Results 1 to 5 of 5
  1. #1
    RC poster
    Join Date
    Feb 2020
    Posts
    3

    My fast 1/10 rally build.

    Hi all, just want to document my build here.
    Currently I'm here;
    Deegan fiesta rally.
    Team Orion 3670 3700kv motor rated 3s
    Xr8 sct esc rated 4s
    Fastrax driveshafts
    Alloy centre shaft
    Slash 32dp slipper
    54t spur
    18t pinion

    I ran this setup today on 4s as it's sensored with thermal cut offs, hit cut off briefly twice and traxxas telemetry was going mental, saw 222mph at 129k rpm , obviously this is seriously wrong although all the car setup figures were correct... All I can assume is there's a threshold where the telemetry magnet becomes a blur?
    I know with this setup it's the fastest it's been tho.
    Only done this as the new motor is in the post.
    On 3s with a 14t pinion I hit 42mph gps verified with a weak esc.
    I reckon it was touching an unreliable 60mph today at least, wondering if the slash slipper needs tightening up and maybe that was giving wierd readings on the link?
    Was completely un driveable without tsm, ok with it on.

    Already bought awaiting arrival
    Alloy steering hubs and c cups plus the rear bearing carriers.
    Alloy motor mount
    Revo slipper parts
    17mm hex conversion
    17mm buggy road wheels and tyres 100mm that I will tape.
    Hobbywing 2600kv 4270 motor 1/8 4s
    50t spur
    22t pinion
    Should be good for 65mph on 4s (sound about right or will it be quicker?) and nice cool running. I will start at level 1 punch and see how it goes.

    Considering x01 diff parts but it's another 50 / 80$ here in the UK.
    I will get some videos up once it's all together.

    The 4s I was running was 2x 2s 5000mah 50c in tandem.




    *Traxxas has a strict language policy here. Do not use such language and if the filter has been tripped remove the "*" that replaced the word you used.
    Last edited by Double G; 02-17-2020 at 04:30 PM. Reason: merge & language

  2. #2
    RC Champion zedorda's Avatar
    Join Date
    Sep 2015
    Location
    S.E. Michigan
    Posts
    1,256
    I would bet you were doing more around 50mph. Because over 50mph you will start to experience the front end lifting and possibly becoming airborne. The stampede/slash/rally/rustler all have this problem each with its own unique flare. The rally might be the one that can go the fastest before liftoff but it will still be around 50-55mph depending on if you are headed into the wind or not. Speedrunners have dozens of ways to combat this but without extensive effort and modification 50-55mph will be the likely limit.

  3. #3
    RC poster
    Join Date
    Feb 2020
    Posts
    1

    I would stay 65mph or down

    Quote Originally Posted by zedorda View Post
    I would bet you were doing more around 50mph. Because over 50mph you will start to experience the front end lifting and possibly becoming airborne. The stampede/slash/rally/rustler all have this problem each with its own unique flare. The rally might be the one that can go the fastest before liftoff but it will still be around 50-55mph depending on if you are headed into the wind or not. Speedrunners have dozens of ways to combat this but without extensive effort and modification 50-55mph will be the likely limit.

    50-55mph is very common for the comfortable setup from what i have been seeing too and in all honesty I can't see taking it much past 65 as this would be the fastest i would ever want to go with it. The setup in my rally ST is below:

    Upgraded Velineon Brushless motor (with Fan) and the ESC.
    These were due to the Traxxas power-up upgrade program (Same with the remote did the 5 channel due to the other vehicles i have)
    Traxxas 3cell 5000mah lipo. (you could run the 8400, but speed is about a 1mph less due to weight)

    I have ran all the way up to a 21-tooth and here are my experiences along that journey.

    Using (54 tooth spur) - GPS Results and observations
    1) pinion 16T, was about 50-53 mph
    2) pinion 18T, was about 57-59 mph (My Favorite area to stay)
    3) pinion 19T, was about 59-63 mph
    4) pinion 20T, was about 63-67 mph
    5) pinion 21T, 67 to 70+

    I was originally just wanting to up the speed from the boring 18-20 mph that it comes stock with, but along the way the child in me (which probably lives in all of us lol) wanted to go faster so i started trying each pinion size and noted my results.

    Honesty 13-15T is really all i would recommend to keep it in the fun side of the equation.
    16T+ is just the insane speeds.

    With 16T i noticed it would eventually overheat after a little hard play (I Live in Arizona so that hard play is short or long depending on the season)

    With 18T+ it heats up faster as the pinion gets larger, no surprise there.
    However, at 21T it will go 70, but you have to baby and give it plenty of room or it can go flying once it looses grip, but you also have to be watching the tires as they do balloon badly (to an uneasy level IMO).

    Basically at 19T i started having the tire ballooning issue, although 19 it was still controllable and TSM was set to 25%. it just seemed more difficult to keep it tracking straight, and obviously every pinion up from 19 it progressively got worse.

    After 20T+ i noticed stability was very unpredictable, hence doing 21T in the right condition (Smooth track, no wind, and 2 runs.) hit around 71mph (New Tires too).

    After the crazy testing i have decided to bring mine back down to 18T. I eventually will go back down to 13-15T (Haven't done it yet thought but will here soon) as i feel that will be the fun zone. The sweet speed spot seems (from my observation) to be the 18T/54T combo with the brushless motor. Also 16T is fun/fast too.




    I Hope this helps
    Tom
    Last edited by TBAZ; 04-18-2020 at 03:45 AM.

  4. #4
    RC poster
    Join Date
    Apr 2020
    Posts
    1
    Hello so I just got the fiesta st rally. I put a 4870kv 9t brushless motor and 120amp esc. I did the slash 32p hd slipper 54t and put a 17t pinion but it's running super hot after 5mins. Should I get a 13t. Also running 2s 5200mah 80c and 2s 6200 50c batteries. Need help

  5. #5
    RC Qualifier
    Join Date
    Jul 2013
    Location
    Northern Norway
    Posts
    895
    Quote Originally Posted by Deadeye227 View Post
    Hello so I just got the fiesta st rally. I put a 4870kv 9t brushless motor and 120amp esc. I did the slash 32p hd slipper 54t and put a 17t pinion but it's running super hot after 5mins. Should I get a 13t. Also running 2s 5200mah 80c and 2s 6200 50c batteries. Need help
    Are you only doing speed runs? For more general use and with such a high kV motor, you'll have to gear down to a 11 or 12T motor pinion. You may get away with a 13T also, but cooling fans on the motor and ESC are recommended.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •