Project S4: Whiteline Rear Swaybar & Camber/Caster Kit

As a motoring features editor and editor, I’ve taken the trouble of running project cars on all the titles I’ve worked on. They are a fabulous way of getting to grips with the huge product range on offer out there in the world of aftermarket tuning… and there’s no substitute for first hand testing, rather than believing a press release and running it in your magazine as a new product, without proper editorial testing. Project S4 is pretty tame compared with others I have created, being a daily driver, fast road and an occasional track day fun tool, but nonetheless, it’s been great to test tuning products (see all the posts below) and much improved over standard. You can teach an old dog new tricks… if you pick the right products.

One brand I have tried and tested extensively with my project cars – and had nothing but positive things to say about – is Whiteline ( “Activate more grip” is one of their marketing mantras, and boy… do they! They also claim to be the best “bang for your buck” when it comes to suspension tweaks. A fair claim. Affordable, effective, long-lasting products and with a fabulous customer service. On top of this, their website is a font of knowledge on suspension… check it out!

Whiteline are a global brand manufacturing replacement, enhancement and performance suspension components “that deliver significant gains in vehicle balance, steering precision, grip levels and outright driving performance.” Their massive range consists of adjustable sway bars (also known as stabilizer or anti-roll bars), chassis bracing, alignment products, camber/caster and toe kits, roll centre and bump steer correction kits, chassis control bushing kits and strut and chassis bracing.

They say: “Using a range of sophisticated testing and data logging tools, we rely on comprehensive testing to maximise the product benefits and ensure that they work as a complete package tuned to give you the best handling outcome. Whiteline has the products and practical experience to maximise the potential of your vehicle whether it be a daily driver, street performance or motorsport vehicle and guarantees a quality, tested and tuned outcome using Whiteline products.”

What makes Whiteline different from other brands? Well, they make a range of unique products, being the only brand globally to market a full range of undercar chassis and suspension components, designed to complement your spring and damper/shock absorber set up (standard or aftermarket upgraded, like Project S4). They use the latest engineering techniques and designs to create products – aiming to keep the tyre in contact with the road surface as much as physically possible, to generate maximum grip. This is the key…

I’ve tried the bulk of their products over the years, and every one of them has been a winner – great value, perfectly engineered, easy to fit, durable and damn effective at reducing inertia and maximising grip levels.

For Project S4, being fairly tame, and already a very good handling car (especially since I fitted the Bilstein PSS9 coilover kit, see post below), I did not want to go mad and fit lots of braces and all the chassis controlling devices. I wanted to keep things simple.

The front swaybar on Project S4 is already pretty thick and I’m not a fan of too large a bar on a car, unless it’s a racer: Tends to induce understeer, unless set-up absolutely bob on with a bespoke alignment. But the rear bar on the S4 is puny… just 14mm. So, I ordered the Whiteline heavy duty 18mm swaybar upgrade. And I also ordered their rear upper control arm upper inner bushing camber correction kit and front radius control rod caster correction kit.

The upgraded swaybar (BAR13): As the name suggests, their objective is to reduce sway, or body roll, and stabilise a vehicle under lateral (cornering) forces. Formula 1 cars still use sway bars along side the shocks and springs as it is the ONLY suspension component principally designed to control body roll. Whiteline say their swaybars “dramatically improve the grip, handling and performance of your vehicle. Cornering loads are spread more evenly across the tyres delivering more grip. You also get improved tyre wear as your tyres stay flatter and more upright. Also, comfort improves because your car sits flatter through bends meaning less movement inside the vehicle.”

The camber correction kit (KCA420): These are designed to replace the standard rear upper inner control arm, providing a camber adjustment range of +/-0.75 degrees of camber. Incorrect camber settings reduce traction, increase tyre wear and are detrimental to the general handling performance. These elliptical bushes will allow me to add negative camber, which will assist with turn-in, suspension accuracy, traction and mid-bend stability.

The caster correction kit (KCA422): Fitted between the front radius rod with uprated chassis bushing, this anti-lift chassis control device also provides a +/- 0.5 degrees caster adjustment range. This should enable Project S4 to have more complaint suspension during braking and acceleration, quell understeer with increased front end grip and create sharper more precise steering due to added caster.

If you want to know more about camber and caster, toe and all things alignment-based in suspension world, check this useful guide out:

I’ve fitted two out of three of these products before, to other cars (front, rear and four-wheel-drive) and with great success… but every car is different, so we’ll report back here soon, with a road and eventually, track day test on Project S4. We’re going up to our pal, Dave Green at Henstead Motorsport ( later this month, to fit them. Stay tuned here and also on

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