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engine position????
Barker - 3/5/02 at 11:40 AM

I have started building a locost car with Ron Champions book except I will be using a bike engine and making it mid engined. I assumed this was best merely by copying the layout of all single seater cars and top sports cars like the Lotus Elise, Esprit etc.

What puzzles me is that many front engined locosts seem to have near perfect weight distribution [50:50 ?]

Is mid engine still the best way to go and why?

Dunc - 3/5/02 at 12:37 PM

It doesn't mid rear or front engined doesn't really have an effect on handling if the weight distribuiton, c'of g' and inertia are all the same. I think this was proven a few years back in GT class racing, with the majority of the cars being mid engined, Panoz I think came with a front engined car and it was just as good as the other cars in the field.

Where a mid engine car would be better than a front engined car is when a low leading edge, bonnet is required and there isn't enough room to fit an engine.

If you did go mid engine then you would need to move the seating forward quite a bit to compensate and that might not look too great. If you're going to Stoneleigh this weekend and have a look for some owners of CC Cyclones. They were mid engined seven look a likes.

Jon Ison - 3/5/02 at 05:09 PM

if you go mid engined with a bike engine you will find, unless you sit with your feet poking out the nose cone that you will have a very rear biased weight, and loads a under steer, my chassis is pretty much book other than the passenger footwell is 6" shorter allowing the engine to sit 6" further back than it would have done normally, mounting the engine over there helps the left/right weight too when your driving alone, i have 50/50 distribution that way. Just to back up the point i have built several single seater grass cars, some with bike engines, and the name of the game there is get the power down to the rear wheels, hence (mid mounted) 20/80 weight split, and get around the understeer with bias brakes and plenty of right foot on the loud pedal. Hope this gives you a few pointers, Jon.

jmbillings - 4/5/02 at 09:44 PM

We have standard book chassis/engine location, and at SVA got pretty close to 50/50

Liam - 6/5/02 at 07:22 PM

quote:
What puzzles me is that many front engined locosts seem to have near perfect weight distribution [50:50 ?]


A standard Locost has the engine comfortably between the two axles - much further back than most front engine installations. (in fact you could argue a standard Locost technically IS mid engined). Add a gearbox practically in the middle of the car, and a driver and axle at the back cancelling out the engine in the front, and you can see why a standard Locost is usually very close to 50/50.

With an engine right over the rear axle, the driver right infront of that, and nothing at the front of the car, you'd have a heavy rear weight bias. You'd get understeer going into corners and whenever the car is settled, especially in the wet, and lethal oversteer if you really throw the car around and unsettle it, or get too happy with the load pedal.

Couple that with the relative simplicity of a front engine rear drive build, and you'd probably be better off sticking to the book and keeping the engine where it should be

Liam