Behind The Scenes // Building an 8S INFRACTION to take on a supercar.

We’re sure that by now you’ve seen our behind the scenes look at how we got ourselves into a 4 way drag race with the guys at carwow, so we thought maybe you’d also like to see a closer look under the hood of the actual ARRMA INFRACTION used in the race.

Fresh from the filming of the race the ARRMA INFRACTION and Spektrum DX5R Tx look ready to go again. We started with a stock INFRACTION 6S BLX and with the addition of the LIMITLESS spool and 8S electronics we were able to very consistently run hard launches and high top speeds.

Mean muggin’ with multiple 100mph runs under its belt throughout testing and filming.

A hallmark of high speed running, flys and dirt still pepper the front of the INFRACTION.

We ran the wing in the lowest cut position, this has two key benefits in high speed running. By trimming the wing down it reduced drag, this also results in a reduction in downforce at the rear of the car.

The front of the truck is very square and creates a lot of drag so it was important to shave drag where possible. The reduction in rear downforce may at first seem like a compromise, but in this case it was an advantage, less rear downforce means the car retains its nose-down rake more easily at high speed. This helps stop too much air from getting under the car and flipping it at high speed.

The dBoots Hoons were developed with high speeds in mind, so were the perfect choice to provide safe consistent performance over multiple runs.

The runway was very abrasive and with 8S power on tap gave the tyres a thorough work-out.

We elected to use a Spektrum DX5R to allow the AVC setting to be more extensively customised.

AVC setting used: STR Gain: 40% THR Gain: 0% Priority: 0%

Although the race was in the dry, later in the day it was necessary to shoot some establishing and launch shots for the carwow video. By this time the weather had turned, the fully waterproof electronics took it all in their stride. It has however taken its toll on the screws a little. We always recommend brushing and drying off your ARRMA RC after wet weather running to keep it in top shape.

The KRATON 8S was still unreleased at the time of filming so during the interview Chris only gave the vague ‘8S’ answer to the power system. We knew this system could handle launch-after-launch without breaking much of a sweat so it was the perfect choice. Coupled with the ARRMA 4685 heatsink and 50mm fan we had a very solid and consistent power system. We used the LIMITLESS spool with the 39T gear and a 27T pinion.

The stock ARRMA ADS-15M and Spektrum SRS6000 Rx were retained, these were prefect from right out of the box.

The ALL-ROAD ability of the ARRMA INFRACTION was fully capitalised on to allow it to soak up the imperfections and gaps on the surface. We ran a raked setup with the front sitting lower than the rear to help air pass over the top of the car.
Front ride height was set at 19mm with 9.4mm of preload and rear ride height 25mm with 11.2mm of preload.

Although we only had one race with carwow testing was extensive and repeated top speed runs had taken their toll on the underside of the splitter and chassis. Function was of course not compromised, but it’s interesting to see the patina of speed.

If you’ve not seen the race and want to see how out ARRMA INFRACTION 8S stacked up against the competition you can check it out below!

Carwow INFRACTION 8S Spec:

Transmitter: Spektrum DX5R 5CH DSMR Tx https://www.spektrumrc.com/Products/Default.aspx?ProdId=SPM5000

Receiver: Spektrum SRS6000 DSMR AVC Surface Rx https://www.spektrumrc.com/Products/Default.aspx?ProdId=SPMSRS6000

ESC: Spektrum Firma 160 Amp Smart ESC with Capacitor https://www.spektrumrc.com/Products/Default.aspx?ProdID=SPMXSE1160CP

Motor: Spektrum Firma 4685 1250Kv Brushless Motor https://www.spektrumrc.com/Products/Default.aspx?ProdID=SPMXSM1200

Heatsink/Fan: ARRMA 4685 Size Motor Heatsink / ARRMA 50mm Motor Fan https://www.arrma-rc.com/part/ARA390296https://www.arrma-rc.com/part/ARA390295

Batteries: Spektrum 5000mAh 4S 14.8V 100C Smart LiPo Hardcase; IC5 https://www.spektrumrc.com/Products/Default.aspx?ProdID=SPMX50004S100H5

AVC setting used: STR Gain: 40% THR Gain: 0% Priority: 0%

Gearing: Pinion 27T / Spool 39T