Chassis Heeltoe Explains

BC Racing BR Series, Swift & Extreme-Low Unboxing & Product Lap

Heeltoe Automotive offers the complete line of BC Racing Coil-over damper kits, including all the custom options you want to get the perfect set for your car!

Swift springs are offered to improve the quality and consistency of the ride. Custom spring rates can be selected at no extra charge, and include appropriate damper valving changes. The Extreme-Low option gives you a shorter damper to allow for the lowest drop possible (for those looking to lower 3.5″ or more).

Check out this video from Heeltoe showing you more of the features of the BC Racing coilover kits, in living color!

Chassis Universal Fit Blogging

When A-Spec and HFP Suspension Kits Are Discontinued, What To Get Instead?

Updated as of December 2017:

With the popularity of this posting, we have added the Koni STR.T Dampers and popular spring options as pre-built combos on Heeltoe! Find links to them here:

2004-08 TL:¬†Heeltoe Automotive “A-Spec/HFP Evo” Coil-Over Damper Set, 2004-08 Acura TL

2004-08 TSX:¬†Heeltoe Automotive “A-Spec/HFP Evo” Coil-Over Damper Set, 2004-08 Acura TSX

Updated as of December 2016:

Times are tough for the Honda/Acura Enthusiast looking for a conservative drop, comfortable ride, but highly enhanced driving experience. The A-Spec & HFP kits from Honda/Acura were awesome but short-lived, solutions with factory quality you could count on. Then the Neuspeed Supercup Kit was a fantastic option, and promptly itself became discontinued in 2015.

NOW what do you do if you long for that “factory sport package” feel in your Honda Accord, Acura TSX, TL, or other naturally sporting Honda sedan?

Heeltoe has settled on the “next-best” answer… Combine a set of Koni STR.T dampers with a set of Tein HighTECH springs.

Koni STR.T Damper:

Tein HighTECH (HTECH) Spring:

This high-quality combo offers the long stroke and long life of a Koni damper, with excellent body control balanced with proper damping to soak up everyday road hiccups. It also features a slightly firmer spring than stock, with minimal lowering range.

So while this is decidedly not an A-Spec kit it will function excellently and keep your Honda/Acura performing better than new for years to come!

– Marcus


Legacy Post from January 2016:

The Acura A-Spec and Honda Factory Performance suspension packages for popular Honda and Acura models are the perfect suspension tuning parts for the conservative enthusiast. But as they become unavailable, what is the next-best package?

What made the A-Spec kit great for people with a conservative performance goal in mind for both lowering and for sport, was that it utilized springs that were similar to stock in ride height and firmness. The dampers were better at controlling body motions. The combination was great for someone with worn factory suspension but was looking to replace the part with just a bit more athletic ability.

A last look at the much-loved Acura A-Spec Suspension package.

So, with the A-Spec kit gone…what is the conservative-minded enthusiast’s best bet for minimal lowering with great improvements in weight-transfer management and reduction in float as compared to stock suspension? And all that at a reasonable cost?

We would say, the Neuspeed Supercup Kit featuring German-made Sport springs and Sport/Yellow Shocks from Koni are the ticket!

For a little more of a lowering rate, the Neuspeed Supercup Kit is an A-Spec suspension on ‘roids.

Yes, there are a couple of compromises.

  1. The A-Spec kit came with new upper top-hat mounts pre-installed from the factory. Many viewed this as a great value feature, and the value was certainly there. Our counterpoint is that the upper mounts on these cars really do not wear from the factory. Replacement is something better done out of convenience rather than necessity (incidentally, does offer an Upper Mount Option on Neuspeed kits, as we know many customers do like replacing these parts oftentimes).
  2. While the Neuspeed Supercup Kit does come with a Race or Sport spring option, the Race is too aggressive for conservative drivers. The Sport is a great choice, however, the 1.5″ average lowering is a bit more than some drivers are looking for. holds that 1.5″ is a very reasonable lowering range for the average Honda or Acura. It is a compromise, but one worth considering.

Of course, if someone really did not want to lower their Acura but wanted all the sport and control benefit of an A-Spec kit, simply grab a set of Koni Sport replacement dampers!

The Koni Sport dampers do offer a relative degree of height adjustment, but more importantly, they have adjustable dampening. This allows a driver to tune in just the right amount of rebound for their particular tastes. Plus, as they wear, these dampers can be firmed up. They are extremely high quality, and with this tuning feature, can effectively last longer than most drivers will ever need them to.

Yes, the passing of the Acura A-Spec (and likewise, Honda Factory Performance) suspension kits is an unfortunate reality for enthusiasts. But thanks to Neuspeed and Koni, we are not without suitable alternative choices. is here to advise every customer on their specific needs, so don’t hesitate to¬†contact us¬†today for a consultation!

Chassis Universal Fit Blogging

BC Racing Coilovers: Implications of Ordering Custom Spring Rates

Many people are aware that BC Racing will allow you to customize your coilovers to your liking. Here are a few things to keep in mind when considering a custom BC kit.

  • Swift Springs upgrade is mandatory for rates above 18k. This is because BC does not make a wide variety of springs (length, diameter) at rates above 18k. The Swift Spring upgrade does come at an increased cost as well.
  • Off the shelf, your kit can handle spring changes of 2-4k in each direction. Beyond that will require shocks with different valving.
  • Any kit that varies in specification from its “Off the Shelf” version is considered a custom kit. These are not eligible for cancellation or return once your order has been processed, and the build time will be 2-3 weeks. You must be committed to your custom kit, so be sure to think about this before you place your order!

With this information, you see that BC Racing has a lot of flexibility and capability when it comes to building a kit tailored to your specific needs. is the place to go for all your BC Racing needs, from mild to wild.

Chassis Heeltoe Explains

What is the difference between “shocks” and “struts,” and what is a “damper” and a “coilover?”

It is a major pet peeve of ours. The customer calls and says they need to replace their shocks and struts. Or just their struts. This wouldn’t be so bad but invariably the car they are calling about doesn’t happen to have any struts at all. If they are calling Heeltoe it is probably a Honda or Acura and bunches of them don’t have struts.

Then you’ve got companies like TEIN making replacements for these units they call “dampers?” And then some guy in the forums is telling you to forget it, and you need to buy “coilovers.” Huh?

Shocks and struts are both dampers. 

Shocks and struts are both types of dampers (do you say damper or dampener?) A damper is basically an absorber. The springs hold the weight of the car and allow the suspension to move as the car goes over bumps and dips. Without springs, the car would not be compliant at all. But while springs spring over thing things they should, they will keep springing long after you want them to stop. There needs to be something keep them in check. If you hit a spring it would “sproing” and shake and bounce around for a while before it comes to a rest. It is called vibration or oscillation. This is no good in a car because that means the car would bounce around up and down over the slightest of bumps and you’d have little or no control.

Where springs give compliance, dampers bring control.

Dampers (shocks and struts) keep the springs in check by allowing them only to be as springy as they need to be to provide comfort, but not so springy as to allow the car to float around and feel as though it were not connected to the ground. But really, all you really need to grab on to is the damper controls the ride, the handling, the body motion, and the response of the suspension to road inputs. A system is “under-dampened” when the damper is too weak to keep the mass of the car from bouncing around on the springs (like a Caddy). A system is “over-dampened” when the dampers are very firm and resist movement of the body, even with a softer spring in place. Some movement is needed for the suspension to work properly, or the car will slide over instead of grip the road. What you are shooting for is “critical dampening,” which is when the damper is tuned to match the spring and the mass in such a way that any given input results in the car returning to its neutral position on the spring as fast as possible without oscillating.

But now, on to the rear question: If shocks and struts are both dampers, what is the difference?

The difference between a shock and a strut is in their mounting. To understand the difference you need to “zoom out” and think of the whole suspension system.

The wheel is connected to the hub, which rides on a bearing, which is housed in a hub carrier (also known as a knuckle or an upright). The hub carrier is also the thing that the brake calipers bolt to. The hub carrier can be held to the car in a few different ways, and herein lies the difference between a shock and a strut.

A Subaru WRX has a strut. This is a front strut in a WRX (that’s a Tein FLEX damper):

What is it missing in the above picture that this TSX with a shock configuration has?

If you said UPPER CONTROL ARM, you get a gold star!

The simplest way to think of it is that if you were to take the shock out of a car, the wheel would still keep the same geometry and alignment as with it because the hub carrier is not located (positioned, held in place) by the shock; it is located with arms. There can be two, three, or even five arms holding the hub carrier in place. But the shock is not one of the things doing that job. It doesn’t move other than to compress and rebound over bumps. The mounts are rigid and the only compliance from bushings is there to provide comfort.

By contrast, if you were to take the strut out of the WRX in that pic above, the hub carrier would not be located. It would flop around and not be able to hold a wheel straight. The strut serves as both the damper AND a suspension member. It turns with the steering, so there is usually a bearing in the upper mount to allow it to spin to allow that movement.

Shock = damper. Strut = damper + suspension member.

This should help explain why you won’t ever see Skunk2 making camber-adjustable front upper arms for RSXs and Civics newer than 2001; they all have struts. And it should also explain why the upper mounts in TSXs and TLs will never have camber adjustment; moving the location of the shock mounting won’t change the alignment because you need an adjustable upper arm for that.

So, know the difference, and when talking about your car say the right thing. When someone says it wrong, you can either correct them or find someone else who is more well versed to talk to.

Hopefully, that clears things up a bit, and we’ve held on to you thus far. Now, what is a “coilover?”

Coilover is really a term that is short for “coil-over shock” or “coil-over strut.” The damper in the suspension system need not be all in one assembly like most of our customers see it. Many trucks have leaf springs in the back, and a separate shock. Likewise, the 1984-87 CRXs and Civics that Heeltoe caters to have struts in the front with a torsion bar for the spring.

The damper above is a strut because there is no upper arm, but also notice there is no coil spring! This is not a coil-over strut. Also, you’ll see a lot of cars where the rear suspension has a trailing arm, and the shock is mounted separately from a coil spring, such as on the later RL or later model Civics.

Coil-over literally means there is a coil spring and the coil is over the damper.

A stock TSX a coil-over shock suspension design.

But “coil-over” and “coilovers” are different. These days it is common that an adjustable-height suspension, one where there is a threaded spring mounting, to be called a coilover suspension. It is really nothing more than a damper and a spring, but you can adjust the height.

Aside from a pretty color, coilovers are typically shorter in overall length allowing adequate shock stroke when the car is set to lower ride heights. They usually come have all kinds of features such as adjustable ride-firmness and new upper mounts (and if you have a strut-type car, you’ll probably get camber adjustment on those upper mounts).

So, hope that clears things up for you!

Heeltoe Explains

A note about squeaky shocks

I get asked from time to time about squeaky shocks so I thought I’d make a post about it.

Why do shocks squeak? Well, there are a number of reasons. And trust me when I say it is really not a brand-specific issue. I spend a lot of time on Acurazine where people tend to complain about Tein dampers squeaking. Well, they don’t really buy anything else there with any great volume so of course, more people have noises with Tein! In reality, any shock can develop a squeak and I will give a few reasons why!

I will preface the following by mentioning the “science of a squeak.” Squeaks are caused when there is a moderate pressure-force over a small cross-section. Usually, the ideal squeak would involve a rigid item that encounters some flat surface with minimal abrasiveness (in other words, more smooth surfaces provide higher friction). Like nails on a chalkboard, right? Or rubbing your finger on a dry slip-n-slide. You need some pressure and some friction to make a squeak.

Worn shaft seals or shock shafts.

As the seals wear they can become firm and loose lubrication. As shafts wear they can heat and become harder than normal. The seal provides the pressure, and the movement of the shaft against the seal provides the friction. Hence you can get a squeak. This noise can be remedied by applying some light liquid silicone spray lube to the shaft. Try to not use anything with petroleum in it as it can break down the seal further and/or attract dirt causing a leak!

Bubbles in shock fluid.

More prevalent with street-use twin-tube dampers where there is high-pressure nitrogen gas in direct contact with shock oil. Vibration and heat can cause the gas to emulsify into the oil. When you get bubbles in the fluid and it passes through the small orifices in the shock piston you can get a noise. The pressure is caused when the oil forces the bubbles through the piston. The friction is provided by the variance in coefficient of friction of material going through the piston (oil, then air, then oil, then air as bubbles pass through). The system can be designed to minimize sounds from one material, but not both. This situation is a lot less prevalent in mono-tube shocks as the oil and nitrogen are divorced. 

It’s a performance shock. Compromise is built in.

To a certain degree, you need to expect that if there were no compromise in noise or ride the automotive engineers would have put a superior handling system in the car from the get-go! Therefore you might expect that part of the reason you are getting squeaky shocks is that they work better in other ways than non-squeaky shocks.

One instance is that the viscosity of the fluid in performance dampers may be thicker than stock and the piston orifices many times are smaller, or adjustable in size. Thicker fluid through a tighter hole: Pressure = hydraulic pressure of the oil forcing through the holes. Friction = higher viscosity fluid inherently “sticks” to the surfaces it contacts better and has a greater resistance to flow…stick, resistance….FRICTION caused by the fluid itself!

Temperature Change.

To add to this point, many people notice more squeaking as temperature drops and with some ability to warm up it goes away. Lower temps increase viscosity which only enhances this effect of fluid friction causing the noise. Temperature change can also cause seals to swell or contract, or change in suppleness.

In closing…

There are a number of other reasons why a suspension system might make a sound. Loose fasteners, worn bushings, etc. Shocks themselves can make noises like squeaks in varying conditions which don’t necessarily indicate a failure. Assuming all else is normal the noises you are hearing from the shocks may not really much to be alarmed about.

Chassis Heeltoe Explains

Stock shocks with Sport Springs : Yay or Nay?

I am asked this question frequently, and I have an answer.


Back in the mid-’90s when I started with this import stuff, we did not have much choice. Lower the car with shorter springs. Usually, with shorter, you get stiffer too. Both these factors will improve the handling of the car. The problems with lowering a car on sport springs with stock shocks are pretty significant, though.

#1 Reduced Travel

The stock dampers are designed to work within a given travel range. They will stroke up and down as the car goes over bumps. This movement is needed to maintain a good, safe ride. By lowering the car you are actually moving the range that the shock is asked to work under. You are asking the dampers to do something they are not designed to do by working them in a range that is smaller than they normally do. And one result of this is “bottoming out.” When the shocks compress completely they bottom out, and the car crashes on the bump stops. This causes the car to pogo and bounces over bumps in the road, drastically hurting the ride and performance of the car. It is highly recommended to use dampers that are short-stroke or short-case with lowering spring to maintain travel in the damper system.*

#2 Degraded damper life

Speaking from experience, dampers in import cars generally last a very long time under normal conditions.

I have seen numerous Accords, Civics, etc go well beyond 100,000 miles with the original shocks only showing hints of softening. You know a shock goes bad when the car seems to float around like a boat as though the springs are allowed to oscillate freely. The shock/strut system is designed to match the stiffness of the spring and keep it in check. The spring compresses to absorb bumps, and it expands to maintain contact with the road over dips. The shock is there to keep the spring from exhibiting natural perpetual motion which would allow it to bounce up and down forever.

The combination of lowering the car into a modified travel range, and making the spring firmer (disrupting the stock shocks/spring balance) combine to cause advanced wear in the shocks. A shock that might normally last 10 years now won’t last 6 months under normal driving conditions.

Here it is recommended that shocks be replaced in conjunction with lowering springs to better match the performance characteristics of the springs.**

#3 Perceived savings result in more costs.

Typically, the savings associated with installing springs onto stock shocks are counteracted by the need to later replace the shocks with new units, aftermarket or otherwise. If shocks and springs are replaced at one time the labor costs are combined into a single cost. Shocks will be needed sooner than normal, and the labor to install them being paid twice; once when the springs are installed, and once more when the shocks are replaced. In effect, while saving money in not upgrading the dampers, you will just be deferring the cost that you will eventually need to pay anyway, and indeed paying more by paying for labor twice. Save if you gotta. Do the shocks at the same time as the springs.

So, that’s my story. I’m stickin’ to it. Besides the fact that the stock shocks are not designed to accommodate the lower ride height of sport springs, they are often valved wrong and will not provide the performance or longevity you expect from a sports suspension. You’ll end up replacing the dampers sooner and pay more labor in the end.

* Note that Tein coil-over damper kits all have short-case dampers and are designed to work at reduced ride heights without bottoming. They provide ideal travel, ride, and handling characteristics; all of which we strongly recommend for street sports driving. These kits are also adjustable for a range of ride heights, along with options such as firmness adjustability and rigid upper pillow mounts.

** We strongly recommend either Koni (twin tube) or Bilstein (monotube) dampers be used in conjunction with any aftermarket spring, soft, stiff, low, mild, etc. Koni Yellows have the advantage of adjustability to tailor them to nearly any given spring available. Bilsteins offer a monotube design which is an upgraded design over twin tubes that provide better driver feedback, response, and accuracy.