Main features

  • Full electronic servo assisted brakes
  • External alternator with dual battery charging
  • Fan assisted heat removal from rear engine bay
  • Adjustable hydraulic clutch
  • Reverse gear
  • Extended accelerator pedal movement to help with quick revving engine
  • Crush drive to take the impact load of the gear change... without this, the gearbox would be put under unnecessary stress
  • Front spoiler, splitter with new full under pan (underside floor) to stop uplift at the front that all Smart Cars suffer with over 70MPH... keep in mind this car is capable of 150MPH!
  • Full new suspension design with bump, rebound and camber control
  • Wide alloy wheels and tyres
  • Hayabusa clocks fitted
  • Nylon brushed engine to stop engine vibration

How we developed the Hayabusa Smart Car

This project has taken many years to develop not months like some companies; we looked into every detail when developing it.

Why did we chose the smart roadster and smart for two to put a Suzuki Hayabusa 1300 bike engine in?

Roadster Hayabusa conversionSimple answer, the roadster is well known as been a very good handling light 2 seater car, and the smart for two has EXACTLY the same suspension geometry as the roadster !!!!! The roadster is simply just a stretched smart for two. Suspension geometry plays a major role in the way a car drives on normal roads and also on a race track. People are very misinformed by thinking that putting stiffer springs and dampers on a car will make it handle better; this is not the case if the suspension geometry is not correct to start with. I can honestly say after driving many supercars that they got it just right. Why play games with perfection? We didn’t, we decided that if it was good enough for Brabus then its good enough for us. But the big question was, would it be good enough for a track day car as well? Mercedes had designed under steer into the car to keep it safe for the driving abilities of the average person on normal roads (understandably), so we had to address this problem immediately. We will come to explain more about the under steer problems later on.

Admittedly we tried what we thought would be the easy way first, we first purchased from another company that puts GSXR1000 engines in smart cars, a rear frame with new independent rear suspension. After trying this in a car and then realising that the rear suspension geometry on the frame was no way near matched with the front suspension, we decided to try and adjust the rear setup on the frame to perform better with the existing smart front suspension. This was a long and painstaking job.

Trying to make the frame we were given handle correctly would mean altering all the front suspension geometry as the front suspension geometry works alongside the rear so to put it in simple terms they both complement each other. Please do not confuse suspension geometry with stiff springs and dampers they are two totally different things. Here is a simple link to those of you interested in suspension geometry.,-Handling,-and-Suspension.htm

Due to us not wanting to alter what Mercedes had spent a large amount of money developing (front suspension) we looked into putting an engine into the existing rear sub frame.

As you could imagine this was no easy task but eventually we got the GSXR1000 engine we originally purchased for the aftermarket rear frame to go in the original sub frame of the smart car.

These are the problems that we found while developing the car

Problem 1 - Engine Power

The GSXR1000 engine does not have any more torque than a standard smart car 80 lb-ft of torque 160bhp that only comes in at high rpm. The smart cars torque comes in at a lot lower rpm. The gsxr1000 engine also is not built to push heavy loads, its internal components are very fragile so will break after heavy loads for long durations. It is designed to push a very light sports bike. The only advantage we could see over a tuned smart car engine is that it revs high and makes lots of noise.

So we decided to use the GSX 1300 Hayabusa as it has 100 lb-ft of torque and 180bhp. The 2008 Hayabusa has 105 lb-ft of torque and 200bhp. The torque comes in lower down on the Hayabusa so becomes drivable at very low rpm in the smart car. The hayabusa engine is more than capable of coping with pushing heavy loads for long durations; this makes the car reliable and is nice knowing the engine can cope with the heavy smart car. The Hayabusa engine is the most tuned bike engine in the world so if your wanting more power, then its available, up to 300lb-ft of torque with 600bhp. Although we would not advise this sort of power in a smart car I am sure there is some lunatic out there that would enjoy it!!!!!

Problem 2 Venting the engine

Using two venting holes in the rear boot (hatch) near the number plate would not extract the hot air the engine created in its confined space in slow road traffic. The engine uses the smart car radiator at the front of the car to cool it but the engine itself naturally still gives of a massive amount of heat that needs to escape out the car. We then created a fiberglass cover for the engine to try and keep the heat from entering the car with heat and soundproofing also installed in it, this made things worse by the heat then heating up plastic and rubber components on the engine, motorcycle engine manufacturers do not design there components to be concealed in tight concealed spaces.

The answer to the problem

To install high volume radiator fans used as extraction fans in the rear of the car to keep cool air flowing over the engine and its components. A visit to our factory will easily show you the massive heat increase when we unplug the fans to when it is turned on in normal use.

Problem 3 Wires overheating

A fire started on several occasions due to the bike engine alternator (stator) not putting out enough amps to power the smart car in its general road use.

The smart car in its simplest form (no heated seats etc etc) has a 45 amp hour battery. This meant at any one time the car can be pulling 45 amps of power and the standard smart car alternator is measured at 85 amp hour to cope with this. A car or bike alternator should never run at its maximum output for long periods of time as this can cause it to heat up tremendously and burn out. The gsxr1000 and hayabusa1300 only have a maximum output of 30 amps so even if you have the most standard of smart cars with no electrical extras you need 45 amps. This means going down a dark street with your high beam on, windscreen wipers on also with rear demist and heater fan going your car after a few minutes will stop working as it cannot even power the engine let alone the lights and everything else (for you own piece of mined ask any auto electrician what could happen). To put the icing on the cake wile your car was deciding it was about to stop working the standard bike engine alternator wires would be thinking to themselves I need to set on fire.

Many people don’t think of simple but important things when building bike engine cars. Small race cars using bike engines with only lights to power do not suffer with this problem but the smart car does. All motorcycle auto electricians will tell you even though the gsxr1000 and hayabusa 1300 have 30 amp alternators they will also tell you that they will never pull more than 20 amps at any one time, this is to allow the alternator or alternator output wires to never overload.

The answer to the problem

We had to install an external alternator driven by the bike engine to solve the problem with a double battery charging system so as to not overload the smart car battery and allow equal charging when necessary. Without the double battery charging system the bike engine alternator and wires could still overheat and set on fire.

Problem 4 Clutch

To make a clutch work like a normal car with a bike engine is a massive task in its self. We tried the one given to use with the original aftermarket frame, this was to say the least, a joke. It was like a switch either on or off. A motorcycle engine does not have a flywheel which means that the engine will not hold low revs while setting off.

The smart car in its simplest form (no heated seats etc etc) has a 45 amp hour battery. This meant at any one time the car

The answer to the problem

After several months of work designing a full new clutch system we finally managed to get the clutch working exactly the same as normal clutch in a car.

Problem 5 Accelerator pedal

Bike engines are very quick revving engines so when setting off and in slow traffic they want to rev very quickly (rapidly) so to have a clutch like a switch and a quick revving engine is a recipe for disaster. As we had solved the clutch problem we now had to solve the quick revving problem at low revs. Due to the normal smart car accelerator pedal only having 2 inches of movement (top to bottom).

The answer to the problem

We had to design a new accelerator pedal with 4½ inches of travel. This allowed the clutch to work well with the accelerator and also work well in slow town traffic.

Problem 6 Brakes

The smart car has servo assisted brakes; this means the engine needs to draw a vacuum on the brake servo to make the brakes work correctly. There is no way to make the bike engine draw a vacuum from the brake servo so we had to find a solution. What would be simple would be to use and electronic vacuum system but the servo works from a specific vacuum draw.

The answer to the problem

After months of using different set ups we finally designed a system that would electronically draw the correct amount of vacuum on demand.

Problem 7 Crush drive

A motorcycle has a crush drive in the rear wheel to take the impact load of the gear change, without this the gearbox would be put under unnecessary stress.

The answer to the problem

We designed a full new drive system to incorporate a crush drive.

Problem 8 Are the standard brakes good enough to withstand hard braking on a race track

No they are not; they are perfect for street use but will overheat with intense braking on a race track. This problem was awkward to solve; do we put vented discs on the front and replace the rear drum brakes with discs? Doing this would make our customers needing to go to many different manufacturers for replacement parts which is inconvenient and would also change the un sprung weight of the car that Mercedes had obviously tried to keep to a minimum. We tried to force vent air to the front discs but found the brake callipers over heating only with track use. The information on brake heat was achieved by using 6 brake temperature sensors strategically placed around the disc and calliper. So we had to vent both calliper and disc from both sides using a complex air distribution system, unless this is done perfectly it will cause brake disc distortion and calliper seal failure as well as the brake fluid boiling causing complete brake failure. The system we have developed now works perfectly for the race track. The standard rear drum brakes now also use a similar air distribution system for what we have designed for the front discs.

Problem 9 The smart cars handling problems

The rear De Dion tube has a centre bush that does not hold the rear wheels true to the car under excessive cornering or going over a bump while cornering. This is a serious issue to a confident driver. Mercedes have done this for a good reason as to not give people too much confidence in the car and push it into a situation they cannot deal with. We tried several polyurethane centre bushes to solve the problem but none gave us a huge increase in confidence with the car. So we had to design our own bush to solve this problem. Many people are misinformed as to thinking that replacing the four rear arm bushes will help with this problem, it will not, 90% of the movement is in the centre bush.

Problem 10 Suspension design and under steer

The smart car has been designed for normal road use not fast road use or a race track. It has under steer designed into it by the manufacturer (Mercedes) to stop people getting over confident and pushing the car into a situation they cannot deal with, a confident driver does not want this. Here is a link to those of you interested in under steer.

Obviously a standard smart car has soft suspension which is not good for fast cornering as the car will tend to lean and through its weight to one side. There are a few suspension manufacturers that make suspension for the smart car, but one of the main problems with the suspension geometry is that it only has a negative 0.2 degrees camber angle on the front wheels. This is to induce under steer into the car to stop people getting over confident with the cars normal suspension handling. A car with negative 0.2 degrees camber is never going to go round a corner fast with the driver having full control.

The answer to the problem

We have designed a full new suspension strut with full camber, bump, rebound and height adjustment incorporated into it. This enables the driver to put up to 3 degrees of camber on the front wheels along with bump, rebound and height adjustability.

ATB, limited slip differential

Smart cars suffer with under steer. This has been corrected with the new suspension design, by using an ATB or limited slip differential it induces under steer when driving the cars fast on the road or track. Under steer is very undesirable in any car, if the front of the car was to be heavier ATBs would be possible. If for what aver reason you would like an ATB or limited slip differential this can be installed.


There are many modified car insurance companies if you put modified car insurance into Google. We use: Performance direct and Adrian flux

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