Spring Rates - Why I went M030 + H&R

With the track season upon us it sounds like a lot of us are researching suspension options right now. I thought I'd provide some direct feedback and some of my research regarding why I ended up with a much more basic setup than I intended. Initially, I was going to go with the Ohlins Road & Track system. I have driven BMWs with their setup and its absolutely fantastic. Their dampening technology is superb and the adjustability is painless. To make sure I had explored every option before dishing out $3k, I started researching the valving of the various OEM struts and the spring rates of all of the different manufacturers. Many phone calls later, here's the mostly confirmed and estimated spring rates of the various options for 996s: When comparing each side by side, you can come to your own conclusions on where the right rates are but for me somewhere near the 400/800 mark seemed appropriate. Typically stock struts are not usually valved for the shorter springs and will blow out due to excessive travel/compression, however I was able to find a cheap set of ROW M030 struts in my area as an inexpensive test before committing most of my budget to coil overs. The ROW M030s differ from the US and C4S Touring as they have slightly firmer valving and by strut length are better suited for the 0.5-1" drop. I was able to source a full set of front and rear struts for only $300 shipped and decided to give them a shot. After about a week, they arrived and I installed them with H&R Springs for Turbo's (340F/800R) as a low cost test to see how they'd work out. First Problem: Camber and Toe. The car had to be aligned properly which was not possible with stock adjustments. Ordered a set of rear dogbones, toelinks and front tie rods. I would recommend anyone that is planning on lowering their car to do the same as it would have been much easier to install these at the same time then to have to come back to it later and wait for parts to arrive. Second Problem: The actual alignment. I went to reputable shop and was charged slightly extra for the amount of additional time it took to get the car within spec. I went with the GT2 numbers and they nailed them perfectly. Camber: -1 Front/-2 Rear. Road Testing The very next day (after completing some light maintenance that night) I drove from Seattle to San Francisco and back. 1800 miles down on I5 and H101. Road Testing The day after I got back from San Francisco, I went to a PCA Track day. Result: Two huge thumbs up. Why? 1. Function: When combined with the adjustable Eibach sway bars, adj. dogbones and toelinks, this setup performs really well on the road and track. For the road trip I left both the front and rear sway bars set to the neutral setting. For the track I set both to firm. Between the two, the car handled every bump and pothole SF could dish out while keeping the car perfectly balanced and planted on the track. Zero complaints. 2. Performance: On the track, this setup had me outdriving my street tires (and giving me thoughts about slicks with the extra dough) while putting up consistent lap times within a few seconds of each other depending on traffic pace. I have no doubt that the Ohlins I wanted would absorb/dampen more and it would be nice to be able to adjust rigidity for the track but I seriously couldn't be happier with this setup for the price. The biggest question thats tough for me to answer is "Do I think I would be lapping any faster, or at least enough to justify the additional amount spent if I had purchased Ohlins?" To be honest, I really can't imagine I would be in comparison to this. I saved nearly $2500 which will now go towards other necessary items such as IMS retrofit, track time, and more. 3. Price: I was able to get all 4 M030 struts for $300. The springs were $350. For a fraction of the price of most coil over systems, I got nearly the exact handling and ride I wanted for daily driving and track. 4. Form: The car settled at around 1.25" dropped on all 4 corners and looks stunning. https://www.youtube.com/watch?v=Lm3_B1oja3g https://www.youtube.com/watch?v=XiC5KPmMOfE

Interesting that the stock M030 Bilstiens were capable of controlling nearly 3X the spring rate of a M030 Euro Sport spring. (170 F / 260 R)

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X2 I'm not sure if he had new shocks. Non-monotube shocks tend to fall off in dampening over time in a linear fashion so this optimal ride could just be short lived. I guess we shall see. Best setup IMO for a primary street car on this car specifically is to be over damped and undersprung imo(aka gt3 setup) with larger sway bars. I feel you can get most of the performance this way while still maintaining street civility.

The old C4S shocks were blown in the front and worn out in the rear so anything really would have been an improvement. We'll see how long these last. I didn't expect it to handle quite this well on the track while still work on the street. I'm hoping on they'll make it through one track season but who knows. Suspension -ROW M030 Struts -H&R Lowering Springs -Adjustable Toe Links -Adjustable Rear Dogbones -New Tie Rods -Eibach Sway Bars F/R -Custom Sway Bar Endlinks -Alignment (-1 Camber Front/-2 Rear) Brakes -EBC Pads Front Yellows/Rear Reds -Zimmerman Rotors F/R -SuperGold Fluid

Welp. Now I'm a complete walking contradiction. Found some KW V3s for the C4S at less than half price:

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LOL, I'm gonna expect you to report back after your next track event evangelizing how your old setup was crap compared to this.

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I expect the old butt dyno to be pretty happy about this pick up at the next DE.

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vandersmith, Could you share which brand of toe links and dog bones you bought? Thanks! Mike

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Torque Solutions off ebay - work great!