Twini

[Jon9372]

Hi

I have had a look on here and elsewhere online. Does anyone know the rules on having 2 engines on a road going car like the twini?

Would like to know definitively before deciding to do 2 engines or just the 1.

[rpb203]

I think the best person to answer that would be Neil Preston as he's built a couple of super examples before.
I'm sure that he posts on here every now and then?

[smithyrc30]

Hybrid vehicles have two 'engines' albeit one electric one.

Some have an electric motor for the front wheels and a gasoline/electric motor for the rear, so actually have three.

I think there are some floating around as concepts with four motors, so I don't see if these comply with construction and use regulations any reason 'legally' to limit the number of power units a vehicle has.

Having built one back in the eighties, top tip. Unless you have better reaction time than a fighter pilot, do not shut the throttle in a corner. It will swap ends faster than you can say it.

[mk1]

I have always understood that only one engine can drive the wheels at any one time, meaning one engine or the other has to be disconnected on the road. This is backed up with a bit of googling. However, I am not managed to track down a regulation stating this as a fact. On the face of it, some Hybrid cars seem to contradict this.

Twin engined cars are also banned in a lot of motorsport.

They are all more of a quirky sideline than a genuine tuning route.

[smithyrc30]

This is one of the cars I was alluding to.
https://www.google.de/search?q=porsche+ ... IvP7H-1IMM:

According to this article, the new Honda NSX has four power units, two electric at the front and a gasoline/electric at the rear.
http://elementemagazine.com/supercar-mc ... ybrid-nsx/

BMW I8:
https://insideevs.com/details-bmw-i8s-g ... eed-eaxle/

So there must be some loophole or other that allows more than one 'engine'.

A lot of manufacturers are now offering drop in electric drive trains that would go in either end of a car. Aisin Warner, Bosch, Continental, ZF to name but a few and generally seem to be around the 200hp number. They are small as well, they would easily fit in a mini front subframe. As this is the 'traditional' way of fitting an additional engine in the back of a mini it would be a relatively straightforward task to fit it in if there are issues with two gasoline powered units and you 'really want' a twini.....

[Jon9372]

Thank you all so much for your input.

I have tried to find a definitive answer regarding the rules on a government/vosa website but can't find anything to say either way.

Anyone who has been able to build a twin engined vehicle please share your knowledge.

I understand that with 2 engines it will not be allowed in most/all motorsport cattagories but my main aim is a road going show car, with odd track day.

[mk1]

The rules & regs on radically modified cars have changed so much in the last few years I doubt that anyone has a correct & current answer.

Probably best to ask DVLA, although that could be fun.