I’m looking for technical help or recommendations on: __Poly vs Rubber bushings or a mixture?
Hi folks, first post so be gentle
I’ve had an alignment to the Flyin’ Miata specs done today and they found that one of the bushings on the FOS was spinning and preventing the camber from being adjusted properly. They’ve evened things up and it drives ok but it’s nowhere near the suggested figure.
Since I’m having to replace one bushing before they can re-align it, it seems to make sense to look into replacing all of them as they’re going to be wearing, and doing so will help tighten my car up a little
My question is Poly or Rubber all round or a mixture (and if a mixture which to replace with poly and which to leave as rubber?)
Use case is a weekend toy. It’s an auto so never going to be a track weapon. As I fettle it over the coming years I’m looking for an OE+ outcome and don’t wish to lose the “Sprightly GT” feel in favour of a bone shaker
I’m leaning towards rubber as I have poly in my Jeep and they drive me nuts with the noise. But I’m open to suggestions if there’s a combination that will help tighten things up yet still retain a comfortable ride
I’m very much a beginner in this space so any suggestions are welcome
Cheers
Dave
I would say rubber going off how you use the car.
No point making it more uncomfortable by adding in vibration and spoiling the ride if you dont intend doing track days.
Regards
Rob.
Auto and weekend toy I’d go rubber all round. Recently done rubber all round on my 20 something year old NBFL which I drive 18k miles a year and it drives like it just came out of the show room. Do you need any more than that ?
I had some Poly Bushes (from a very well known maker) on my road/occasional track car (Not my MX-5) in the end I took them off and went back to OEM because they squeaked too much which did my nut in.
Yeah, the ones on my Jeep drive me insane with the noise. That’s part of the reason I was leaning towards rubber. Interesting to hear you’ve gone back to rubber as a result.
I’ll have to bite the bullet at some time too. I think it’s all about the lubrication. I cut and pasted this quote for future reference off someone who used poly bushes on various cars which squeaked…
“I now use SuperPro, which seems to be polyether based, and have no such issues. They supplied a teflon based grease with the ones I bought”
I’ve got superpro poly bushes in my NC and they’re absolutely fine, there’s no noticable increase in NVH, they don’t squeak and the car feels a lot better for having them fitted.
Definitely one of the best mods I’ve done to the car IMO.
Yeah I get you on that. I’m looking for tightness and poise in handling but at the same time not wanting to introduce too much of the vagaries British roads give us, leading to my fillings working loose
I took it out for a good run round the Peak District on Friday after the alignment was done, and even though it’s not dialed in correctly the handling has been massively improved by the Flyin’ Miata alignment. The rear (which was done to spec) feels like it’s glued to the road now and I’ve got way more confidence chucking it through the corners. Just need to get the front sorted as it’s still lacking a little.
I have a full upgrade path worked out with bracing and anti-roll bars first but wanted to drive it for a full year before doing any real work on it (bar the alignment and a mild Versatuner remap to open up the bottom end torque) I would have come to the bushings in time but my hand has been forced by not being able to complete the alignment properly.
It’s a very kind offer Gary. Maybe a ride out would be good but I’m stuck driving an auto these days due to some mobility issues (gutted tbh I’d have loved a manual, but it’s no big deal, I’ve still got an MX5!) If anyone with an auto and poly’s is reading and wants to offer a spin I’d be very grateful.
Just to add to this - the vast majority of polybushes are made from a hard plastic-type material and, crucially, not made correctly.
As far as I know, ALL poly that isn’t Superpro should be avoided like the plague. There is a video demonstrating why the non-SP ones are pretty much universally bad as they’re nearly all like this as far as I know:
The design of most of them don’t use a proper “squishy” material, they don’t fit the same as the OEM ones, they stick out too far and they don’t hold any grease. It’s common to see the suspension arms stick like this within weeks of installing the “cheap” ones. I think the full Superpro kit for our cars is ~£600 in some places, with the very cheapest full kits being about £400? SO not worth it to go back in there again, and why compromise here of all places?
If done right with SP there should be a NVH decrease. And possibly lifetime warranty?
SP also have a cool offset kit (think they’re all a little stiffer though - maybe just buy the stiffer offset and the rest standard for a cruiser?) that allows for additional alignment adjustments past factory specs.
Anecdotally, my dad bought some Powerflex brand bushes back in the 2000s for his Legacy estate that also had these cool offset pins - and they broke while being installed. I think he eventually had them put in but they were held in by being mounted and were now in more bits than intended!
He said they made the NVH worse.
I have the full “Energy Suspension” kit on my NC1.
All of my wishbones & links are as free as the SP demo he does.
Been in about a year now - no squeaking from them at all.
Glad to hear. I know that proper install will make a huge difference. I’ve also seen speculation that the black colour ones may have graphite in them as a dry lubricant?
I’d just be worried about QC consistency and long-term longevity with anything less than “the best” with bushes. It’s such a job to do them all (I think I will start later this year with my new 4.1 diff ) that I won’t look anywhere else, personally - but I am insanely picky with things like this.
I do know that they won’t have the ride comfort or stability on rough roads that the SP will - on track they will probably be better.
By all means - if you’re happy, then it’s a good install. Maybe I’d even be happy with them - my car isn’t great on NVH as it’s on 155,000mi rubber bushes and does skip around corners a lot. The cheapest polybushes will likely be better if they aren’t total crap. I just would love to do all SP ones and get it for a first drive (will also DIY align it as I’ll get some tools to measure) and think “yeah. this is it” - more stability and comfort.
I had super pro in mine along with miester coil overs fast road/ track. NC2 No issues at all , but as adjustable obviously helps but no NVM from bushes.
Appreciate the replies.
In the end I’ve gone with the Autoexe rubber bushings (waiting for them to be delivered) via Rev9
They average out at roughly 30% stiffer than oem, but are tuned for the particular position so vary between 109% and 146% according to what’s actually required whilst still retaining a comfortable ride quality and decent NVH. Should firm things up but not be as hard as poly. They advertise as “more than a sportscar, but not quite race car” which is exactly what I’m looking for.
Comes in around the same price as a full set of SP poly’s (maybe a touch over), although I do lose out on the lifetime warranty. I also had my eyes on a particular front strut brace from Rev9 anyway with an integrated master cylinder brace, so I told myself it was a good excuse to pull the trigger on both
They will replace everything apart from the spherical bushings so ordered a set of them from Performance Bushes.
Lastly, I’ve got new front arms so I can replace the ball joints, plus new tie rod ends, anti-roll bar links, and alignment bolts
Basically, everything to do a full overhaul of stuff related to the suspension and alignment that can wear out over time, apart from the anti-roll bar mounts which I’ll replace when I do the bars next year.
Once fitted I’m going to get booked in at Roddisons in Sheffield and get a proper alignment done.
I’ll report back after I’ve had a few runs out
) that I won’t look anywhere else, personally - but I am insanely picky with things like this.