hpi micro rs4 brushless

Home Forums 1/8, 1/10, 1/12, 1/18 – Discussion hpi micro rs4 brushless

This topic contains 16 replies, has 8 voices, and was last updated by  dgs73 11 years, 2 months ago.

  • Author
    Posts
  • #12693

    Admin
    Participant
    • Posts: 5949

    Hi, hope everyone had a good christmas break.. I had made some mods on a standard micro rs4, these include 300 size brushless motor, smaller steering servo, and a 11.1volt lipo. The problem is that I can not get any traction. I accelarate and the car spins out of control (donuts). I am using the car on the road surface so it is not all that slipery. Great fun in the kitchen though.. PLEASE HELP…

    • This topic was modified 4 years, 11 months ago by Aaron Aaron.
  • #59838

    betty.k
    Participant
    • Posts: 2485

    well for starters you got a whole lotta power in there, no matter what shoes you put on it’s gunna be able to break traction easily.

    i’m guessing you have rubber tyres?
    a quick fix if you do is to get some foams. aim for more grip on the rear. :8ball:

  • #59839

    kevsta
    Participant
    • Posts: 973

    You could also look at your diff settings and adjust them so there is a tiny bit of slippage.

    Next thing to look at would be your suspension setup and ensure there is no tweak if it donuts in one direction all the time.

  • #59840

    merc-blue
    Participant
    • Posts: 1547

    you gotta learn to feed the power, very slowly,
    I had a brushless TF B4 for a while that even if you squeezed in the last 10% in a stright line it would lose it , and your power/weight is alot bigger and probly with worse suspention setup (fact of life that 1:18 cant fit great suspention)

  • #59841

    Admin
    Participant
    • Posts: 5949

    Thank you so much for your help, Im just getting started in 1/18th scale from nitro 1/8th scale. Thanks again Jim.

  • #59854

    AdamC
    Participant
    • Posts: 51

    Hi Jim,

    I have 2 540 powered micro RS4’s and my wife has a 9 cell powered 480 mrs4.

    I know what you mean about the power.

    I can suggest a couple of things, adjust the esc so that your power curve is a little softer, sounds like torque is your real issue so try a larger pinion on your motor, what do you have on there now? (make sure you don’t overgear though! go up in slow increments) learn to feather the throttle, don’t just ‘gun it’.

    If you have ball diffs in there, as kevsta said allow some slip in there.

    Betty is right about the foams too, I loose traction at low speed but find it improves dramatically as speed increases. I use soft rears and medium fronts. HPI, Elegi and TRC all make foams that fit.

    A good aftermarket chassis would help too, look for penguin or dragon, I’ve heard good things about both. I own AktionRC chassis and am happy with those but they’re more for jamming a 540 in there.

    Hope this helps.

  • #59855

    klims
    Participant
    • Posts: 332

    i know this is a litle off the topic, but have you guys ever had any problems with the belt drive system? that really the one thing holding me back from getting one. i much preffer the shaftdriven 4WD

  • #59856

    leonli17
    Participant
    • Posts: 602

    Apart from u can’t change toe or camber on the rear. It’s still good. I’ve owned a few different Micro RS4 chassis and the rear suspension setups are more of a pan car than 4WD TC. MRS4 would be cheaper now on the 2nd hand market than a M18 so it’ll all depend on ur intention for the car.

  • #59857

    klims
    Participant
    • Posts: 332

    drifting pretty much. although my preffered surface would be road so i was worried about pebbles getting into the belt drive and ruining it.

  • #59858

    betty.k
    Participant
    • Posts: 2485

    belts survive pebbles and grit way better than gears;) :8ball:

  • #59860

    AdamC
    Participant
    • Posts: 51

    I don’t know much about drifting but I’ve not had a problem with my belts.

    I only drive my cars on smooth surfaces though, just netball courts.

  • #59861

    AdamC
    Participant
    • Posts: 51

    Forgot to mention, HPI are now making drift kits and RTR’s they include a gyro to help you control the slide.

    http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXNXP5&P=7

  • #59867

    klims
    Participant
    • Posts: 332

    that looks pretty mental. hope you guys are right about the belt drive.
    sounds like i’m gonna have to start saving again!

  • #59872

    AdamC
    Participant
    • Posts: 51

    Nope, looks like I was wrong. The new drift kits don’t come with the drift assist gyro, you have to buy it separately 🙁

    http://www.hpiracing.com/kits/kitMain.php?partNo=617

    sucks a bit.

    I did notice that HPI now have a locked spur as an option too, no rear diff. Looks like its marketed for drifters.

  • #59874

    klims
    Participant
    • Posts: 332

    yeah i noticed it wasn’t mentioned in the description. don’t really care about the gyro though. sounds like a bit of a cop out.

    P.S: sorry for hijacking the thread…

  • #62066

    dgs73
    Participant
    • Posts: 2179

    dont know if you guys still run these, but they’re a cack… especially at speed. Foams as mentioned earlier are a must, i actually run the same set up of soft rear and medium front… have a Mamba 6800 with a 14t pinion and 2s lipo and yeild approx. 70k’s… got a losi 9400 that im going to pair with a 16t pinion and see what results… now, an answer and a question; first, the answer… the belts seem to stretch a fair bit under this load, but dont seem to be able to slip. Yet… Now, the question; are there any 3s lipos that’ll fit in the stock (sorta – HB carbon upgrade but same gap for cells) chassis??

  • #62074

    dgs73
    Participant
    • Posts: 2179

    oh, AdamC; i got one of those drifters… the Trueno, as a rtr it has a locked front diff and spider gear diff in rear and an option locked rear in the box… not very fast drifting out of the box but added the hpi mod motor and that helped abit… rtr also does come with the gyro, but is better left unplugged i find… d

You must be logged in to reply to this topic.