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Suspension... cones or coilovers?
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Author:  Starmag [ Thu Nov 13, 2014 11:28 pm ]
Post subject:  Suspension... cones or coilovers?
Hi guys, just looking for everyone's opinions/knowledge on the matter of rubber cones vs coilovers.

First of all, my coupe is going to be for road use, with the odd track day, and maybe one day some competition use... I want it to handle well, comfort doesn't bother me as long as it performs.

I'm going to be changing some of the suspension components on my coupe to updated ones, such as rose jointed tie rods, rose jointed lower arms, s steering arms, rossabitz rear locking kit. I have a few things that I'm not sure about and wandered if you could share your experiences on a few things. Apologies if anything has been covered before, I have been making good use of the search function!

Bumpstops - rubber or poly?
Lower arms bushes - rubber or poly?

And the big question, cones or coilovers? I understand that the reason that many switch to coilovers is because its difficult to machine the front cones and get the desired spring rates. Has anyone had much success doing this lately? Or come up with a good alternative?

If I was going for coilovers I would just go for a set of mini front coilovers for the front and rear, and put the coil overs on the front on an incline.


So what you you go for or what have you gone for and why?

Any advice is much appreciated.
Thanks in advance.
James
Author:  Ken555 [ Fri Nov 14, 2014 12:46 am ]
Post subject:  Re: Suspension... cones or coilovers?
I have Mini coil spring that replace the cones.

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http://www.minitastic.co.uk/suspension.htm

"Racing" spec all around.

Image
Author:  kano nordie [ Fri Nov 14, 2014 9:51 am ]
Post subject:  Re: Suspension... cones or coilovers?
Hi Ken,
Are you using steel springs on your Coupe??
I like the look of using steel springs in place of the old Moulton doughnuts, but they have the same dilemma as the doughnuts in that we need different rate springs front and rear as we are using 2 sets of front suspension with a lot less weight in the front, would the suppliers of steel spring split a set and supply 2 softer rate and 2 harder rate springs??
The steel springs are possibly lighter than the doughnuts, which is also attractive as I have to carry them back in my baggage to Africa.
I still have not been able to find any upper arms or doughnuts locally, but do have all the bits (almost unused) I need in my twinni Mini if I have to strip it.
John
Author:  gtmdriver [ Fri Nov 14, 2014 12:01 pm ]
Post subject:  Re: Suspension... cones or coilovers?
I completely re-jigged mine front and rear.

Image

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Keeping the rubber cones makes it very difficult to modify the spring rate in a controlled way.
Author:  Ken555 [ Fri Nov 14, 2014 5:03 pm ]
Post subject:  Re: Suspension... cones or coilovers?
kano nordie wrote:
Hi Ken,
Are you using steel springs on your Coupe??
I like the look of using steel springs in place of the old Moulton doughnuts, but they have the same dilemma as the doughnuts in that we need different rate springs front and rear as we are using 2 sets of front suspension with a lot less weight in the front, would the suppliers of steel spring split a set and supply 2 softer rate and 2 harder rate springs??
The steel springs are possibly lighter than the doughnuts, which is also attractive as I have to carry them back in my baggage to Africa.
I still have not been able to find any upper arms or doughnuts locally, but do have all the bits (almost unused) I need in my twinni Mini if I have to strip it.
John


Yes steel springs, and yes they do a split set, you also don't need the extra struts for the rear setup.
I also have their height adjusters/hi-lo's
Author:  kano nordie [ Sat Nov 15, 2014 11:22 am ]
Post subject:  Re: Suspension... cones or coilovers?
I sent a mail to Minitastic to see what they can offer to give me long travel suspension to cope with our few good bits of road in between many large potholes :lol:
John
Author:  Starmag [ Tue Nov 18, 2014 10:24 pm ]
Post subject:  Re: Suspension... cones or coilovers?
I've been looking at the mouton smootharide cones from minisport to fit on the front as it seems they give a much softer ride on a mini which be suited more to the coupes light front end? Has anyone tried this before?
Author:  West [ Tue Nov 18, 2014 11:02 pm ]
Post subject:  Re: Suspension... cones or coilovers?
I know when I emailed some of the coil spring replacement companies a few years ago none of them would give me any spring rate specs, I was not going to just buy a set I wanted to make an informed choice. I did however look into getting my own made but never followed it up.

Currently I am probably going to go coil over to get some good raising rate characteristics or maybe give another crazy idea a try.

Neil
Author:  kano nordie [ Wed Nov 19, 2014 4:38 am ]
Post subject:  Re: Suspension... cones or coilovers?
I'm seriously thinking the coil spring replacement for rubber springs are the way to go and in my case the softest long travel ones with a coilover shock with a light helper spring on the back end to compensate for the rear weight bias, that would give me the chance to adjust to alter settings.
Spring rates are a funny business, I know from my single seat race car where Jedi have progressively increased spring rates over the years and found higher rates,almost double the rears, on their front and lighter end gives the better result :o
John
Author:  Steve Shield [ Wed Nov 19, 2014 6:21 pm ]
Post subject:  Re: Suspension... cones or coilovers?
When I get my cars rebuilt/back on the road I've got 2 approaches to try:
1. White car -- track use -- has hydrolastic arms on the rear which have a different ratio that is supposed to stiffen the wheel rate
2. Primo car -- road use -- will be fitted with Moulton Smootharides on the front -- I already have these springs ready to fit.

I don't think anyone knows the rates of the rubber springs any longer -- many years ago I had a copy of an IMechE paper written by people at Dunlop which included all this data but I can't find it -- MiniSport certainly don't know what the Smootharide rate is and a short exchange of e-mails with Dr Moulton just before he passed away didn't provide any info. I think the real reason for the progression in rate is due to the very short suspension travel on the base Mini -- only about 2 1/2" in jounce as I recall -- without the rising rate the car would be constantly hitting its bump stops especially when loaded.

John -- I no expert but the rates you quote for the Zedi appear very extreme unless there something else they're trying to control-- induce a little understeer? -- or they don't use anti-roll bars. Of course they aren't subject to road comfort requirements. I think its in Staniforth's book where front front frequency which is a function of sprung mass and spring rate should be around 1.2Hz with the rear a little higher so that the rear end that hits the bump later oscillates into phase with the front resulting in a flat "bounce" with no pitching. Someone else on the site will probably have more technical knowledge on this subject and prove me wrong!

Now don't get me started on roll centre heights!

Steve
Author:  turbocox [ Wed Nov 19, 2014 11:18 pm ]
Post subject:  Re: Suspension... cones or coilovers?
I nominate Neil :wink: :shock: :lol:

But what I will say tyre pressures make a big difference to how these cars seem to handle :wink:
Author:  Steve Shield [ Thu Nov 20, 2014 10:41 am ]
Post subject:  Re: Suspension... cones or coilovers?
Turbocox -- good call -- Neil's probably the expert.

Thinking we're hijacking the OPs thread with this -- maybe start a new one in the suspension area?

Steve
Author:  kano nordie [ Fri Nov 21, 2014 7:25 am ]
Post subject:  Re: Suspension... cones or coilovers?
I met with Alan Staniforth on several occasions after he had written his book, and he told John Corbyn and myself that his passage on spring rates were to be used as a guide for a starting point and that in his experience the rate needed would invariably be much greater :wink:
My hillclimb Jedi is now using spring rates that the circuit cars would normally use in the wet, but is nowhere near as stiff as some more modern 1100 class hillclimb cars.
John
Author:  Starmag [ Fri Nov 21, 2014 10:14 am ]
Post subject:  Re: Suspension... cones or coilovers?
Keep going, it's all relevant :)

I have found information on the minispares website about spring rates on the standard cones:

"Measured at the wheel, the spring rates at the static load position are 118 lb/in at the front and 98 lb/in at the rear. With three passengers and 50 lb of luggage, the loads per wheel at the same position are respectively 468 lb and 355 lb.

These loads rise to 1,050 lb and 670 lb at full bump and fall to 240 lb and 100 lb when the rebound check is in operation."

I have emailed minisport to find out the spring rates of the Moulton smooth ride cones but I'm yet to get a response..


I'm learning towards the Moulton smooth ride cones, and just for an experiment I'm going to get the rear cones and fit them on the front! They aren't as tall as the front ones, when people fit them to minis they often say about the increased body roll, and I think it might be due to the extra height which is just thin rubber at the top.
If there is still some body roll on the front then an anti roll bar could be a solution.



Whilst we are on the subject of cones, is the norm to fit standard cones on the back? Is there any advantage from fitting red dot cones which are a bit firmer?

When buying new mini shocks, what is more suited to the coupe, standard height (332mm open) or lowered height (303mm open)?

James
Author:  SportsLibre [ Thu Nov 27, 2014 10:21 pm ]
Post subject:  Re: Suspension... cones or coilovers?
remove all the rubber from the rear bushing, as for the springing it seems a good idea if the spring is the correct rate.
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