What are coilovers?
Technically, all Merkurs are equipped from the factory with coilovers. The term "coilover" simply means that the spring "coil" is installed "over" the strut or shock absorber. Well, clearly the stock front springs are installed over the stock front strut, so Merkurs have coilovers. Now, the term coilover is thrown around quite loosely these days, and generally when somebody mentions coilovers, they are referring to "adjustable-perch coilovers". Adjustable-perch coilovers have lower spring perches that can be adjusted up or down to adjust the ride height of the vehicle with ease. Generally, a threaded sleeve is installed over the strut body, and the lower spring perch is spun onto the threaded sleeve. Spin the lower perch up the sleeve, and the car will sit up higher. Spin the lower perch down the sleeve, and the car will be lowered. With regular struts and springs, you're stuck with whatever ride height your car ends up at. With coilovers, you have an infinite number of ride heights to choose from, and you can change whenever you want. Do you want your car to sit higher in the winter to clear the snow? You can! Do you want to slam the car to the ground for a car show? You can!

What is a damper?
A damper is any object that controls or "dampens" the oscillatory motions of any spring system. Basically, for our purposes a damper is a shock or a strut. The term "damper" is often useful, as it is much more convenient to ask "what kind of dampers do you have" than to ask "what kind of struts and shocks do you have".

Why do people convert to coilovers?
There are many reasons to switch to coilovers, particularly for Merkur owners. As discussed in the first question, the infinitely-adjustable ride height is a tremendous benefit. However, besides simply being able to change your ride height depending on your mood, those owners who race can greatly improve the handling of their vehicle by precisely setting the ride height of their car to optimize camber, caster, and toe curves, and also by "corner weighting" their car. Corner weighting is beyond the scope of this discussion, but racers should definitely seek to understand it. Another huge benefit of converting to coilovers is the availability of a vast array of spring rates. Without coilovers, you're stuck having to choose from a limited selection of lowering springs, and often the manufacturers are tight-lipped about their spring rates. Who in their right mind wants to stick a spring of unknown rate on their car? That's like buying a car without knowing the mileage. With coilovers, you can choose any spring from a cushy 85lb/in rate to an ultra-stiff 1000lb/in rate. The choice is yours! Coilovers also look much better on the car, and it's a blast to show them off.

There are a couple more reasons that many Merkur owners in particular select coilovers. First, the gigantic stock spring perch is removed from the stock strut, which allows you to install significantly larger wheels and tires. This is a very nice benefit. More important to Merkur owners is that the currently available lowering spring packages for their cars are all garbage. Lowering spring manufacturers generally add somewhere between 0% and 20% to the spring rate, and then make the shorter spring. The problem is, the stock front springs on all Merkurs are less than 100lb/in, which is far too little, particularly with our heavy engines. This means that even a stiff lowering spring will only be about 120lb/in, which is just as worthless as a stock spring. This causes a huge number of problems for owners that like "spirited" driving. While cornering, the weak front springs compress with ease, and the bump stops are contacted. Once the bump stops are compressed, the front spring rate shoots to infinity, and the car begins to push. Increasing the front spring rate keeps the car off the bump stops, and front end grip is INCREASED. Yes, to an educated observer this sounds backwards, but as you increase the front spring stiffness on a Merkur (to a point), front end grip is increased. Even Merkurs with 500lb/in front springs will push less than a Merkur with stock springs.

Needless to say there are a ton of reasons to convert to coilovers. If you're not running coilovers, you are driving an underperforming car.

Should I install coilovers on the front or rear of my car, or both?
You should absolutely install coilovers on the front of your car for all the reasons mentioned above. However, you should not install rear coilovers on a Merkur. Whereas there are many advantanges to running front coilovers on a Merkur, there are many disadvantages to running rear coilovers. First of all, there is a vast array of springs available for the rear of the car. Why? Well, it just so happens that Merkur rear springs are the same as circle track front springs! We are extremely lucky to have been given this gift from Ford. Why else should you not convert to rear coilovers? Another reason is that the car is simply not designed for them. The semi-trailing arms (STAs) were not designed to support the weight of the car at the shock attachment point, and the chassis' shock tower was not at all designed to support the weight of the car. Race teams that run rear coilovers on their Sierras or XR4Tis either have roll cages that incredibly strengthen the rear shock towers, or they have their rear shock towers "double skinned". They also weld the crap out of their shock attachment points on the STAs. They go through all this work, but what does it really gain them? They don't get a better spring rate selection since we already have a wide array of springs for the stock location. They're not saving much weight, if any (with all the strengthening and additional perches, they're almost certainly gaining weight). Plus, with coilovers installed in the rear, there is less room available for wider wheels and tires. So why do it? The only (and I mean ONLY) reason anyone could ever justify installing rear coilovers is for infinite ride height adjustment. However, we're currently able to infinitely adjust rear ride height with shims. True, this isn't exactly convenient, but since mc²racing is currently working on a stock-position adjustable rear ride height kit, there will soon be absolutely no reason to ever convert to rear coilovers. Don't do it! You'll basically be spending a lot of money to have your car slowly rip itself apart.

It should also be mentioned that rear coilover conversions are not reversible due to the chassis strengthening that is required. Once you weld that chassis, there's no going back. Front coilover conversions are completely reversible. Perhaps we should also state that although there are a few cars running around with rear coilovers successfully, those cars all have weak springs that kill the chassis very slowly. Their cars are slowly dying though, and they should certainly be inspected on a routine basis for cracks in the shock tower and on the STA.

Who can benefit from the use of coilovers?
Everybody! Whether you have a daily-driver or a full-time race car, coilovers can help you by allowing you to choose your own ride height, choose the spring rate that matches your driving style and level of comfort, increase space for larger wheels and tires, and greatly improve handling.

What is involved in a coilover conversion?
Coilover conversions aren't exactly "bolt-in" modifications, but they're not rocket science either. We'll only discuss a front coilover conversion since you now know enough to not do a rear coilover conversion. Simply stated, to begin the stock spring perch is cut off the strut with a lathe. The weld bead that once connected the spring perch to the strut body remains, and that is what supports the adjustable lower spring perch components. Next, the threaded sleeve slips over the strut body. On mc²racing coilover conversions, we create an aluminum collar that sits nicely on the weld bead and serves as a nice seat for this threaded sleeve. Preferably a large bushing is installed to take up any gap between the threaded sleeve and the strut body, but O-rings can also be used. Structural fiberglass packing tape is also a great solution for filling that gap, and it certainly does a much better job than O-rings. Anyway, once the threaded sleeve is in place on the strut, the lower spring perch is spun on to the sleeve. Then, the coilover spring is installed, the new upper spring perch is installed, and the rest of the stock components (rotator bearing, bearing cap, strut mount bushing) are installed. The tough parts of the conversion are using the lathe to remove the stock spring perch and creating the collar that the threaded sleeve sits on.

By the way, notice that you do not have to use a spring compressor when reassembling the coilover strut! You'll never have to use a spring compressor again on your Merkur!

What spring rates should I run?
This is a difficult question to answer. Generally, you should ask mc²racing. Some of the variables that should be considered are the driving style of the driver, the desired ride, and the intended purpose of the vehicle (daily driving, drag racing, autocross, road racing, etc). These considerations will get you close to a suitable spring rate, but additional work must be done to match the front and rear springs. You can't just slap springs on a car and be done with it. A mismatched spring set between the front and rear can create a poorly handling and potentially dangerous car. Cars with excessive rear spring rate can oversteer easily, which is unsafe for public roads. Sway bar sizes obscure the identification of the proper rates. In addition to handling balance, the front and rear spring selection much consider the natural frequency of the chassis, which is a function of the wheelbase. When a car travels over a bump, the front suspension oscillates at it's frequency, while the rear suspension oscillates it's own frequency. If these frequencies are not selected properly, the vehicle can exhibit a number of bad ride characteristics, such as hopping or pitching and porpoising.

What dampers should I use?
If you're using springs with a rate of 85lb/in to 150lb/in, then you can use pretty much any damper that is available for your car. However, just about anyone that installs coilovers will never select a spring under 200lb/in, so you have to pay special attention to the dampers you use. Generally, if your damper doesn't say Koni or Spax Adjustable on it, you should purchase ones that do before performing a coilover conversion. In truth, the Spax Adjustables have not been proven to handle large spring rates, and there is no doubt that they're not as good as Konis, but they should be able to handle moderately upgraded spring rates. Gaz, Boge, KYB, Monroe, AVO, and Bilstein do not make "off-the-shelf" dampers that are well-suited to coilover conversion with spring rates much over 200lb/in.

What are helper springs, and should I use them?
Helper springs are something that every Merkur owner with coilovers should know about, particularly if you set your front ride height lower than stock. Consider a 300lb/in spring. This spring will compress only 1/3 of the distance that a stock spring will. Thus, to achieve the same ride height, the spring must be much shorter than stock. That's all fine, but what happens when the strut is fully extended and you have a short spring installed? As the strut extends, the spring eventually fully unloads, and the top of the spring separates from the upper spring perch, leaving a gap. When the strut compresses once again, the spring and the upper spring perch will meet, and not necessarily in a nice way. Situations like this happen when your car jumps into the air (rare), when you hit a pothole (not-so-rare), when the car is on jack stands (not-so-rare), or when you race your car like the mc²racing guys and lift your tires off the ground (common). You'll know when the spring and upper perch meet back up from the audible clank. You'll also know the next time you look at your spring and see the paint chipped off. Helper springs eliminate this problem by filling the gap that forms between the upper perch and the spring when the suspension droops. They're basically flat-wire springs with a very small rate (10lbs/in) that compress to about 0.3", yet fill gaps up to 4". Helper springs are a good idea to use in any Merkur coilover conversion, but they may not always be necessary. If you run a 250lb/in or lower rate spring at stock ride height, you might not have any gaps to fill with helper springs. If you lower your car from there though, you'll want to use helper springs. If you have 150lb/in through 225lb/in springs, you can lower your car a little bit below stock without using helper springs. The helper springs have no downside to them (other than cost), so if you want to be sure you won't have a clanking car, you can install them with any spring and go through life worry free.

Will your coilover kit work with my dampers?
Yes. The coilover kits, which include the threaded sleeve, the upper spring perch, and the lower spring perch, will work with any Merkur damper.

Why should I have mc²racing do my coilover conversion?
At this point we've experienced just about all of the situations that can make a coilover conversion a very unpleasant task. We know what to do, and what not to do. We have first-hand experience with what spring rates do and do not work. We know what spring length you should use. We know what coilover conversion kits are good, and which ones suck. We know when you need helper springs. We know which springs will make your car handle the best. We know which springs will make your car ride the best. We know how to cut the spring perch off your new or existing dampers properly. We can have your Konis valved to match your springs if you want, and we can also have them made double-adjustable. We've experimented with spacing the threaded sleeve using a variety of methods and materials, not all of which were a good ideas, and we've settled on what works best. That kind of trial and error is not fun, and it is not at all cheap. At the end of the day though, with mc²racing you'll have coilovers that work and are ready to install. When we do the conversion for you, we include the threaded sleeve seat collar, but if you do the conversion yourself, you'll have to create the collar yourself since we don't know the diameter of the strut bodies. Again, coilover conversion isn't rocket science, but it's one of those things that becomes enormously frustrating if it doesn't go right the first time. We take the guesswork out of the task.