Motorcycle-engined race cars are one of the many wonders of the automotive world. But how do they work? How are they applicable to motorsport, and what are they like to drive in the real world and the sim?
When you think of motorcycle engines, you tend to think of motorbikes... obviously. However, installing these incredibly high-revving engines into cars has created some of the craziest machines known to the road and track.
But it is not just the extremely low power-to-weight builds that use bike engines. Refined and professional race cars also utilize them. From Radicals and Caterhams to full-on Sports Prototypes, the DNA of a race car is often defined by its powertrain. Putting something that could rev up to 17,000 rpm into a car that weighs well under a tonne is only going to give mind-bending results.
Crazy bike engined classic Mini competing at Castle Combe
This incredibly engineered Mini was competing at the Castle Combe Spring Action day earlier this year. I was fortunate enough to be able to photograph this event and this car induced simple boyish excitement every time it came past. The noise it made and the instant power delivery were simply incredible to hear and watch.
As you can see from the photo, there is not much of the original Mini shell left. It has been extended quite considerably using what is known as a space frame or tube frame chassis.
In both a space frame and a tube-frame chassis, the suspension, engine, and body panels are attached to a skeletal frame. The plus side of this in cars like the Mini above is the dramatic weight loss as an extension of space to add parts in or just simply to work on the car. The downside, however, is that the body panels have little or no structural function which is not good in the case of a big crash.
Radical SR3, Spa. Image: Doomwarrier via Wikimedia Creative Commons Attribution-Share Alike 3.0 Unported
These incredible cars are mostly powered by bike engines. The engine from the Suzuki Hayabusa 1300 to be precise. This bulletproof sportsbike engine is used in the SR3 RS 1300, SR3 RS 1500 Turbo and SR3 RSX. Some of Radical's bigger models use the Ford Ecoboost engines from the Focus STs, but they are a significant jump in price compared to the famous SR3 range.
The engine is partnered with the original sequential gearbox from the bike, but it is not as simple as clicking the paddle or pulling the gearstick as it is in the simulator. When driving the Radical, there's a button on the steering wheel to engage what bikers call 'Half shifts'. This is essential to the workings of the Radical because neutral is in between the first and second gear.
2020 Radical SR3, the top right black button engages the half shift. Image: Arise Racing
Engaging the half shift means that you can skip neutral and jump from first to second gear without redlining the car in neutral when you go to change up.
In layman's terms, this means that the half shifts are essential for moving the car from a standstill and into second gear from first. However, the clutch only has to be engaged when pulling off from a standstill and selecting first gear. Once the car is moving and you can change up to second gear, the Radical becomes a clutchless sequential transmission.
The balance and difficulty of their broad range of cars in perfect for sim racers, especially if they own multiple different simulators that they use. Radical even created their own mod, alongside UnitedRacingDesign, to be used within the original Assetto Corsa!
Radial's official SR3 mod for the original Assetto Corsa
This level of commitment and belief in sim racing is refreshing to see, especially when the mod is free to download right here on OverTake.gg. The quality is top notch and the car is used in a variety of online championships and leagues, it has previously featured in our very own Racing Club schedule in past weeks.
So with the sim racing side of motorbike-engined cars being so accessible, and the real-life cars being so complex and brutally powerful, it is clear to see why this combination is so popular. Not just in Radicals, but in any car that you can figure out how to connect everything up in.
If you could put a bike engine in any car, what car would it be? Let us know on X @OverTake_gg or down in the comments below!
When you think of motorcycle engines, you tend to think of motorbikes... obviously. However, installing these incredibly high-revving engines into cars has created some of the craziest machines known to the road and track.
But it is not just the extremely low power-to-weight builds that use bike engines. Refined and professional race cars also utilize them. From Radicals and Caterhams to full-on Sports Prototypes, the DNA of a race car is often defined by its powertrain. Putting something that could rev up to 17,000 rpm into a car that weighs well under a tonne is only going to give mind-bending results.
Superbike-powered Hot Hatches
Crazy bike engined classic Mini competing at Castle Combe
This incredibly engineered Mini was competing at the Castle Combe Spring Action day earlier this year. I was fortunate enough to be able to photograph this event and this car induced simple boyish excitement every time it came past. The noise it made and the instant power delivery were simply incredible to hear and watch.
As you can see from the photo, there is not much of the original Mini shell left. It has been extended quite considerably using what is known as a space frame or tube frame chassis.
In both a space frame and a tube-frame chassis, the suspension, engine, and body panels are attached to a skeletal frame. The plus side of this in cars like the Mini above is the dramatic weight loss as an extension of space to add parts in or just simply to work on the car. The downside, however, is that the body panels have little or no structural function which is not good in the case of a big crash.
The Radical Revolution
There is no denying that Radical is building some of the most recognisable racing cars of this and past generations. Whether it be in sim racing or on the real race tracks around the world, Radical has multiple series across the world that have produced incredible talent and have given a lot to the international motorsport landscape.Radical SR3, Spa. Image: Doomwarrier via Wikimedia Creative Commons Attribution-Share Alike 3.0 Unported
These incredible cars are mostly powered by bike engines. The engine from the Suzuki Hayabusa 1300 to be precise. This bulletproof sportsbike engine is used in the SR3 RS 1300, SR3 RS 1500 Turbo and SR3 RSX. Some of Radical's bigger models use the Ford Ecoboost engines from the Focus STs, but they are a significant jump in price compared to the famous SR3 range.
What are the practical mechanical differences?
Driving a car with an engine and transmission designed specifically for that car is easy enough to understand for the average driver and sim racer. However, the Hayabusa engine and transmission found in the SR3 have to be treated differently.The engine is partnered with the original sequential gearbox from the bike, but it is not as simple as clicking the paddle or pulling the gearstick as it is in the simulator. When driving the Radical, there's a button on the steering wheel to engage what bikers call 'Half shifts'. This is essential to the workings of the Radical because neutral is in between the first and second gear.
2020 Radical SR3, the top right black button engages the half shift. Image: Arise Racing
Engaging the half shift means that you can skip neutral and jump from first to second gear without redlining the car in neutral when you go to change up.
In layman's terms, this means that the half shifts are essential for moving the car from a standstill and into second gear from first. However, the clutch only has to be engaged when pulling off from a standstill and selecting first gear. Once the car is moving and you can change up to second gear, the Radical becomes a clutchless sequential transmission.
Radical's Assetto Corsa Contributions
Radicals are very popular in the world of sim racing, but simulating this halfshift technique is certainly a rare and somewhat overlooked feature when it comes to most simulators. However, Radical still manage to be one of the more popular brands when it comes to sim racing both online and offline.The balance and difficulty of their broad range of cars in perfect for sim racers, especially if they own multiple different simulators that they use. Radical even created their own mod, alongside UnitedRacingDesign, to be used within the original Assetto Corsa!
Radial's official SR3 mod for the original Assetto Corsa
This level of commitment and belief in sim racing is refreshing to see, especially when the mod is free to download right here on OverTake.gg. The quality is top notch and the car is used in a variety of online championships and leagues, it has previously featured in our very own Racing Club schedule in past weeks.
So with the sim racing side of motorbike-engined cars being so accessible, and the real-life cars being so complex and brutally powerful, it is clear to see why this combination is so popular. Not just in Radicals, but in any car that you can figure out how to connect everything up in.
If you could put a bike engine in any car, what car would it be? Let us know on X @OverTake_gg or down in the comments below!
