Coilover damper piston sizes

[edwagon]

Im looking at buying some new coilovers, and am trying to compare brands and specs etc.
How important is the size of the piston for the shock? The better shocks have larger pistons and the cheaper ones smaller pistons, but how much weight should this have in my final descision?
Im comparing coilovers of a similar constructin and quality, one has a 36mm piston, the other a 46mm.

[atmosports]

If it's going to be a rally car or a circuit car that gets banged over kerbs all the time then I'd go for the bigger pistons as you'll be seeing a lot higher compression speeds & the bigger piston allow bigger ports and/or more ports & generally you can produce a better shaped port in the larger piston. Then you also get more oil/gas volume too generally speaking which also means longer to heat etc. Only real downside to going bigger is friction which isn't as much of a concern on car as it is on a bike. Depending on how they are valved etc most people probably couldn't tell the difference, well from my experience with what I've seen on the shock dyno & then going to the track & testing unless you've got a good driver or a really good data system.

In you case I'd say go with whatever you think is the better brand, the one that has the better reputation, is more reliable most of all one that can be rebuilt here. I've worked with most of the common brand stuff & to be honest most car stuff is pretty backwards compared to current motocross stuff with regards to coatings,piston port sizing/shapes & valving.

[method]

Bigger is better for track work or hard driving.

Will stop the hydraulic fluid boiling over or overheating which will lead to sloppy dampening.

Most track cars will not only have suspention with large pistons, but remote oil reservoirs for the suspension, some have 1L+ reservoirs to make sure the oil in the pistons stay cool.

What will you want your car for?

Occasional track days i wouldn't worry too much, if you do a few a year and enjoy driving that car id go for larger pistons. Or if you're more serious go for a setup with remote reservoirs.

[Mr Revhead]

a remote reservoir set up is usually pretty serious!

what car is it for?
your pretty safe with top brands like TEIN and TRD, just make sure you chose a kit to suit your needs. ie not a road kit!

however my preference for a semi serious track car would be the likes of bilstein or koni. make your own coil overs using their inserts.
as atmosports mentioned, a brand thats rebuildable here is the wise choice. koni, tein and bilstein are rebuildable in nz, while TRD sells replacment inserts for their kits. however price wise one of the former 3 would probably be better.

buy, if you are really serious.. something like drummond or prosport etc is the bomb! but thats getting up to and over 2k a corner!

[method]

When i last tried rebuilding one of my tein HA shocks (about a year ago) autolign said they could do it, but would offer no warranty on their work.

They said they are just the NZ importers/distributes for tein.

Things may have changed now though?

[edwagon]

The car is an s14 for road and the odd track (Drift) day
I had a set of tein HR which were great, but they were getting a bit tired and one started leaking so I have decided to replace rather than rebuild.

Im looking at the cheaper end of town, (remote reservoirs etc are far beyond my requirements!) - and was comparing a couple of the better cheap brands, and piston size was basically the only difference between them - both can be rebuilt locally.
It would be nice to have $2-$3k set (or per corner!) suspension but then Im paying for quality and performance that I'll never make use of - if the basic specs and dimensions of the cheaper ones is up to scratch then Im happy enough

I got a quote to rebuild my Teins from Autolign and they didn't mention 'no warranty' - They were helpful and happy and gave me a price but I got the feeling that they wern't jumping at the chance to rebuild it for me

[Mr Revhead]

down here they say they are the agents and offer full service including rebuild.

id have a real good look at making your self some koni coilovers if you can do the work. will be around the same price as some of those $12-1500 coilovers, but be much better quality and you know you wont have any issues with getting them rebuilt.