Suspension: What to do?

[m3f_drtwofish]

On the question of the Dinan stage 1 set up I have some personal experience. I have a 94 M3 and have the Dinan springs and shocks set to the recommended specs. They are generally matched at the vendor and supplied preadjusted. The car also has Vorshlag camber plates, poly FCA bushing and turner aluminium control arms at the back. Camber is about -2.5 in front and - 1.6 in the rear. With Z3 steering rack turn in is fierce. On this combo it rides better than a stock e46M but has far more front impact harshness. Does just fine on the street and on the track. It does not chew up the front tires on the track but does have more inside wear on the front tires even with zero toe on the street.

Interesting, thanks. Did you mean to say that it has more harshness? I'm guessing the poly bushings probably contribute to that too, though.

[m3f_EricSMG]

Interesting, thanks. Did you mean to say that it has more harshness? I'm guessing the poly bushings probably contribute to that too, though.

That and I've found that a race plate like vorshlag increases harshness considerably. Avoid this type of plate if you're looking for maximum refinement.



The OE strut mounts are great with mild camber washers/bolts.

[m3f_drtwofish]

BTW, looks like I linked the wrong setup for '96 and later cars - this is the correct one and is cheaper yet. Really seems like a decent deal if the Dinan springs compare favorably to H&R etc.

[m3f_scoobiedoo2029]

I'm curious as well, haven't tried it. That said, the dinan front springs are no stiffer than stock according to vorshlags site so I'd be concerned with too low/too soft, potentially. My friend SG_M3 tried this, I'll see if I can find his notes.



Oh - I'm almost certain you still have to cut your struts as koni doesn't make a complete unit for this car. But that's a cake walk.

I didnt have any issue with the dinan setup, it was stiffer then stock and oem shocks, but not by much, the rear is noticeably stiffer though. i really liked the dinan setup, id still be running it if i was still dd'ing the m3. i highly recommend, its the least compromising of all options.



i had dinan stickerd strut housings, was a used setup though.

[m3f_EricSMG]

I didnt have any issue with the dinan setup, it was stiffer then stock and oem shocks, but not by much, the rear is noticeably stiffer though. i really liked the dinan setup, id still be running it if i was still dd'ing the m3. i highly recommend, its the least compromising of all options.



i had dinan stickerd strut housings, was a used setup though.

Sounds about right - Dinan puts all the extra rate out back (which I prefer).



Do you recall the approximate change in ride height front and rear?

[m3f_Radmobile]

I ran that setup years ago on my Estoril sedan and liked it quite a bit. But I was younger and more tolerant so I'm not sure if I'd like it today. I remember it handling extremely good, though. A little trim of the front bumps would help in this case as the Billy sports are travel limited. But I would not attempt this without a thorough analysis of travel limits, etc.

I can see that. Certain roads in SD can be brutal at times. I'm early 30s, and while it's my daily, I work from home so don't need to worry about a commute. So I think that makes it more pleasant than it may be to others.

[m3f_scoobiedoo2029]

Sounds about right - Dinan puts all the extra rate out back (which I prefer).



Do you recall the approximate change in ride height front and rear?

i have measurements somewhere i cant find atm. i set my coils to the same heights. it has a a decent bit of front rake, the rear is not very much lower



best pic i have on stock wheels. ground is relatively flat in front of my garage.

[m3f_SG_M3]

I've run a lot of setups, pretty much everything being discussed in this thread. Here are my quick thoughts.


Level set: 33 year old driver, NVH and ride quality are my pet peevs. I'm very picky, Eric picky, on these two things.


Koni + OE Sports - Surprisingly stiff, feels ok, but for the ride height its a bit annoying.


Koni + Dinan - Linear in rate, because of that it bobbles the chassis at low speeds. Rear ride height is too low compared to the front, that is annoying.


Koni + Eibach pro kit + GC Street Plates - this is the big winner thus far. The camber plates give that little bit more bump travel needed with lower the front this much. Rates are really well matched for road use, ride height is spot on.


TCK 300/400 - Its a great setup, but the linear springs can make the chassis annoying at certain speeds. Its very close to being perfect, but is let down by the damper/linear rate springs.

[m3f_aeronaut]

Interesting, the HR OE rear springs are a lower/softer rate than the EIbach Pro rear springs.


I'm not convinced the progressive springs that are available are better due to their progressive rate. Anyone got a picture of a Eibach Pro or HR progressive spring installed and under load? I'm *guessing* the progressive portion of the rate is taken up in preload.


I'm thinking the progressives feel softer mainly because all the progressives available ARE a softer/lower rate? Thoughts?

[m3f_tripitz]

Why not focus on putting in a high quality damper like an MCS 1-way with lower spring rates? Ride quality will be amazingly impacted by the quality of the damper. Spring rates are easy to change.

[m3f_aeronaut]

Throwing $2700 worth of dampers (plus springs, plates, etc) on a $12k car isn't for everyone. IMO, the MCS are overkill for most street applications.

[m3f_twentyseven]

Why not focus on putting in a high quality damper like an MCS 1-way with lower spring rates? Ride quality will be amazingly impacted by the quality of the damper. Spring rates are easy to change.

Clearly you're new here. lol



Ride quality will not be "amazingly impacted" with MCS, JRZ, etc.

[m3f_tripitz]

Clearly you're new here. lol


Ride quality will not be "amazingly impacted" with MCS, JRZ, etc.

The job of a damper is to control motion; higher quality ones do a better job than most of the lower/mid tier ones described here. You can run much higher spring rates precisely because those better dampers can do a better job managing motion. Conversely, even with lower spring rates, they do a much better job than their cheaper counterparts.


I do agree that putting expensive stuff on an inexpensive car may be crazy as to the other post. There was no mention of budget anywhere though...

[m3f_Bimmerman325i]

Similarly picky driver here. Have all refreshed stock on my sedan, have MCS DA on the coupe. The coupe sucks to drive on the street, even with spring rates aimed to be a compromise at street manners when not on the track. Since it's not my daily, I put up with it, but it's not very pleasant to drive 99% of the time. On track or autocrossing the MCSs are fantastic, but do you really do that frequently enough to hate driving the car to Safeway, or to apologize to passengers for their discomfort?



I've been looking at changing from all OEM on the sedan to something else, but have not found anything that will improve the ride quality and decrease the NVH, without losing the sporty character of the car.



I've used TCK, AST, MCS, and have plenty of street/track/autocross experience in other cars with TCK, AST, PSS9, Moton, and JRZ. What I've learned is that the fancy dampers are great when being used for autox/track but have consistently underwhelming and frankly disappointing street manners. I once had a set of Koni + LTW springs that I sold before I knew better, that would have been an awesome setup now.

[m3f_EricSMG]

The job of a damper is to control motion; higher quality ones do a better job than most of the lower/mid tier ones described here. You can run much higher spring rates precisely because those better dampers can do a better job managing motion. Conversely, even with lower spring rates, they do a much better job than their cheaper counterparts.



I do agree that putting expensive stuff on an inexpensive car may be crazy as to the other post. There was no mention of budget anywhere though...

Unfortunately, it doesn't work that way. High quality doesn't mean "good at everything".



With few exceptions, racing stuff sucks on the street. The quality might be there but the 'tuning' is wrong.



Further, spring rate has a HUGE affect on street compliance and comfort, contrary to the common misconception.