Has anyone ever backyard-engineered a twin engined Bug by simply grafting in a second drivetrain up front driving the front wheels?
Double the horsepower, and all wheel drive.
Off to GQ.
Vroom vroom.
Putt putt.
Unless I misunderstand the OP, the linked article did not do what was asked.
A second engine was added, but it was to the back and it did not drive the front wheels.
If it did, I must have missed it in the article.
It seems I jumped the gun-Sorry.
I have seen people do weird things to Beetles. I’ve seen Beetles with rocket engines. I’ve seen Beetles with engines that are so big that the Beetle almost flips over onto its back when accelerating. I’ve even seen Beetles with front engine conversions done to them.
Since folks have done front engine conversions, it should be fairly simple to end up with a twin engine Beetle, just don’t remove the rear engine from a front engine conversion. I’ve never seen anyone actually do that though, and wasn’t able to find one while poking around on google.
You’d probably end up needing to move both the gas tank and the battery, since just about the only place left for the gas tank is where the rear seat is, and since the battery is under that you’d maybe have to move it up to the front passenger seat area, or maybe just on top of the gas tank once it is in the back seat, I dunno.
I know this is in GQ now, but I’m trying to imagine how the two engines would be synchronized to provide the same RPM to both the front and back wheels. Wouldn’t this be necessary, and wouldn’t it need to be very precise?
I remember that Car and Driver magazine put a second engine in a car, a Honda I think, and that was one of their biggest problems.
Wasn’t there one with a jet engine?
I’m sure some idiot has done it; like engineer_comp_geek says, people do all kinds of strange things to Beetles.
Making a vehicle 4wd by grafting an engine onto the idle pair of wheels is a terrible way to go about it; you’ll notice no manufacturer does it that way, for good reason. You’d have to make absolutely sure the engines were exactly in sync lest the torque differential between the ends stresses the car in half. It’d be much, much easier–not that it’d be easy–to convert a Beetle (or, again, any car) from 2wd to 4wd by putting in a front differential, driveshaft, and related components.
I recall them being worried about it but finding in practice that the drivelines tended to be self-synchronizing. I don’t remember that there were any serious problems with the twin-engine Civic except for gas station attendants spazzing out when they started the engine twice.
Maybe there were problems later. I recall the wonderful, tech-y, neat-o “Project Fairmont” being dissed pretty heavily a few months later, when the miles of wiring for the car computer and such lead to a fire and it was scrapped as “Project Firemont.” But I recall the original TwinCivic article as describing a complete success.
I don’t think the sync issues would be all that huge. Who much cares if the two ends are pulling at slightly different forces. The car’s already strong enough to handle the difference between one end pulling at WOT and the other end pulling at zero. Any amount of non-synchrony is far less than that.
Remember, throttle position does not cause RPM or speed. Throttle position causes power output. Which, net of air drag, rolling friction, and road slope, produces a speed. Having a second engine pushing, even a little, would just make the first engine “think” the car was on a downhill slope.
IMO, the real problem as it relates to a two-ended Beetle is that wheel / axle / suspension assemblies for steering and for powering are two very different things. Cars that are factory-built for front wheel drive have wheel / axle / suspension features to do both roles. But it’d be non-trivial to take an existing steering-only front end and graft on the powering features from a rear wheel drive rear end. None of those parts were designed to work together even a little bit.
It’d be a lot easier, IMO, to start with a front wheel drive car and use a second set of front end running gear and engine on the back instead of the standard passive rear end. You’d have powerplant and power delivery in one unit; just lock the unneeded rear wheel steering to dead ahead.
So a two-ended VW Rabbit is easy; a two-ended VW Beetle is hard.
Not a VW but the Hurst Hairy Olds was pretty cool.
Perfect synchronization of the engines is not that important but bad things happen when one end or one wheel loses traction.
VOLKSWAGEN played with the idea as an engineering exercise, but not in a beetle.
I hope we can agree that there is an inherent difference between dragging someone by the hand and holding hands with someone who’s running at a different speed than you are. Having separate drivetrains at each axle is a hell of a lot different than having one idle axle.
Your example is engineeringly irrelevant. As such it’s confusing you, not enlightening you.
The drivetrains don’t connect. Front engine drives front transmission drives front wheels while rear engine drives rear transmission drives rear wheels.
To be sure they’re tied together in that the tires at both ends are turning roughly the same RPM as dictated by the vehicle speed. So you do need to shift both transmissions more or less together so you don’t end up with one engine below idle or the other above redline at any given vehicle speed.
But within the range where both engines are turning above idle and below redline, it doesn’t matter a bit whether one engine is at full throttle and the other is at closed throttle or vice versa or anything in between. Each will be either contributing thrust or contributing drag to the total system. And the overall vehicle speed will be the sum of air drag, rolling friction, road slope, and the net thrust or drag provided by each engine. Nothing more and nothing less.
Don’t some electric vehicles (car or bus or locomotive) have a separate motor on each wheel or axle?
If you did this with electric motors, you’d be totally wrong. What would happen is the motors for one set of wheels would end up fighting the motors for the other set if their RPM settings were slightly off. Wasted energy, the tires would slip. I’m uncertain how much slippage modern drivetrains actually allow.
Not quite sure what you’re saying. If the drive trains are completely independent of each other then they absolutely must stay synchronized. So much so that without fine computer control two independent drive trains connected to two separate pairs of drive wheels on the same vehicle would make it ungainly, almost undriveable, to run on anything but soft soil.
Unless your assuming some kind of ‘slack-absorbing’ transmissions…