Infraction Inexpensive 8S Speedrun Build

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RedondoBeachRC

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Arrma RC's
  1. 4x4-Mega
  2. Felony
  3. Granite
  4. Infraction
  5. Limitless
  6. Kraton EXB
  7. Mojave
  8. Senton 3s
  9. Typhon 6s
  10. Typhon 3s
Acquired this V1 RTR on OfferUp. This will serve as the base for the build.
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Had a new Spektrum 160A 8S esc and 2050kv motor laying around, not in use. Perfect for this build. Side note: mounting tabs have to be trimmed is you’re putting this in the V1 or Limitless. The V2 Infraction or Felony have mounting holes for the 160A, so no need to trim the tabs.

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V1 and V2 side by side for reference
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Re-did the suspension following the tips given in Raz’s speedrun series (episode 5). Had some nitro tube on hand and some some pieces to length. Gonna try out some 3k cst diff fluid for the shocks. Stock weight is 2k cst, so just a bit stiffer.

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Got everything wrapped up and took it to a parking lot. Ran pretty well, but the stiffness of the suspension had it bouncing like a bunny over bumps.. but perfect for smooth roads.

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Randomly I decided to take it out for its first official speedrun and it didn’t disappoint. Got a new all time PB of 107mph (172.2kph for those on the metric system) using 27/34 center gearing, 8S LiPo and Perfect Pass set to 7secs. Motor and ESC were still pretty cool to the touch after two back to back passes.

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Cost breakdown:
- $350 used RTR
- $180 motor/esc
- $60 spool
- $20 new sealed bearings
- $50 Perfect Pass
- $7 diff fluid
- $20 wires, bullets for esc

Total: $687

Can probably sale the old electronics that came with it for $100. Which will be bring the total cost under $600.

Not bad for a 100mph+ build that can perform pretty reliably.
 
Real nice work on those rigs.(y)(y)(y)
Yea I scrutinized all of his build series. Raz's advice will get you into the 130's for sure. Space to run limiting.:)
If you study that video series and understand it all, any Speed Runner newb can get nice results. He left out nothing. It's's all there.
 
Last edited:
Acquired this V1 RTR on OfferUp. This will serve as the base for the build.
View attachment 173060

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View attachment 173062

Had a new Spektrum 160A 8S esc and 2050kv motor laying around, not in use. Perfect for this build. Side note: mounting tabs have to be trimmed is you’re putting this in the V1 or Limitless. The V2 Infraction or Felony have mounting holes for the 160A, so no need to trim the tabs.

View attachment 173065

View attachment 173063

V1 and V2 side by side for reference
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View attachment 173066

Re-did the suspension following the tips given in Raz’s speedrun series (episode 5). Had some nitro tube on hand and some some pieces to length. Gonna try out some 3k cst diff fluid for the shocks. Stock weight is 2k cst, so just a bit stiffer.

View attachment 173067

View attachment 173068

Got everything wrapped up and took it to a parking lot. Ran pretty well, but the stiffness of the suspension had it bouncing like a bunny over bumps.. but perfect for smooth roads.

View attachment 173069

View attachment 173070

Randomly I decided to take it out for its first official speedrun and it didn’t disappoint. Got a new all time PB of 107mph (172.2kph for those on the metric system) using 27/34 center gearing, 8S LiPo and Perfect Pass set to 7secs. Motor and ESC were still pretty cool to the touch after two back to back passes.

View attachment 173071

View attachment 173072

Cost breakdown:
- $350 used RTR
- $180 motor/esc
- $60 spool
- $20 new sealed bearings
- $50 Perfect Pass
- $7 diff fluid
- $20 wires, bullets for esc

Total: $687

Can probably sale the old electronics that came with it for $100. Which will be bring the total cost under $600.

Not bad for a 100mph+ build that can perform pretty reliably.
Heck yeah brother 🤘🏻
 
Gutting the Inexpensive Infraction build and moving some parts over to the limitless.

Gonna take this thing apart and inspect it more and then hit up my favorite part shop (Jenny’s RC) for some replacements.

Might even get some GP5 diffs for this one.

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Rebuilt the damage rear end. Because it’s a budget build I didn’t order new arms. I just reused the metal ones that came with it.
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For now it’s put back together.
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I moved the 1 million weight rear diff to the front and put 100k in the rear.
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Now I just need to put in the electronics. Initially was gonna go with the K8 electronics again but I might go up on budget and do the MMX8/1650kv combo. Found a spare S652 Kraton servo and put it in too
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Also got some connectors for the cap pack.
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New Inexpensive 8S build

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Acquired this through a trade for brand new TLR Typhon.

Spektrum 8S electronics in there with 1250kv motor and 27p/34s gearing.

Currently at 99mph.
 
Updates on the 8S Budget Build:

After a couple of crashes I decided to switch it to a Limitless body.
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The current setup:
- 8S Spektrum 160A ESC
- Yokomo V4 drift gyro
- Perfect Pass
- Spektrum S652 servo
- Spektrum 2050kv motor
- GP5 diffs (heavy weight fluid - feels like 500k)
- Stock Hoon wheels
- 25/39 gearing

Current top speed is 117mph on 8S but I don’t think it’s maxed out yet on this gearing given how short the run was.
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The limitations of this budget setup is how easy it is to reach LVC. The 160A ESC’s cutoff is 3.4v I believe.. on programming you can set it to Low, Medium, or High. With 27/39 gearing I was getting LVC at around 113mph. But on 25/39 gearing there was no LVC and I was able to get to 117mph.

So the challenge moving forward will be trying to make this car as efficient as it can be to manage the amps on the tallest gears possible.
 
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