Looking at MX5 Parts shocks, I see that they say “fits convertible 16” wheels only" or “fits17” wheels only".
So can I fit 17" wheels to my 2005 NC which is currently on 16"?
It seems a bit odd that the wheel size makes any difference to the shock part number?
any help much appreciated.
Marc
Nc comes with 16 and 17 inch wheels so either will fit all nc. The most usual size is 17" wheels.
Now its true that the wheel and tyre is part of your suspension and is part of the unsprung mass. The tyre carcass acts as a secondary spring and the more tyre sidewall you have the more compliance the tyre will have (if everything else is equal) - basically the more tyre wall the softer the ride.
I believe the 16" wheels and tyres are slightly less heavy if compared to a stock 17" wheels and tyres - lighter is better because the suspension has to do less work to absorb the bumps.
Some use 18" wheels from the rx8, don’t even go there.
Which to go for? I think 17" wheels look great and in my car with a 215/45/R17 Michelin ps5 work extremely well
My inference would be that cars supplied with 16" and 17" wheels use dampers with different part numbers.
Whether they are materially different is another question. Do the cars with the ‘sports suspension’ come with 17s, and the other with 16s? If so that would account for the options. Dimensionally they should be similar - the difference in ride height from wheel size is accounted for in the tyre size.
The Sport came with 17" Wheels and stiffer suspension. The 1.8i and 2.0i came with 16" wheels
Thanks for your replies guys. i am aware of sprung vs un-sprung mass and arguments for and against larger rims. It was only whilst looking at MX5 parts website that I have ever seen wheel size referred to as a material question.
My factory 16"s are tatty inside mostly and I saw some 17" for sale on here and just wanted to check. Back in the day working on Rally cars we often swopped tyre and rim sizes for the conditions and didn’t usually have to physically change the dampers. Tweaks to compression and rebound maybe but not actual size.
Many thanks again
Marc
You don’t need to change the dampers. I think they are using the wheel size to define the 2 specs of the cars
12+ y old car dampers have passed their prime anyway. Later nc versions sit lower as well. My suggestion is get the 17" wheels you want and when its time for the suspension to be renewed get the bilsten parts for the 3.75 sport model (or go koni or any other brand you want but that’s a different discussion l)
Not sure that the dampers are original but are oe spec. I’ve fitted 25mm lower springs and had full geo done. Thought it was trying to kill me when I first got it, on stilts with caster, camber and everything else all over the place:) Handles very nicely now on Rainsports all round, (living in “sunny” Devon) rain does happen!
cheers