what is the point of having upgraded dampers?

what is the point of having upgraded dampers?

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Discussion

vrooom

Original Poster:

3,763 posts

268 months

Thursday 18th November 2004
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will they make harder ride but same cornering performace or what

jay

Cooperman

4,428 posts

251 months

Thursday 18th November 2004
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Damping technology is a bit involved, but to simplify it, on smooth tarmac a stiffer damper will improve both handling and road holding (which are not the same thing, by the way). Standard dampers allow the wheels to 'float' up and down and on rebound the wheel/tyre does not have the same contact pressure with the surface, thus reducing available tyre grip.
With its small wheels a Mini is especialy susceptable to loss of grip due to poor damping.
Yes, stiffer dampers make the ride a little harder, but for road use there is no need to go really hard. As a guide, if you fit a set of SPAX, use 3 clicks from soft on the front and 2 from soft on the back as a start point. That is a nice compromise and you can alter it to suit your own use and driving style. For track use you would need a bit harder than that, whilst for rallying it depends on the road surface, whether it's tarmac or gravel.
You can go too hard, then the car bounces from bump to bump and is no better than over-soft dampers.
That's why adjustable dampers are best.
As a personal preference I like SPAX and use them on both my rally Minis. However, some people prefer Koni, which are softer on bump and stiffer on rebound. The problem with Koni is that you have to take them off the car to re-set the stiffness (unless they've changed the design). I have not tried any of the other options and I do strongly recommend SPAX.

I hope this helps,
Peter

tim williams

36 posts

250 months

Thursday 18th November 2004
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theres a thread over here about it:

www.minifinity.com/PNphpBB2-viewtopic-t-11918.html

GreenV8S

30,208 posts

285 months

Thursday 18th November 2004
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Its worth noting that 'upgraded' does not necessarily mean 'stiffer'. Some dampers have much lower friction levels and better damping versus speed characteristics, which can translate to better ride comfort *and* handling compared to bog standard cheap dampers.

love machine

7,609 posts

236 months

Friday 19th November 2004
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I use the weights/stiffness settings. Weigh a front and a back wheel.
You get a ratio. Do some calculations so that you set the dampers up with the same ratio of stiffness. (dependent on the number of clicks your dampers have). Set the back to minimum and the front to how ever many clicks you need. Then you can click up and down in parallel, so to speak. I find this is generally a good rule of thumb. Try a click each way.

I personally like mine hard as the 10" wheels running a relatively low pressure. Take some of the bumps.

Again, I havent done this yet but will work out my tyre pressures with some water, a mirror, a load of jacks and a piece of glass. Get the contact patch "the right shape". Should work a treat. I reckon that most people are running tyre pressures too high.

GreenV8S

30,208 posts

285 months

Friday 19th November 2004
quotequote all
love machine said:
Again, I havent done this yet but will work out my tyre pressures with some water, a mirror, a load of jacks and a piece of glass. Get the contact patch "the right shape". Should work a treat. I reckon that most people are running tyre pressures too high.


That's an interesting approach. Do you already know what shape of contact patch is optimal? Would you be able to do this by lowering the car onto something that would take in imprint of the tyre, like paper or something that would show visual evidence of where the tyre had sat on it?

love machine

7,609 posts

236 months

Saturday 20th November 2004
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I suppose you could use a piece of paper.

My idea was to set the camber up at exactly 0 deg, make a "print" and then adjust the contact patch until it is exactly rectangular. Should be harder on the front. As the tyres I am using are pretty slick, I should be able to do this with quite a bit of accuracy. Paying particular notice to the leading/trailing edges. I will then set up my camber front/rear as I did the shocks, weight dependent as a starting point. IMO people use too much rear camber. As I am running a rear anti-roll bar, I have realised the significance of rear wheel geometry. With skinny tyres, it causes oversteer!!!! and fat tyres, your breakaway seems to be proportional with the amount of rear camber (as you are 3 wheeling through corners).

So, I am going to try running a miniscule amount of tow out on the front and a weeny bit of tow in on the rear. Distortion of the tyre tends to give a slight amount of rear steer on hard cornering with my newly softer rear tyres!

The overall theme seems to be making everything super stiff as necessary, with minimum upset over bumps. I reckon my idea is getting there more than looking at figures in the book.

Probably a load of bullshit, but I'm convinced running through all the variables, you would be in the right ballpark. After all it's only a mini.

>> Edited by love machine on Saturday 20th November 12:22

haynes

370 posts

243 months

Monday 22nd November 2004
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The first thing i did 8 or 9 years ago was to fit some spax adjustables to my cooper and set them up 1/2 way on the front 1/3 on the back, it had chronic understeer for years as a result. Softer suspension improves grip, harder reduces it. So by then setting the front softer and the back harder i reduced the understeer now it handles like a mini should. OK im oversimplifying and generalising, but i think you need to play around with the settings to get it right.

love machine

7,609 posts

236 months

Tuesday 23rd November 2004
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Having said, I was developing the whole car and was "saving" my special tyres. In the mean time, I fell in love with 145/10's.

I did a "dry" conversion on my '66 and used Spax, I also bought shock brackets (lowered) and decided to weld them on as there were no captive nuts and also it would have been stronger. I plug welded everything together to make it bombproof.

Putting the brackets on upside-down resulted in bottoming shocks, sheared the pin one side and RIPPED A CHUNK OUT OF THE INNER WING on the other. What a tosser! GET THE BRACKETS THE RIGHT WAY UP IF YOU DO THIS!!!! It was a pain in the arse to fix.