Durango shows of the DNX408’s rear end

Durango continue to tease us with close up shots of their prototype DNX408 1/8th scale buggy. The car’s rear-end design is all about low weight, keeping weight forward, putting the wing over the rear wheels and giving the most ground clearance. The 408 claims to ‘probably be the lightest car on the market’, which is thanks to many design considerations such as the minimalistic gearbox case, slender but tough bulkheads and the smallest rear overhang of any car.

We wanted the shocks of the DNX408 to be ahead of the axle, for better weight distribution, better wheel control over bumps/landings and for better protection when the going gets tough; the benefits are just too big to ignore.

However, one possible down side of this forward shock layout is heat soak from the exhaust header on the left rear shock, so we set about removing this problem. Firstly our tests showed that the effect is minimal, but something worth fixing and here is how we did it. After many handmade test cars, we settled on an engine forward position for the best possible weight distribution, it is also only 1mm off being the most centrally mounted engine of the cars on the market today. So, our engine and its exhaust header are the furthest forward and the most in-board of any current car, taking it well away from the left rear shock.
Problem solved! …well pretty much, but we carried on.

The DEX408 has the lowest bodyshell around – this has many benefits, like low centre of gravity, minimal frontal area to punch through the air (perhaps giving more run time or speed?) more air flow over the rear wing etc (so that too can be lower), but it also helps with heat management. The engine head in a DNX408 gets the most direct clean airflow of any car, plus the body is designed to direct as much air as possible over the bodyshell at the engine head, rather than through the body. The central engine and low bodyshell mean that all shock bodies are also in clean airflow. The DNX408s body is long and slim at the rear which encloses the exhaust header and insulates the left rear shock, while it is trimmed to help direct/suck hot air away from either rear shock. Still worried? …then foil tape will be available for inside the body.

Anyway, back to the rear suspension; well it has all the necessary toe-in, squat, top-link and shock position adjustments as standard. It has outdrive and CVD boots to minimise debris problems in the race and minimise maintenance between them. We also fitted shock guards to the suspension arms, which are probably also useful at helping rear grip on slippy tracks, you choose; either way the shocks are kept in good order by super flexi & durable shock boots.

Rear wing – it is as close to the rear wheels as possible, thanks to the forward shock position, this drives the down-force directly to the rear wheels. Too many wings on 1/8 buggies are way out back which means more more wheelies than down-force and heavy supports to stop it getting snapped off.

More tuning options; on the DNX408 it is easy to switch the rear arms around (shocks out back) to change weight bias and range of wheelbase adjustment. This feature gives the widest range of wheelbase adjustment of any car. We doubt you will need this feature, but no harm in keeping options open.

Source: Durango [team-durango.com]