The Goal
The SW20 is an amazing chassis in theory, but from the factory alongside 30 years of wear, they feel soft and slow to respond. This can all be improved.
For the front suspension, the main areas we wanted to look at were:
- Camber behaviour through bump travel
- Caster angle
- Wheel and tyre clearance
Starting With a 3D Scan
The first step was to capture the front suspension area properly.
Rather than taking measurements traditionally, the front chassis and suspension components were 3D scanned so the key pickup points, wheel arch clearance, strut tower position, and surrounding structure could be brought into CAD.
This gives a much clearer picture of what space is actually available, especially around the top mount, inner arch, wheel, tyre, and damper.
For a car like the SW20, packaging is a major part of the problem. The front end has limited space, and once you start increasing tyre size, lowering the car, and trying to improve geometry, everything becomes a compromise.
The scan gives us a base to work from before designing any parts.
Identifying the Problems
Once the front suspension was measured and modelled, three main issues became clear.
Camber Loss in Bump
One of the key limitations is camber behaviour through bump travel.
On a track car, the outside front tyre does a huge amount of work. As the car rolls and loads the outside tyre, you want the suspension geometry to help keep the tyre in a useful contact patch.
If the car loses camber in bump, or does not gain enough negative camber as the suspension compresses, the tyre ends up leaning onto the outer shoulder. That means less grip, more tyre wear, and a car that feels less consistent.
Static camber can help, but it is not the whole answer. You can keep adding static camber, but that comes with trade offs in braking stability, tyre wear, and straight-line contact patch.
The better solution is improving the geometry so the car uses the tyre more effectively through travel.
Low Caster
The SW20 also does not have as much caster as we would like for a fast road and track setup.
More caster can help with steering feel, self-centring, and dynamic camber gain when steering lock is applied. For a mid-engined car like the MR2, front-end confidence is extremely important. The car needs to communicate clearly and build grip progressively.
Increasing caster is not about chasing a number for the sake of it. It is about improving how the car feels and how the front tyre works while cornering.
Bushing Bind
A common issue on many cars, but the SW20 front lower wishbone configuration is one of the worst offenders. As the bushes are not aligned, instead of the arm moving freely, the rubber bushes twist and resist the movement.
The result is a wheel rate that is not as consistent or predictable as it should be. Rather than the spring and damper controlling the wheel cleanly, some of the load is being taken up by the bushes. This can make the car feel less responsive to driver inputs, reduce feedback, and make setup changes harder to interpret.
One solution is to move to a spherical bearing arrangement on the front end. By allowing the arm to articulate more freely, the suspension can move with far less bind and less unwanted compliance. This gives the spring and damper more direct control over the wheel, improving response, consistency, and steering feel.
The trade-off is that spherical bearings generally require more maintenance than rubber bushes and may have a shorter service interval, especially on a road-driven car. However, for a fast road and track-focused setup, the benefits can be significant, and the negative effects are often less dramatic than expected when the parts are properly specified.
Wheel and Tyre Clearance
The other issue is clearance.
As tyre size increases, especially with wider front wheels and more track-focused fitments, clearance around the damper, spring, inner arch, and bodywork becomes tight.
This is one of the reasons the top mount and damper position matter. A small change at the top of the strut can make a meaningful difference to tyre clearance, strut angle, and available adjustment.
For the 7 Works SW20, the aim is to create a package that allows a more serious front tyre setup without relying on awkward compromises.
Developing New Front Top Mounts
After identifying the issues, the first major part to develop was a revised front top mount.
The purpose of the top mount is not just to hold the damper in place. On a MacPherson strut car, the top mount is a critical suspension pickup point. Moving it changes strut angle, caster, camber behaviour, and clearance.
For the SW20, the revised top mount concept is designed to:
- Increase caster
- Improve front suspension geometry
- Help tyre clearance
The idea is to move away from simply accepting the limitations of an off-the-shelf coilover installation. A damper package can be good quality, but if the mounting position and chassis geometry are not right, the car still will not work as well as it could.
This is where proper chassis-specific development matters.
A generic suspension kit has to fit a wide range of customers, wheel setups, ride heights, and use cases. The 7 Works approach is to develop around the actual requirements of the chassis, the tyre, and the intended use.
Developing Lower Arms
The next area of development is the front lower arms.
The lower arm is another major part of the geometry picture. Once you start changing ride height, top mount position, caster, camber, and wheel fitment, the lower arm needs to be considered as part of the same system.
The lower arm development is aimed at improving:
- Track width options
- Camber adjustment range
- Roll centre and arm angle behaviour
- Wheel positioning in the arch
- Clearance around wider tyre packages
As with the top mounts, the goal is not just adjustability for the sake of it. The goal is controlled, useful adjustment that allows the car to be set up properly and repeated accurately.
A good setup part should make the car easier to understand, not harder.
Why This Matters
Suspension development is often reduced to a list of parts: coilovers, arms, bushes, top mounts, anti-roll bars.
But the parts are only useful if they work together.
The 7 Works SW20 is being used as a development platform to test these changes properly through installation, measurement, road use, and track use.
The aim is to build towards a more complete front suspension package for the chassis, combining geometry correction, damper setup, braking performance, and real-world feedback and data.
What Comes Next
This is only the beginning of the suspension development work on the 7 Works MR2.
The next stage is to build a far more detailed model of the front and rear suspension, allowing the geometry to be analysed properly through more dynamic situations. From there, the aim is to optimise as much as possible while retaining the stock body, stock chassis structure, and inboard pickup points.
The goal is to extract as much performance as possible, while keeping the package easy to replicate on any car. The end goal is a suspension package that is properly developed around the SW20 chassis, modern tyres, and serious fast road and track use.