The Mercedes-Benz 300SL SportLine from SLSHOP… Why?

The passion that our customers, and we ourselves, have for the Mercedes R107 runs deep, but in developing the SportLine, we would push the capabilities of this car to unlock its full potential. We’ve spent many years repairing, restoring and maintaining these beautiful cars for our customers as well as owning some ourselves. While the classic beauty, sophistication and performance of the 107 can never be faulted, in developing the SportLine we set about answering some common questions about the car.

Why produce the SportLine?

The inspiration for the Mercedes 1R107 SportLine was most definitely our customers. In our years of experience working with these classic cars, customers old and new commonly ask us the same types of questions. They relate primarily to performance. Not faulting the traditional performance, but certainly asking how far it could be pushed? What are the opportunities to tune the car further? Can the handling be improved to bring it more in-line with other sports cars of the modern day? In producing the SportLine, we wanted to answer these questions. We wanted to give the car more of that “driver’s feel” that so many car enthusiasts love. The ingredients were already there in every Mercedes R107 SL. It’s an open-top sports car that’s safe and reliable. It packs a straight-six engine. If we could apply some modern technology, we could give the 107 a new lease of life. After all. in the 30 years since the car finished production, there has been considerable advancements in the world of motoring and mechanics. If we could apply some of that newer technology to the SportLine, we felt we could really have a special car and could push it somewhere near fulfilling its potential.

How we produced the SportLine

To be truly confident in answering the questions outlined above and to accomplish the goals we set out to achieve, we would have to be thorough in our work. The SportLine was a ground-up rebuild and involved many hours of work from the team at SLSHOP. It’s a significant investment of time and money, but a worthwhile one. The first task was to firm up that suspension a little bit without losing the characteristics of the car. We started out by adding new pistons and a revised crank which was both lightened and balanced. The crank shaft was reprofiled to give the car greater torque. Torque is what makes the car feel like it’s accelerating. It gives you that kick, and for car enthusiasts, it excites you and brings a smile to your face. So, by adding more torque, we were increasing that feel of acceleration and enhancing the authentic drivers’ feel of the car. A key aspect to any fine-tuned car is to make sure that the engine can breathe properly. The key to that, as we all know, is to supply it with as much air and fuel as it needs to ensure optimal performance. For this, we totally re-designed the injection system by installing a modern rail with longer fuel injectors. There’s a different ignition system in there too, not to mention a bespoke and programmable ECU. These modifications meant that we needed to give the exhaust some modification as well. We designed and developed a bespoke exhaust specifically for the Mercedes 107 SportLine. All of these modifications led us to achieve more power overall from the engine. We had increased horsepower and increased torque. However, that’s only half of the battle. As the old adage goes, power is nothing without control, so we had to ensure that these changes were fed through to the driving experience itself. We fitted a five-speed Mercedes gear box and at the same time balanced and lightened the fly wheel. That not only improves how the engine feels, but crucially, it improves how it drives through the transmission. From there we then went on and fitted a bespoke limited slip differential. The 300 SL did not have a limited slip differential, although the V8s did. Therefore, we felt it important to fit one on to the SportLine. It aides the driveability of the car through and out of a corner. Making those subtle changes really positively impacts the driving experience.

Developing the chassis for the SportLine

In developing the chassis for the Sport Line, we knew it was a vital part of the project. Many hours were invested in this element of the rebuild to ensure we got it right. Throughout the SportLine project, we were careful not to lose the original feel and character of what the 107 is all about. This was never as important as when we were working to develop the chassis. While we had that in mind, we knew there was also an opportunity to just firm-up that suspension and make it feel and handle a lot better than it did originally. We fitted progressive springs that allowed us to adjust the ride height of the SportLine, giving us freedom to really fine-tune how the car rides. The shock absorbers were tuned for the specific GT feel – we were careful not to go as far as giving it more of a race car feel, but it was vital that we got that right level of compliance from the dampers. We believe we did that. The chassis part of the project also required that we look at the anti-roll bars on the 107. We uprated the front and rear anti-roll bars to aid the handling through corners. The SportLine needs to go through corners nice and flat, and these tweaks allowed us to accomplish that. The work that was carried out on the SportLine suspension really allowed us to get the correct stance of the car. The ride height was exactly what we wanted. After completing work on the chassis, we were confident that we had managed to really refine the 107. Many hours spent of fine-tuning the 107 has enabled us to really successfully refine the dynamics of the car. It maintains that 107 feel both on a smooth road surface as well as a bumpy or undulating road surface as we all experience when taking the car on tours and trips. Despite our 107 being a post-1986 car, we were able to get some larger and wider pre-1986-looking wheels. Fitting these wheels served two purposes. Firstly, aesthetically, we felt it really enhanced the look of the car. But from a driving point of view, it also allowed us to fit some larger performance tires to the car.

Finishing the SportLine off

Once the mechanical side of things was complete with the SportLine, we wanted to just finish the car off. It was about making subtle little differences which could just give the car the edge when you look at it. While obviously being a 107, we wanted to suggest a slightly different and more sporty appearance. The changes made were not massive, but they were enough. We picked out some of the black accents from the SportLine badge while also reducing the size of the mirrors. The mirrors are still Mercedes mirrors, but we took them from an earlier SL car. We also made the fine eyebrows above the headlights on the car black; again, it’s about just giving it an edge and making it catch your eye. Moving on to the interior, we started with the seats. We recovered them in a soft napa leather around the outsides while using alcantara on the centre. We had to maintain the iconic Mercedes pleats in the design, but we removed the traditional piping from around the edge and instead double-stitched them. They retain a classic look, but with that sporty GT edge to them. They’re also incredibly comfortable. The steering wheel, dashboard and that brand-new manual gear lever were covered in a soft black leather, with the edge of the dash having a red double-stitch accent around it. It looks sporty, we love it. We also chose to reprofile the steering wheel to give the car a better feel when driving – this is a really important element of the driving experience. In developing the interior of the car, we were keen to again make subtle changes without ruining the classic 107 feel. The seatbelts were redesigned with a slight red edge to them while the wood inside the car was re-laid using a dark black pepper wood-effect. The SportLine logo was added just above the glove box to one side, which looks fabulous and is a constant reminder that you’re driving something a little different. In the centre of the dash, we did make another addition that you wouldn’t have found on the original 107s; the fuel-air mix gauge. As we’ve returned the engine and ensured the injection system is a high-performance one, these dials can now give you an indication of what is happening in the engine while you’re driving along. Finally, the dials in the dashboard were given a slightly more sporty edge as well. We installed white dials which genuinely do just finish off that special feel when you slip into the driver’s seat.

The Mercedes 107 SportLine

In summary, we are delighted with the SportLine. Not only did we love it, but customers also loved seeing the car and what we had done to it. The 107 oozes class and we knew it had potential – we believe we have created something that fulfils that potential and truly is something special. While it may not be for everyone, here at SLSHOP we believe that we have created the best handling and driving experience you will get from a 107 – you’re going to want to jump behind the wheel yourself! Tempted and want to add some SportLine parts to your SL? Click here

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