As many of you may know from reading my other threads here on Prime, my hopes for an OEM Type-S suspension were dashed when I discovered they have been discontinued. The similar unavailability of the NA2 NSX-R suspension and very limited support for the system here in the US led me to embark on a quest for a street/track suspension option for my NA1 NSX refresh project. Of course, my budget was limited to the price of a new Type-S or used NSX-R: $1,500. After weeks of research online, talking to some motorsports friends, and discussions with suspension shops I know, I was led to a somewhat unlikely place: BC Racing. After setting forth my goals, the general advice was “if you have unlimited funds, just get Motons or Penskes and be done with it. But for your budget, BC Racing is a good option and the best bang for the buck at that price point.”
Frankly, I was surprised. BC Racing is little known in the NSX community and what information I could find lumped them in with the “cheap asian coilover” crowd of Megan, D2 and Ksport. However, as I researched the company I was pleasantly surprised. Turns out these dampers are being used and actively campaigned on tracks all over the world with good results. Moreover, they seem to be overwhelmingly well-regarded by other sports car groups like STi, Evo, M3 and GTi. Thus, the initial research looked promising and I decided to dig deeper.
The following were my initial concerns about these coilovers:
CONCERNS
1. Made in Taiwan. Let’s face it- this can be an issue. We have all seen the horror pics of failed Megans, D2’s and others. BC Racing coilovers are indeed made in Taiwan by the Bor-Chuann suspension company. The BC Racing factory is ISO9001 certified for quality control and its coilovers are German TUV certified. That’s a big deal (especially the TUV, which is a rigorous standard) and it alleviated much of my concern.
2. Inconsistent adjustment between shocks. A big problem I found with entry-level coilovers (and why I initially was not interested in them) was that people were reporting the dampening adjustment clicks were not consistent left to right. However, BC Racing shock dynos each coilover before it leaves the factory, physically records the value on the damper, and then matches pairs to ensure 5 clicks on the left side is the same as 5 clicks on the right. Again, I was both surprised and impressed. Below is a picture of my new coilovers. Under the dust boot is a marking showing the damper rates of each shock as tested on the dyno before it leaves the factory. My dampers were matched to within 2% tolerance. For reference, OEM acceptable tolerance is 13%.
3. Lack of droop travel. Like all entry-level coilovers, the BC Racing units have less droop travel than a standard twin-tube shock, meaning the damper piston has a shorter amount of travel distance before it hits the bump stop. This can be a real problem if the system is undersprung or, like many cheaper coilovers, the user lowers the ride height by compressing the spring (thus reducing travel even more). What happens is that you end up blowing through the droop, hitting the bump stops and the ride is horrible. BC Racing solves this issue by making ride height adjustment independent of the spring perch, by way of a threaded lower mount. Thus, no matter how much you lower the suspension, you have the full droop travel of the shock available. Again, I was both surprised and impressed.
4. Poor damper valving. This is really one of the biggest issues with entry level coilovers and a major driver of the vastly lower price compared to industry leaders like Penske and Bilstein. These coilovers, as well as many of the JDM name brands, follow a fairly typical damping profile. Compression (bump) damping is digressive and generally low. Rebound damping is generally very high and follows a progression of progressive, linear and digressive curves as the adjustment is increased. This presents a problem for tuning because if rebound is set too soft, the progressive curve will result in the car pogo sticking over even small bumps at low speed. If rebound is set too high, the suspension will not be able to return to neutral at high speeds because the damper is over-controlling the springs. The result can be a “jacking down” of the suspension as the car goes through the turns on a road course. The result of this valving scheme is a somewhat limited “middle window’ of adjustability and lack of overall compression damping that will cost performance on the track. Like the JDM name brands, BC Racing addresses this issue by using stiff springs to control suspension movement. The standard kit for the NSX is 10kg/10kg. Also, in a move that really impressed me, they sent me the shock dyno data for the NSX coilovers. I appreciated the candor and the attitude that they have nothing to hide. Below is the dyno plot they sent me for the NSX kit.
As you can see, the curve is what it is. There’s no way around it- these coilovers will lack some performance on the track. Indeed, Evolutionm.net tested the BR kit on its shop race car on the Sebring 12 hour course and found that while the kit performed exceptionally well, it was about 2 to 3 seconds slower than their normal race suspension (unnamed, but likely Motons or something similar). Is 3 seconds worth $5,000 to me? No. But, it is clear that the less than ideal valving profile is hurting the BR kit on the track, especially through the high speed turns. This is to be expected, as the BR kit is about 5 times less expensive than a full-up triple adjustable race suspension. I’m ok with that. In addition, during my discussions with them directly, BC Racing was clear that the BR kit is designed primarily for street driving with occasional track use. Thus, for my 80% street 20% track application, they fit the bill.
Evolutionm.net Review
5. Ridiculous number of adjustment clicks. It seems like the less expensive the coilover, the more “clicks” you get for adjustability. The BC Racing BR kit is no different, with 30 advertised clicks. My research revealed single clicks do not make any discernable difference on the BR and the adjustment should instead be viewed as 15-way with half click increments.
6. Adjuster “cross-talk”. Many entry level coilovers use valve adjusters that affect both rebound and compression. This is not always ideal and can cause tuning nightmares. Thankfully, the shock dyno shows the BR kit has virtually no cross-talk between rebound and compression, which only slightly increases even on maximum stiffness. This means it truly is a single adjustable damper and indicates better quality internals.
Overall, my concerns about these kits were largely alleviated by a little detective work. Turns out most people who have them like them. They are great on the street and decent, but not ideal, on the track. Of course, as I drive them I will report back with any problems. They will be tracked and I will be honest. Now however, let’s talk about some positives about the BC Racing BR kit that led me to my decision:
1. High pressure monotube design. Monotubes offer advantages over twin tubes in that they allow for more fluid volume, which better controls shock temperature. Also, they allow use of larger pistons, which can provide smoother ride quality through fluid displacement.
2. 46mm piston. One of the tricks that makes the Bilstein and other race monotubes so comfortable is the use of a large piston. A large piston can displace more fluid with less movement, resulting in a more refined ride quality.
3. Concave lower locking ring. I don’t know much about coilover tuning, but I know that the perch often can work itself loose. This mechanism prevents that.
4. Japan-made pillowball mounts with spherical bearing. This was a big deal to me. Through feedback from actual customers, BC Racing has refined this design several times and the mounts now used are very robust.
5. 1 year warranty and afterwards only $95 to replace the entire damper unit.
6. Rebuildable at BC’s Florida facility and custom valving offered for FREE.
7. Swift spring upgrade offered directly from BC Racing. This is awesome. For a ridiculously low price, BC hooked me up with Swift springs in a 10kg/8kg setup, re-valved the rears for 8kg, installed them on the dampers and shipped to my door. Incredible service and the feedback I got regarding the Swifts was an enthusiastic “go for it” and “they will transform the shock.” Swift racing springs are simply the best in the world.
8 kg Rear Springs
10 kg Front Springs
8. OEM Fit. Unlike other units, the BC Racing coilovers do not make you use zip ties to mount your brake lines. They spend the extra money to give you proper mounts, seen below on my front coilovers:
9. Positive actual user reviews. I did a ton of research on these coilovers and I would say at least 90% of purchasers were happy. These reviews in particular were very helpful to me:
The S2000 is a close performance analog to the NSX. Moreover, this owner evaluated the system from the track to the ever-important “wife/gf ride test.”
S2000 Review
This is a review of the top-line ER double-adjustable damper, but indicative of the quality of construction and a good discussion of the valving limitations
Sti ER Kit Review
Moreover, NASIOC has a 90-page thread on these coilovers with nearly a unanimous positive review.
The coilovers arrived in a very well-packed box. Pics are below.
I will not have a chance to drive and track these coilovers for a couple of months, as my refresh project is continuing. But, I will update this review once I have the chance to do so. My initial impression is very positive. These appear to be a very well made coilover boasting many features that typically cost a lot more money.
Frankly, I was surprised. BC Racing is little known in the NSX community and what information I could find lumped them in with the “cheap asian coilover” crowd of Megan, D2 and Ksport. However, as I researched the company I was pleasantly surprised. Turns out these dampers are being used and actively campaigned on tracks all over the world with good results. Moreover, they seem to be overwhelmingly well-regarded by other sports car groups like STi, Evo, M3 and GTi. Thus, the initial research looked promising and I decided to dig deeper.
The following were my initial concerns about these coilovers:
CONCERNS
1. Made in Taiwan. Let’s face it- this can be an issue. We have all seen the horror pics of failed Megans, D2’s and others. BC Racing coilovers are indeed made in Taiwan by the Bor-Chuann suspension company. The BC Racing factory is ISO9001 certified for quality control and its coilovers are German TUV certified. That’s a big deal (especially the TUV, which is a rigorous standard) and it alleviated much of my concern.
2. Inconsistent adjustment between shocks. A big problem I found with entry-level coilovers (and why I initially was not interested in them) was that people were reporting the dampening adjustment clicks were not consistent left to right. However, BC Racing shock dynos each coilover before it leaves the factory, physically records the value on the damper, and then matches pairs to ensure 5 clicks on the left side is the same as 5 clicks on the right. Again, I was both surprised and impressed. Below is a picture of my new coilovers. Under the dust boot is a marking showing the damper rates of each shock as tested on the dyno before it leaves the factory. My dampers were matched to within 2% tolerance. For reference, OEM acceptable tolerance is 13%.
3. Lack of droop travel. Like all entry-level coilovers, the BC Racing units have less droop travel than a standard twin-tube shock, meaning the damper piston has a shorter amount of travel distance before it hits the bump stop. This can be a real problem if the system is undersprung or, like many cheaper coilovers, the user lowers the ride height by compressing the spring (thus reducing travel even more). What happens is that you end up blowing through the droop, hitting the bump stops and the ride is horrible. BC Racing solves this issue by making ride height adjustment independent of the spring perch, by way of a threaded lower mount. Thus, no matter how much you lower the suspension, you have the full droop travel of the shock available. Again, I was both surprised and impressed.
4. Poor damper valving. This is really one of the biggest issues with entry level coilovers and a major driver of the vastly lower price compared to industry leaders like Penske and Bilstein. These coilovers, as well as many of the JDM name brands, follow a fairly typical damping profile. Compression (bump) damping is digressive and generally low. Rebound damping is generally very high and follows a progression of progressive, linear and digressive curves as the adjustment is increased. This presents a problem for tuning because if rebound is set too soft, the progressive curve will result in the car pogo sticking over even small bumps at low speed. If rebound is set too high, the suspension will not be able to return to neutral at high speeds because the damper is over-controlling the springs. The result can be a “jacking down” of the suspension as the car goes through the turns on a road course. The result of this valving scheme is a somewhat limited “middle window’ of adjustability and lack of overall compression damping that will cost performance on the track. Like the JDM name brands, BC Racing addresses this issue by using stiff springs to control suspension movement. The standard kit for the NSX is 10kg/10kg. Also, in a move that really impressed me, they sent me the shock dyno data for the NSX coilovers. I appreciated the candor and the attitude that they have nothing to hide. Below is the dyno plot they sent me for the NSX kit.
As you can see, the curve is what it is. There’s no way around it- these coilovers will lack some performance on the track. Indeed, Evolutionm.net tested the BR kit on its shop race car on the Sebring 12 hour course and found that while the kit performed exceptionally well, it was about 2 to 3 seconds slower than their normal race suspension (unnamed, but likely Motons or something similar). Is 3 seconds worth $5,000 to me? No. But, it is clear that the less than ideal valving profile is hurting the BR kit on the track, especially through the high speed turns. This is to be expected, as the BR kit is about 5 times less expensive than a full-up triple adjustable race suspension. I’m ok with that. In addition, during my discussions with them directly, BC Racing was clear that the BR kit is designed primarily for street driving with occasional track use. Thus, for my 80% street 20% track application, they fit the bill.
Evolutionm.net Review
5. Ridiculous number of adjustment clicks. It seems like the less expensive the coilover, the more “clicks” you get for adjustability. The BC Racing BR kit is no different, with 30 advertised clicks. My research revealed single clicks do not make any discernable difference on the BR and the adjustment should instead be viewed as 15-way with half click increments.
6. Adjuster “cross-talk”. Many entry level coilovers use valve adjusters that affect both rebound and compression. This is not always ideal and can cause tuning nightmares. Thankfully, the shock dyno shows the BR kit has virtually no cross-talk between rebound and compression, which only slightly increases even on maximum stiffness. This means it truly is a single adjustable damper and indicates better quality internals.
Overall, my concerns about these kits were largely alleviated by a little detective work. Turns out most people who have them like them. They are great on the street and decent, but not ideal, on the track. Of course, as I drive them I will report back with any problems. They will be tracked and I will be honest. Now however, let’s talk about some positives about the BC Racing BR kit that led me to my decision:
1. High pressure monotube design. Monotubes offer advantages over twin tubes in that they allow for more fluid volume, which better controls shock temperature. Also, they allow use of larger pistons, which can provide smoother ride quality through fluid displacement.
2. 46mm piston. One of the tricks that makes the Bilstein and other race monotubes so comfortable is the use of a large piston. A large piston can displace more fluid with less movement, resulting in a more refined ride quality.
3. Concave lower locking ring. I don’t know much about coilover tuning, but I know that the perch often can work itself loose. This mechanism prevents that.
4. Japan-made pillowball mounts with spherical bearing. This was a big deal to me. Through feedback from actual customers, BC Racing has refined this design several times and the mounts now used are very robust.
5. 1 year warranty and afterwards only $95 to replace the entire damper unit.
6. Rebuildable at BC’s Florida facility and custom valving offered for FREE.
7. Swift spring upgrade offered directly from BC Racing. This is awesome. For a ridiculously low price, BC hooked me up with Swift springs in a 10kg/8kg setup, re-valved the rears for 8kg, installed them on the dampers and shipped to my door. Incredible service and the feedback I got regarding the Swifts was an enthusiastic “go for it” and “they will transform the shock.” Swift racing springs are simply the best in the world.
8 kg Rear Springs
10 kg Front Springs
8. OEM Fit. Unlike other units, the BC Racing coilovers do not make you use zip ties to mount your brake lines. They spend the extra money to give you proper mounts, seen below on my front coilovers:
9. Positive actual user reviews. I did a ton of research on these coilovers and I would say at least 90% of purchasers were happy. These reviews in particular were very helpful to me:
The S2000 is a close performance analog to the NSX. Moreover, this owner evaluated the system from the track to the ever-important “wife/gf ride test.”
S2000 Review
This is a review of the top-line ER double-adjustable damper, but indicative of the quality of construction and a good discussion of the valving limitations
Sti ER Kit Review
Moreover, NASIOC has a 90-page thread on these coilovers with nearly a unanimous positive review.
The coilovers arrived in a very well-packed box. Pics are below.
I will not have a chance to drive and track these coilovers for a couple of months, as my refresh project is continuing. But, I will update this review once I have the chance to do so. My initial impression is very positive. These appear to be a very well made coilover boasting many features that typically cost a lot more money.
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. I'm purely a street driver and with reviews like Paul's...I know I made the right decision.
