPG)

Kyosho Ball Diff, weight is 8.2 grams.
(http://www.saltlakemini-z.com/forum/gallery/2/thumb_1_08_11_09_2_37_28_7.JPG)

QteQ Ball diff, with Reflex light weight diff rings, ceramic balls, Qteq Diff housing, and PN ultra light weight diff shaft, weight is 4.4 grams.
(http://www.saltlakemini-z.com/forum/gallery/2/thumb_1_08_11_09_2_37_28_8.JPG)

now here is what a lighter diff will do for you,  since it's lighter it spools up easier, meaning it will get to it's top speed quicker with less energy, it also has the same effect while braking, it will allow your car so slow down more effectively as well. Along with lightening the car.  Even though it's light you still maintain the same action as the Kyosho ball diff, with less weight then the stock gear diff.  It's a Win-Win  :angel:

Next I turn my attention to the Damper system,  I went with a Carbon Fiber Disk damper system that I had.  it's the older version so I had to modify it slightly for it to work with the new design of the battery clips.  The new PN dampers #MR2060 or #MR2061 don't need any modification.

I again won't post the whole process but again point you to Reflex racing for their Damper Build.  Be sure to sand down the disks and the plate so everything is nice and smooth,  use a flat surface to do it on.  I also hit the inside circle on both top and bottom to break the edge, also around the outside of the plate.  this will allow the oil (if you choose to use it) to stay on with out being wiped off by the sharp edge that will act like a squegee (sp?).

Reflex Racing Damper Build (http://www.reflexracing.net/disk_damper.asp)

Now turning attention to the front of the car,  note it's a completely new design and has similar action to an A-arm setup.  The first thing you need to do is make sure that everything is completely free and isn't binging anywhere.   I followed Tjay's tutorial from Fast Pace Racing in how to get a bind free front suspension.

Fast Pace Racing MR-03 Bind Free Front End Tutorial. (http://www.fastpaceracing.com/content/mr03-bind-free-frontend).

the last thing I did was go through the entire car and replace every steel screw with Titanium Screw to save on weight.  there is quite a few more screw in the MR-03 than the MR-02 so this is a good thing to cut weight.  I also installed PN Racing steel bearings, cleaned and ran dry.  I'll post a complete list of parts I used at the end.

Next I chose to try out the new PN double spring shock,  it provides both positive (acceleration) and negitive (braking) dampening.

here is a picture with both the ML Disk Damper and the double spring shock installed.
(http://www.saltlakemini-z.com/forum/gallery/2/thumb_1_08_11_09_2_37_28_2.JPG)

I broke in my new HFAY 70 Turn motor in on my motor break-in stand for about 1-1/2 hours.  then installed in my car using the PN ML 94/98 LCG motor mount.   I am just using the stock H-plate as nothing was available at this time.  PN Racing will have parts shortly.  I decided to keep the car as a 98MM setup for the time being and run the Nissan GT-R Body that came with the chassis I purchased.

Each chassis also comes with a "Wide" and "Narrow" front end assembly so it is compatible with every Mini-Z body produced.  you will however need the correct offset wheels.

The front of the car sits a bit high,  I'm sure there will be some aftermarket parts that will allow the front to be lowered.  We'll have to see what comes out for this.

now for the finished weight of 87.6 grams,  that right .3 grams lighter than stock, in full race trim.  :flex:
(http://www.saltlakemini-z.com/forum/gallery/2/thumb_1_08_11_09_2_37_28_6.JPG) (http://www.saltlakemini-z.com/forum/gallery/2/thumb_1_08_11_09_2_37_28_4.JPG) (http://www.saltlakemini-z.com/forum/gallery/2/thumb_1_08_11_09_2_37_28_3.JPG)

Notes:  I have tested a bit using my small track at home,   the car handles very well and rotates around the corners nicely.  I'll have to get it on a big track and see how the tires and the rest of the setup are for that track.  at home on the HFAY Time Trial track # 1 I was able to run the 50 laps in 3:56.18 after a couple of tries. In comparision I ran a best time of 3:53.14 with my MR-02 that I have been racing for years.  I'm sure I can beat that time with a few more runs with the MR-03.   So for now I'd say it's a worthy competitor.

best lap times:  MR-02: (4.36)   MR-03: (4.41)  


Parts List:
PN #2294S MR-02 94-98mm LCG Motor Mount
PN # MR2161 MR015/MR-02 Dual Spring Center Shock Set
PN #MR2061 MR-02 ML Graphite Disk Damper Set
PN #600120 Steel Ball Bearing Set.  (Cleaned and run dry).
HFAY 70 Turn Spec Motor (shortened wires).
PN #200408, 2mm locking wheel nuts.

Diff Build consisted of the following.
PN # MR2045UL,  Ultra light weight diff shaft.
PN # MR2045N, Ball Diff Shaft Pin
Kyosho #ORG04, Silicon Diff o-ring.
Reflex Racing #RX1132, 53 tooth 64 pitch spur gear.
Reflex Racing #RX1134S, Light Weight 8mm Diff rings (low weight)
Kyosho #96506, Ball Diff Grease
QteQ #080802, Left Rear Wheel Nut
QteQ #081101, Ultra Light Weight 2wd differential housing set
QteQ #080801, Light Weight 2wd Differential Left Hub.

That should cover everything,  If I remember something else I'll be sure to add it.  

Click the scrolling marquee for my gallery

Cool!! Nice Write up. I think you must have had a glitch or something when you ran the best time of 3:53.14 with your MR-02 if the MR-03 is about a minute slower. Hmmm...  :D  

No that is a Typo,  great catch.  I've fixed it.

   Cant wait to see that baby in action this week.. 

I've ordered 3 of the new PN Racing 98MM T-plates and 3 of the 94MM T-plates for the MR-02 along with a set of the front springs.

Hopefully they will be here for Thursday so I can test them out with the car.  :D :flex: