- My model of MX-5 is: __NA 1990
- I’m based near: __Amleria (Spain)
- I’m looking for technical help or recommendations on: __ Question; i have Eibach lowering springs fitted on my NA and found the ride a bit “bumpy” on the oem shocks. What would be my best option to improve comfort; buy adapted shocks or go for a coilover set. First option is also my first choice (as i have the springs already fitted) it is for regular use, no track just occasional “dynamic” driving and the actual ride height (with Eibach springs) suits me so no need for adjustability .Dampers would cost me 60-100 eur each and a Vmaxx coilover set is about (410 eur).
The bumpy ride is due to two reasons:
- The Eibach springs are stiffer than standard.
- The Eibach springs lower the car, reducing shock travel. What is happening is that the rear shocks are spending more time hitting the bump stops.
You can get upgraded shocks like the KYB AGX, so you can better match the shock rebound rate to the spring. But you will still be riding on the stops. KYB (Kayaba) did do a series of shocks called Gearclimb, which had shortened bodies, so giving you more travel. I’m not sure these are available anymore, and the cost was monstrous.
Jass do extended top mounts; not exactly an original idea, as I think Nipro was doing this 25 years ago;
Obviously not TUV approved, if that matters in Spain.
A Dutch company doing something similar, and a little less gash looking, but more expensive,
With these, you are only replacing the rears. I’d imagine these would interfere with the spare wheel location.
Unless the Jass pieces have some options, the BC Racing its, allowing 30mm of travel, would seem to match better the Eibachs, which are a nominal 30mm drop.
Flyin’ Miata also sold these. Lots of threads on the topic on Miata forum, eg Keith Tanner of FM chipping in here:
https://forum.miata.net/vb/showthread.php?t=475500
Top mounts is probably the low cost way. Some will say a complete new adjustable coilover kit. I would go with essentially upgrading the NA to NB standard. The NB addressed shock travel with different top mounts. This is what Mazda did in about 2005, when they (Mazdaspeed) did a limited run of I suppose what is now called restomd NA MX5s (they fitted NA 1.6s with all new NB suspension hardware). Those on all standard NB gear looked like they were riding a little high, I suppose because of the lower NA kerb weight. NB lowering springs though would work really nicely, in giving a car with a decent stance, but nice roadhandling manners.
Since 2008, my 1996 car has been on Protech shocks (adjustables), combined with pigtail springs from Performance 5, and NB tp mounts with a cut down PU bumpstop. I’ve done about 100k kms on these, and very happy with the ride quality. These springs have a diameter matched to the NB top mount at the top, but narrow to match the Protech spring perch at the bottom. The Protechs have an aluminium body, so maintain the low unsprung weight. Protechs still supply these shocks, but with a conventional spring and their own top mount.
Thanks, usefull info and yes ITV (Spanish MOT) is very severe so it has to be an “approved” solution.
As one who registered his Eunos in Spain about 25 years ago, I concur with your comments re the ITV, I prefer it to the MOT though..
But they are OK with lowering springs? How do they know you have changed the rear top mounts from one black set to another black set? “Eibach” on your springs would be a giveaway, but I suppose you had a plan for that.
ILM also sell the Mahura part for cars with the NB suspension
Aftermarket
Factory part
A Spanish ITV inspector is never going to know the difference. Well, if he knows his NA MX-5 ride heights, he’ll already know the car is modified without taking a look at any suspension parts.
Don’t think they ever changed the top mounts at all…..Eibach was an original Mazda accesoires supplier and i have the TUV-approval papers if needed. But so far nobody made a story of it. Both (NA and NC are on Eibach’s. The NC just passed ITV for the second time next week its the NA’s turn but they might be a bit more comliant obn this one as i am going to make it “historic”….