B3 Sport Suspension - BMW E92 335i, 330i, 335d, 330d

The B3 Sport Suspension uses specially valved Bilstein dampers and matched springs to offer the ultimate improvement in ride quality and handling on UK roads.

With help from a professional chassis specialist - Rhoddy Harvey-Bailey - our B1 Suspension Kit was developed on our E92 335i demonstrator over thousands of miles, and is one of the few kits truly designed for day-to-day road use.


These kits use different spring rates and dampers depending on body type, year, RHD/LHD and more. Please provide your VIN when you enquire so that we can specify your exact set up. Alternatively, come down to Birds for a demonstration in the 335i demonstrator and see why the B3 Sport Suspension is the ultimate suspension upgrade for your 3 Series!

Prices and Applications

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B3 Dynamics Package 


Why not have both ride comfort and handling?

Watch one of our customers demonstrate how the B1 Suspension (1 Series equivalent) upgrade was developed to work equally well on track as it does our U.K B-roads in his B1 Dynamics Package equipped 130i (standard engine) at Silverstone and the Nürburgring below:




BMWCar Magazine's review of Birds 335i demonstrator

"Birds' B3 is a revelation. They have turned a nervous chassis that was at best 'entertaining' into a seriously quick and comfortable missile, proof positive that you can have both ride quality and performance." Bob Harper.


More editorials and customer testimonials can be found in our library!


How we created the B3 Sport Suspension...

Modifying a car suspension system can be likened to walking a tightrope. Enthusiastic drivers will want the ride to be firm, whilst still offering reasonable comfort. The chassis must perform with all of the standard cars’ positive attributes, removing the negative ones, whilst offering a more direct handling stance and improving all of the dynamic criteria.

The first tool in the suspension tuners’ armoury is the road springs. They dictate the primary stiffness of the suspension, and control the ride height of the car at front and rear axles. They also have a significant impact on the roll stiffness and aerodynamic stability as secondary factors. It is clear therefore that this starting point will be critical in its influence over every chassis tuning component. The problem here is that most tuners have a hugely mistaken belief that a sporty suspension must be inherently stiff, moreover it must also always be stiffer than standard.

When we set out to address ride quality problems, we took characteristic data from some of the industry's foremost experts, and compared professional road testers opinions of various vehicles. We determined that the characteristics we required were those of the finest handling cars on the planet. There could be no doubt that if we could achieve a ride quality and handling balance of the E30 M3, our job would be done. We did not restrict ourselves in our search to only the BMW marque. We also identified Lotus and Jaguar as particularly competent exponents of the “Art Of Ride And Handling”.

We tested the rates of standard springs, and renowned tuner's products too. Testing of the E87 chassis ultimately dictated the final prototype spec. With the first prototype set on the car, it was immediately obvious that the balance of the car had become more neutral, had vastly reduced the tendency of the car to hop across the peaks of bumps, loosing traction at the same time. More importantly, the ride quality had improved to a massive degree. We were definitely on to something...

"Show me an adjustable suspension, and I'll show you one hundred ways of getting it wrong." - Rhoddy Harvey-Bailey.


After consultation with our suspension guru Rhoddy, we were told to restrict our search for the correct shock absorber components to Bilstein. Their gas assisted shock absorbers can be easily tuned to achieve genuine damper curves. That is to say you can have different damper rates for slow and high speed damping. Thus it is possible to achieve good ride quality characteristics alongside superb handling capabilities at high speeds and loads.

Many shock absorber manufacturers publish damping curves, but in truth cannot really produce anything like the reverse gradients required for our project.

So, armed with the test car on the prototype springs, we set about the task of drawing damper curves. Once again, we road and dyno tested various different damper sets, found the versions that were closest to our ideal set-up, and produced drawings of our ideal curves using existing curves as a basis.

Bilstein quickly re-valved an existing damper set to our spec. We can only say that on installation, the results were a revelation! In the “before” settings, this amazingly quick car would communicate “back off”, causing the driver to hold back on the power when driving through and out of curves. After installing the complete prototype set, the car encourages use of the power much earlier, and without fear of the consequences of overambitious throttle application. Indeed the immediate impression on our "B road circuit" was that exit speeds were now so much higher - approaching to previous braking points seems we were at least 20mph faster! You can feel the tyre smearing itself into the tarmac, the gentle build up of roll oversteer, but without the feeling that the car may suddenly loose grip on a bump, and pitch you through a hedge.

Adjustable suspension kit?

No way! Firstly, there is no means of adjusting the spring stiffness. Secondly, there can only be one correct standard damper rate for any given spring. Thirdly, anyone capable of correctly specifying spring and damper rates correctly is usually an industry professional. Leave this task to even the most experienced tuner, and what you are being offered is a hundred ways to get the set-up wrong.

Even professional race teams tend to have only two settings. One for the wet, and one for the dry.

What else do you need?

As previously documented on this website, there are three things that immediately bring the 1 and 3 series chassis up to scratch. Despite the revelations achieved by the B1 suspension (1 series) and B3 suspension (3 series), our views have not changed in that respect. So to enjoy this car in it’s ultimate configuration, you will need to consider the Quaife differential, conventional (Non-runflat) tyres, and our Anti-roll Bar set. We can recommend the perfect combination of equipment for your specific needs.

However, drivers will still benefit from the B Sport Suspension kit on an otherwise standard car. The ride quality improvement over the M-Sport suspension is massive, as is the handling balance and accessibility of performance. We also offer B-Sport Spring sets separately, which are available for both M-Sport and standard BMW suspension dampers. 


What the press and customers say...

Some of our best customer feedback can be found on the BMW internet forums. Google us and our products for real, unsolicited feedback from genuine BMW enthusiasts!

"On the motorway, bumps and lumps in the road are dispatched in one fluid movemet and the front tyres remain resolutely welded to the tarmac whenever you hit those expansion joints. However where the B1 (Birds' 1 series demo) really shines is on the back roads, amply demonstrated on  the section of road where we do our cornering photography - everything you'd expect from a British B-road. I attack it, and the B1 just blitzes the straight, putting its power down perfectly and shrugging off the surface imperfections like they weren't there. All that's required when you tackle the corner is to pick your apex and power through, with the front end remaining on its chosen course. Ultimately this has to be one of the best 1 series I've ever driven." - Bob Harper, BMWCar magazine.

"Birds' B3 (Birds' 3 series demo) is a revelation. They have turned a nervous chassis that was at best 'entertaining' into a seriously quick and comfortable missile, proof positive that you can have both ride quality and performance." Bob Harper, BMWCar magazine.

"I can only say that the improvement is utterly remarkable! It feels like a different car. The set up actually initially feels tighter and stiffer,until you realise that you have so much more feel through the steering wheel, you can really feel the suspension and chassis talking as never before. Gone is the tram lining along motorway surface seams, gone is the loss of direction over undulating surfaces, and gone is the spine jarring crash, especially at the back end,through our friend the pothole. It may take me a few days to realise that no longer do I need to weave my way along our road system,avoiding potholes,sunken manhole covers etc,but what a joy the car now is. I do hope that you will feel able to publish this email, it is a genuine and heart felt attestation to the quality of the kit which Kevin and his team have put together." - Mr Hodkinson

(Use the filters in our library to see all editorial features and our growing list of testimonials!).