Can You Fit 9.5J Wheels to an S2000 Without Rolling the Arches?
17×9.5J +63 Square Fitment — Wheel Offset and the Suspension Parts Behind It
Part of our Honda S2000 Restoration & Tuning Journal Series
Our demonstrator S2000 with a 17×9.5J +63 square wheel setup, retaining the standard wings without rolling the arch lips.
Over the past few weeks, we have talked about springs and coilovers. Have those articles helped you reassess your S2000’s suspension setup? Or perhaps helped you give your planned winter project a clearer direction?
My guess is that a widebody conversion is probably not on your ToDo list. You want to retain the S2000’s original appearance while fine-tuning it towards track use—and fit the widest wheels you reasonably can within the standard wings. Does that sound familiar?
This time, we will use our demonstrator S2000 to explain how we fitted 17-inch, 9.5J wheels with a +63mm offset without rolling the wheel arches.
And no, we are not just talking about the rear. The front wheels are the same size: a square setup, front and rear.
However, this is not simply a matter of buying the wheels and bolting them on. Coilover clearance, ride height, camber and steering lock all need to be considered together. On our demonstrator, we built this setup using Öhlins DFV coilovers and CSO suspension components.
To be clear, “without rolling the arches” means leaving the folded lip around the wheel arch unrolled. Modifying the small tabs that secure the arch liners, which we will discuss later, is a separate job.
We will leave tyre size and brand to your own choice in this article. However, the tyres you choose and differences between individual cars will affect clearance. Let us look at our demonstrator’s combination and what you need to check on your own S2000.
Our Choice: 17×9.5J with a +63mm Offset
Our demonstrator S2000 wears RAYS VOLK RACING CE28 N-plus wheels: 17×9.5J with a +63mm offset, front and rear. When discussing sizes with Japanese shops, we sometimes shorten this to “1795+63”.
The 17 refers to the wheel diameter in inches, 9.5 to its width, and +63 to the offset in millimetres. Another size we considered, “1790+61”, means 17×9.0J with a +61mm offset.
The important point is not to choose by width alone. Even with the same 9.5J width, the offset changes where the wheel sits relative to the car. A higher offset moves it further inboard; a lower offset moves it further outboard.
We want to keep the wheels within the standard wings, so we cannot push them too far out. But moving them inwards brings them closer to the suspension. Both sides need to be considered.
We chose this size drawing on Mr Ohara’s experience with S2000s at CSO. However, we did not assume that an “S2000-specific size” would simply bolt on and fit. We checked it in combination with the coilovers and suspension components fitted to our demonstrator.
So, let us start inside the front wheel arches. There are two clearances to check: the wheel relative to the coilover, and the wheel relative to the upper arm as the steering is turned.
What Can the Front Wheels Contact on the Inside?
The first clearance to check is between the inside of the wheel and the coilover.
On our demonstrator, we have checked the combination of Öhlins DFV coilovers and 17×9.5J wheels with a +63mm offset. However, that does not mean another coilover will provide the same clearance. It is not just the damper body that matters: the position and shape of the spring and spring seat also play a part.
In the previous article, we chose coilovers; in this one, we are choosing wheels. That gives us a neat sequence on the page, but on the car, the two choices need to be considered together. If you already have coilovers fitted, check the available space before ordering your wheels.
The second clearance is between the wheel and the upper arm as you turn the steering.
A wheel may fit with the steering straight ahead, yet its inner rim moves closer to the upper arm as you approach full lock. With wide wheels positioned further inboard, as in this setup, contact can become an issue.
Our demonstrator therefore uses CSO steering rack stoppers. These limit rack travel so that the steering cannot turn far enough for the rim to contact the upper arm.
Of course, that also reduces maximum steering lock. We give up a little steering angle to accommodate the wider wheels. That is one of the compromises built into this combination.
However, fitting the stoppers does not resolve every possible clearance issue on the inside. Coilover clearance still needs to be checked separately, and the fitment needs to be verified on the actual car through steering movement in both directions and suspension travel.
Once the inside is accounted for, we can look outside. How did we combine ride height and camber to keep the wheels within our demonstrator’s standard wings?
Outer Clearance: Considering Ride Height and Camber Together
Once we have clearance on the inside, the wing is waiting on the outside.
Looking neatly tucked in while parked is not enough. We also need to check whether the tyre contacts the wing as the suspension compresses over bumps or under cornering loads.
Our demonstrator S2000 sits approximately 40mm lower than standard, with around −3° of front camber. Viewed from the front, the tops of the wheels lean inwards towards the car.
That angle helps us create clearance on the wing side. However, this does not mean that lowering any S2000 by 40mm and setting −3° of camber will make the wheels fit. Tyre choice, differences between individual cars and suspension movement all affect the clearance required.
For me, −3° is not simply a number chosen to tuck the wheels in. It is also a setting I have chosen for my own track driving and cornering. I am looking for the point where a setup that suits my driving also works within the standard wings.
So, I would not suggest simply adding more camber until the tyres stop touching. How you want to use your S2000 needs to be part of that decision too. We will leave the detailed alignment discussion for next week’s article.
On our demonstrator, however, adjustment using the standard eccentric bolts alone could not achieve the −3° we wanted.
We therefore fitted CSO adapters that combine roll-centre correction with additional negative camber. Next, let us look at these parts and the supporting suspension components we used with our lowered setup.
Supporting Our Lowered Setup with CSO Components
Our demonstrator uses CSO bolt-on roll-centre and negative-camber adapters. These combine roll-centre correction with approximately one additional degree of negative-camber capability.
For us, this combination provides the camber we could not achieve within the standard adjustment range, while also correcting suspension geometry after lowering the car.
Of course, fitting the adapters does not automatically produce −3° of camber. We measured and adjusted the setup after installation, bringing our demonstrator to approximately −3°.
On this car, we did not retain the bump-steer adjustment components that could not be used alongside the RCA. We chose these adapters instead. Rather than adding everything, we selected components that work together as a combination.
We also use CSO front stabiliser performance brackets.
Lowering the car changes the relationship between the stabiliser bar and its links. These brackets reposition the stabiliser mounting points to correct the link angle altered by lowering.
They do not directly resolve wheel clearance. However, if we lower the car to accommodate wider wheels and then drive it in that configuration, this is another part of the overall suspension setup worth considering.
Rack stoppers address inner rim-to-upper-arm clearance. Ride height and camber help us manage clearance on the outside. Roll-centre correction and revised stabiliser positioning support that lowered setup. Together, these form our demonstrator’s specification.
But even with those parts in place, there is one small detail we do not want to overlook: the tabs that secure the arch liners.
No Arch Rolling—but the Liner Mounting Tabs Are a Separate Job
The final detail to check is the small metal tabs that secure the arch liners.
Rolling the folded lip around the wheel arch and bending or trimming these tabs are two different modifications. “Without rolling the arches” does not mean leaving every part around the wing completely untouched.
With wider wheels and a lowered setup, the tyres can approach these tabs as the suspension compresses or the steering is turned. If a tyre catches a tab, the result may be more than a minor rub: it can damage the wing.
Where necessary, we therefore consider bending the tabs slightly or trimming the interfering section. Exactly where and how much to modify depends on checking clearance on the actual car. Protecting exposed metal against corrosion and ensuring the liner remains securely attached are also part of the job.
After working through this combination to retain the standard wings, it would be frustrating to damage one because of a small mounting tab.
Bolting the wheels on is not the finish line. Checking clearance through movement, including these mounting details, is part of completing this setup.
What Combination Will Work for Your S2000?
Considering wider wheels but unsure how they will work with your current suspension? Get in touch with your current wheel sizes, coilovers and how you want to use the car.
Before ordering parts, let us work through what needs checking and what may need changing.
Next time, we will look at how to make that combination work on the road and track—with a discussion of wheel alignment.
See the Complete S2000 Restoration
Explore the complete restoration and development of our demonstration S2000—and the workshop experience behind it: