Which model of Ohlins are these (FD3S) ?
 

Hi guys,

I bought a jdm front clip and it came with this set of Ohlins coilovers. I'd like to know what model they are and if they are the height is adjustable. They seems adjustable but I've never seen this kind of mechanism before. I've found some threads about these but not much useful info.

Thanks.

No one?

I have seen these for sale before in japan. They are some older model. They are probably pretty good dampers too irrespective of their age as long as they still have gas pressure and oil in them.

If you can move that bottom perch upwards and downwards they are height adjustable. Is there some circlip that holes the perch in place around those rings spaced on the shock body? If you can move the perch, then you can adjust the preloading of the spring. You never want less than 2mm preload on the spring to hold it captive.

If you raise the vehicle by moving the bottom perch upwards, basically you are preloading the spring to hold that weight of the car.

Say the car weighs 1400kg / 3100lbs. Each corner has roughly 1/4 of that weight on it. 350kg. If the springs are 10kg/mm that means you get 35mm of spring compression by resting the car on its own weight. If you go and preload the spring by 20mm (200kg), the car will sit 20mm heigher.

These maths hold but they are approximates because springs are not perfectly linear and you also have rubber and motion ratios at play. If the wheel moves 15mm for every 10mm of shock absorber/spring movement, which I think is about right that 20mm of spring preload will actually raise the car by 30mm.

Preloading the spring also adjusts what the bike guys call suspension neutral. Guys here would probably call it wheel droop. It basically means how far away the wheel can fall from the body. It is meant to reduce comfort. I tried playing with it before when I had shocks that were really short for road use. I found that it improved comfort and also made the steering feel better. It keeps the car flatter around corners if you have less suspension droop.

These are the predecessor's to the PCVs, we have imported a few sets with mixed reviews - for the price they are fine. FYI, Japan just recently tightened regulations where they restrict any suspension with gas to be exported. It is extremely extremely difficult to get a set of coilovers out of the country now.

Thanks for the info guys. I'll take a look at how to adjust them.