damper ratio

[CMF_frank2]

i never realized the effect before :O
been trying out some daewoo matiz front suspension legs this week and noticed that the front-end can now take speedbumps like they dont exist (yet the handling/comfort seems the same as stock ??)
so i tested the compression and rebound damper times of the 2 shocks (with a weight on top and a weight hanging off the bottom)
the stock k11 shock recorded 8 secs recoil and 7 secs compression
the matiz shock recorded 7 secs recoil and 2 maybe 3 secs compression

frank

 

[CMF_Bishop]

It's a much debated point, but arguably you don't 'need' a whole heap of compression dampening, it's basically what makes any car often feel 'firm', but really like many people will say, that is what the spring is there for.

Some cheaper 'sports' shocks will bump up the compression to give a sports like ride with stock springs, but it's not what you would call ideal, on a well sorted car what you often need, if much harder springs, very light compression, and lots of rebound.

My last couple of Volvos had top quality shocks, Sachs on the first turbo, with had very little compression, but lots of rebound, made it very plush while giving a still very controlled ride, next Volvo got Bilstein mono tubes, while they had more compression, they still did not have what you would call a lot, result being it still rode well for something firm and highly controlled.

What you say about the Micra shocks explains some of the things I have noticed since I bought mine, as when I first drove it I felt it was harsh on compression (although one of my fronts is stuffed).

 

[CMF_frank2]

thanks bishop so a decent ghetto setup could be the 3:1 ratio matiz shock with a pretty stiff spring (for a good compromise between comfort and handling eh)

frank

 

[CMF_Bishop]

I believe lots of new cars go that way now, much higher spring rates, less compression dampening, heaps of rebound, which I think is what you find on most old high spec euro cars, and probably what allows most newer cars to run such lower profile tyres with bigger wheels and still stay comfortable to drive.

 

[CMF_mycra]

i'd prefer hard than soft...crashed my first car that way.

 

[CMF_frank2]

thanks again bishop, i have to revise those calculations tho
on reflection i should,nt have used different weights for the testing (the flywheel for compression and somewhat lighter vise for rebound)
using only the f/w it comes out at
7 secs compression and "5" secs rebound for the k11
and 2+ secs compression and "4" secs rebound for the matiz
so corrected ratio is nearly 2:1 on the matiz, and less than 1:1 on the stock one

frank