190 replies to this topic

[J4EY D]

Didn't a Vx with an uprated fuel pump get 'crash tested' with a very big impact on sunday?

[techieboy]

Wrong kind of impact.

[J4EY D]

Good point. It reminds me though, i need to fit an uprated fuel pump... Joe bring your dremel to stuwys

[The Batman]

what about a hammer? you know you have touched a nerve when the arogance dies

[vocky]

Scuffers answer my post now!

Why?

pretty much anything goes on a race car, if you need to modify something to win a race then modify it.

Mr Cliffie did rather well, he had to modify a wishbone to get a good result and it worked

[The Batman]

still a bodge though

[VIX]

So Nick, did you get that new panel?

[Spitfire Engineering]

http://www.youtube.com/watch?v=0UHCV-PoY9c

Jesus that has got to be the funniest thing I have seen for years. it's beyond brilliant, who made this??

[Bargi]

Interesting...

[Dave E]

[leevx2.2]

fcuk me nick look what you started I got some alli at home and can make you one just no more trouble making lol

[Dave E]

Not as obviously inflammatory as asking about ARB's though, come to thing of it there does seem to be one common denominator........

[VIX]

to be one common denominator........

Both questions from old blokes?

[Spitfire Engineering]

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
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.

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?


1. initially the rail itself
2. this is supported by the upper panel in discussion and the roll bar.
3. Once the rail has twisted and started to resist the load along with the two other components, the entire section of chassis rail will start to load up, this is resisted by the shear panel underneath and by the rather large rear subframe which you seem to have missed? which is odd as it is much closer that the front cross support.
There is also so the floor panel which will also act as a shear panel to some degree though probably marginal.


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.Err and all the stuff above.

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)
I don't think anyone has suggested going so close to the fold, you started with the ill founded comments well before someone posted an image which showed an example which I agree is extreme. In fact to some degree it was a bit of a let off for you.
The basic technique of enlarging a hole and fitting a larger cover (shear panel) with several well positioned fasteners is neither unsound nor dangerous if done correctly.
They even use the technique to patch up structural panels of aircraft.

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.

True, but then my son when he was 6 could have told me that.

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.
What I find scary is that for the third time in as many weeks you have shown you have little technical knowledge to back any of the claims you make, offer no technical analysis whatsoever, yet you seem incapable of registering the fact and argue with poeple who do have said knowledge and experience.
To start with the post about "it's all wrong" as usual, without even offering an example to analyse, is as you mention, talking crap.

I'm really not being funny now or smart but have you ever claimed to have developed the Honda Elise?
If it's true I wonder what Joe McArthy and then Johnny Leroux (with Joe's kit) would think of that claim?
I was aware you polished it up a bit.

[NickB787]

So Nick, did you get that new panel?

fcuk me nick look what you started I got some alli at home and can make you one just no more trouble making lol

maybe I shouldn't ask for things in future look at the trouble it caused
cheers Lee

[Mangham54]

So Nick, did you get that new panel? :dry:/>

fcuk me nick look what you started I got some alli at home and can make you one just no more trouble making lol

:blush:/> maybe I shouldn't ask for things in future look at the trouble it caused
cheers Lee

Should have done a search.

[Dunk]

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
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.

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?


1. initially the rail itself
2. this is supported by the upper panel in discussion and the roll bar.
3. Once the rail has twisted and started to resist the load along with the two other components, the entire section of chassis rail will start to load up, this is resisted by the shear panel underneath and by the rather large rear subframe which you seem to have missed? which is odd as it is much closer that the front cross support.
There is also so the floor panel which will also act as a shear panel to some degree though probably marginal.


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.Err and all the stuff above.

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)
I don't think anyone has suggested going so close to the fold, you started with the ill founded comments well before someone posted an image which showed an example which I agree is extreme. In fact to some degree it was a bit of a let off for you.
The basic technique of enlarging a hole and fitting a larger cover (shear panel) with several well positioned fasteners is neither unsound nor dangerous if done correctly.
They even use the technique to patch up structural panels of aircraft.

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.

True, but then my son when he was 6 could have told me that.

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.
What I find scary is that for the third time in as many weeks you have shown you have little technical knowledge to back any of the claims you make, offer no technical analysis whatsoever, yet you seem incapable of registering the fact and argue with poeple who do have said knowledge and experience.
To start with the post about "it's all wrong" as usual, without even offering an example to analyse, is as you mention, talking crap.

I'm really not being funny now or smart but have you ever claimed to have developed the Honda Elise?
If it's true I wonder what Joe McArthy and then Johnny Leroux (with Joe's kit) would think of that claim?
I was aware you polished it up a bit.

BOOM!

[Seb.F]

I have an odd story of my younger years. I used to have a 206 and was/still am admin of the largest 206 club on the net. A German chap came along and used to bang on about he was pretty much omnipotent. He used to make custom silicone induction kits for the 206 and some of the Citroens. In short - they were terrible, did ABSOLUTELY NOTHING to the power of the car, and only made the induction noise louder I think. Despite having many issues with mine, presenting him with hard fact and engineering evidence (I was at Warwick uni at the time doing an Automotive Engineering degree), he was having none of it. The last I heard he was living somewhere in the middle of India making Bollywood films..... Just thought I'd share it with you as this topic is so full of rubbish already.

[smiley]

Jesus that has got to be the funniest thing I have seen for years. it's beyond brilliant, who made this??

No idea. Came from here: http://wiki.seloc.org/a/Engine_Wars

[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.

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?

It takes two to argue Lee and when it potentially damages my sponsorship deal I feel I have the right to speak up.