Hi scribbler, I run on carpet too and here is the scoop on what I believe will solve you rear end swinging out
Firstly I've got a few questions:-
1. Is your car weighted up?
2. What tyre combo front\rear are you using?
3. If your car is weighted up, where is it placed?

Ok after studying some of the threads on what guys have been doing on their MO5 this is how my car is set up and I will share a bit on its performance.
Firstly I run a tight TAO5 ball diff with lead placed behind the front bumper. If you can manage epoxy resin mixed with leadshot in the cavities behind the bumper even better.
One of my Lipo’s has lead on it and depending which one I use with body on the AUW of my MO5 can be between 1350grams to 1385grams.
I use blue springs front with oil weight 50 and yellow springs rear with oil weight 40 built as per Jilles Groskamp and here is the link
The tyres I use are the Tamiya radial S grip front & M grip rear.
Short wheel base and 40% exponential on steering

So after some meticulous building, my MO5 straight out of the box intially and onto carpet performed like this
Ok just joking, it drove like it was pushing into the corners, like a lot of understeering which made me feel a bit uncomfortable. After about 10 maiden laps I pitted. I lowered the ride height in the front about 2mm off the deck approximately and raised in the rear 3 to 4mm. You might want to experiment here but just remember low at the front higher in the rear. You know 'suck it and see' type experiment
Well the verdict from me is that this thing is PLANTED and I couldn't believe the transformation, no more understeer. It felt great and my lap times where great too. Comparing lap times to my MO3 well, would you believe we started a new racing series going in reverse direction out at the regular indoor track I race on an was hard to get a good comparison.
It was quick and even going in reverse I belive my overall lap times will beat the MO3 hands down with a couple more meetings.

How will it go on a conventional outdoor track with this set up you might ask?
Good question, maybe someone can give me some feedback because I race midweek on carpet only.........period.

Wow that was almost like a mni review on the MO5, and a bit long winded but thats how it went for me ..........thumbs up

Cheers


John

Some further information regarding the M05 that drivers might find of interest:

The M05 in medium mode is actually heavier than the M05 in long mode (extra plastic piece)

In my M03L the weight distribution was 60:40 F:R

In a M05M the weight distribution is 55:45 F:R

In a M05L the weight distribution is 58:42 F:R

This shows that in actual fact the medium has a bigger weight bias to the rear than the long version. Taking this further it would be reasonable to assume that the short wheel base is even worse. This to me means a bigger pendulum effect on the shorter cars

My idea would be to see if I can balance the car so that the bias is similar to the M03L. At this point it is not far wrong

Hope this gives you something to think about

so do you think an mo5 would be quicker that an mo3 on a tight carpet track?

This is the same findings that I had on my first run outdoors with the front lower than the rear it swaped ends less and was just as fast as the MO3.

I run a tight ball diff ( may as well be a spool ), white fronts blue rears ride hard front 32 spice rears.

Yes for sure, the car feels better ballanced and comfortable to drive, that can only mean eventually faster lap times!


John

Mine isn't a Cooper-but it is a mini. WB is 225. Not quite done. I will have to cut out the lower front of the HPI Civic to fit. Don

that y i kept my M03-R....and build another M05-pro

So your saying your test findings have an M03 quicker than an M05

Fish .. two weeks back you're set-up advice was to just throw the mini on the track.
The next week you're publishing high tech weight distribution data.

My original statement was in reference to a M03. The M05 needs a bit more thought.

As for the high tech data .. the more information the more confused the other racers will get

He He... good to see some old FF01 parts flying round... still bashing my full size one, but this looks pretty cool.

hey what is the better buy a spektrum 2.0 or 3.0

The only real difference between these two radio's is the 2.0 is two channels, and the 3.0 is three channels. I believe, for the most part, the fatures are identical. For a mini you don't need a third channel, but in applications like rock crawlers a third channel is a must. I bought mine when they first came out, so I can't remmember if there is any further advatages of one over the other.

The DX3 has 4 memory slots, DX2 has only 2.. something to consider if you're running multiple chassis.

The 3.0 also has exponential, very useful for Mini.