Suspension upgrade or repair?

stevo2, Oct 6, 7:18am
So Mrs Stevo and I just got back from a roadtrip in the MX5 and we covered around 500km of it on back roads.
The problem is that after 17 years and over 100,000km its starting to bottom out on some of the big bumps.
I guess I will need springs or shocks or both. I want to keep the brilliant roadholding (or even improve it) and dont want to lose too much comfort so do I put stock back in or go for something a little bit more upmarket like Bilsteins or Tein?
Im not really interested in lowering it.
Any suggestions?
Do coil-overs need a cert?

tamarillo, Oct 6, 7:23am
Depends on Mazda, but I found good aftermarket shocks were less than originals on BMW's, and a Toyota MK X.
Suspension place can test coils to see if they're saggy. I thought replacement coils are fine if they don't lower car.
Bet it will feel soo much better.

clark20, Oct 6, 8:00am
Get a set of Bilsteins , import them from the US, springs will be fine. Coil overs will be too hard and need a cert

stevo2, Oct 6, 8:05am
Coil overs are Goneburgers.
How can I tell if its shocks or springs or both?
Car bottoms out to easily.

tamarillo, Oct 6, 8:38am
If it bottoms out then springs are suspect I think. To my simple mind the spring alone will keep car from bottoming out, and set ride height. The shock then controls it when it moves. An expert might say it's not that simple but it used to be!
I took mkX to a place with suspension testing gear. Car sat on pads and got shaken and it recorded movement. It diagnosed only shocks needed but car was not low or bottoming out. Maybe get Mazda tested on such a machine? Suspension shops have them.
They used to reset springs but I guess new ones are cheap now so it's not worth doing.
Still, sounds like springs needed with shocks.

serf407, Oct 6, 8:52am
Check the other parts of the suspension while you are doing the shocks/ springs.
http://www.georgestock.co.nz/Stocks/products.asp?cat=35 http://www.autolign.co.nz/

mm12345, Oct 6, 9:39am
Maybe the load's getting heavier or the roads are just getting worse.

NZTools, Oct 6, 10:30am
if the car is sitting at or near its standard ride height, there is little wrong with the springs. Their job is to hold the weight of the car. If the shocks are poked, it will bottom out easily, as there is no damping, to add resistance. Stiffer damping rates, means a harder ride, or less suspension travel on the same bump as apposed to soft or worn shocks. Replace the shocks with good quality Bilstien units, and that will be any amount firm enough.

sr2, Oct 6, 10:58am
I'm in absolute agreement. Unless the ride height has changed invest in the best set of shocks you can afford; my racing preference is Koni or Bilstien for a cheaper alternative but there is a huge range of good aftermarket shocks out there.

Best advice I can give you is join the MX5 Club of NZ and get your answers there.

I would be lloking

stevo2, Oct 6, 4:56pm
Thanks sr2. Have been a member for the past 10 years.
A lot of our driving is on secondary roads which are a lot harder on suspension than the main highways and yes, Mrs Stevo and I have gained a few kgs over the 11 years we have owned it lol

scuba, Oct 7, 10:02am
talk to the supplier and other club members about your needs and their personal experiences- some of the aftermarket shocks are quite firm riding as people look for different specs as opposed to a straight stock replacement. not knocking other posters just your idea of hard ride and theirs may differ.

jesus2000, Oct 7, 7:26pm
I have just been through all this with my Mazda 6. My recommendation in short. Go to your local Mazda dealer and price the standard shocks.

The springs are probably fine. Shocks are meant to be replaced after 80k. The Mazda 6 standard shocks cost about the same money as aftermarket. If you liked the ride of your car when it was newer, then going with originals will restore that feel. If you go with aftermarket, it is a roll of the dice and you may not like the result.

bill-robinson, Mar 13, 9:18am
very sensible and practical advice