Ground Control spring rate question.

[Ihatecars]

So, I'm lookin into a Bilstein/Ground Control setup for my car. Would 375f 250r be "too soft" of springs ride comfortably as a daily, while still having performance benefits?

I'm going to upgrade my front sway bar to something like an FM or RB bar in the near future.

I've looked for some answers, but keep getting that the rates either too low or perfect. Nothing that breaks down way the rates are "good" for street driving in terms I understand.

Does anybody have an experience with a Bilstein/GC setup? Wanna tell me why you like what you have whilr we're at it? Wasabi? Etikoner?

P.s. I'm hectically typing this out on my phone so please forgive the poor structuring and the inevitable punctuation/grammar errors. Thanks.

[MX5RACER]

Depends on what your butt defines as street-able. If you really are looking for more handling performance, you need higher rates and better shocks. If it was me, I would just get a new set of Koni Yellow, sport shocks and save the money. Later down the line you can get the GC sleeves for the Koni's and get higher rates and have the front shocks revalved to race valving and get the magic 750f/450r springs and be done.

The factory springs are light, but not that much of a performance killer. You can gain time on a road course/autocross with the rates you are asking about, but for the money it would not be worth it.

Think about how much stiffer these are than the factory spring rates, if we assume that the difference in spring rate is a 1:1 ratio compared to time dropped on a 60 second autocross run how much lower per dollar are these rates vs the factory rates or the 750f/450r?

[etikoner]

Depends what model Bilstein damper you're going with??

IF NA HD's
Front dampers: 500-550 lb/in springs
Rear: 320-400lb/in springs.

NB Sports/ HD/ Hard-S
Front damper 375- 450 lb/in springs
Rear 275- 325 lb/in springs.

Front springs you'd want 6" and rear 6" or 7" depending on what top hats you wanna use.
I'd seriously consider a different set of coilover sleeves, other than GC. they're so damn expensive....

I have a set of NA HD damper sitting in my room that I wanna build together with 125$ 5xRacing sleevs that are pretty high quality... I just can't build them up right now bc I don't has funds... But like I've said many times, if you set the Spring rates high enough where you can combat the super high rebound Forces NA Hd's have, combine them with proper bump stops, and top hats (as well as keeping a nice Spring rate spread to work with your sway bars) and that'll pretty much out perform any sub $1200 coilover kit, and still get you low enough...

Just look at JoeyZ31, and Storman Normin's build threads on CR and you'll see what i'm talking about..

Also, KONI's suck dick. period.

[— Dandy —]

My set-up:

• Bilstein R-Package shocks
• Eibach Springs 400lbs front, 300lbs rear (7" front length and 8" rear length)
• Ground Control sleeves
• Ground Control spring locators/isolators
• Fatcat Motorsports shock mounts, MCU bushings, f36mm/r46mm bumpstops
• Racing Beat 28.575 mm - 1.25" wall tubular adjustable front sway bar
• Front sway bar urethane bushings & brackets
• Front sway bar brace hardware
• Mazdaspeed 14mm rear sway bar
• Rear sway bar urethane bushings
• 949 Racing - SuperMiata - front and rear adjustable end links

I don't have harsh roads or conditions to deal with.

[MX5RACER]

Also, KONI's suck dick. period.

Everyone is entitled to their own opinion, but yours is wrong... Lol.

I have raced on HD's, custom valved Bilstein's, Koni Yellows and Koni Race valved yellows. Koni's have always been faster for me on my cars.

[etikoner]

Pure Auto-x? Do you care about ride quality around town? Koni race is a different beast than the standard yellows, sure. But have you been 100% sure your yellows came matched from the factory? They are a quality damper, no doubt but *most* people who run them are for dedicated autox cars and don't care about ride quality.. Also, not many people can revalve them..

[radmachine]

I run bilstein hd and 550#, 375# daily and its fairly comfortable. I'm actually thinking of going up a bit on spring rate in the rear.

[HarryB]

Apologies for the thread resurrection, but I could use some feedback and this thread seems like the appropriate. So, after hijacking the "ultimate Miata suspension" thread a while back, I am still set on building a Bilstein coilover setup, and a "reality check" for my intended setup would be great. Note, I haven't measured anything on my car yet; would love to remove springs and do stock travel measurements, but since it is a daily, that's not a real option. So, until a volunteer comes up, I have accumulated as much knowledge as possible to work out some "arbitrary" numbers. If anyone has run sth similar, please chime in.

Since this is for my daily, 90% of the time it is b-roads or potholes, therefore I want sth relatively comfy. I also want it to sit moderately lower than stock, 12.5" would be the absolute lowest. I already have a set of Billies off of a JDM Type RS NB2 (same as HardS I believe). I am looking in using 375/275 Eibach springs in 8"/7" lengths, AllStar-style sleeves (with "captive" c-clip) and 1" extended top mounts at both ends, with stock NB2 bumpstops. Things I am still debating on are spring lengths and top hats "extension" length (might go 1.5").

By checking the block height of the Eibachs and doing some assumptions, I believe I will not end up with coil binding. Moreover, I also think that the lengths are enough for the springs to be seated without tenders/helpers under full droop. Any comments?

Of course, as mentioned, I would love to verify those ballpack numbers with exact calculations, but I lack the necessary measurements... When and if I have them, I will create a spreadsheet so to be easier to calculate such things.

[— kung fu jesus —]

If coil bind is a concern, look into using Swift springs.