- My model of MX-5 is: MK3.5 NC2 1.8l SE
- I’m based near: Bristol
- I’m looking for technical help or recommendations on: Suspension wallow
I just recently replaced the shocks in my NC2 with Meister Zeta CRDs, they are brilliant however one issues which was present before is now still present even with new shocks, at speeds over 50mph the whole car feels very wallowy (which is odd because it simulatenously feels very stiff due to how i’ve set up my suspension), as in lets say i’m going 70mph on the motorway if i was to slightly swerver around in the lane it feels really quite sketchy, the whole car pitches and yaws a lot side to side. It’s even more peculiar as when i have it on autosolo it’s absolutely brilliant but get it out on the public road and it’s downright scary to drive.
I’ve owned it for 20k miles and i think this issue has gotten progressive worse, the last time it was serviced i noticed the rear drop links had play in them, i’ve bought a new set for the rear but i wouldn’t have thought this could cause a noticeable gradual increase in noticeable body roll, unless the stiffer shocks have made it more noticeable?
Just looking for advice as it’s really killing my enjoyment of the car at the minute.
Sounds not too dissimilar to what I experienced when I first had my NC1 aligned after having Zeta CRDs fitted. The setup was quite a track orientated one and I found the car felt as if it was trying to push me into bends and also felt twitchy at speed on faster roads. This was I believe due to a bit too much rear castor. They made the response a bit more neutral and the feel is now great, gently easing me into bends and dead stable on motorways.
If you’re up for a trip up the M5, I can recommend Performance Link, betwixt Cheltenham and Tewkesbury.
Addition :- After reading Adam’s comment below I recall it was toe, not castor which was the factor.
My experience was exactly what he describes.
Did you get an alignment done and which tyres do you have, all matching?
I have yes https://imgur.com/a/2K6NPe3, it’s a fairly neutral allignment from my understanding.
I also have 4 matching Continental Premimum Contact 6
From my understanding, that alignment sheet is showing toe out at the rear. That would explain the weird behaviour in straight lines at speed, and why it feels great for autosolo. It’s like skiing - having the tips of your skis pointing outwards makes you constantly want to make turns, no stability at all.
Suggest 10 minutes toe in per side (+ve values) on the NC. At the moment you have 2 and 3 minutes toe out (-ve values), making a total of 5 minutes toe out across the rear axle.
The rest of the alignment looks sound.
What you are feeling is compounded by the NCs dynamic toe, which goes to toe out upon initial loading from bushing compliance, and then toes in under roll / bump. I know exactly how your car feels and it is un-nerving!
hope someone competent has fitted the suspension and not sure who setup your car but try this.
set tyre pressures to 28 psi
if you track the car you should weight balance the thing aiming 51.5% front bias
Caster: ~ 5.0 degrees
Camber: 1 degrees negative
Toe out: 0.15° each wheel
Rear
Camber: 2 degrees negative
Toe-in: 0.15° each wheel
Bushes make a huge difference, replace with a slightly harder shore rating. That worked for me on an NB
Fitting MeisterR suspension and having JUST the alignment done is like buying a new TV and putting a plug on it……… yes it may work to some degree but to get the full potential it needs ‘tuning’ in
A bit like the suspension needs a proper set-up not just alignment
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When was the last time you bought a TV, the 80s? 
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Toe in is a positive figure, he already has toe in.
I have read a lot that people run 0.5 more front camber than the rear. My setup was done recent and I also find it twitchy. Im I have slight toe in and that would normally give straight line stability. Im going to try one change at a time, first the front camber to higher than rear, this will change the toe, so that will need changing as well.
lucky enough I have some kitcar friends with the tools to do it.
Maybe we are seeing different things. This is whats shown when I open up the link:
I would be looking for a minus sign for it to be toe out. The arrows are how out of spec it is compared to the settings entered in the machine.
Towards the bottom of this article shows it
Example
I do understand. The rear toe shows negative values, hence toe out.
You don’t have toe out, its toe in.
Please can you explain?
Perhaps we are looking at different things. I am referring to…
Zdos123 is the original poster mentioning he has weird handling.
This alignment sheet shows -0°05’ rear toe.
Yeah sure, we are talking about the same thing.
Normally to use these machines the operator enters what car they are working on and the machine brings up the standard settings. The arrow that moves from left to right is showing how far away from the standard spec the wheel is. It is not indicating whether it is positive or negative.
For example look at the left rear camber below, the range for the arrow is -0.04 to -2.40, so the arrow is just showing where in that range the current number is. You can also see on the whole document that all the arrows are in the centre, with your thinking they should all be zero’s, but what its stating is that the spec is spot on compared to the figures set in the machine.
If the posters toe was negative the number would have a minus before it (as you see in my previous post on the right rear that’s got a minus). The arrows on his sheet just mean that the machine operator didn’t set the spec to the one in the machine.
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Thanks for explaining your thoughts! I understand what you are saying.
However, no targets seem to have been set when doing Zdos123’s car, hence there being no small values in the top corners of the boxes (the -0.04 and -2.40 you mentioned). So how does the machine know where it is relative to target? This is why I believe what is shown is an absolute figure, relative to parallel.
The downward pointing arrows hovering over the green boxes are also off to the left at the left rear, and off to the right on the right rear, which to me indicates toe out on both sides.
Do you work with alignment etc? I have done quite a lot (for paying customers) over the years so understand this area well - but I use my own kit rather than a laser machine to ensure better accuracy (at the expense of time / effort!), so I may have interpreted this incorrectly. Edit: Having looked again - do green boxes mean a target has been set, and the setup is currently within the target? And grey boxes mean no target set? That makes sense now - just seems odd not to show the target values on the sheet. Front toe in on an MX-5 with coilovers threw me a bit! So it looks like the rear toe values are (from middle of target) towards the toe out end of the scale, but still 5 mins toe in across the rear axle. I would suggest that running so close to parallel would make the rear wheels switch from toe in to toe out under bump, and also give a very odd sensation (thinking again, the front end will probably do the same thing too). More toe in across the rear axle would help, IME.
I guess my overall point is that rear toe out would explain the odd driving behaviour, and to me it looked like the alignment sheet indicated that.
Where are you based @Zdos123 ? If you are anywhere close to Preston (Lancashire) I would be very happy to take a quick look for you, no charge. Edit: Just opened my eyes properly and see Bristol. Hmm. Performance Link are about an hour from you, but I am certain they would be able to take a look and assist if you wanted to explore this. Or even a quick ‘alignment check’ at a local Halfords (shudder) to get another reading - just make sure they don’t get the spanners out, haha.
