190 replies to this topic

[Seb.F]

Guys come on, I mean I totally saw someone crash once and I can tell you with 100% confidence, he would have died had he have cut out the fuel pump hole. 100% Confidence. I saw it with my own eyes in my head.

[Dunk]

I crashed a VX once. There was a fairly large gap between the top of the windscreen and the rollbar. To a layman like me, that seemed to be an area of structural weakness. Despite a quite spectacular spin, hitting a substantial dry stone wall, a road sign, shrubbery, several saplings and rolling it onto its side, coming to an abrupt halt up against a tree, I walked away unscathed bar a scratched arm from a rogue branch. I know this doesn't help or add to this "debate" but then again, it seems that's the theme of this thread.

[fezzasus]

Look, you can argue it all you want, but any structural engineer will tell you the same, cut that hole out makes a significant difference to the structure of the car (in the same way the shear panel does under the tank).

if your too lazy to take the tank out to change the pump, then that's your lookout.

I have seen a few cars hit side on where that part of the chassis has folded up because it was cut out, but I guess if you have somebody sitting there that's their lookout is it?

And yes, I have seen that Mikes car is like this and have spoken to him about it, however, it's his car and his decision.

Personally, it's not something I would ever even consider doing, the original hole is questionable, but at least that was crash-tested like that.

Anyway, I am sure some of you will ignore me and carry on.... Not my problem.

(I do wonder what an insurance companies view would be on this kind of thing though...)

I can point you at three different automotive engineers who will say the opposite. As long as none of the folded edges are cut the middle of the aluminium section has no structural properties to it at all.

[Scuffers]

Neil, no one does

It's all bullshit. It's not worth responding to. You'll just get a reply with more capitalisation and spelling mistakes. with the same knuckle dragging mantra of 'what's your lap time' and 'I've seen crashes where you would have DIED'. Rolleyes

We've actually done quite a lot of interesting analysis around stresses and strains around a hole or an ellipse in sheet, I-section, t-section and box section over a variety of materials including aluminum. The radius of the hole of course has a significant effect on the ultimate tensile strength of the material, but it's a small factor compared to the thickness of the material. Growing the existing hole by 20% would have insignificant effect in this application.

Given that the hole on the other side is smaller and in a different position, one suspects that lotus were completely unbothered about the hole in the fist place. I wouldn't cut out any angles and I would avoid cutting squares as that creates stress points (which become foldpoints) but even then you'd have to be a little funny in the head to go around telling people they'd ruined their chassis

I won't get drawn in any further and wont reply again.

for somebody that professes to be a structural engineer, I find it somewhat amazing reading your posts.

Looks like the OEM hole is an afterthought anyway (ignore the yellow circle)

that picture actually illustrates the point very well

if you apply a load to the top of the chassis rails where that circle is to the same spot on the other side, what part of the chassis is there to resist said load?

At the front of the tub you have the extrusion that's got the door supports on the end of it, at the back, all you have is the tank enclosure.

to then cut into that so close to the fold takes what little rigidity and strength away, this is basic structural stuff, you don't need to model it in CAD/FEA to see the issues (which is why I am amazed at a self-professed Structural engineer can post such bollocks)

A flat sheet of ali has sod all strength against compressive loads without being formed, much like a sheet of paper won't support any load as a flat sheet, but if you put a couple of folds in it and make it into a channel, then close the open side (like the shear panel does), suddenly it can take compressive loads.

Now, what I find scary about all this is not so much that some of you think it;s find and dandy to basically trash your cars chassis, but that you are so vociferous about how it's find and there is no issue here and I must be taking crap etc etc.

All I can say is what you do to your own cars it your business, but don't go encouraging others to do the same to theirs.

[The Batman]

Scuffers answer my post now!

[Bargi]

Guys come on, I mean I totally saw someone crash once and I can tell you with 100% confidence, he would have died had he have cut out the fuel pump hole.

100% Confidence.

I saw it with my own eyes in my head.

Your signature has never been more relevant than now

[Scuffers]

Scuffers answer my post now!

Why?

you are way too stupid to understand any rational answer, given that you already ignored the minor fact that I have already answered this one.

perhaps if you had a modicum of intelligence you could actually start to understand it yourself without having to try and goad me into your childish prattling on.

come back when you have found more than 1 brain cell to work with...

[Seb.F]

Your signature has never been more relevant than now

Tell me about it. It's like trying to beat life into a rock.

[The Batman]

As you won't answer my simple question, can you answer one simple question for me? Why use a k24 in elise trophy when you are only allowed a k20?

[The Batman]

Is it because you are a dirty rotten cheat and that's the only way you could win?! And this is why you are banned for life from elise trophy?

[Bargi]

As you won't answer my simple question, can you answer one simple question for me?

Why use a k24 in elise trophy when you are only allowed a k20?

Is it because you are a dirty rotten cheat and that's the only way you could win?!

And this is why you are banned for life from elise trophy?

ehhh? say it ain't so!

Edited by Bargi, 11 April 2013 - 03:09 PM.

[Seb.F]

ehhh? say it ain't so!

I will not go
Turn the lights off
Carry me home
Na na, na na, na na, na na na na, na na.....

[Darcini]

[Mike (Cliffie)]

Thanks for all this guys, its not as if I have a big enough challenge this year in Time Attack without my core team falling out with my technical sponsor and my technical sponsor falling out with my core team.

[The Batman]

Just because he works for your technical sponsor doesn't mean I have to shut up

[techieboy]

Agreed. It's all getting a bit stupid now and does all of us a disservice.

[siztenboots]

Guys! Guuuyyys! Look at us! Arguing, bickering! Like children! What's happening to us? We never used to be like this!

Yes we did.

[CocoPops]

Thanks for all this guys, its not as if I have a big enough challenge this year in Time Attack without my core team falling out with my technical sponsor and my technical sponsor falling out with my core team.

Sorry Mike, but when someone comes into an established forum and starts shouting the odds, taking very little onboard and making out they know everything, it's never going to go well.

We (the moderator/admin team) have received a number of complaints about his manner, his conduct and his rudeness to others.

What are we supposed to do?

[anz3001]

We (the moderator/admin team) have received a number of complaints about his manner, his conduct and his rudeness to others.

What are we supposed to do?

IME i'd say offer him a position on said team!

[Scuffers]

As you won't answer my simple question, can you answer one simple question for me?

Why use a k24 in elise trophy when you are only allowed a k20?

you really are a moron aren't you?

I don't have a customers car in LOT


That said, I cannot think of a single K24 car in LOT?

and also, there's nothing in LOT regs saying you can't run a K24.

So, once again, you're talking out your backside.