The Ultima RB5 body shell is a contrast to that of its sibling, the ZX-5. Whilst that shell is all about classic lines and simplicity – the RB5 is on the cutting edge of what’s considered ‘cool’. The swoopy design almost outdoes the likes of JConcepts, who are known for this style of shell.
The sides of the shell are quite high, and provide decent room for the electrics. The sides have plenty of interesting swoops, raising up to direct air flow up toward the wing at the rear. The front of the RB5’s shell is where things are pretty unique – the front window being shaped a little like the small front air scoops from companies like JConcepts. I can’t comment on the effectiveness of this front window, but I can say that we got several comments about how the shell looked to have taken a nasty impact or melted. I love everything about this shell – apart from that front window, which slightly detracts from the rest of the design - at least it does for me.
The RB5 comes with window masks, the front having small cuts to enable it to better conform to the bulging window. We didn’t use the masks since the shell was being painted to match Stu’s other oOple review car, the TRF 501X. The resulting job looks great I have to admit.
A large wing is included, and can be cut down to fit track conditions / personal preference.
Comparing the RB5 to the Associated B4 brings up some striking similarities - the majority of which could be boiled down to the fact that - other than the mid-motor X6, Modern 2WD design has reached somewhat of a plateau, and there really is only so much these cars can vary in layout and geometry, and still be competitive. Or at least that is the safest option.
Some things that jump out are:
The Shock positions are virtually the same from the side - but the rear are more angled inward at the top looking from the rear.
The cells and motor are in pretty much exactly the same spot (both had cells in the same forward position for the photos). So the mass of weight is laid out the same.
The front camber link looks deceptively low since it is further back (and on an angle with the kick up) but is probably a similar height to the B4.