Which suspension mods make the ride harsh?

[scz4]

I would appreciate your advice on the following concern\dilema for my M3 Evo.

I really want to improve the handling of the M3, but I am so so worried about creating a car where the ride is very harsh, like another example I was in a month ago. Normally I would try each upgrade individually, but I am working in Norway just now and I only have 3 days to sort the car out before I start my 4000+ mile trip across Europe, inc a stop off at the 'Ring. 4000 miles with a harsh ride is not going to be fun, even less so for my passengers bouncing up and down, it'll also be very tiring. The ride quality just now is perfect for a long journey compared to my Z4, it just doesn't go round corners

So far I have bought the following kit ready to fit:
Eibach Pro Street Coilover Kit
Eibach Anti Roll Bar Kit
Powerflex Rear Trailing arm bushes
Powerflex front Lower Wishbone bushes

Option 1
Fit Everything

Option 2
Eibach Coilover kit, ARB kit and standard BMW bushes

Option 3
Buy Eibach lower springs, ARB Kit, Powerflex Bushes

Option 4
Buy Eibach lower springs, ARB Kit, Standard Bushes

Option 5
Eibach Coilover kit, Standard BMW bushes, No ARB kit.

Option 6
Eibach Coilover kit, Powerflex bushes, No ARB kit.

What do you guys think?

[dan101smith]

Assuming you're coming from standard setup, you'll notice an increase in harshness from fitting the coilovers and the bushes.

I've not tried those coilovers - mine is on Intrax with a big drop, and although fairly harsh, it doesn't really bother me on long otorway trips - but apparently poly bushes have a big impact on refinement. For that reason, I've not bothered with Powerflex, instead using OEM replacements, and would continue to do so.

Are you going to deck the car on the coilovers? If you leave plenty of suspension travel for normal use, then it ought to be fine.

[scz4]

dan101smith said:

Assuming you're coming from standard setup, you'll notice an increase in harshness from fitting the coilovers and the bushes.

I've not tried those coilovers - mine is on Intrax with a big drop, and although fairly harsh, it doesn't really bother me on long otorway trips - but apparently poly bushes have a big impact on refinement. For that reason, I've not bothered with Powerflex, instead using OEM replacements, and would continue to do so.

Are you going to deck the car on the coilovers? If you leave plenty of suspension travel for normal use, then it ought to be fine.

Thanks for that. No don't plan on decking it at all, in fact almost running it as high as it'll go. I am concerned I'll need spacers if I deck it.

[dan101smith]

Again, I only have experience of Intrax kit, but with that it matters not whether it's wound up or down, mine still needs front spacers. Perhaps the Eibach stuff is different though.

[Frik]

Describe what you mean by harshness.

Big jolts or general transfer of road surface generated vibrations for instance.

[scz4]

Frik said:

Describe what you mean by harshness.

Big jolts or general transfer of road surface generated vibrations for instance.

That's a hard one... I guess I mean tramlining, feeling every little defect in the road, car jumping about when changing surfaces with no give in the suspension to absorb smaller bumps.

The ride with my Z4 on run flat tyres was pretty much unacceptable to me, for day to day driving like the M3 will be used for. I changed to non run flats but still have the M Sport suspension which is great. My Westfield was very solid, but to be expecteded in that type of car.

[clabcon]

I have that exact setup you described, along with an underchassis X-brace from the M3 GT, adjustable rear camber arms and a few other suspension mods. It handles like a dream, much better than the shagged out suspension thats inherent with the age/miles of 90% of E36 M3's out there.

To be fair the smoothness of a suspension thats in full working order more than compensates for the slight increase in stiffness and dramatically improved handling of such a quality aftermarket kit.

P.S. Eibach alu 10mm prospacers are much better than the 15mm steel ones I had before!!