JQ Products THE Car – THE Release Part 4
Part 4: JQ Takes Us Through The Rear End Geometry
Rear Arms
The Rear Arms are super short compared to all other cars. That’s simply because they are the same length as the front arms, which because of the front end geometry I ended up with, are also really short. The arm holders on the rear are not as wide as the front. They are old school, medium width. Nothing special there, except, if you draw a line viewing from the bottom, co-linear with the front hinge pins, it intersects the rear hinge pins halfway between the rear arm holders. Also the outer arm-to-hub attachment line intersects, and the upper link locations also. Something maybe only in my head, or then something that really makes the car work more as one. But in any case, in testing, the best set-ups have tended to be where the front and rear links are also equal. THE Car feels balanced and predictable with linear steering. By linear steering I mean, the same throughout the corner, and smooth even as speed increases or decreases, so no sudden changes in the amount the car turns. I think this is due to the fact that the front and rear ends are in-sync. They are afterall bolted to the same chassis, so they shouldn’t be too different, or else they will end up working differently from each other. This is my opinion. My goal was to try and make the front and rear roll the same in corners, have similar traction, and act the same in all conditions and speeds. All in all, I found that these short arms gave THE Car a lot more steering and just made it plain FAST!
Rear Hubs
The hubs are quite different to anything else on the market. I wanted to have the same offset on the rear as on the front. By offset I mean the distance between the arm to hub attachment and the centre of the wheel. In order to get the same offset, the hubs now clearly have a lot more offset than all other cars (actually opposite to many, meaning the attachment is on the inside of the wheel centre, not outside). This increased rear traction a ridiculous amount. First I had too much, the thing wouldn’t turn anymore. But what I ended up with was, the car could be set up with more aggressive steering, yet when exiting a corner, and getting on the gas, the rear end would just square up (straighten out) quickly, and have crazy forward bite. The rear hubs is the one thing that made me most excited when testing, because when I tried them back to back with standard hubs and arms early on, they felt like crap, but the stopwatch thought otherwise! The problem with them was, that the car could do unexpected things when it got out of shape, and it was not good in bumps. This was because it required a very different set up compared to conventional cars, and different shock positions. I managed to solve these issues, and ended up with a car that has superior corner speed, forward bite, and acceleration out of corners. I bet there will be other cars with more offset on the rear hubs and short arms in the future.
Rear Roll Centre Adjustment
Another unique thing about the rear end geometry is how there are vertical holes on the rear arms, as well as on the hubs. There are actually 3 holes in the arms, but that is just so that the arms work on both sides of the car, so only 2 holes are used, middle and top. The reason for this is so that the suspension, up and down travel and ride height, will be unchanged, regardless of which hole is used. On other cars it’s always a problem with one of the set ups, either there is not enough up travel, or down travel, or the shock end needs to be changed etc. That’s all it is, easier to make the adjustment, the result is the same as on other cars. Or so I thought! Actually it is similar, but not quite the same. But in any case, the top hole gives the car more traction and makes the suspension stiffen up more when compressed, the lower hole reduces traction, and the rear end will slide more. As for bumps, that comes down to preference, some prefer the upper hole, some the lower.
Just in order to make it confusing though, in testing I found, that most of the time, I got even more traction when I used the top hole in the hub, and the middle hole in the arm. This set up made the rear end of THE Car seem like it was sucked down on the ground, not only when cornering or accelerating, but quite surprisingly, also in bumps and jumps, it stayed flatter, and didn’t hop around as much. The only logical explanations for this increase in traction, that I could think of, is that the upper link is lower compared to the inner arm attachment, and the piston position and movement is slightly different. In any case, the rear end is adjustable enough that anyone can find their preferred set up, no matter what their driving style is. I will create an extensive set-up guide for this, and all other features on THE Car.
On THE Car you can set the ride height with clips or threaded collars, to each his own…
Source: JQ Products
