GAZ Gold Professional - Bouncy?

  1. My model of MX-5 is: 1989 NA
  2. I’m based near: Chesterfield
  3. I’m looking for technical help or recommendations on: Bouncy Suspension.

Bought and fitted some GAZ Gold Professional coilovers last weekend to replace my old suspension. I was fully expecting it to not be perfect straight off the bat, but my lack of technical knowledge has me struggling.

The car is VERY bouncy. Some Googling has led me to deduce that I probably just need to adjust the dampening. Which I have done (from 10/10 Clicks to 14/13 Clicks - Front/Rear respectively). Just took the car for a test after the adjustment and it feels a little better, but still nowhere near the no-porpoising I would’ve expected.

I understand that the Golds are designed as more of a track coil; however I had thought it would be fine in the road considering the website itself said they would be fine for such a task.

Has anybody got any pointers? Maybe someone with Gold’s that could share their dampening settings? I’m expecting a bit of bounce, but nothing like the pirate ship I’m currently experiencing. It’s worth noting I have yet to get an alignment done, but I’ve been told that shouldn’t affect it much.

I crave your wisdom :slight_smile:
Cheers,

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Which springs are on it? What top mounts and bump stops?

You may be adjusting the wrong way, id start at about 7 front and 9 rear (from soft)
Its normally advised to adjust from full hard though. oo er missus.

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All about spring rates. What are they?

I have blue springs on the front and black on the rear.
Slips my mind which one is which but I know one of them is the 300/xxx spring rate according to the website.

Just to confirm Mike, have you bought the GAZ GGP449 kit? With the ‘road’ springs rated at 350/250? Did you spec the Gaz top mounts, or are you using standard NA units?

Also what ride height have you set them at, to start with?

Cheers,
Steve

Maybe the springs are so stiff the dampers aren’t getting a chance to work?

Surely the supplier would provide springs rated suitably for the car?
Who did you buy from?

So either the trackday or race. That and the top mounts options are pretty important details. If you reused your 30 year old stock top mounts, they may have collapsed, which might also cause a harse ride.

If you ended up ordering “race” springs, that would be pretty bouncy on the road. The Trackday set won’t be a ride comfort spec that’s for certain. Though I think probably not far different from the specs on my Puredrives; I never got the full specs from Phil Dixon (P5) who has utterly disappeared, but I think it worked out to 400F/240R, but I’m on Mk2 top mounts and cut bumpstops. That means I have plenty of rear travel, and the ride is nice. Touch wood, the shocks have held up pretty well since 2008 (though the brass adjusters have probably welded themselves).

Also, what height you have every set up. As mentioned, set to highest dompression/rebound, then back off. Once you hit a number you are happy with, leave them alone. I haven’t touched the settings on my Protecs in about 13 years now. Forget what settings you might see on the internet.

There are 4 spring combinations available for this kit. 2 are ok for road use, the other 2, not. That one pair of the springs is blue is making me thing that might be a very stiff set. But I don’t know the colour coding used by Gaz.

To clarify, I bought these second hand.

They were listed as “GAZ Gold Professional” and were recommended to me by the seller as a coilover that is both comfortable but firm. Top mounts etc. I have no clue. They are just GAZ shocks as far as I am aware. I was looking for a coilover that was better than my old suspension, with dampening and also that would lower the car slightly.

It was either these or MeisterR Sportives, of which I was continually steered away from by “experts”. The science behind what is what is completely lost on me. I understand that they are 60% track 40% road, which is completely fine.

However, from a layman’s perspective, the car is borderline undrivable after fitting a suspension set that retails for £980 on the official website. Which is why I’m so confused. Maybe alignment will help, but so far the changes I’m making are just making it worse and knocking my enthusiasm for the entire thing. Especially when I was told that this would just be a simple switch where I only had to worry about adjusting damper settings.

Before anyone says anything, the seller is reputable. Me and many people I know have bought items from them before. So it’s not one of those “dodgy deal” things I keep reading about when I google advice.

Forgive the lack of technical jargon but what I have currently is:
• +1 full rotation of preload
• Ride Height set to maximum (to be changed after alignment)
• Dampers on 15R/16F (out of 20 from what I’m told)
I will be reducing dampers tomorrow because today’s changes have just near enough broken my spine.

I’m all for learning, but so far I have the highest level of buyers remorse and everything I try seems to go the opposite way to solving the problem.

Did they come with fatory or aftermarket top mounts. The seller ought to know what spring combination they are. If they were off the car, you can calculate the spring rating, but you need the free length.

What height have you set it at?

In the worst case scenario, you might need a different pair of springs, which won’t cost that much. Sounds like you fitted them yourself, so just time used.

I once, for one day, fitted a set of Racing Gear (Corn’s) shocks with Swift springs that had a stupidly stiff spring rating (race spec). The car was comically stiff and bouncy. Swiftly changed.


Maybe these aftermarket suspension kits are what vendors want to sell us rather than what is best for the vehicle?
All MX cars come with coilovers, ie: the coil is over the shock, not in another location. All, I believe, have much wider diameter springs than the aftermarket stuff ( apart from Koni). This can give a more subtle springing possibly? A uniform diameter is going to be easier and cheaper to manufacture I’m thinking.
I got some new standard Meisters on the cheap recently so hope to test this out so I’m not just guessing😀

The diameter of some (not all) aftermarket springs that come with “coilover” shocks is based on industry standard widths. My Puredrives came with Pigtail springs, that is, a wide width at the top to fit ith Mazda top mount hardware, but a narrow end for the Protech spring perch.

Industry standard springs are (inner diameter) 1.9", 2.25" and 2.5". Spring rating, or weight, can be calculated from free length (the uncompressed length), the outer diameter, the number of active coils and wire thickness.

Cheap lowering springs are basically shorter springs, though the the good ones will have thicker wire. Cheap ones don’t and don’t last long, before they sag. Good ones have a variable rate, like FM springs.

Front springs are stiffer than the fronts, unless you have certain Spax kits, which are the same all round. You have to think about rear spring bias. For the NA MX5, Mazda set it at a little under 60% of the rating of the fronts. In Japan, they like these gymkhana type events, and to have sporty handling, you want rear springs to be a bit stiffer than stock, to induce oversteering behaviour. So the S-Special, which came with Bilsteins, has stiffer rears (and a bit of Antiroll bar tuning, fairly mild). In general, Japanese after market setups aim for this. Less rear spring bias (softer rears) is considered to offer better stabiilty for circuit racing. Some even disconnect the rear anti-rollbar for a little less oversteer.

In short, its really really easy to screw up the handling of the MX5 with poorly chosen components. Fitting adjustable coilovers to get a lower look is probably a really bad reason, because you will find drawbacks. Make sure you know twhat you are fitting.

One extreme example of terrible advice was experienced by a MX5OC member. He was a retired police driver, and could drive very fast. He was happy with the ride height of his UK spec Mk1; he fitted Konis and had taken a coil off the stock springs So it was very slightly lowered, maybe 14" wing lip to wheel centre. But he wanted to control the roll, so he called a well known supplier, to ask for professional advice, or so he thought. He wasn’t just sold thicker ARBs, but sold tubular ARBs, which are very stiff. Fantastic flat handling on B-roads, but he had no warning from the factory sized tyres on 14" wheels, when the bead started to seperate from the rim. So the car ended up in a ditch, on a road he was familiar with.

I’ve been a fair few setups over the past 27 years. From a budget set of Racing Beat Street springs on factory Konis, Japanese Apexis (lowering spring on fixed perch adjustable Gab shocks), looney Racing Gears (they were an experiment), anf Protech Puredrives. The one time I went with the herd was Meister Zeta Pros, and I wasn’t impressed. I even had a car with M2-Inc uprated stock Showa shocks (interesting ride quality).

Good luck with the Meisters. Look out for rust on the springs, at the top, where they can fracture. And speaking of industry standards, the Chinese shocks don’t conform to any. At least according to Iain Gardiner, who rebuilt my rear shocks a few years back. He has spares for AVO, Gaz, Protech, Koni, Bilstein. He has a business rebuilding vintage shocks. With Japanese shocks, he has no problem using seals etc from European brands, because the Japanese kept to recognised standards. He tried rebuilding some Chinese shocks (90% of them come from a white label factory, Bor Chuann, in Taiwan). No can do, nothing fitted.

The Puredrives came with English made springs. Flakey paint after 17 years, but quality steel. I had Meister Zeta Pros on another car; the springs didn’t last all that long before cracking right through at the top.

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Soften them up and see how you go.

Seller never told me any of the info. And, as a total newbie, I didn’t think to ask.

Here’s a picture. As far as I’m aware, they are exactly what you’d get if you were to buy them brand new off of the GAZ website. Or at least they look that way.

I’m softening the dampers today as I’m pretty sure it isn’t helping so I’m going to slowly backtrack. After that, I’ll leave it until next weekend when it gets aligned and see if the me habit I take it to is kind enough to go with me on a road test or something.

Sucks that all the friends I have are either taking the ■■■■ or pretending to know how to do it when they know sweet FA.

P.S. While I have the ability to jack the car up at home, I don’t have the space or tools to take the suspension apart. Yes I did it myself, but I rented the ramp at the garage I go to.
So every time I take the suspension off etc. it costs me £200.

Could be an expensive lesson but i hope you get some success. Ive used this company in the past and they have been ok.

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It might be worth taking the car up to Roddisons Motor Sport in Sheffield (not far from you). He should be able to help you as he has extensive knowledge of suspension setups on MX5s.

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I have been following this thread hoping to get a better idea what @ohhiitsmike meant by “bouncy”.

Do you mean that it carries on moving up and down after hitting a bump, or that initial effect of the bump feels too much of an impact?

The softest version of the GAZ Gold pro at 350/250 lbs per inch is similar to the Meisterr Sportive that I have at 336/280 lbs/in (6/5 kg/mm), and these are quite stiff when hitting bumps but totally controllable when hitting sleeping policeman at excessive speeds. The fixed damping is a good compromise with a small amount of bump rebound. The stiffer GAZ gold pro springs could be more difficult on UK roads

However, the rear does lack sufficient travel in the lowered state and bottoms out on aforementioned SPs but it doesn’t cause control problems.

Damping should be adjusted to get that slight bounce, which can be checked when stationary, lower means a repeated-bouncing front end, higher will increase the feeling of impact and lead to a slow return to full extension.

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I believe it is advisable to have alignment done with the final ride height.