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BC Racing Coilovers - Comprehensive Review

Joined
27 July 2007
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Location
Denver, CO
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%.

Swift4.jpg
Swift4.jpg

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.

BCR_NSX_Dyno.jpg
BCR_NSX_Dyno.jpg

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

Swift5.jpg
Swift5.jpg

10 kg Front Springs

Swift8.jpg
Swift8.jpg

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:

Swift7.jpg
Swift7.jpg

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.

Swift1.jpgSwift2.jpgSwift3.jpg

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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very nice writeup and review..I will have to drive your car at xpo:cool:
 
Well you did a lot more research than me, but I went with swift springs 10/10 from Ravi and have been very happy so far.

If anyone is interested in this setup, call Ravi.
 
Great write up and very relevant to me as I am searching for coilovers. I am very interested in your first impressions once you get them set up how you want them on your car. And of course after you get it balanced by a shop. I also want to have the coilovers for about 80% street and 20% track. My main question is why did you not spring for the KW's for an extra $600-$700? Thanks as your info is much appreciated.

Jacob
 
Great write up and very relevant to me as I am searching for coilovers. I am very interested in your first impressions once you get them set up how you want them on your car. And of course after you get it balanced by a shop. I also want to have the coilovers for about 80% street and 20% track. My main question is why did you not spring for the KW's for an extra $600-$700? Thanks as your info is much appreciated.

Jacob

More like $1000 more and you have to re- use your Oem top hats or buy new ones from SOS.
 
I ordered the VRH kit with BC coilovers from Ravi this week...if you order the VRH kit,, Ravi will work a great deal on coil-overs....the price difference between the BC's and the KW3's was $1,800:eek:. I'm purely a street driver and with reviews like Paul's...I know I made the right decision.
 
a lot lexus vip guys are also running bc coils with good reviews also
 
Good review.

If the BC ER had been available when I was in the market for my coilovers, they would have been near the top of my list too.

Dave
I had asked them about the ER series 2yrs ago and unfortunately they had no plans of making them. Inverted shock, external reservoir.. yum.

Honcho - great review. impartial and honest... who'd have though "cheap asian coilovers" may actually be a viable option. What a concept!!!
 
I also riding on BC Coilovers and I have to say it ride way better than the Tein flex suspension on the streets.
 
Thanks guys, I've updated the review with more pics and some edits. I did this last night while sitting in the airport, so I will tweak it a little more to get it right. I'll try to upload the shock dyno tomorrow.
 
Thanks for the write-up! These coilovers sound great.
I am looking for a setup that is 95% street and 5% other.

I would like the ride closer to the R-type setup. Do you know what spring rate that would be? And do you have a source for the coilovers for a great price?

Rich
 
Thanks for the write-up! These coilovers sound great.
I am looking for a setup that is 95% street and 5% other.

I would like the ride closer to the R-type setup. Do you know what spring rate that would be? And do you have a source for the coilovers for a great price?

Rich

I ordered the 10/8 kit, which is the same as NSX-R. I had the rear dampers re-valved for the 8k springs at the factory, so I had to wait a couple of weeks for them. The standard NSX kit is 10/10. I ordered through Circuit Motorsports and BC directly.
 
nice write up, however, for most hardcore track rats, $5000 is bargain for 3 seconds. :smile: Wonder how these taiwanese made shocks never copied the double adjustable designs. i'll be itching to try if they do that.

I just love my Koni and it's with proven performance before you going up to Moton's / JRZ.
 
Frankly, I was surprised. BC Racing is little known in the NSX community...
I wish some of the old school guys would be more open minded to new developments and technology. NSXPrime is like a big bubble sometimes. Though every so often you get outliers who say such things as Hawk pads are garbage *shrug*...which makes me want to shoot myself.

The BC's aren't perfect but you sure get a hell of a lot for a fraction of the price.

nice write up, however, for most hardcore track rats, $5000 is bargain for 3 seconds. :smile: Wonder how these taiwanese made shocks never copied the double adjustable designs. i'll be itching to try if they do that.

I just love my Koni and it's with proven performance before you going up to Moton's / JRZ.
I thought hard before passing on the BCs. I ended up not going with them because I wanted a setup that rode well on the street but prioritize features for aggresive driving. It was #2 on my list though. If they come out with the ER series i'd like to give it a shot. I ended up going with a set of DG-5s which I believe there are only two known sets installed, at least on Prime, which was hell for my researching efforts. They've completely transformed my driving experience and would recommend them as a cheaper option to JRZs for example. Though, JRZs/Motons are suppose to be the cat's meow. I can't afford those prices though and as happy as I am.. I see no need for them. Ignorance is bliss!
 
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nice write up, however, for most hardcore track rats, $5000 is bargain for 3 seconds. :smile: Wonder how these taiwanese made shocks never copied the double adjustable designs. i'll be itching to try if they do that.

I just love my Koni and it's with proven performance before you going up to Moton's / JRZ.

Amen!

koni yellow for most people on a budget and if they want to "win" then the proper route is to jump right to KW V3, moton or JRZ
 
Wonder how these taiwanese made shocks never copied the double adjustable designs. i'll be itching to try if they do that.

Actually, the BC ER's are dual adjustable with remote reservoirs.

And the KSport's Circuit Pro's are too. These also come with the shock dynos included and are similar to the Tein N1's (which are dual adjustable too):

splash.jpg
 
Not the NSX. FD I was at Laguna a few times. Used the Koni yellow and GC with a 350/450 spring rate and got 1:44~ about 10 years ago back in December.
Well, when you track your NSX (if you ever do) you can get back to us with your thoughts. I'd be interested to know how you like the soft 350# spring rate. If I had KW V3s i'd like to get the 450# (Swifts?) at least but that just increases the cost even more.
 
Lap times mean nothing to me other than as a tool to evaluate and improve my driving skills. I drive my car for the enjoyment of driving it. Driving, including track driving, is an experience that is personal to me. Other than for safety, I am not generally concerned with what other people are doing. Therefore, it is immaterial to me whether my NSX is the fastest car on the grid, or the slowest. However, I could see how one would be concerned with lap times and ultimate speed under the following conditions:

1. I drive my car competitively against other cars in a road race series like SCCA or NASA;

2. I drive my car competitively against other cars in time attack events;

3. I am insecure about myself and my car and I feel embarassed and/or inadequate when other cars pass me or are faster than me at the track;

4. I am insecure about myself and my car, and I feel embarassed and/or inadequate when other cars have better paper stats then my car;

5. I am obsessed with having the best of everything and I am willing to pay for it, regardless of whether I actually need that capacity in my car.

If you fit into any of the above categories, then yes, maybe you need to shell out the $$ for Motons. However, none of the above applies to me, so there is no sense in spending a large sum of money just so I can say I ran a 2:07 at HPR instead of a 2:09. But, that leads me back to my original basis for looking at the BC coilovers- and what I think all owners should do before purchasing any mod: decide FIRST what your goal is and then find a product to match.
 
I thought hard before passing on the BCs. I ended up not going with them because I wanted a setup that rode well on the street but prioritize features for aggresive driving. It was #2 on my list though. If they come out with the ER series i'd like to give it a shot. I ended up going with a set of DG-5s which I believe there are only two known sets installed, at least on Prime, which was hell for my researching efforts. They've completely transformed my driving experience and would recommend them as a cheaper option to JRZs for example. Though, JRZs/Motons are suppose to be the cat's meow. I can't afford those prices though and as happy as I am.. I see no need for them. Ignorance is bliss!

Prime often is a bubble. The Sti guys, for example, track their cars far more than most NSX owners. I bet if you got a group buy going, BC may do a run of the ER for you. The M3 guys did it over on one of their forums...I think they needed 20 cars.
 
Prime often is a bubble. The Sti guys, for example, track their cars far more than most NSX owners. I bet if you got a group buy going, BC may do a run of the ER for you. The M3 guys did it over on one of their forums...I think they needed 20 cars.
I definitely echo your point about the enjoyment factor over lap times. I prioritize that over lap times always (since i'm not a professional racer/driver) but as I continue to have more fun at the track I view laptimes as a great tool. With that said, I'm considering buying a new cheaper car so I can retire the NSX - it's just too damn expensive to maintain. Hence, why I may still try out the BRs in the near future for light and aggressive street duty.

Unfortunately, 20 ER units sounds like a lot especially for the NSX. 20 BRs sounds more realistic but not by much considering our small'ish community.
 
Thanks for the write-up! These coilovers sound great.
I am looking for a setup that is 95% street and 5% other.

I would like the ride closer to the R-type setup. Do you know what spring rate that would be? And do you have a source for the coilovers for a great price?

Rich

Call Ravi. You will pay less than buying directly from bc or eBay. Bc wouldn't even match an eBay price if I went there and picked it up.
 
very nice writeup and review..I will have to drive your car at xpo:cool:

You are one of the few who I would let take it out for a few laps. :cool:

Great write up and very relevant to me as I am searching for coilovers. I am very interested in your first impressions once you get them set up how you want them on your car. And of course after you get it balanced by a shop. I also want to have the coilovers for about 80% street and 20% track. My main question is why did you not spring for the KW's for an extra $600-$700? Thanks as your info is much appreciated.

Jacob

The KW's are over $1,000 more than what I paid, so it was not really an option anyway. I think the KW's are the equivalent of the BCR for motorsports people- absolute best value for the dollar. Nothing else gets close to it at that price point, and if my NSX was a dedicated track car, I would have the KW clubsports.
 
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