V.E.N.O.M. .:. Volkswagen Enthusiast Network Of Milwaukee

Magazine: European Car Magazine - June, 2000
Authors: James Sly

It was a quiet night out with friends. Annie and I picked up another couple in our 1986 Passat TDI and headed up California Route 154 to the top of a mountain pass where a favorite restaurant is located. The road is not straight, traffic was light, and the torque of the "chipped" TDI with the Techtonics Tuned exhaust made short work of the mountain curves.

We were moving. Fast. Cur passengers weren't enthusiasts, and I always worry about driving too fast with people who aren't used to it. Still, no one professed any pangs of nausea along the way, and we arrived in good time. Getting out of the car, our friend (a school teacher used to driving a Honda wagon) asked, "Why does your car ride so smooth and level?"

That might not seem like too extraordinary a comment but let's throw a little light on the subject: We were riding on a test set of Sumitomo HTR ZII tires, 205/40-17, mounted on lightweight 7.5x17-in. SSR wheels--a well-mannered combo, but the short sidewalls definitely limit compliance. These weren't "boulevard tires."

More importantly, the morning of the night I drove up the hill, the guys at Schneider Autohaus had installed an H&R threaded-body coilover suspension set--with whopping 400 lb/in. spring rates up front, and 275 lb/in. in the rear (compare to the stock Passat spring rates of 120 lb/in. up front, and rear progressive rates from 95 to 120 lb/in.). Schneider also aligned the car, an important step in tuning a suspension.

In spite of the firmer-than-stock spring rates and the low-profile tires, this schoolteacher, a decided non-enthusiast, pronounced this a "smooth and level" ride. What gives? Well, this suspension does give a smooth and level ride. Body roll is minimal, even on a curvy mountain road taken at speed. Small bumps go unnoticed, there is minimal dive under heavy braking and the ride is firm yet comfortable. Yet, the spring rates are way up there.

Does 400 lb/in. up front sound like a lot? It should. For comparison, H&R's "Sport Performance" spring for this car falls into about the same rate range as

many other sport springs. The H&R Sports are progressive front and rear, with 180 to 220 lb/in, in the front and 150 to 200 lb/in. at the rear--stiffer than stock, but less than half the rate of the H&R springs on the threaded-body coilovers. The Sport Performance Springs lower the car 1.25 front, 1.0 in. rear, about the same height as used for the coilovers.

How can the higher spring rates on the threaded-body coilover suspension still ride comfortably? The answer is in the shock absorber--or, more correctly, the shock absorber's valving. H&R's careful valving values are designed to match the upgraded spring rates and are designed to offer decent street performance. There's sufficient rebound to control the spring, while compression damping is set at levels that make the street ride much better.

It Just Plain Cranks

I didn't really push the Passat that night, in deference to our friends in the back. When I've had the chance, when there's a clear on-ramp or a curvy stretch of road, the H&R coilovers are incredible. Heavy braking, hard cornering and even dips in the freeway that make a normal sport suspension wallow like a pig on a hot day are all just taken in stride. That the H&R suspension can do this without knocking your teeth out is a tribute to the shock engineering. The biggest downside? That would have to be the price. However, for the quality of product that's offered, the price is in line. For the quality of the shocks, the system remains quite a deal. Above all, the price is competitive, as similar quality coilover suspensions cost as much or more.

What is a Threaded-body Coilover Suspension?

Other than a totally cool buzz word to toss around, just what is a "coilover" suspension--or more correctly, a threaded-body coilover suspension? On a Volkswagen Passat like mine, the H&R threaded-body coilover kit consists of front struts (much like a normal strut but with a coarse thread on the outside), a lower spring mount that can move up and down on the thread, and a threaded locking ring that will lock the lower spring mount in place. In back, the rear shocks are equipped with similar threaded bodies to allow up and down adjustment. Which leads me to the really big question.

Why a Threaded-body Coilover?

The answer to this one is at once simple and complex. Sure, we could take a long drag on a pipe, take a learned engineer's stance and lean back and reflect a bit and say, "A threaded-body coilover suspension is an excellent choice because it offers the ability to precisely tune the ride height and corner balance the car for better handling." However, the first answer that comes to mind is more simple. Coilovers are totally cool in the most techie sort of way, they're used on real race cars and, in the best Tim Allen sort of manner, they're complicated and have lots of shiny parts.

All of the hype, technoid fantasy fulfillment, alleged corner balancing abilities and "it's good enough for Porsche" stuff aside, there are several very good reasons to choose a threaded-body coilover suspension. You can set the ride height pretty much where you want it. You get H&R's ultra-quality springs, and, last and certainly not least, you get H&R's shock absorbers. This alone is probably worth the price of admission. I've said it before, and I'll say it again: The shock absorber is the key component in getting the best out of vehicle ride and handling. By this, I don't necessarily mean the technologies incorporated in the shock, I mean the design choices in the valving.

Why a Coilover Suspension?

Coilover suspensions were designed and constructed to allow race cars to carefully set ride height and weight balance. As late as the early 1 970s, even factory Porsche racers at Daytona used shocks with simple clip-on adjusters to change the ride height for different track conditions. In 1974, the Porsche factory RSRs first came with the higher-end threaded-body coilover adjusters. Since then they've become almost standard for racers as the sport has become more and more sophisticated.

How do the racers use coilovers? There are several ways. One is to adjust the ride height and attitude of the car--front-to-rear-height relationship--to get the aerodynamics right. This small, precise adjustment is extremely critical for the modern aerodynamic race car.

A second use can be just as critical--scaling or "corner balancing" the car. The NASCAR boys, who have been using this tuning trick for a long, long time, call it "weight jacking" or applying a "wedge." The car in ready-to-race condition is placed on a set of scales, one wheel on each scale. In the old days these were just scales, but in these high-tech days the measuring is likely to be done on a set of precise linked scales which automatically compute the balance of the car.

The goal of corner balancing is for every tire to do an equal amount of work by carrying an equal amount of weight. For an all-out race car, equal weight distribution is part of the design criteria and is relatively easy to achieve. If one corner is heavy, the opposite corner is lowered, using the threaded coilover until the corners share an equal amount of weight.

With a production-based car, which isn't designed to have equal weight distribution, perfect distribution may not be possible. A good example is a front-wheel-drive car, like a modern Volkswagen. With all of the weight up front, simple ride height adjustments can't even things out. In cases like this, the tuner looks to adjust "cross weights" to be equal--in other words, for the weights on the left front wheel and right rear wheel to be equal to the weights of the right front wheel and left rear wheel.

What's the result of corner balancing? Experienced race drivers swear to the difference a good balancing job can make. In endurance racing, it cannot only reduce lap times but also even out tire wear and reduce driver fatigue-- critical factors in a long-distance race. Will corner balancing solve all the handling problems of a daily driver? Not likely. For the typical street car, there's enough compliance in suspension bushings and even the chassis that the effects of corner balancing will be moderate at best.

So, the fact of the matter is, full-on threaded-body coilover suspension like this H&R set is most likely overkill. You could get the same results with similar spring rates and equivalent shock valving. There's the catch--to get shock valving this good, you need to get the H&R coilovers. (At least until H&R's new line of shock absorbers comes out.) As an added plus, you can set your car at just the height you like best and have a radical looking set of shocks and springs to show off.

Installation

Installation of the H&R threaded-body coilover suspension was similar to any suspension install. On a Passat B4 wagon, that means the front was relatively simple and the rear was a bitch. Essentially, the rear half of the interior has to be removed, including the seatbelt retractors, just to get to the top strut mounts. That's VW's fault, not H&R's, and replacing stock shocks would be the same. Afterwards, all that trim and so on had to be carefully replaced.

I initially installed the threaded-body coilover suspension adjusted at the halfway setting on the threaded bodies. This proved to be way too low--more than 3-in, lower than stock. I wasn't interested in dragging it on the ground--I wanted a car I could drive and carry stuff in and all of that. So I readjusted the suspension to the up position, with just a touch of rake, the front a bit lower than the rear.

Adjusting any coilover suspension is not an easy task--you have to first unload the springs and then crank up the adjusters. This takes some physical effort. It is a simple job but not an easy one.

Installation Notes

The H&R Coilover kit I installed on this 1996 Passat TDI arrived fully assembled. If you or your installer can't figure out which shock/spring assembly is front and which is rear, they are marked, with an "F" or "VA" on the front springs, and an "R" or "HA" on the rear springs. These. and most H&R threaded-body coilovers for Volkswagen applications, use a second set of springs, called "tender springs," mounted at the top of the spring/shock assembly. These smaller, lighter springs are designed to be compressed when the suspension is loaded and are not there to create a progressive rate.

Note: If the H&R threaded-body coilover suspension isn't stiff enough for you the way it came, the springs can be upgraded by about 100 lb and still work well with the shocks. H&R has springs available in 10-Newton increments (about 57 lb/in.).

Not Just For Racing

H&R's Roland Graef went to great lengths to make one thing clear: "The H&R coilovers are not designed for racing only; they are designed for performance street use and some track use." In my experience, the H&R coilover suspension does a great job at both. "On the track," Graef reported, "You might want to go more severe with the shock valving, and use more compression. These shocks are biased for street performance, with adequate rebound to control the spring rates, but with milder compression settings to offer the ride comfort you want on a Southern California freeway. You can drive from San Francisco to Los Angeles on this suspension without getting out halfway at the Harris Ranch and calling it quits."

The high spring rates allow aggressive lowering without letting the car bottom out. They also increase the roll stiffness, reducing body roll, making an upgraded anti-roll bar unnecessary in most cases. Another positive effect of the high rates is far better control under braking. Slam on the brakes at high speed, and there is minimal nose dive--and maximum control.

Who is H&R?

H&R is a medium-sized company which is constantly growing to meet the increasing demand of a market it virtually created with the first TUV-approved sport springs some 22 years ago. Werner Heine and Heinz Remmen--the "H" and "R" in H&R--are the enthusiasts and pany. Heinz Remmen is the racer of the two, with one race car or another occupying his free time and his time on the track, providing firsthand feedback about the H&R product line.

At the 1993 Essen Motor Show, H&R became the first manufacturer to introduce suspension springs with ABE-type approval. ABE stands for Allgemeine Betriebs Erlaubnis, "All Encompassing Certification," and what ABE means is the H&R springs are pre-certified for installation and require no TUV inspection after installation. As a company, H&R also meets ISO 9001 certification regarding quality standards.

Shocks are not a new product for H&R. It has been working on shocks since the beginning and holds several patents on adjustable shocks--we'll be seeing more about that in the near future.

What else is in the future from H&R? Next out on the market will be a new line of "Cup Kits" that will have H&R springs and special shocks. This new system is designed for the entry-level enthusiast. Also coming are adjustable shocks designed to work with H&R's Sport springs. Another new line of threaded-body coilover suspensions will feature new adjustable shock absorbers. Finally, for the high-end crowd, there will be adjustable, threaded aluminum-body coilovers, with the first kits available for Volkswagen and BMW fitments.

All of these new H&R adjustable shocks will be adjustable in rebound and compression simultaneously, with the relationship between the two determined by the application. I expect great things from the wizards at H&R--and I know they won't disappoint.

I first drove a car equipped with H&R coilover suspension back in 1993--a VW GTI. It was my first drive in a VR6-powered car, and my first drive of any threaded-body coilover suspension on a street car. I was as impressed then as I am now.

H&R springs am warranted not to sag, break or lose spring rate, with a lifetime limited warranty. H&R Coilover kits are also available for Audi, BMW and Porsche. For VWs and Audis, there are also a of pair Ultra Low kits--when even 3.5 in. isn't enough. Both Ultra Low.1 and Ultra Low.2 are not for the faint of heart and may require serious modifications, including fender well removal and fender lip modifications.

Cost-effective Alternative

Euro Sport's Coilover Conversion offers the serious racer an economical threaded-body coilover suspension

Funny as it may seem, the real racers sometimes deal with more limits than the street guys. They can be limited by rules, or they can be limited by budget-and more often than not, it's both. While the street guy may throw everything he's got into a daily driver, the racer typically has to separate his budget into the daily driver and the race car--and the race car part includes tires, entry fees, fuel and all the other little racing expenditures that add up. Both the rules and budget restrictions tend to disallow full threaded-body coilover suspensions like the one from H&R. What's the alternative?

Raffi at Euro Sport is a serious club racer, with a number of IT wins under his belt. He's worked out a great, cost-effective way for racers to get the advantages of a true coilover at a lower price. Designed to be used with existing sport shocks from Tokico, Koni or Bilstein, the Euro Sport Coilover kit features Eibach ERS race springs in a variety of rates, a weld-on adapter for your stock strut housing, a threaded-body sleeve to slide over the strut, and all the required spring retaining hardware.

Like the H&R kits, the Euro Sport conversion are adjustable, allow a choice of spring rates and allow corner balancing. Unlike the H&R kits, the Euro Sport conversion is legal in SCCA IT racing. Also unlike the H&R kits, the Euro Sport conversion is designed primarily for racing and not for street use. There are no tender springs, and typically they are used with race-valved shock absorbers.

Euro Sport offers the threaded-body coilover conversions for A1 and A2 cars (A3 cars require purchasing a Bilstein or Koni strut to make the conversion and require a large adjuster diameter). No cutting or modifying is required. A wide variety of spring rates are available, in 25-lb increments up to 500 lb, with 50-lb increments from 500 lb/in up. On Raffi's ITA Golf II 16V, he runs 550 lb/in, front and 350 lb/in, rear. On the street for an A2, approximately 325 front and 250 lb/in, rear are a good starting point. The price is $399,00 for a complete set, excluding shocks. The conversions are also available as a front or rear set. "A lot of people already have shocks but aren't happy with the spring rates," Raffi reported. "This way they can get the spring rates and ride heights they want."

Euro Sport's coilover conversions for IT racers include Eibach ERS race springs in a selection of rates, threaded sleeves and top hat and all the hardware required to make the conversion. There are three kits for the different shock shaft sizes. This is a front kit for one side; similar kits are available for the rear as well. Comparatively inexpensive at $399, the kits require a little simple welding and are designed to use your choice of shocks. For the serious racer, it's a great way to go.

The front Euro Sport conversion struts installed on a Golf II. They adjust as effectively as the H&R units and have the added benefit of being legal in a number of SCCA racing classes, which the H&R units may not be. They are not as good a choice for the street because they do not have the trick H&R shocks and valving.

The laser-cut adapter for the front struthousing and a struthousing that has already been converted. It is not a complex installation, and most any machine shop should be able to do the work for you.

Automotive jewelry? Industrial sculpture? Kinetic art? Call it what you want, the H&R threaded-body coilover suspension is as beautiful as it is effective. From the gloss-red powder-coated springs to the anodized aluminum hardware, this stuff looks great. Careful shock valving, matched to some serious spring rates, makes this suspension extremely comfortable on the road--and a serious contender on the track. Whether you're lapping the Nurburgring or the Santa Monica Freeway, you'll find H&R has done this suspension up right.

This peek up under the Passat's rear fender shows just how tight a fit the coilover suspension is. I needed a Trak+ spacer to move the wheel out a few millimeters to clear the tire in all situations. Note that the smaller "tender" spring is fully compressed when the suspension is loaded. The wild tread pattern is the Sumitomo HTRZ II.

H&R includes a pair of spanners matched to the coilover height adjusters and locking nuts. These make the job of adjusting the car's ride height simple-but not easy. The car's weight has to be removed from the coilovers before the adjusters can be turned, and even then it's no easy task. Still, once you have the car where you want it, you probably won't be adjusting it very often.

Have no doubts about it: A precision wheel alignment is an essential part of any lowering spring installation. Lowering your vehicle's ride height changes the toe-in as well as the camber. On this Passat, lowering the front 1.5 in. changed the toe-in so radically that steering became absolutely numb. A correct alignment brought back sharp turn-in response--not to mention saving our tires! The sharp-looking wheels are SSRs from the Tire Rack. They are extremely strong and quite light.

Most H&R threaded-body coilover suspensions use shock technology similar to Bilstein--essentially an "upside-down" shock for the front strut, which allows a relatively large strut tube diameter. This allows the shock body to carry the load rather than the shock rod. This inverted shock allows the tube and shock body to stay better aligned. As a result, the top seals are under very little stress and last quite a lot longer. In this design, the front bump stop is included inside the shock, at the bottom of the strut as shown here. It looks solid, and it is. More importantly, H&R engineers have chosen valving that is a perfect match for real-world driving.

In recent years, what we have casually referred to in the past as "bump stops" have become an essential part of the car's suspension and must be included in any calculation of spring rates. These three examples are just part of dozens of different foam polymer bump stops from the H&R parts bins for use in different applications. H&R threaded-body coilovers include the correct bump stops for excellent ride and handling.

H&R Trak+ spacers are part of the industry's most complete line of suspension spacers and wheel adapters. TUV approved, precision machined of aluminum alloy, these spacers are a popular choice in Germany, where moving the wheel and tire out to the edge of the fender well is considered essential if you want to look cool. Lightweight and hubcentric for a perfect fit, they can also move a wheel and tire out to clear the lower spring mount of a coilover suspension.

The Trak+ spacers are available in a number of different widths and bolt patterns. Here are two examples--it took the thicker 10mm spacer to clear the rear shocks on my Passat. As a plus, it pushed the 205/40-17 Sumitomo HTR Zlls out closer to the fender lips, without them rubbing. I added H&R Trak+ spacers up front for the same great look and wider track. If your wheels and tires have a different offset, they may clear the threaded-body coilover suspension without spacers.

If the range of the standard H&R threaded-body coilover suspension doesn't go low enough for you, H&R has a really radical idea: Ultra Low.1 and Ultra Low.2 suspensions. I snapped this photo of a pretty serious Golf II at Velocity Sport Tuning.

The 16V Motronic-equipped Golf is decked out with an H&R Ultra Low.1 kit. It took more than a little bit of massaging to stuff those fat tires under fenders that low--in other words, there was more work to it than just bolting on the suspension. In spite of the radical stance, the car was acceptably comfortable to drive, and the ride wasn't bad at all. The handling and turn-in response was like a slot car. It's impressive H&R shock technology that allows a car this low to be comfortable. You'll see more of this Golf in a future series on 16V cam dyno tests.

The H&R Ultra Low.1 compared to the "standard" H&R threaded-body coilover suspension (right). A rear Golf II shock is shown in this example. A shorter shock and stiffer springs, along with carefully matched valving, allow the Ultra Low.1 to deliver acceptable ride at extremely low ride heights. In Germany, they really look to get low--typically, using 195/45-15 tires for the ultra-low kits, taking the car down even further. Watch out for twigs in the road!

This close-up of the top of the standard and Ultra Low.1 rear shocks shows the difference in the bump stops. Each component in the system is carefully engineered to deliver the best handling possible--even in an extreme set-up like the Ultra Low. 1.

It Must Be Aligned

Changing the ride height also changes the wheel alignment, and it is absolutely essential that the car be realigned following lowering. There are no exceptions to this rule.

Some cars are worse than others in this respect--and this 1996 Passat had some of the biggest alignment changes I've seen from a lowering job. A quick drive around the block to the alignment shop showed absolutely numb steering response. Once the car was up on the rack, it was clear why.

Lowering the car 1.5 in. in front had given the car an enormous amount of toe-in--if I hadn't realigned the car, those Sumitomos would have scrubbed off in record time. While A4-chassis New Beetles, Golfs, and Jettas and B5 (1998-up) Passats are much better in this respect than my B4 car, alignment is still critically important when lowering a car either a threaded-body coilover suspension or standard lowering springs.