Noble suspension geometry.
Noble suspension geometry.
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Discussion

Chapppers

Original Poster:

4,483 posts

220 months

Friday 23rd March 2012
quotequote all
Hello all!

I was having a car-based discussion with my colleagues here last night and I happened to mention that the M12 does without anti-roll bars due to its particularly special suspension geometry. When they then asked "what?!? how?!" I realised that whilst I had read or been told why some time ago, I couldn't actually remember enough to explain it.

Does anyone have an explanation or some link that explains it in depth? I think I've spent about 2 hours googling but have come up with nothing but statements without the detailed engineering reasoning behind them.

Cheers, Chapppers.

anotherdom

535 posts

197 months

Friday 23rd March 2012
quotequote all
Nothing particularly special about the geometry. The MP4-12C does away with roll bars too, and that is very clever.

Dom.

Chapppers

Original Poster:

4,483 posts

220 months

Friday 23rd March 2012
quotequote all
Hmm, perhaps, except that the MP4-12C's entire suspension system is hydraulically linked and computer controlled, whereas the Noble is a collection of steel tubes welded together by South African children.

Blu3R

2,380 posts

228 months

Friday 23rd March 2012
quotequote all
.... And they were the finest children to be had for 10 Rand smile

R0162

2,435 posts

193 months

Friday 23rd March 2012
quotequote all
Chapppers said:
Hello all!

I was having a car-based discussion with my colleagues here last night and I happened to mention that the M12 does without anti-roll bars due to its particularly special suspension geometry. When they then asked "what?!? how?!" I realised that whilst I had read or been told why some time ago, I couldn't actually remember enough to explain it.

Does anyone have an explanation or some link that explains it in depth? I think I've spent about 2 hours googling but have come up with nothing but statements without the detailed engineering reasoning behind them.

Cheers, Chapppers.
the M400 came with anti roll bars...?...but i seem to remember certain people removing them..i cant remember why..to reduce understeer?? to reduce body roll?...somebody also once explained to me how an anti roll bar works..but its gone..gone..gone...i think it was on the old Noble rossion forums where somebody gave a long and technical explanation of pros and cons..

Mattt

16,664 posts

247 months

Friday 23rd March 2012
quotequote all
Chapppers said:
Hmm, perhaps, except that the MP4-12C's entire suspension system is hydraulically linked and computer controlled, whereas the Noble is a collection of steel tubes welded together by South African children.
laugh

Chapppers

Original Poster:

4,483 posts

220 months

Friday 23rd March 2012
quotequote all
No, the M400 came with a front anti-roll bar to induce understeer in higher speed corners. After some more brainstorming we think it's something to do with moving the roll centre laterally as you corner, but we're not really sure how that might be achieved.

Maybe it's just light enough and low enough and stiff enough not to need them, there might be nothing complicated about it. It may just roll by an acceptable amount.

anotherdom

535 posts

197 months

Friday 23rd March 2012
quotequote all
If you don't want a car to roll you can increase the effective wheel rate, either through geometry or spring rate - but that will also reduce compliance. An ARB or sway bar (for Bill's benefit) physically links the suspension, forcing both sides to react and so reducing roll. The extent of this control is adjusted by moving the pickup points or adjusting the stiffness, either through diameter/wall thickness/material or, if you want to adjust on the fly, a rotatable blade. Changing ARB rates (or removing altogether) will have a massive impact on handling balance.

Chappers, you're absolutely right - the McLaren achieves this through some very clever opposing hydraulics and magic.

Dom.

honestbob

316 posts

263 months

Friday 23rd March 2012
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Not long after I bought my GTO3 new from Kerridges in 2003 they had a viewing evening with suprise guest. Lee Noble was his name and many questions were answered by the main man including why no antiroll bar and why no limited diff. His reply was that the turn in was sharper without a roll bar (they had tried one and decided it was better without). Also the limited diff caused the car to understeer more than he was happy with as two wheels driving the rear tended to push the car wide.

(Awaiting the chassis experts to have their two pennyworth)

Blu3R

2,380 posts

228 months

Friday 23rd March 2012
quotequote all
Any idea why the change of heart in both those areas later on?

jdearden

1,746 posts

206 months

Friday 23rd March 2012
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Blu3R said:
Any idea why the change of heart in both those areas later on?
Surel the diff was due to the fact it fell to pieces when drivin hard. I have a lovely chewed diff as a ornament to prove this ;-)