If you plan to track, vinrem sir, go coilovers...they would have dampers built to match the significantly increased springrates on the likely linear springs they come w/. Expect a firmer ride as most coilovers have double the stock springrates. Height & dampening adjustability are a coilover advantage...Cost-wise, they are at least/around 4x the cost of springs. ...
On springs, not all are created equal. Again, the HTechs are of practically the same rates as stock. Linear rated up front & dual on rears to absorb bumps better. As comfy as stock, w/ a mild conservative drop & designed to work w/ stock struts. Should your stock dampers go, there are really good upgrades out there...Koni already has FSDs out for our Ms at around $500.
Which is the better product in general? Good, tried & tested coilovers...esp if you track. Bear in mind that like springs, not all are built alike....& a set of good springs will do you better than bad coilovers.
The wisdom here is to let budget & use dictate your choice. For daily street comfort?....HTechs will give you that, better handling & just the right drop for our roads w/o the cost.....bang for buck.....Ask Geo, Marc & The King....you'll likely hear this chorus: good as advertised.![]()
Its also a given that you also need to change to firmer bushes like PUs, reinforced suspension bits from stock parts. Hindi nagtatapos sa baklas at kabit ng springs at shocks. Also expect more frequent adjustments and visits to the shop for maintenance. Such is the price for looks and performance.
I concur.
I agree w/ Yatta & I understand why you seem to be overwhelmed, vinrem sir.
Been tweaking suspensions for ages. As adjustment options increase, so will a system's complexity....& we haven't touched on camber, caster, swaybar tuning yet.
On Polyurethane parts, true, they're more durable than your standard stock rubber bush, but comfort gets affected as the material's durometer increases. Not only that, PU requires periodic lubrication, otherwise, you'll hear all kinds of unpleasant noises. Besides, notable PU manufacturers, like Powerflex, have yet to come up w/ gen3 M3 upgrades, last I checked. They might still be in development & testing.
Should you opt for coilovers, you might need a good wrench or shop at your disposal for those frequent checks. Even that initial tune to chase that coilover sweetspot is a challenge to do in a few takes. Brand/make familiarity & experience are pluses here. Not all suspension shops know about every make & model. To cite a sample, I had to supply my trusted Hunter equipped alignment shop w/ M3 alignment specs for them to program.
Unless you're up for the adventure, learning curve, tweaking & maintenance, I'd suggest going the simple HTech route, vinrem sir. Way lesser things to worry about.![]()