Introduction
I was on line the other night and started to play with the Google AI. I asked it if the front suspension of the MX5 NC 3.5 should be harder than the rear. The first answer was no, as that would affect handling; but it gave me options regarding the cars intended use, suspension and tyres fitted. Suddenly I was disappearing down the rabbit hole once again.
Damping
The AI suggested that the with the DS shockers the front suspension should be hardest and there should be a differential of two to four clicks between the front and rear shockers.
It suggested a start point of -10/-12 clicks from the hardest setting (-10/-12 Fr & -14/-16 Rr).
Spring Rates
Again the AI suggested that springs should follow the front bias and suggests an 8/6 (kg/mm) split or a 12/9 split – I have 6/4 but as I said in my last post I’ve no plans to make the suspension firmer.
Ride Height
The suggestion was for a front differential of 5 to 10mm lower than the rear. It suggested that the ideal was 330 Fr/ 340 Rr and that the rake improves turn-in without sacrificing rear stability and allows for squat.
I’m using 345/355mm at the moment and handling seems pretty good.
Anti-Roll Bar
The suggestion was that for track a a harder ARB such as the RX8 yellow dot , Whiteline or SuperPro.
Again there is an option to use an aftermarket front ARB and retain the rear OEM one or even do without the rear all together (I don’t think I’m that brave. It’s likely that replacing the front ARB this will be my next mod and I’m also thinking about using Rose-jointed adjustable drop links.
Tyre Pressures
The AI also offered the suggestion that the correct track day tyre pressures were:
COLD: 1.9-2.0 Bar (27-29 psi)
HOT: 2.2-2.3 Bar (32 – 33 psi)
By default I’ve been running them at 1.9 bar cold (1.8 in the rain)
So what will I do ?
I’m off to Thruxton again in August so I plan to combine the wisdom of the magic eye with my the progress made at my last outing. As I’d wound the rebound up to full hard minus 1 click this means I’ll need to set the rears between -3 and -5. I plan to do this over several sessions to find the proper balance for this circuit. I’m guessing in my inexperience that tis will vary track to track.
As I’ve recently posted I’ve already built in some rake to the cars settings before my Silverstone trip when I swapped the suspension over and so I am happy with what I have.
The ARB suggestion started an idea around a replacement for the OEM front ARB fitted at time of writing…
