We finally got our suspension back together and working, though as mentioned last week one issue was that the suspension on the Exocet angles in towards the body and engine subframe. This meant that the suspension foul’s on the engine subframe whenever the car bounced. A small amount of grinding of the subframe (Less than 2mm) fixed this, so we were finally down and flat on all 4 wheels.
Except for one small issue. Our wheels aren’t deep enough. Or are too deep depending on how you measure it.
So whilst we had heard of the words “Deep Dish” in relation to rims, we did not realise that these had a specific scale and rating. We just assumed that you went to a car modification place and asked them to ruin your car and they threw on the most horrendous and inappropriate thing they could find.
So by way of explanation of wheel offsets - ET, the abbreviated version of the German word Einpresstiefe translates as Offset, and is measure in MM. You will see on allow wheels the rim size, width, bore (Bole in the Middle) and the ET rating, which basically means how far away from the centre line of a wheel if it before the hub connects to the wheel.
So on deep dish rims, the deepest rims have an offset of zero (ET0). The rim sits with the hub in the centre of the wheel. With an offset of 49, the hub connects on the outer edge of the wheel.
With a larger offset, more of the wheel will sit under the arch. With a Zero offset, the wheel will protrude from the car and you need wheel arch extensions.
In our case, if the wheel sits too far under it rubs against the wheel arch. This is because on the MX5, the original wheels have a 40+ offset. The MEV build requires a maximum of a 15 offset. So if we fit our existing wheels -
One option would be to buy new alloys all around, at around £100-£150 per corner plus the required rubber to go on them. Another option is to buy a spacer, which sits between the hub and the wheel.
Spacers come in a range of flavours, a super basic one is just a layer of metal which sits between the hub and the wheel and moves the wheel out by the width of the spacer. There is a limit to how far these can go, as the bolts that hold the wheel on are a set length. More advanced spacers bolt to the existing hub and then add a new set of bolts which the wheel connects to. We will get some photos when ours arrive.
Since these spacers are the cheaper option, we have decided to use these for now, but we have not totally ruled out some new shiny alloys in our future.