Suspension problems.

[bmcecosse]

Yes Jonathan - but here we go again - my dampers cost £5 for the pair - and were almost new ! And I like them WITH the standard dampers (which are also almost new - and are filled with 20w50) - the car rides over undulations very smoothly - go over a 'hump' bridge and the car absorbs the bump (without touching the bumpstops) and settles immediately - it's remarkable ! If the dampers that were fitted at the rear of Cam's Minor were almost solid - then yes the car would skitter about with no suspension movement - but it would not 'bounce' - because that's what dampers do - they damp out bouncing - but to do so they need to move ! I know you are in the business of selling fancy bits for Minors - and for those that can afford them I am sure they are great ! I have to use my mechanical skills and initiative to sort things out without spending large amounts of cash ! Did this whole thread not start because the tele dampers had failed ??

[jonathon]

Bm,
I don't think Cam's rear damper's are giving him problems of a skittish nature, he actually made the point that he had lightened the damping.
I was congratulating you on your inspired guesswork by fitting an unknown product, yes you may have guaged the open and closed lengths to see that they had the required travel, but what about their damping properties when balancing them up to your cars weight, ride height and your driving style.
For most people modding their car, the approach you have taken would be fool hardy, I appreciate that you have some sort of motorsport background and as such are probably in a better position to assertain the properties of junk yard products. To recommend this approach to the non technical minded modifyer would be foolish, and dangerous.
I'm afraid that the Minor owners have suffered at the hands of amateur modifiers for too long. It was my meeting with Chris Street of C.S Autoclassics now the Opus car company who inspired me, that cars should be viewed as a whole package of individual parts acting in union. Chris had been saying for years that minor owners were being short changed by "cheap and cheerfull products" many of which either just did not work or were actually very dangerous. His solutions came from an extensive engineering background, one which I have tried to carry over into the products that we at JLH now supply.The term "Fancy parts" is a bit of a cheap shot, we supply tried and tested products suitable for most applications that the minor owner is likely to follow. Yes the cost is more but research and tooling all have to be paid for, and most of all, we have a responsibility to those purchasing our products that they, one work, and two that they are safe.
By all means follow the scrap yard parts route, as granted it is cheap, but then you only have to be responsible for yourself. Don't get me wrong though, I'm all for motoring on the cheap and for the home mechanic to service and maintain his/her car, but there are some aspects such as modifying handling and brakes where, unless you are a mechanical engineer or technician, you should leave well alone, or at the very least research the subject.
On a lighter note, why fit modern gas/oil dampers and keep the original lever arm as a damper, surely one will make the other redundant to a large extent.

[Multiphonikks]

BMC,

I think it's a bit harsh to call upgrades "fancy parts". It's truly horses for courses. I have personally driven one of the scarily expensive K series Minors and it's not until you actually drive one that you see why they cost the amount they cost. The R&D which has gone into these is phenomenal and they handle better than many brand new cars!

Owning a minor is sometimes about using your initiative to solve a problem and if you've managed to get dampers you're happy with that's cool. There is no substitue for engineering know-how though and there are times when Minor owners decide "Right, I'm getting a pro in". I could, for example, wire my own loom up to replace my (increasingly dodgy) current one, but although I have an A level in Physics and a fair amount of electrical expereince I'm leaving it to the pros.

If your modifications to your minor are working and they have been borne out from your own technical knowledge then great. Just remember, not everyone is willing to trust their own knowledge and JLH, unlike some other "bolt on*" suppliers, does seem to have it's corporate head squarely screwed on.

Why don't you take your minor up to JLH and try out the kits there. I'm sure you'd like them

There's nothing wrong with heath robinson in small doses, as long as you have the engineering skills to back it up and justify it




*A case in point when a certain "hydraulic boot lid kit", (which I've brought so that my musical instruments don't get left on a wet ground when unloading my instruments at schools) breaks before I've even had a chance to fit it and clearly has been "made to work".

[Cam]

On the back of a Minor if you have too much damping it bounces around all over the place.

Right, I did not explain myself very well there.

The damping was so 'hard' that the only thing 'giving' was the tyres. The dampers were holding the rear suspension so rigid that only the tyres were acting as the suspension medium (an issue that a lot of people actually forget ). That's why mine was bouncing around as it was almost like having the axle bolted to the body!

[Onne]

And tyres aren't that good at daming shocks?

[Cam]

Nope but they bounce well!

[bmcecosse]

So I was right - it was 'skittish' because the dampers were far too hard. Bouncing (when talking about suspension) means wallowing about with the suspension acting throughout it's travel with no effective damping, not settling after each movement. I use the additional tele dampers to enhance the lever arm dampers - they are fine on their own - i present it that way for MOT each year just to save them getting too excited - but when I refit the teles the difference is amazing. Perhaps i was lucky - i like to think i judged it. The tele dampers are long units with plenty of travel to spare both on bump and sag. I would LOVE to have the K series Traveller - I promise if I win the Lottery to come and buy one !! Sadly at the moment it's way beyond my means - and since I have to work everyday (Aerospace Defence Industry) I just don't have time to make my own K series car. Actually - I suspect a Vauxhall twin cam engine or a Honda V-tec would be even better !

[Multiphonikks]

Hehe. . Be like me, (I'm working my way there via a few years of rolling work!)

As for the engines... well, I'd go for a Honda if there was a modern Honda engine which fitted (and wasn't from the oh-so-expensive S2000!!! :D:D

[Cam]

So I was right - it was 'skittish' because the dampers were far too hard. Bouncing (when talking about suspension) means wallowing about with the suspension acting throughout it's travel with no effective damping, not settling after each movement.

No, the back end was bouncing around when I reversed it out of the garage over a bump. I never got as far as a test drive as it felt truly AWFUL so I adjusted it before driving it on the road.

The tyres were causing the bouncing, not the suspension (or lack of it).

Actually - I suspect a Vauxhall twin cam engine or a Honda V-tec would be even better !

Gosh! you can tell you are from a Mini background

[martylemoo]

ok an update,
i removed all of the front dampers from my car, fitted new dampers spax and lever arms and the car is still the same. I have come to the conclusion that the damping is working but the car is just far too softly sprung. The odd thing is the car worked quite well before on the same torsion bars but now it bounces around all day long. The dampers are settling out every bounce fine but it bounces at the merest stone. Now here is my question, if i happened to mount the torsion bars on the oposite sides to their original 40 yr old positions will it make them virtually useless? and very bouncy? as i guess they would be unwinding or am i talking rubbish? there is a possibility i might have done this as i never marked them left and right because i never invisaged fitting them back on the car. any help much appreciated
Cheers
Martyn

[ColinP]

Martyn,

From my reading of the manuals, the reason for not swapping the torsion bars over is that they have been stressed in one direction. Changing the stressing is one of those things that may causes problems (unspecified).

With regard to damping, the theory is from "simple harmonic motion" analysis. No damping and the system keeps oscillating.
Sounds like your experience...

Too much and the system doesn't respond (i.e very harsh), too little and it oscillates to rest.
The "critical damping" is such that the system returns to rest after one half cycle.
It's easy to set up the simple weight on a spring model, but more complicated with a couple of "springs" - like the torsion bar and the tyre.
Factors involve the spring rates, the masses involved, the travel ('cos in the real world there are bump stops!), plus the damping rate and distance the dampler will displace.


Colin

[martylemoo]

but what i cannot understand is the car worked fine before. All i did was fitted uprated torsion bars and it then worked fine. Take the uprated torsion bars off and fit the originals back on and i have this problem, so you could say that maybe the rough roads over here might have caused the dampers to fail so i have purchased brand new spax dampers and fittted them in exactly the same place as the existing spax. So now i have the exact same setup as i did originally but with this problem. I do feel that the car is damping correctly as each bounce is damped to just one rise and fall but it bounces at every small bump like it is way to softly sprung