Improving ride quality with coilovers

[ChrisTW]

My S15 came from Japan where it was a track car with HKS Hipermax III Sport coilovers. On Scottish roads they are extremely bumpy and crashy and they do not cope with any kind of uneven road surface well let alone enormous pot holes and such.

At the moment the spring pre load seems to be at the lowest possible setting (you can spin the spring when the car is jacked up) and the damping settings are on 5/30 all round. At the back there are helper springs.

So basically its all loose and soft and the ride is bad. Are there any adjustments I could make that might improve ride quality?

I've got 205/55/16 tyres at the mo and 235/45/17s to go on which may help a bit. It also has Sard adjustable anti roll bars.

All help appreciated!

 

[Clarkey]

If the damper force is too low then it won't be able to keep the spring oscillation under control and will result in a terrible ride. Try turning it up and see if it helps. If it has mega tough springs it will never cope with broken up roads though. Most likely the coilovers are ****e and/or old and blown, many that come over from Japan are. HSD monopro is the only option I would consider personally having used a few. If the roads you drive are very poor though then it will still be rubbish and you'd ultimately be better off with a spring/shock setup like Nismo S-tune but you won't have the super low down look.

 

[ChrisTW]

Ok all worth trying. They are track/competition type coilovers so its always gonna be fairly rough. It's the bounce I want to inhibit. Would a bit more spring preload stop it bouncing perhaps? The coilovers are ok had them checked out. Might be worth moving them around a bit cos they will have been Sat still on the boat during import.

 

[Auss15]

If you want to keep them I would get them revalved to suit the spring rates and ride height...

 

[sibbers]

I have monopros on mine and while they are competnet shocks, they are too hard. I'm investigating the idea of getting springs that are 2kg's lighter than the 7/5's the HSDs come with now. I oringally intended to get Smoothie's but my impatience got the better of me. Last I heard a pair of springs was about £50 so with a bit of inflation all four are likely to be £175ish? Hoping for less. Will let you know what I'm quoted, but if I were you I'd just go asking for HSD smoothies and control the damping instead. A decent set of ARBs offers a better setup for being fast on UK roads than teh average coilover anyway - that way you can go over bumps *and* nail corners!

 

[sibbers]

Decided to buy 4kg springs from DW at £85 (ish) to replace my rear springs, which I'll put on the front leaving the 7's aside for the day I visit the track. Am fitting ARBs too to complete the handling, as even with full damping the HSDs can't control the springs. I've not tried other coilovers so unfortunately can't conpare, but I expect more damping from £775 coilovers. Imagine it'll be plenty for the springs I'm after tho.

 

[Clarkey]

Your HSD are definitely broken if they can't control the original springs.

 

[sibbers]

Nah they're not broken. They don't bounce on harsh roads at normal speeds, but I'd like them more damped when set to full. I would want more than say KYB AGXs. Maybe I'm expecting too much, but even at full damped when going over some bumps at high speed they compress and rebound more than once which they should easily manage with what I think is more sensible springs. I'll post my findings once I get em on.

 

[sibbers]

Ok well I have 5/4's on now and it's loads better. Still firmer than standard by a fair way and the damping is better suited imo too. I think this is the correct setup for our roads.

 

[TomK]

Very similar to the Nismo s-tunes at 4.5 and 5.5, except the nismo shocks have the stiffer springs on the rear.

 

[sibbers]

Doesn't surprise me at all. Everything I learn about nismo is that they keep getting everything they do right!