‘Author’ Chetan Bhagat is now apparently ready to quit writing and move to something more up his alley. Or so, he would make you believe. Here’s what he tweeted.
While a lot of things have been said about his books, based on his tweet here are the problems with his electric car project.
Problem 1: Turning Gears
Really? When was the last time you turned gears? Agreed, the gears do ‘turn’ around inside the gearbox, but all we do is ‘shift gears’ from one to the other. Don’t know what car he’s driving really.
Problem 2: From writing to setting an electric car project
I’ll let twitter take this one.
Problem 3: Always a mechanical engineer
Here’s the ironic bit. Chetan Bhagat was actually an engineer. He should have known that electric cars don’t have gears. Or rather they don’t need to have gears. That’s reason enough for him to rethink the electric car project. Makes one wonder what he learnt at the IITs. Now I’m an engineer too. Though I do not know much about the mechanism, yet I would try and do some explaining.
A petrol/diesel engine produces torque (that’s the turning force Mr Bhagat if you’re reading) in a narrow band. It increases gradually and then tapers off after peaking at a certain engine speed, depending on engine characteristics like stroke, compression ratio and the like. A set of gears are utilised to keep the engine spinning in the power band (that’s the rev range where it makes most of the usable torque and power Mr Bhagat) to make the most efficient use of fuel.
Electric motors, on the other hand, make nearly 100% of the torque at very low speeds. The fall off in torque is gradual while the power increases as motor speed increases. This is important for cruising once the vehicle picks up speed. (With me Mr Bhagat?) Good.
In the Mahindra E2O for example, 91 Nm of torque is produced at 2000 rpm while max power is produced at 3500 rpm. A direct drive with a tall ratio of 10.83:1 is used to handle all that torque. A Maruti Alto, on the other hand, makes 69 Nm of torque at 3,500 rpm and uses a 5-speed gearbox. The electric motor produces enough torque past the peak torque revs that it can carry on cruising without a change in gear ratio. Now that’s not to say that electric cars can’t use multiple gears, it’s just that they don’t really need them. And making a gearbox to deal with comparatively higher torque is quite a challenge too.
Problem 4: Time to get smarter.
Well Well! From being an IIT and IIM graduate to being an author and then judging a dance reality show. How much smarter Chetan?
Solution: It would be better if you stick to writing and leave that job for the car companies.