Suggestions for Dual-Purposed Coilovers for Tracking and Spirited Driving

[bimmerfan08]

Hi, everyone. I did a brief search but figured I'd ask outright. I've had my E46 M3 for 13 years and used to frequent the old forum (M3forum) more from those who know me. My M3 currently has TCK S/A coilovers that need to be refreshed soon. I am considering replacing the shocks or going with a different set of coilovers. Here's some info to help scope the discussion.

Current setup:

• TC Kline S/A coilovers
• 600# front springs
• 700# rear springs
• Stock sway bars

Other factors for consideration:

• I like the current ride stiffness - the spring rates aren't too aggressive for me, yet
• I want the suspension to maintain some level of civility to it so the car can be street-driven
• 18" wheels
• Michelin PS4s for street and some track
• Budget for new coilovers/suspension refresh: $2k-$3.5k (will consider slightly above the upper threshold if there's an exponential gain to be had)
• FCABs, tie rods, suspension bushings, control arms, etc., have all been replaced in the last few years
• The car is driven predominately on track and for spirited drives - about 50/50, with annual mileage averaging ~2k miles
  • To put things into perspective, I haven't driven the car since tracking at VIR last November

What are the latest coilover options out there that meet these criteria? Thanks for the suggestions!

[jvit27]

1) Why do your S/A's need to be replaced? If they are blown and you are the original owner there is a warranty.
2) What is it you want out of a setup that the car is currently not doing?

[Slideways]

Warranty or get a quote for rebuilding the dampers before buying a new setup. To gain some comfort back, the front spring rate can be softened and a stiffer sway bar can be added. The flat ride PDF should give you an idea of which spring rates and sway bar would be best with that 700lb rear spring.

[Tbonem3]

Cut the fonrt spring rate almost in half - 350lb, but with 60mm ID, easier to get a 6k (336lb) or 60N/mm (343lb) spring in 7". Increase front bar setting or get aftermarket front bar. Konis are probably fine, can slow the rebound down further to make up for their age. Or Call TCK, though he's not a member of the flat ride cult I don't think.

[usdmej]

Hi, everyone. I did a brief search but figured I'd ask outright. I've had my E46 M3 for 13 years and used to frequent the old forum (M3forum) more from those who know me. My M3 currently has TCK S/A coilovers that need to be refreshed soon. I am considering replacing the shocks or going with a different set of coilovers. Here's some info to help scope the discussion.

Current setup:[LIST][*]TC Kline S/A coilovers[*]600# front springs[*]700# rear springs[*]I like the current ride stiffness - the spring rates aren't too aggressive for me, yet

i'm currently at 400/600# on my TCK setup, previously ran 500/600# and with r-compound tires was not happy with the ride quality, i cant imagine how brutal 600/700 is but, if you think that's liveable, the most cost efficient way to go about it is just refresh the dampers and stick with what you're running.

flat ride will most likely feel way too soft for you

[cobra]

I would drop to a 450 front spring and leave the 700 rear.

Konis are not what I would consider a performance option so I don't blame you for switching it up.

Look into the KW V3, Bilsten PSS10, and MCS 1WNR. Each has pros/cons.

[Ramps]

I have TCK DA running 400/500lb springs. It’s a good balance of tightness and smooth ride as long as roads aren’t awful. I have Vorshlag plates up front which to transfer a lot more harshness, I think a street plate might make the setup perfect. I’ve considered dropping to 350 front springs but i wanna try the street plates first.

Also consider your tire, 18s obviously offer better ride than 19s but even the brand makes a huge difference.

[Tbonem3]

I have TCK DA running 400/500lb springs. It’s a good balance of tightness and smooth ride as long as roads aren’t awful. I have Vorshlag plates up front which to transfer a lot more harshness, I think a street plate might make the setup perfect. I’ve considered dropping to 350 front springs but i wanna try the street plates first.

Also consider your tire, 18s obviously offer better ride than 19s but even the brand makes a huge difference.

First thing you should do is up the rear rates. Even stock goes up to 685lb.

[IamFODI]

Öhlins.

Can buy from FCP Euro and end up with a ton of store credit if you ever have to buy a new set down the line.

Or you can buy from 3DM Motorsport and get excellent support from people who work closely with Öhlins USA and know this platform well.

[Pklauser]

I am oooooh so close to buying the Ohlins from FCP for my dual-purpose car.

[bigjae46]

I think the TCKs are the best dual purpose coil over out there. Drop your front rate.

My track car with 450/700 springs rides better than my E90 M3 on stock non-EDC shocks and dinan springs.

First thing you should do is up the rear rates. Even stock goes up to 685lb.

Can the singles go that high? But 350/700 would be flat ride. I had to increase the fronts 450 to prevent the splitter from scraping.

[Ramps]

First thing you should do is up the rear rates. Even stock goes up to 685lb.

Increase the rear rates for more comfort?? That sounds counterproductive, or do you mean for better track handling? I feel like the back rides great and it’s the front that a little too harsh.

[Tbonem3]

I was responding to RAMPS who has the d/a, I would assume they can handle up to 700lbs, at least if you slow the rebound down considerably.

In my experience, every off the shelf option like bilstein b6 or koni yellow (even slowed down) struggles with that high of a rate - always seemed like 550-600 was it in the rear and like 300 up front.

[Tbonem3]

Increase the rear rates for more comfort?? That sounds counterproductive, or do you mean for better track handling? I feel like the back rides great and it’s the front that a little too harsh.

I know, it's funny, but we've done a big circle in terms of suspension tuning philosophy at the enthusiast level, back to the same, basically, ratios as stock (stock is 143lb/385-685lb). Compliance/soft = fast (not upsetting/smooth) & roll = grip. To a degree ofc, and depends on driving usage/speed. In my sport of motocross, you didn't just pick spring rate based on body weight, you increased it based on your speed (beg, novice, inter, exp, increasingly)

I would also say to lower your front a bit based on my persoanl and some friends' experiences (esp if you have a bigger front bar), but increasing the rear is key to keeping up with the front - due to its location inboard (effective wheel rate is different than spring rate).

As far as harshness, for me, that comes much more down to your materials - is the front mount's material rubber, poly, solid? Are you using some rubber isolation like ohlins gives with their rear perches or just spring on metal like Ground control?

I went from 550lb ground control to 628lb ohlins and it's more comfortable! But more importantly, the car feels better from more closely matched ratio, more predictable, doesn't bottom out on big dips (scrape). I always loved how 550lb felt in regular driving, but it never kept up at speed, no matter what damper settings I chose (MCS 1w), and the car was pitching oddly due to stiff front (400lb at first, then I went to 343). I also had too much understeer when I went up to 400lb up front with medium sway setting, but it feels better now at 343lb.

[Ramps]

I know, it's funny, but we've done a big circle in terms of suspension tuning philosophy at the enthusiast level, back to the same, basically, ratios as stock (stock is 143lb/385-685lb). Compliance/soft = fast (not upsetting/smooth) & roll = grip. To a degree ofc, and depends on driving usage/speed. In my sport of motocross, you didn't just pick spring rate based on body weight, you increased it based on your speed (beg, novice, inter, exp, increasingly)

I would also say to lower your front a bit based on my persoanl and some friends' experiences (esp if you have a bigger front bar), but increasing the rear is key to keeping up with the front - due to its location inboard (effective wheel rate is different than spring rate).

As far as harshness, for me, that comes much more down to your materials - is the front mount's material rubber, poly, solid? Are you using some rubber isolation like ohlins gives with their rear perches or just spring on metal like Ground control?

I went from 550lb ground control to 628lb ohlins and it's more comfortable! But more importantly, the car feels better from more closely matched ratio, more predictable, doesn't bottom out on big dips (scrape). I always loved how 550lb felt in regular driving, but it never kept up at speed, no matter what damper settings I chose (MCS 1w), and the car was pitching oddly due to stiff front (400lb at first, then I went to 343). I also had too much understeer when I went up to 400lb up front with medium sway setting, but it feels better now at 343lb.

Great input, thanks! Looks like I might need to get some other sets of springs to play around with rates. I can also try swapping the Vorshlag plates for some GC street plates, I think some of the harshness is coming from there. The Vorshlag plates are awesome, but I have some really bad roads in my area and I'm getting old and so I'm leaning more towards sporty street vs track setup these days.