(05-27-2014 09:36 PM)NoHachi Wrote: * Your suspension/shock does not typically top out over a pothole. If it does the wheel simply becomes airborne. Full droop is usually reserved for the inside wheels during cornering.
I was thinking more about the travel after the car comes out of the hole and the spring becoming uncompressed and the suspension reaching back to it's fullest travel. But, my thought process didn't take into consideration the weight of the car restricting the shock from topping out 
* 20mm of negative preload (spring to short) is not a good thing. NOTHING is controlling the wheel in that part of its stroke, it can accelerate at will to great speed, the spring can rattle, get dislodged etc. Its not a good place to be.
This was more of a theory when combined with helper springs to decrease harshness, I wasn't intending to opt for a gap in the spring as I would consider it dangerous and my car would fail an MOT. Although I know it's been touched upon having spring gap here: http://www.driftworks.com/forum/chassis-...rrect.html where people have minimal issues
* More droop will not usually cure your comfort problem. The shock needs to allow the wheel to make use of the droop, not something that happens with many of the hugely rebound biased shocks.
* Rebound biased shocks like these typically have a bump travel problem. Don't ask why, but as you hit bad asphalt the car lowers itself and this creates reduced bump clearance. You hit a pothole and its the upstroke that upsets the car as you hit the bumpstop.
So, regardless of whatever I do, I'm going to have the rebound of the shock causing ride harshness and can only resolve this with a different spring and shock setup?
* What you want is stroke and as much of it as you can get. That means measuring a few things: how much stroke does the shock have at between full bump and droop?
How much does the spring compress from fully extended to when the car rests on it (no preload)
What is the coilbind height of the spring (in a pinch number of coils x diameter will do.
The trick is getting the car to use the full range of travel and have it resting in the middle of the travel.
This is where I believe the idea came to mind. Making sure that the car has enough droop to allow the spring to move down when being the outside wheel or lowering into a dip in the road, but enough bump to make sure that when hitting a bump in the road it doesn't bottom out and hit the bump stops. I think this may need some more tinkering to get right, regardless I've never had the car hit the bump stops under any conditions
* helper springs are a good idea if you need them. Longer, weaker springs are better in your case.
This kind of relates to my comment earlier about making sure the spring remains secure
* Doing all of the above usually means raising the car a few cm's, even on shortstroke setups.
Raising the car wouldn't be an issue, but in my case, I think it would be more likely to lower it, as the preload and height adjustment are separate and the height is fairly well set. Removing the 0 preload would only lower the car, unless I put in helper springs, which would likely keep the car at the same height with the right adjustment
* Strongly consider going to a milder tire setup. Going to a 14inch wheel, with 65 series tires (165-70 165-65, those kinds of sizes) on a not to wide rim (max 6.5J) will do wonders for potholed roads. Nothing you do to the suspension will ever come close. Run them at 1.6-1.7 bar. I quite like the feel it gives the car too, very progressive and toss-able.
I did opt for softer tyres (Toyo Proxes) when moving onto the CS2s. Previously, I had a Cusco setup which was more harsh than the CS2s, but I think it's safe to say that whilst they are great for smooth roads, bumpy roads causes the handling to suffer somewhat. I think that looking at a standard koni or Bilstein/Spring combination could be among my options, unless you have any other opinions? I know you've looked deep into this before NoHachi, so your opinions are highly welcome
(05-27-2014 09:21 PM)totta Crolla Wrote: Don't forget that the weight of the car will compress your 6kg spring by approximately 35-40mm so you still have that much sprung droop before the spring is not captive.
Eibach make a really nice dual spring set up that effectively gives a progressive rate.
http://eibach.com/global/en/motorsport/p...system-ers
Yeah, that's something I had overlooked (as shown in my response to NoHachi). Is Eibach what you've been running mate? If not, what's your best experience on UK roads with the 86?
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Another suspension topic - The deal with droop
