The ZD Racing EX-07 Is a massive 1/7 scale street bash RC car based on the looks of Ken Block's restomod Hoonicorn Mustang V1. It is available as a ready to run car with everything or a kit version without the electronics and I've chosen the latter. They have got the looks 90% of the way to looking amazing but let themselves down on the final execution, with the body drooping badly around the front of the windscreen it kicks the nose up awkwardly and makes it weaker too. In this guide I will show you how to fix that and make some other easy improvements to the stance to make it look even better than the Arrma Infraction and Felony that it competes with.
A quick note that this is not a review - I plan to do that soon but it's taking a while since I bought the kit version knowing that the stock electronics are a little sketchy. This allows me to choose my own servo, ESC and motor to get the performance and reliability I want. In this article I'll show you how to fix the horrible sag in the body the makes the nose point up, adjust the stance to make it more even by modding the body posts and droop screw settings and lastly an option for different wheels which in my opinion really set the car off.
I've now completed a number of articles that have improved the handling, power and efficiency of the WL Toys 144001 and 124018 and 124019 which can be found here: All my WL Toys 144001 /124018 / 124019 upgrade articles. The next item I am addressing is the tyres. The stock wheels and tyres (like the rest of the car) are modelled closely on the LR Racing EMB-1h micro pins which are designed for carpet and hard packed dirt racing. Outside of these grip isn't great, and when you take into account the the rubber is firmer on the 144001 tyres then you are left with a tyre that is not really suited well for bashing off-road. In this article I'll explore some better bashing alternatives that shouldn't compromise the rest of the car
Stock wheels and tyres
Stock tyres have an outside diameter of 72mm which is the same front and rear (it needs to be on a 4wd). Widths are staggered meaning they are slightly wider at the rear - 30mm compared to the front - 26mm. Again typical for a buggy because on acceleration weight transfers to the rear and the extra width provides more grip. Drive on the wheels is provided by a 12mm hex drive which is something of an industry standard on cars around this size
The problem is that a combination of the design and compound of the tyre mean that they don't grip well on the majority of surfaces we run (off road bashing and tarmac). Since the 12mm hex drive is common there are a lot of wheels that physically fit but not a lot that work well because of the uncommon diameter. On to the theory: