MR4 BC 2003 special

[kriss]

Ive just got one and was wondering if it goes well out of the box or does it need anything doing?
Also could anyone answer these questions?
1) What is the internal ratio of the car?
2) Which weight oil is in the kit and which oils are reccomended to make it handle well?

Chris

[Dan Hughes]

to find the info go to www.yokomousa.com/manuals/mrbc1s_manualsupplement_eng.pdf (http://www.yokomousa.com/manuals/mrbc1s_manualsupplement_eng.pdf)

[Gaz_Stanton]

Yes, it does go extremely well out of the box. The only upgrade I currently run is Associated shocks. This is purely because I've been running them for years so know alot more about the piston/oil set-ups.
I wouldn't advise going out & getting the AE shocks straight away as the kit ones are probably the smoothest and best looking shocks i've ever built. :D Just need some to do some actual testing to figure out the piston/oil combo set-ups. ::)

[BC Rog]

If you want to stay with the original shocks here is a quick quide.

Use the smallest hole 2 hole piston in the front and the largest 2 hole piston in the rear.

With these pistons in you get something very close to the common Associated set up (35wt #3 in front and 30wt #2 in rear) by using 30wt all round. This will give the car a bit more pack at the front compared to running the Associated set up but that will just serve to make the car react a little slower but that isn't a bad thing for the arverage driver as most of the people I know claim it bites into a corner too hard anyway!

Personally I think that there are no shocks better than the Yokomo ones at the moment but would like to see some different pistons . Maybe the Mako project will mean these are available, or at least the knowledge as to what to drill the pistons to will be available!!!

Watch this space.

Rog

[AzNDRAGster]

Rayspeed makes some different pistons.

[BC Rog]

All the Rayspeed pistons give more pack than the standard Yokomo ones, completely the wrong way for off road!!

I use the Rayspeed pistons in my Rayspeed chassised SD.

Rog

[kriss]

I will be running the car on a slippery sports hall floor. Any setup tips?

Chris

[BC Rog]

I can not help you I'm affraid ... never run one on that type of surface.

Rog

[JV]

BC Rog^H^H^H^H^H^HShortfin Mako writes:
>All the Rayspeed pistons give more pack than the standard Yokomo ones,
> completely the wrong way for off road!!

How about the 3x1.2mm pistons, with - say - 50W oil ?

Regards,

John.

[BC Rog]

I've not seen that one!

I must admit that I'm not into TC and only run a car to prevent the off roads car getting smashed up mid week at club..

Will look into it though, must get up to date!!!! :D

[JV]

Rayspeed offer:

RS-11 (no holes)
RS-12 (2 x 1.0mm holes)
RS-13 (2 x 1.1mm holes)
RS-14 (3 x 1.2mm holes)

There's also a 3-hole RS-17, for the RC10B4

See: http://www.rayspeed.jp/ (You may need Babelfish.)


I guess the RS-11 parts would have a bit too much pack for most people.

There's a very big jump from the RS-13 to the RS-14.

Doom couldn't get the RS-14 parts from CML - I got some from a nice man at 675 Brea Canyon Rd., Walnut

I don't think I have a good way of measuring the hole sizes, particularly without damaging them. I guess I could try measuring photographs of them. Do you know a good way ?

The 1.1mm holes looked to me bigger than the largest holes in any of the Yokomo supplied pistons, but I could be wrong.

How do you propose to drill holes in the pistons ? Making a hole is easy, but I don't know how to make them accurately (to 0.02mm?) and reproducibly, and with a reproducible profile.

Regards,

John.

[sosidge]

In the US they use small hand drill bits, to get a consistent hole.

Surely a quality vernier will answer your diameter questions?

[JV]

sosidge writes:
> Surely a quality vernier will answer your diameter questions?

But my vernier calipers won't fit inside a ~1mm hole :-(

... or do you mean trying to line the holes up with a vernier ?
Then there seems to be a parallax problem

Shining a light through them was another idea.

[BC Rog]

Use pin gauges ..... just keep going up a size until they don't fit!!!!
The size before is the size of the hole ..... used to working with orifices of as small as 0.1 mm at work!!!

[JV]

Shortfin Mako writes:
> Use pin gauges

Bleh. Well really I know that's the correct answer, though I've never tried using them.

The cost of the car is negligible compared to the instrumentation...

OK. Who sells them, then ?

[Dave G]

i use some tiny reamers that are for oversizing jets in 2 strokes..you could get one of the cheapo minuture drill bit sets for abbout a fiver,they go pretty small and use an archimedes type drill.

dave

[JV]

JV Writes:
> Shortfin Mako writes:
> > Use pin gauges
>
> Bleh. Well really I know that's the correct answer, though I've never tried using them.

Non-Contact Measurement is your friend !

Put them on a scanner, scan them at maximum optical resolution, apply an edge detect filter in gimp or photoshop or whatever, and count the pixels.

I think I can get 0.2% +/-0.012 mm on my 1200x2400dpi scanner. With some more serious number crunching, I reckon it could be about 10x better.

There may be some errors related to where exactly the edges get detected, which may depend on the colour of the pistons.

Cleaning the dust off the scanner helps.

More later.

John.

[BC Rog]

Using a scanner as a sort of shadow-graph .... inspired .... have to ask the better half to show me how to use the photo packages. Since I can't take a decent photo to save my life I've never bothered to learn the software ..... :D

Rog

[super__dan]

used to working with orifices of as small as 0.1 mm at work!!!


Oh come now, thats just asking for a cheap smutty gag!

Dan

[BC Rog]

You need help Dan!!!!