Saturday, 22 August 2015

MST FXX-S Update

So I've had this FXX for a little while and before running it, I did a lot of reading...

(Image source: Max Speed Technology)

RWD can be tedious work if you don't have the know how or know someone who does. I have a few people to bounce ideas off both face-to-face and on the line but at the end of the day, I take all this information and analyse it before implementing anything.

When I last spoke of the FXX, I was unsure on FDR and running gear but I now have something which works pretty well.


I've had a little time to have a play with the FXX and by play, I mean setup. First thing was electronics.

I bought this FXX-S used but it came with a few components that was enough to get me going. Originally, the ESC and motor had been upgraded but sold to me with the XFS15 brushed MST ESC with MST 21T motor. I had recommissioned that setup to a different chassis but going over my options and ideal outcome, this suited best. I matched it up with a 16T pinion, changed gear A to a 30T and picked up the 40-16 bevel gears for the rear diff increasing my FDR to 8.44.

A good usable number and so on went my (hardest) GA26s all round for some concrete drifting. I should mention at this point that I swapped out the low grade servo that came with it with my Savox 1251MG; I went with this shallow one so it would fit nicely on the plate.


Let's talk geometry..

As I always say, build the chassis using the manufacturer's specification and tune on the run... I broke this rule...

Stop throwing stones at me and read on! I "altered" some points from the start to reflect what I had learnt and had previously experienced so it is justified. They were only minor changes anyway. Here's what I've done:
  • Changed the FDR to 8.44 (may even go higher)
  • Stock springs all round
  • Fastrax 30wt oil all round. Stock 3 hole pistons
  • Stock front damper angle
  • Stock rear damper angle
  • Stock rear lower arm damper position
  • Stock front lower arm damper position
  • Stock front upper suspension arms swapped across axle for more caster 
  • Stock rear camber arms - furtherest in towards bulkhead
  • Stock rear HT uprights - shaft fitted in upper hole
  • Stock steering
  • (Think it's a) stock diffuser fitted with 30g weight
  • 10g weight behind battery
  • Heavy wheel weights (gold) installed on front wheels

So this setup is working pretty well for what it is. I have only really had it out on rough asphalt with varying results but mostly positive. Put it this way, not a lot of spinning out but definitely a lot of smiles.


Next step, carpet trials...

I am unbelievably chuffed with this build! It runs so well on the carpet! I thought due to it's light material and "S" status, it wouldn't work too well but it was keeping up with the resident RWD drifters pretty well. Even got a few tandems out of it! Had to of course change the tyres but silver dot FR-Fs on the front and GA26s on the rear worked very well.


This is a very good chassis and I am very impressed with it. Onto more tuning and testing.