Nohachi's suspension ramblings thread

[NoHachi]

And exhibit no.1: a K-sport dynograph!
These things are pretty rare since K-sports don't usually end up in the hands of people with shock-dyno's. The shocks are for a Nissan S-body. No problem since the AE86 stuff has a 90% chance of being the exact same shock adapted to our setup. The springrates are 100% the same.

source: http://www.mazdas247.com/forum/showthrea...=123666252

Fronts:


Rears:


What do we see:
Only rebound adjustment
Not ideal but common. Koni sports are similar.

Ratio Bump/Rebound = 1/3.6 to 1/5.6 (not ok)
You do need more rebound then bump..as the spring compresses during the compression stroke it stores energy. During rebound energy is released. Shocks dissipate energy so you need more rebound damping then compression. Current wisdom is to have a ratio of 2:1 rebound:compression.
The K-sport range covers the range from too much rebound to way too much rebound. What happens when the damper is much stronger in one direction? The suspension will resist moving in one direction more then moving in another. In this case moving in compression is easier then rebound. If the car runs over bumps it moves downwards more then it moves upwards. This in effect lowers the car and the car "packs down" onto the bump stops or into coil bind. Not good for grip, comfort or anything really. It feels sporty but it isn't.

Rear shock damping ranges do not overlap.
That means that even with the left set to full stiff and the right to full soft the shocks still don't produce the same forces. Try and imagine what that does to your handling. Not pretty.

Front shock damping ranges overlap only above 550lbs
So to get the front left and right equal you have to have a minimum ratio of 4:1 and there is no room for adjustment afterwards.

At least the adjusters seem to be actually working and stiffer settings lead to stiffer shocks.

Difficult to say much more about them without a force-velocity graph.

Conclusion ->
Plus sides: suited to give a stiffer ride so you can slam your ride height to the ultra-cool setting. Better handling at slow speeds due to stiffer springs and less camber change from the suspension. Probably easier to drift.

Downsides: control at the limit likely to be very tricky (mind you, less then 5% of people actually use that limit). Grip and comfort over rough surfaces compromised. Difficult to adjust since there really is only one setting of the adjusters that you can't really use (and you have to find this setting for each shock individually by feel).[/b]

[edit: just for reference, its possible to become a pro-drifter on these things. Vernon's has proven that adequately with his successful Trueno. Just goes to show that drifting is not a comparable to timed-events.