Suspension guru's...

[A900ss]

I have to admit now that I am NOT a driving god

However I can tell if there is something not quite right with a cars suspension if not what is actuallywrong with it.

Case in point, how can I tell if a car is over springed and under damped OR if it's over damped and under springed?

Thanks

[Juber]

Take it to a garage would be my first point of call

[jebus]

This will explain lots and lots about damping Damping MIT

a tad complicated lol

[A900ss]

Juber said:

Take it to a garage would be my first point of call

Not really the answer I was looking for...

I reckon 90% of garages wouldn't really know how to set up adjustable coilovers and I'd do a better job by trial and error.

[A900ss]

jebus said:

This will explain lots and lots about damping Damping MIT

a tad complicated lol

Link doesn't work for me. Can you try again please?

Thanks

[ILoveMondeo]

If you're genuinely concerned get it to a specialist.

Track v road

Center gravity

Sure there are plenty more.

CG transformed my tuscan with a loooong day of tinkering.

Not cheap but worth it IMO

[Tickle]

Would a geo-setup from a specialist not highlight any probs?


http://www.trackvroad.co.uk/upgrades.html

[jebus]

http://ocw.mit.edu/courses/mathematics/18-03sc-dif...

Its not car related, more how damping works in general. the why I understand it is overdamping is why so many cars feel so harsh, the dampers are reacting very fast before the spring has gotten rid of the energy put into it by a bump, the benefit is that the car will respond to inputs faster, but will also make the car roll around a lot, as take the energy from the spring away before it expands again.


But suspension tuning is a dark art that can change things a LOT, look at how much effort goes in to setting cars up for different tracks, let along a car on the road, you do really need to spend a lot of tidy fiddling with the setup.

[A900ss]

I've had a full geo and it's almost there....

I just think that it's slightly undersprung at the rear (front is fine) but I'm looking to read some theory to confirm the feeling I get through my 'seat of the pants'.

Don't get me wrong, it's good, I just feel it's very close to excellent and if it's into £60-£70 worth of springs, I'm there.

[jebus]

What makes you feel its undersprung at the rear, and remember everything you do to the rear springs will change everything else on the car, so could make the back better and bugger the front

[A900ss]

jebus said:

the way I understand it is overdamping is why so many cars feel so harsh, the dampers are reacting very fast before the spring has gotten rid of the energy put into it by a bump

That's what I'm thinking. The damper is restricting the movement of the spring to fully compress and rebound in the given time. I want the theory to ascertain if a firmer spring with less damping will react to compression/rebound better/quicker but still have suitable damping to retain control over the spring.

[A900ss]

jebus said:

What makes you feel its undersprung at the rear, and remember everything you do to the rear springs will change everything else on the car, so could make the back better and bugger the front

Agreed about impact at front !!

It's almost there but on big bumps it feels as if the spring isn't reacting quickly enough, as if firm damping is slowing down its reaction. If I soften the damping however, it's too floaty and feels I controlled.

[jebus]

You could try backing off the damping slightly, will let the suspension move more and the spring todo is job better, have you looked at your tire pressures and tires themselves? changing them will do a lot to alter how the suspension works, as well as the unsprung mass.

[A900ss]

jebus said:

You could try backing off the damping slightly, will let the suspension move more and the spring todo is job better, have you looked at your tire pressures and tires themselves? changing them will do a lot to alter how the suspension works, as well as the unsprung mass.

I've played a little with tyre pressure to get where I want and have stayed with original (small) wheels to keep unsprung mass down. Softening the rear dampers by only 1 click from where I'm at makes the handling significantly worse IMHO. It rolls and wallows more and I dont feel the spring is doing anymore work, just out of control from the damping a little.

Edited by A900ss on Thursday 10th April 21:42

[A900ss]

PS - I'm not thinking too much change. My car has 325lbs/inch springs at the rear and I'm thinking maybe 350 (375 at most) to deliver what I think I'm looking for.

The dampers should be able to support that. Currently running 9 of 13 clicks.

Edited by A900ss on Thursday 10th April 21:45