Greyscale Racing MRCG

[RedSXmodder]

You can't do an AWD in a flex plate/t-bar suspention. CVD shafts would be required, and you'd get alot of binding...

Plus a belt system is extremely impractical at this scale...

[texan_idiot25]

For Color0, the original design was AWD, but costs and complexity drove it into the grave. Or should I say drifted it into the grave?

[XMDrifter]

hah, color0 can drift rwd. what are you talking about.loljk

i don't think AWD would be neccesary for a balanced chasis like that.
complexity is the death of a formidable track car, so rwd would make more sense since it has fewer mving parts.

and flex-plate suspension is a very good system, so i don't think color0 could give it up.

[Sweed]

Originally Posted by XMDrifter

i don't think AWD would be neccesary for a balanced chasis like that.
complexity is the death of a formidable track car, so rwd would make more sense since it has fewer mving parts.

AWD can also need an UNBALANCE chasis becuase of the torque steer from a shaft driven car. Not needed in a Belt driven car, but in a shaft driven car, you want slightly more weight on one side.

So, Mr. Color0 (I forgot what your real name was..), if I have a stock MR-02 and I buy a MRCG, how far off am I from having it running fairly good?

[color0]

Red: The simplest and the most common. Flex plate/solid axle suspensions have one problem though in that pushing on one side affects the other. That's their main disadvantage against independent suspsensions. On the other hand they are vastly lighter and faster to setup since there are fewer parts.

The MRCG does a decent job of minimizing the disadvantage by lengthening the flex plates and moving their mounting points more aft. Thus when you press on one wheel, one flex plate does almost all the work. Effectively this is like a trailing-arm suspension with the trailing arm providing some spring.

The SAS system is extremely advanced, probably too much so because the front end can't keep up traction-wise, and you plow into the outside wall. I have a new AWD coming, once I get an SAS Pro II I'll try it with harder rear tires.

Flex plate + solid axles + shaft drive AWD can be done btw, if you are careful with the design. ABC Hobbies' old DTM-X4 was such a car. HPI's Micro RS4 has a single belt and a solid axle rear. Not that it works extremely well, but it works.

The original 1/28 design was a ridiculously high-end single-belt AWD, but poor weight transfer dynamics led me to design other things, which eventually became more cost-oriented and led me to the MRCG concept.



Regarding AWD vs. RWD. A car like the MRCG certainly doesn't need AWD; it's light enough that in a race, it can generate more steering and nearly as much traction. That said, the MRCG maxes out its traction potential in a race (like all RWD cars) while the AWD's still have some to spare -- if they use up too much of their potential they are guaranteed to traction roll. In the Modified class (high power), AWD beats MR02 because of the traction problem. A low-CG, lightweight AWD with decent balance would absolutely own Mod class racing. The MRCG would need a medium-to-high grip track to beat AWD cars in Mod class.

Sweed -- just get stainless steel kingpins, ball bearings and a servo and you're good to go. If you don't want to modify your rear pod to fit a gear diff, then get a cheapo 3racing ball diff (it's surprisingly good, actually).

[XMDrifter]

isn't color0's name Brian?...
my name's Bryan...

[TripleXmodder(akaXXX)]

Thanks color0 got my MRCG. I just put some MR02 parts I already had. I ordered some wheels, tires, servo etc.



Color0. I want one of those CF linkage plates you cut. How about making me one.

[texan_idiot25]

Originally Posted by XMDrifter

isn't color0's name Brian?...
my name's Bryan...

You are correct, 'Color0's true Identity, for $500'

[color0]

Yeah, I'll be cutting a bunch of those adapters today, I think this will be a popular mod for the car.

[TripleXmodder(akaXXX)]

Originally Posted by color0

Yeah, I'll be cutting a bunch of those adapters today, I think this will be a popular mod for the car.

Color0 I PM'd you about wiring could you check that out please. Thanks alot.

[color0]

PM replied, and I'm cutting those adapter plates as I type. I think I'll send them off to TinyRC and RCKenon because of the demand, and I can't distribute the parts as quickly as they can.

[TripleXmodder(akaXXX)]

Originally Posted by color0

PM replied, and I'm cutting those adapter plates as I type. I think I'll send them off to TinyRC and RCKenon because of the demand, and I can't distribute the parts as quickly as they can.

You gotta send one to me. Make a deal.

[color0]

Ack, forgot about the adapters. PM me your address and I'll give you a price.

-----------------------------

Went to Kenon Hobby for the first testing session in a while. Big Mini-Z shop and track in LA, with abnormally high grip for an RCP track.

Philip (track owner and the man behind PN Racing) hooked me up with a set of 20d slick fronts and 8d radial rears, so I had decent grip for practicing. I think I will need 15d slick fronts and 6d radial rears in a race situation, as the 98mm MRCG has less weight over the front wheels and could use some stickier front rubber.

Actually, Philip and Grant (Worlds' contender and general good guy) hooked me up with a lot of stuff.





New ceramic diff: I was worried about smoothness (to be honest, previous PN diffs weren't spectacular) but this one IS spectacular. Really, really smooth and free. A bit on the heavy side but it feels as good as an open diff in terms of raw corner speed. 52t 64p spur gear.

New PN 70t, and 64p gears: Philip gave me a spare (with 12t pinion) to test out. Although the motor seems pretty loud, it winds up nicely, lots of torque.

F1 top spring: Grant pointed out to me that my rear suspension didn't have quite enough bump stiffness so he gave me a yellow F1 spring (thanks!). I had to adjust my center spring to compensate for the higher ride height but afterwards this thing did help corner exit steering a lot!

Philip also tuned my electronics board a bit on the ICS software, so now I get a bit more power (if less smooth... I'm not sure if I like this better) and faster servo response. My fastest lap of the day was a 7.7 (using 2007 Super GT 350Z body, btw), and Philip said that yesterday's fastest RWD Stock Sedan lap was a 7.9, so I think I may be close to the lap record, if not actually breaking it. Not bad for a first day.

After practice: new bearings (the previous ones were waaay overdue for replacement), installed new Delrin rims and half-worn Kyosho 20 radial rears. The Delrin rims are amazing, I regret not having installed these earlier. I also went to +1W rears (down from +2W) to tuck the wheels into the body a bit better. The 350Z body's actually the narrowest new Super GT body from Kyosho -- kinda weird.

But still, 7.7 with dead bearings and practice tires tells me I can probably hit 7.3 or 7.4 next time -- that'd definitely be a record, I can't wait.

[XMDrifter]

looks like you'e been busy
what ceramic diff is this?

[color0]

PN ceramic diff.

Btw, Philip confirmed that my 7.7 is the new Stock Sedan lap record! Woot.

[2wdpancar]

When you come back to NorCal you should stop by ASH....... did you see the new layout? I think the MRCG would be a blast to drive on the current layout

[mini-z drift]

Sorry for the bump
---
You might have some company:
http://www.redrc.net/2009/01/serpent...scale-chassis/
BUT I've seen these up close and they are very flimsy. Just a little intel.

[color0]

Nah, I highly doubt that the S240 will make much headway over here. No AAA NiMH, no 130-size motor, only foam tires and Lexan body, so it's going into a totally different class, similar to the Robitronic Scalpel in that it's drawing people from larger scales down. It's completely different from the MRCG, which provides a better product for the people already in these smaller classes. Instead of being a competitor, I imagine the S240 will actually boost 1/28 pan car sales once the economy picks itself back up.

[color0]

Recent updates:

Took apart my servo to show you guys how to wire the S3113 to the Mini-Z ASF board:






Also... I saw the McLaren white bodies and swore to myself that I'd buy one, and thankfully Binh at ILR had one in stock for me (thanks again btw!). Here she is with a nearly-perfect Sharpie job.









I even installed the mirrors this time around because Kyosho finally made them flexible! I cut out the rear end to take some weight away and let the air flow out from under the body (works somewhat like a crude diffuser, just look at 1/12 Pan and 1/10 TC). The McLaren actually feels like a pan body rather than a touring body though, with the low height and wide offsets (you're looking at +3N/+3.5W in the pictures!). At Kenon they were just as fast as the Pan Cars so I think this will be a good body to run, even if it is on the heavy side. Can't wait till spring break comes around.

[RedSXmodder]

Everybody stand clear of color0 and his arsenal of whitebody GSR flagships.