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bike engined weight distribution?
stu da rude - 28/10/05 at 08:17 PM

looking at BEC's, obviously the engine has to be positioned so as the drive flange is in line with the diff, yet still sit at the angle it was intended, ala blade. Does this present any weird weight distribution problems? has anyone corner weighted a BEC to see what the distribution is like?


smart51 - 28/10/05 at 08:22 PM

I would have thought that the weight distribution would be good as the engine is in the centre and lo the left whereas the driver sits on the right (in all the best countries )

depending on your choice of engine I thing that it is very close to 50:50. Marc N from MNR will have corner weighted several of his VortXs with bike engines. Drop him a U2U.


stu da rude - 28/10/05 at 08:28 PM

Thanks, will do. that thought had crossed my mind too about the driver... only thing is a bike engine is around 60-80 kilos? and im... well... more than that.....


ChrisGamlin - 28/10/05 at 08:36 PM

Just in case you weren't aware, it doesnt necessarily follow that the corners of the car with lots of weight in actually show up as being heavy when doing the corner weights, most of it is to do with how accurate you get your spring platforms set up.

Mine with me in in it is around 48F/52R, the front nearside wheel actually gets slightly lighter when I get in it compared to without me in the car. There's no huge discrepencies anywhere and I can easily balance the weights across the diagonals, which is the only thing you can do as obviously you can't adjust the weight distribution front to rear with just suspension setup.

Chris

[Edited on 28/10/05 by ChrisGamlin]


stu da rude - 28/10/05 at 08:42 PM

Yeah i see what you are saying, just curious as to how much (if any it would seem) effect having the engine positioned like this has. But then im guessing hundreds have been built by now, so its got to be a pretty good setup!


G.Man - 28/10/05 at 09:11 PM

Chris is spot on for static weight, the engine offset really only becomes an issue in dynamic weight..

and then it is usually offset by the driver...

In a race situation where it counts you would place lead where it was needed to balance statically and dynamically


stu da rude - 28/10/05 at 09:22 PM

forgive my ignorance, but whats the difference between static and dynamic weight? i guess static is just that, the weight distribution stood still, where as dynamic is how each corner loads during the course of a lap say? Not that up on the dynamics of suspension!


ChrisGamlin - 28/10/05 at 10:00 PM

Yep thats basically it, the dynamic weight moves around when you accelerate, brake and turn, eg when braking the car nosedives forward putting more weight and less on the back.

As GMan says, where the heavy parts of the car are positioned come into play when these forces are occuring (ie when the car is moving), if you have lots of weight at one end or other the car will resist changes in direction more than if most of the weight was central, and if the weight is high up in the car it will tend to make the car roll more, hence why you want to keep weight as close to the floor and to the centre of the car as possible to keep the centre of gravity low etc

This website is a great read if you've got a spare few hours and want to grasp the fundamentals of what a racing car does when its moving.


G.Man - 28/10/05 at 10:14 PM

Good site that...

First I have seen that does a good job of explaining what you learn at race school...


stu da rude - 28/10/05 at 11:42 PM

Thanks for that, im gonna have a good read! thanks for the response all!