In a car as light as this, you simply don't need any power assistance for the steering. This is a huge advantage that cars like this have over 'super cars'. The steering is superbly weighted and the feedback is undiluted.
|In the Fisher Fury R1, I used a Momo 290mm Model 26 wheel. For this kind of car and with a 2.4 'quick rack' it is simply the best size to use in my experience. It's a quality item with a nice 'grippy' suede covering. I'd like to use something lighter if at all possible. The wheel and boss weigh 775g when removed. I'm going to look at getting the Momo wheel copied in carbon fibre and plan to reduce the weight by a reasonable amount. If I lost the removable boss, then I'm sure I could get it below 300g.|
These Reverie steering wheels are close but, they don't seem to do one small enough.
Steering Wheel Boss
|This was mounted on a quick release boss, to make it easy to remove the steering wheel. Whilst I don't need to take the wheel off to get into the car, it has proved very useful when working on the car interior. It's a bit of a faff though and has a hex mount, so you have six ways of mounting it. At the time, you could get hex mounts to suit different sized column diameters.|
|Since I built my Fury, Momo have bought out a new quick release wheel boss design. This looks lighter. It is designed to be welded to a 20mm column. It has a 3-hole quick release hub for Formula and Sportscar wheels with a PCD 3 x 50,8mm (2). The elliptical, asymmetric shape of the pin and its base guarantee a very precise connection with no rattling or vibration. The new shape also allows for the ease of steering wheel installation during race situations by only allowing only one alignment position. Part no. is QUICKRGP2R3F. There are cheaper alternatives to this part!|
I'm going to see how the ergonomics work out but, my preference is for a fixed wheel, to save weight. I'm also looking at quick-release wheels though, just in case one is needed.
Steering Wheel Buttons
|I added these two buttons to the steering wheel on my Fury, to test out this design and configuration. The right (yellow) one operates the horn. The left (orange) one operates my radio comms system (back to pit lane). I would have like the buttons to bit a little bit closer my thumbs but, they are reachable as shown. I don't want to clutter the steering wheel with buttons, not least because it makes for complicated wiring.|
|If the wheel is removable, I will need a plug and socket combination (with at least 4 pins) to allow me to electrically disconnect the steering wheel. A lot of the race cars I've seen do away with this and just use a coiled stretch cable to link the wheel to the dash. The wheel can then be moved out of the way but is attached permanently to the car. I want to use a locking plug and socket combination though, so it can be completely removed from the car. I've used one with 7 pins because it gives me spare pins to use later if need be (Maplin part no. FK28F). The plug and socket combined weigh 28g.|
In order to pass the IVA test, the steering column needs to have a collapsible section. Typically, kit cars re-use a refurbished column from cars like the Ford Sierra and this is what I did for my Fisher Fury R1. Whilst this solution was good quality and solid, it is a heavy item.
It is very important that the column spins freely and without any movement in other directions. Typically a fairly cheap nylon bush is used to mount the upper part of the column and this works well, proving a reliable mount that freely and and smoothly. I'm looking to improve on this though.
A challenge in the installation in the Fisher Fury R1 was the presence of the steel footwell and engine mounts. With a mid-engined car, it should be possible to get a better steering wheel angle and take a more direct line to the steering rack.
|My current thinking is that I will fabricate a bespoke steering column from scratch, using parts from other cars where is makes sense. This is the column joint from a Ford Sierra, as used on my Fisher Fury R1. It weighs 688g!|
This is the splined shaft that fits in to the steering rack and is triangular at the other end. AB Performance can supply these.
The 2.4 ratio 'quick' rack used in my Fisher Fury R1 has proved to be perfect in terms of weight, feedback and responsiveness. It really takes a total concentration but that's the way I like it.
The height of the rack needs to be easily adjustable. The plan is to enable the car to have two different ride-heights, one for road and one for track. The steering rack will need to be able to move fairly easily to handle the suspension changes and ride height adjustment. I'm assuming this can be done easily with bolt-through spacers. The rack mounts and mounting points will be designed with this adjustment in mind.
Steering Rack Mount
|On the Fury, I used the standard steel mounting brackets and rubber bushes. There are stronger (and lighter) aluminium mounts available that are also more rigid.|
|Poly mounts are more rigid than their rubber equivalents.|