Happy new year guys!!
Just picked up my first M-car (’01 M5, thread here
), so naturally I’m getting ready to let the wrenches fly. Gonna fix a few known items on my car and would love to upgrade the suspension as one of the first big projects.
After countless searches on the topic, I’ve found… stuff. Much of it is old and opinions vary on what the best setups are. I’ll leave the “what else should I replace while I’m in there” to other threads (like this one
), but thought I’d compile what I found out about coilovers & shock/spring combos specifically. I haven’t seen anything comprehensive for the E39 so this is my attempt. Would love it if others filled in any missing info and please correct anything that aint right!
– loves adjustability and firmness (because racecar). Doesn’t hurt that a budget coilover kit costs the same as shocks & springs. Some that daily their car or want a softer ride need to pop for a kit with adjustable damping and should carefully read reviews to find which kit will be the best choice, paying close attention to spring rates and damping adjustment range.
Spring & shock camp
– has SO/kids/parents/etc. that need to enjoy the car too. Commutes. Lives where roads suck. Doesn’t care about adjustability, wants to set it & forget it.
More about coilovers
- Adjustability – don’t like your ride height? Break out the spanner instead of redoing your entire suspension to get the look and/or driving dynamics you want
- Coilover kits can be had for the same price as or even less than aftermarket shock & spring setups (+/-$1k)
- ePeen (is that still a thing?)
Popular coilover kits
- Owners of some kits report a harsh ride. Depends entirely on your preference as many consider this to be a benefit.
- People seem to have higher failure rates with coilovers than nonadjustable shock & spring setups. Source 1, Source 2, Source 3, Source 4. Its most likely because…
- o Stiffer setups transmit more vibration & impact to suspension (and chassis) components. Shocks, springs and mounts all take more abuse.
- Shocks tend to blow faster because of the above and because of cheaper components used in some kits (hard to beat a Bilstein monotube).
- Coilovers are more complicated. Threaded sleeves can corrode, adjustment knobs can seize or stop working.
- Front inner tire clearance. Helper springs found on most kits require a spacer for even stock 245 width tires. One exception is Ground Control’s kit with notches cut out of the spring perches specifically to address this and allow up to 275 tires up front. Is this also true of the BC kit? I’ve heard yes but would like confirmation before adding it here.
- Some report clunking, rattles and popping. Source 1, Source 2 (Dinan Youtube vid). Some have improved these issues with roller bearings (See: Koyo bearings)
More about shocks & springs
- DGR ($850) - Height & damping adjustable, front camber plates included. Impressions & pics
- BC BR ($900) – Height & damping adjustable, front camber plates included. Giant BC thread
- ST X ($900) – height adjustable only. Similar to KW v1s, except they have a galvanized body (less corrosion resistant). Impressions & pics
- Bilstein PSS ($1,000) - height adjustable only. Pics / Impressions
- (NO LONGER AVAILABLE)Fortune Auto ($1,350) - Height & damping adjustable, front camber plates included. Pics & Impressions
- H&R ($1,500) – height adjustable only. There are two versions that are the same price, clubsport and street performance. Impressions & pics
- KW v1 ($1,700) – height adjustable only. Stainless body. Still looking for good threads & pics of KW setups since KW and V1/V2/V3 aren't searchable
- Ground Control ($1,900) – Height & damping adjustable (uses Koni shocks), camber plates included and four levels of spring rates & matched dampers are available. Impressions & pics
- Bilstein PSS9 ($2,000) – Some say… this is the kit to get if you like the stock suspension (full soft setting is a close match). The damping adjustment knob is on the bottom of the rear shock making for easy adjustments & fine tuning. Impressions & pics
- KW v2 ($2,200) – Height & damping adjustable. Impressions
- KW v3 ($2,800) – Primo gear with a primo price. Separately adjustable height, damping and rebound (3-way adjustable). Impressions
- Balanced ride – fairly easy to get a great ride that is stock or firmer and very streetable
- Cost effective
- The choice of discriminating old guys®
Popular shock & spring setups
- Not adjustable – you might have to experiment with different combinations of shocks & springs to get the ride height, road feel and handling you want (hint: do more research)
- Not cheap. Despite all the additional gear you get with coilovers, you have to pay nearly as much for 4 shocks & 4 springs.
- Not many options. Basically just the three below, besides a couple other spring options (Vogtland, Eibach).
- Stock springs & Bilstein B6 (HD) ($600) – Cheaper alternative to OE shocks. Impressions
- Intrax springs & Bilstein B8 ($950) – Springs need to be sourced from Evolve in the US. Impressions & pics / more pics
- Dinan springs & Koni adjustables ($1,000) – Impressions & pics
- OE ($1,200+) – for those that want BMW parts on their BMW, here’s a great thread by Tiauguinho: Install / pics
Q: What else do I need to buy to install with my new springs/shocks or coilovers?
It depends on the kit, but generally you will need to either buy or reuse top mounts. It’s a good idea to buy new replacements for any stock parts that have rubber bushings or bearings in them as they will wear over time. Any kit that includes front camber plates will not need top mounts as these replace the factory parts. Also remember to buy new lock nuts (if they’re not included with your kit) as they are one-time use only!
Q: I want to run a square wheel setup – 4 stock rear 18x9.5” wheels with 275/35-18 tires all around, or an aftermarket equivalent, without spacers. Which suspension options will work for me?
Ground Control coilovers. Remember to specify “Yes, add 3mm extra for fat tires” when ordering. I believe all spring/shock combos will work but this should be confirmed by someone with one of these setups first.
If you’re willing to run a 3mm or larger spacer in the front pretty much any kit will work without additional modification
Q: Which brands have the best customer service?
YMMV of course, but in the US at least I have heard positive reports about Bilstein, Fortune Auto and Ground Control. On the other end of the spectrum, KW requires you to send in faulty parts before they send replacements which for obvious reasons is a PITA. Oh and what a coincidence, I can’t find an official link to KW’s warranty terms or return policy for US customers, so I’ll link to this instead
. Link to KW UK returns page
, showing that you must send in faulty parts to be inspected before they’ll replace them. Link to Bilstein warranty info
. Link to Bilstein rebuilding and revalving services
…Is that it?