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Mojo
MikeRJ - 17/10/04 at 10:27 PM

A little bit off-topic perhaps, but I have a question for the chassis designers out there..

This is the Sylva Mojo chassis:


Am I being stupid or are there two tubes missing from the side of the chassis that would subtantialy increase the bending strength of that section? e.g.




I find it hard to belive this was an oversight, so why might they have been ommited?

JonBowden - 17/10/04 at 11:09 PM

I hope someone can answer this, I've been wandering the same thing for quite a while. I have seen quite a few apparently stupid chassis designs - are all these professional chassis designers really more stupid than us ?

stevebubs - 18/10/04 at 12:24 AM

The picture in the original post is the re-design of the Mojo 2 chassis.

The original Mojo 2 chassis was put to quite a strong test during an RGB race when it went almost straight into a wall at high speed (60-80mph). I say almost as I believe most of the impact was taken by one of the front corners. As a result of the impact, the cockpit section of the car "lozenged" a bit, with the floor buckling.

There was quite a big discussion over it on the Sylva list at the time, and although the general consensus was that the car held together excedingly well considering the impact, Jeremy Philips introduced extra triangularion onto the chassis.

For race applications, there are extra bars that strengthen from the top of the dash across the low sides that I'm presuming you're referring to.

For more information, visit the Sylva-Chat list at www.smartgroups.com and take a look through the archives

A picture of the strengthening for the race chassis can be found at http://www.sylva.co.uk/mojorace.html

HTH

Stephen

marktigere1 - 18/10/04 at 08:05 AM

I believe those mods to the chassis sides are now standard on the Mojo Chassis.

I have to say I love the car and only wish I could afford to build one.

Not loved by everyone but thats why I want one

Cheers

Mark

MikeRJ - 18/10/04 at 08:35 AM

quote:
Originally posted by marktigere1
I believe those mods to the chassis sides are now standard on the Mojo Chassis.

I have to say I love the car and only wish I could afford to build one.

Not loved by everyone but thats why I want one

Cheers

Mark


Interesting, it does seem to have been either an oversite in the original, or simply a decision that they were not required.

I too love the mojo, if I ever get the Locost finished it will certainly be on my shortlist for another build. The one thing that worries about mid engined designs like this is that the chassis has to be inherently stronger as the engine is behind you, and any head on collision is going to put much higher forces on the chassis. Having an engine and gearbox try to pass through you on the way to the front dosen't sound like fun.

stephen_gusterson - 18/10/04 at 08:47 AM

i know nowt about these things, but I must admit that was the first thing I noted in the picture....

atb

steve

mangogrooveworkshop - 18/10/04 at 09:32 AM

quote:

any head on collision is going to put much higher forces on the chassis. Having an engine and gearbox try to pass through you on the way to the front dosen't sound like fun.


Being rear/mid engined would probally mean you you would be traveling backwards anyway.


Looking at that chassis we are looking at the future locost when all the rear wheel drive donars dry up. just a thought

There will always be rwd but the expense will make this configeration seen quite reasonable. Nice chassis thou.


[Edited on 18-10-04 by mangogrooveworkshop]

stevebubs - 18/10/04 at 05:09 PM

I think the key with mid-engine is to make sure the triangulation is designed right and ensure the weak points are in the right place to protect the cockpit.