Ground control coilovers/KYB AGX adjustable shocks

[7/22/2005] Reviewed by: Tim Langdon

Applicable to: '90 - '97 1.6 liter

Heavier than stock, ride height adjustable coilover springs with 8-position gas shocks.

set up perch height to 12.25" front/ 12.5" rear after reviewing Jamie Villacorte's very informative article on these products. Installation was pretty straightforward. Used stock bumpstops on my '92 M1. Set AGX's on '5' originally, but roads in Alaska too brutal, so settled into '3' which is smoother. Can crank 'em back up stiffer in a minute for more aggressive days.

Firm, predictable platform to push the MX-5 into what it was made to do. With heavier anti sways it allows for even flatter, precise turning at higher speeds. Noticed that it has the amazing ability to keep the tires in contact with the road even when hitting irregularities in the road surface while committed into a turn, whereas a stock setup would have sent the car skipping sideways. Pretty awesome. The GC coils and KYB AGX's are really a great match, and everything's adjustable.Been enjoying them for one year now. Great performance at a reasonable price!

Over 30 minutes to remove completely

Ground Conrol Coil Overs w/ KYB AGX shocks

[3/27/2004] Reviewed by: Noel Smart -

Applicable to: '99 +

Ground Control Coilovers and KYB AGX shocks for 99+

I have only had the setup installed for about 4 hours, but wow. The handling is sharp and predictable, even in the rain. I can control when the back end comes out in tight corners much better now, not to mention take the corners much faster. I expected a harsher ride, but with the KYB's set at 3 all around (settings 1-4 stiffness) the car actually takes bumps, potholes, and highway expansion joints BETTER than before. I am very pleased with the handling and look forward to the auto-x season this year.

Excellent. Worth every penny. Buy it for your auto-x Miata, buy it for your pleasure car. Either way it offers infinitely more than the stock setup, not to mention the added cosmetic touch of not having 3 inches of wheel to fender space.

Over 30 minutes to remove completely

Ground Control Coil-Overs

[11/19/2001] Reviewed by: Jaime Villacorte -

Applicable to: '90 - '97 1.6 liter 1.8 liter

Ground Control Coilover for KYB AGX shocks for M1 cars.

I've owned KYB AGX shocks for the last 2 years, and still have the OEM springs. The springs have sagged noticeably since new, perhaps as much as 1 inch. The resulting ride has been a little harsh and jarring at times. My goal with the GC Coilover was to use the adjustable spring perch to return to ride height back up to stock heights, but also to give better handling on occasional track days, in which a stiffer spring rate reduces body roll. I purchased the coilovers during from Flyin Miata and installed it over the course of the weekend. I'm happy with the fit and finish of the product, and very pleased that I can adjust the ride height. After I did the install, the ride height ended up slightly lower than stock. Yet the ride is a little less harsh than what I started it, and the handling is great. I'm in the process of increasing the ride height back to stock, and I'm sure the ride will get a lot more plush.

I have a complete writeup, including pictures, installation description, and comments on a web page. The link to this can be found in the Installations page of my Miata page: 

Over 30 minutes to remove completely

[6/22/2001] Reviewed by: Anonymous

Applicable to: '90 - '97

Ground Control Coil-over spring & damper package

I am happy with the product and am writing this review purely to highlight an installation detail: When installing the new top spring locator (rubber) ensure that it fits snugly and completely over the modified original boot/bumpstop. This is shown in the instructions however, perhaps it is not clear quite how important this step is. Failure to get this right will result in the top end of the spring moving about and it will cause significant (and deleterious), abrasive modification to the threaded collar. Upon explaining the situation to Ground Control they have agreed to sell me four new threaded collars at a very low price. I think this shows an attitude of customer focus. Mike

Over 30 minutes to remove completely

[1/27/2001] Reviewed by: Michael Wright -

Applicable to: '90 - '97 1.8 liter

The GC coilover kit is designed to be added to an existing set of performance shocks, replacing the springs and sliding over the shock housing. The GC kit came with the following: (4ea) threaded sleeve that slides on top of the shock in place of the old spring seats; (4ea) spring, specific for front or rear, selectable for spring rate; (4ea) rubber pad/bushing to sit between the top of spring and the bumpstop "hat." You should request the collar adjustment tool, as well as the optional rubber seat gaskets that tighten the seating of the coilover to the shock housing. $399 for the Miata kit, plus tax and delivery.

Springs are linear-rate Eibach ERS (375 lbs (f), 250 lbs (r)). My goals: Provide more solid feel, better handling, zero harshness, adjustability. The GC kit with KYB AGX shocks are a great combination. Rubber boot/bumpstop needs to be trimmed. I used the Mazda stock boots, trimming the thin boot off the bumpstop hat. The remaining (hard rubber) bumpstop hat is all that I used on the GC kit. Clean the exposed shock piston every 3mos. Ride height set with the threaded collar. Measure from center of wheel hub to bottom of fender lip. I set the collar to 14 threads (f) and 13 (r), giving corner heights of 13.0" (f) and 13.3" (r). Nearly level, with driver and passenger. I use the 3/2 or 4/3 shock settings. Compared to stock, noticeably firmer, less travel, no harshness, fantastic handling. Also added the Flyin' Miata STB and front sway bar (leaving the rear bar stock, to correct for slight oversteer). 4hr install, with assistant.

I strongly recommend this kit to anyone looking to add firmness, tightness and handling without undue harshness. The ride quality would be even better with the stock sway bars. Not recommended with polyurethane suspension bushings, if you plan on driving your car every day. With the KYB AGX, a good match for a car driven daily, allowing adjustability for autocross days.

Over 30 minutes to remove completely

Reviewed by: Eric Moon -

Threaded sleeve and locking collar designed to fit over KONI shocks. Comes with Eibach race springs in your choice of spring rates.

This kit is a good value at $399. Fit and finish are very good and installation is easy aside from any difficulties involved with the shock install. Since I had already installed the KONIs the first time around a month prior to the Ground Control coil-overs, the procedure was fresh in my memory and took under 2.5 hours. A spring compressor is NOT necessary for re-assembly, and that speeds things up somewhat. The most tedious and frustrating part of the install is getting the initial ride height set correctly on all four corners of the car. This involved car up, wheels off, make a turn here, a turn there, wheels on, car down, measure......repeat as necessary. In my case, 6 tries. Take notes as you make changes! My current setup uses 375 lb front and 250 lb rear springs as recommended by the techs at Ground Control based on my info, driving style and usage. This setup was recommended for a daily driven autocross car. Springs can be purchased separately to fine tune your setup, $50 each. Combined with <review cut off>

I highly recommend this setup to anyone who a) wants to have a lowered car, b) wants control and tunability of their suspension, c) takes cornering seriously.

Over 30 minutes to remove completely

Reviewed by: Bill Lackey -

Koni Shocks with fully adjustable spring perches and coil over springs

One word. WOW. I ridden and raced with other systems in the Miata and this is by far the best. Springs rates can be picked in 25lb increments to customer specs, or Jay at Ground Control will recommend a setup for you. (recommended) If you want the best this is it.

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