Harsh ride

Technical Area Steering & Suspension
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  1. My model of MX-5 is: NC
  2. I’m based near: Corby
  3. I’m looking for technical help or recommendations on: Ride improvement
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Brief question, brief answer:
Better suspension.

Can give a better answer if we knew more about your current set up. Standard? Lowered? What wheels? Etc.

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This is a new type of forum for me so please excuse me if I get it wrong. I do not understand why I could not (apparently) putting this in my OP.

I recently bought a 2008 60k miles MX-5, a car I have fancied for some time and I’m impressed with its performance and road holding.

However, I’m not impressed with its harsh (slow speed?) ride where I feel every small bump ans dip as a jarring motion.

12 or 15 years ago I had an Alfa 156 2.5JTD which also had a somewhat harsh ride. I had a set of Koni shock absorbers fitted which transformed the ride without compromising its high(er) speed handling. I believe the Koni’s were of a fairly new type which tightened up in response to increased speed of the car. I have asked Koni.co.uk of their SRT.T model is this shocker.

Maybe someone has experienced this harsh ride and found a satisfactory solution. Any advices appreciated. Thanks.

Jerry

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4

The car is completely standard, as far as I know. I have a full service history from previous 2 owners and there is no indication of suspension revision or change of wheels from standard.

To pass its MoT before I bought it, it needed 2 new road springs on the front. I presume they are standard springs and the car sits level but fairly high as most on here seem to perceive it :thinking:

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5

Possibly a picture (side on) showing the ride height posted up will give members an idea of what you have. If it’s been lowered previously we’ll know. For instance, is your car a 1.8 or 2ltr and what model will decide (as standard) what suspension it may have, some differences there straight off.

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I have an NC2 2.0l with 17" wheels and I find the ride very acceptable for a lightweight sports car.

What wheels and tyres do you have and what tyre pressures are you running?
Is your car a Sport version?

29psi is the standard pressure, all round.

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OK. So here are some pictures:

As bought RHF side
As bought RHF side1210×680 375 KB

As bought RHR side
As bought RHR side1210×680 348 KB

Before bought LH rear-side
Before bought LH rear-side1024×768 211 KB

First 2 pictures are as it is. 3rd is before I bought it, before new springs fitted on front suspension.
It is a 2.0 litre car with retractable hard top.
Wheels are 16" with fairly new Mechelin 205/50 R 16 tyres at 30psi.
HTH.

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That looks like the std 4x4 style ride height. My first concern would be that the replaced springs are std specification as it looks like the PRHT was originally fitted with different rate springs to the soft top. I would suggest that you obtain a set of Eibach -30mm lowering springs making sure that they are for the PRHT version and get them fitted. This will achieve 2 things, a better ride height and the knowledge that they are matched springs. Alternatively go the full route and fit coilovers, I’m sure plenty of people on here will tell you which ones are the best.
Just to confirm please measure the distance from the wheel centre to the wheel arch, this will confirm what the current situation actually is against the Mazda OE spec.

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is 30psi correct? Also alignment

if it’s just say harsh bilsteins new coil overs wouldn’t be a bad move

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Does look a tad higher than it would normally be in the first 2 pics, third pic looks lower pre new front springs fitted, it could be the light conditions or my eyes.:open_mouth:

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There have been a number of posts on here about fitting lowering springs but the car ending up higher.

This seems to be down to tightening the drop links with the car off the ground, thus locking the springs in an extended position
I wonder if this is what has happened here and if this has also resulted in the harsh ride?

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Front springs were reported as broken by MoT tester so they were replaced, which is probably why the front height was lower in the 3rd picture.

Current wheel centres to wheel arch dimensions are: F ~41cm, R ~40cm

In by book it is not essentially the spring strength which makes the ride harsh (although excessively strong ones would not help) but the resistance to suspension motion provided by the shock absorbers. I’m sure the Koni’s I had fitted to my Alfa were described as being soft during slow motion, hardening up as the suspension travel rate up/down increased; and that is how I found them to behave.

Anyway, I’d agree that the current ride heights of my MX-5 look high and unattractive, so I would not be averse to a little lowering but I am averse to shockers which will harden the ride.

Hence my search for recommendations.
Jerry

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I went for Meisters

IMG_0583
IMG_05832016×1512 1.49 MB

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Check the suspension pivot bushes. If the bolts have been done back up when they were doing the springs with the suspension unloaded then they may have become twisted in the hole & therefore making the suspension very stiff.

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That I suspect is very possible as I doubt that the new springs were fitted by/at a Mazda dealer or specialist.
However, I too am not familiar with the MX-5 front suspension and how it should be set up or reassembled. I do have a good workshop and set of tools though.
Jerry

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Did you buy it from a garage or private sale?

They should get it fixed for you free.

As @Phoenix22 said sounds like the suspension pivots have been tightened with the car on the ramp, instead of on the ground, so the bushes are twisted not allowing the suspension arms to move properly, giving you a hard ride.

So it’s a case of reversing the process, car on lift, slacken off pivot bolts, put car on ground tighten them back up.

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Mazda spec for 16in is 356 - 405 ft 351 - 401 rr 17 in is 4-5mm lower. Mine has the -30mm Eibach on std suspension and new tyres shows 355 ft and 345 rr [image] [image] [image] on a nearly full tank.

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Hi, if you opt for the 30mm lowered Eibachs the ride will be harder IMHO.
I test drove a few standard set ups and found them to be a bit ‘floaty’ over crests so bought one with the Eibachs. It is definitely firmer than standard (but not harsh).
If you want a compliant ride I would be wary about going lower and concentrate on sorting out the standard suspension. Some great advice above.

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Those dims are above the top end Mazda specs so I think you may have a case of the twisted bush syndrome where the suspension has been tightened up with the wheels at full drop rather than in a loaded condition. As previously described the solution is pretty simple or if you get it lowered just make sure the garage know what they are doing.

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Thank you for your advices guys.

I will check out who fitted the new springs and anyway I will check and re-tighten the bush bolting as advised.

As it happens I met a chap at my local gliding club meeting last evening who has an 08 plate MX-5 so I had a chat with him. His car is also on standard suspension and he confirmed to me that the ride is maybe a little harsh on his car so I suspect this is normal and I’m being a little harsh :wink: with my opinion of the ride.

I will still check the bush bolting is done correctly.

Thanks again, Jerry