Falken Azenis RT-615k Review

First of all, I would like to introduce a new contributor. My dear friend Chris Cullen. Chris showed up at Southern California's autocross scenery a few years back and surprised everybody by how fast he was at his first try. He was the champion in SK2 (street tire stock class) in 2007. He has also competed with the LAKC club in the TAG karts. If I remember correctly, Chris was in top three in the competitive TAG field at his first race. He has won many of the races there and consistently places top.

Chris has very good car control as well, and is very comfortable being on the edge of traction. Because of his heightened sense of driving feel, he is especially suited to do driving impression reviews. Please welcome Chris Cullen. Here is his first entry!

Chris: So, on May 2nd, 2010, I drove at Streets of Willow Springs in Rosamond, CA. The weather was warm, about 83 degrees ferenheit, with low humidity and somewhat strong winds. I don't think the winds played too much a part in having an advantageous tailwind going down the straighaways. I acheived a 1.36:684 lap time on the CW configuration. The car is a 1992 Mazda Miata with light modifications consisting of Bilstein HD shocks, a larger front sway bar, and a spec miata exhaust. I also run a roll bar.

The tires were: Falken Azenis RT-615K, 195/60/14

The tires have good turn-in qualities, and in transitions too. They started to get greasy after about 6 hard laps on them, but that could have been a result of my overdriving. They seemed to have pretty good braking abilities, and I only locked-up the tires a couple of times the whole day. Overall lateral grip is better then the existing RT-615s. The lap was about 2.2 seconds faster than my last visit to the track. I can't say the improvement because of the tires alone. The track was made faster, the weather was 30 degrees cooler, and I now have the Bilsteins installed too. I used to have leaking stock shocks. I estimate that about one second was a result of the tires.
 
Jerry's notes: The new Azenis RT-615k looks exactly the same as the old RT-615, and I read that it has the same construction. The only difference is the compound. That is what I read.

Photo credits: Chris' photo was taken by his father I believe. Owned by Christopher Cullen
Tire photo is a falken tire stock photo, cropped.

Going faster with Gerardo Bonilla: a very anticipated interview!

So I got to work early when the office is empty like every new extern should. I was groggy and like everyone else going to work, not exactly looking forward to it. Well, maybe not everyone else, as you will see here. I still do enjoy my job. I open my inbox and there was an email regarding something that I was nearly forgetting about. It was Gerardo Bonilla, the professional race car driver. I was very excited, and went on to spend some time reading the interview instead of working. He had emailed me very late at night from god-knows-where at some hotel room. As you will see from this interview, professional drivers at Gerardo Bonilla's level are very busy people. What a guy! Mind you, my readership isn't anything like a magazine or anything so I really appreciate that he did this interview. 

I talk about this interview in this post: Upcoming Interview!

To recap, Gerardo Bonilla is a past IMSA Lites, Star Mazda, and Skip Barber champion. He has been with the BP-Mazda's LMP2 entry in 2008, and recently drove an LMPC car at Long Beach. Recently he has driven in the Rolex 24 hour race and is a coach for the US Formula 2000 series. Personally, he stuck me as someone sincere, professional, and well-spoken. You will also notice he is a good writer!

I would like to thank those of you at TrackHQ.com, Miata.net for helping me prepare questions, and my friend Chris Yang for giving me guidance on what to ask.

This interview was prepared in early 2010, so some of the recent events such as his LMPC seat are not accounted for. I hope you enjoy reading this and feel free to discuss through comments on this post.

Interview  May 19th 2010

Hi-kick Racing: Please tell us a briefly about your personal background; perhaps about your home in Puerto Rico, your upbringing, etc.
Bonilla: I had a very normal upbringing.  I was born in Puerto Rico, but our family moved to the States shortly thereafter.  Although I am stronger at speaking English than Spanish, I love my Puerto Rican heritage, especially the music and food!  I enjoyed my big wheel as a kid, then biking, and absolutely loved go-karts, despite rarely getting to drive them.  I was into music early on, playing piano from the 3rd grade for a few years, then the trombone starting in the 6th grade. 

Hi-kick Racing: For you, it is probably hard to call racing just a hobby. Do you have any hobbies?
Bonilla: Music performance is a huge hobby for me.  I play the trombone for churches and the occasional concert.  In 2008 and 2009 I played in a broadway style concert at Epcot to help raise money for an arts charity.  I also enjoy photography, computers, financial markets, and live theatre.

Hi-kick Racing: I heard your car caught fire late 2009 season! Tell us about it, and how did it feel?
Bonilla: It was my scariest moment in racing.  Somehow, the cockpit floor filled with fuel during the pace lap of a 1-hour vintage race at Sebring.  On the first lap of the race, the fuel found a spark and exploded in my face.  I could not see anything other than bright red flames.  The heat was instantly trying to penetrate the weak points in the safety gear, such as under the helmet, into the gloves, etc.  I could not breathe or see, but got out in about eight seconds.  Those eight seconds felt like thirty!  In that moment I wasn’t sure if I’d get to live a normal life ever again, but once I was out, I was just so happy that I wear all my safety gear so religiously!

Hi-kick Racing: Most of us have repetitive days that get boring. What about you? Tell us about your typical day.
Bonilla: A typical day for me is either at my home office or at the racetrack.  At home I am either studying to complete a bachelors degree I started in 1993, stopped mid-way for an eleven-year break, then returned in 2009.  Any of you who work and go to school at the same time know what that’s like!  I also spend a lot of time managing my driver and coaching business doing many of the same things a self-employed person does, from booking travel, booking clients, phone calls, emails, inputting expenses for taxes, and more.  This year I started an online coaching program that can be done from my home office.  I always include a little time for family life.  At the track, I do a lot more coaching than driving these days, so a typical day as a coach follows the practice schedule.  I’ll brief the drivers, observe practice, then things get really busy during debriefs with data, video, and further discussion.  It’s usually not boring, but there are tradeoffs to this lifestyle.

Hi-kick Racing: Do you think about racing when you are "off-season?"
Bonilla: Absolutely!  Off-season only applies to the actual races.  My job is very busy in the winter, especially when working on securing a drive for the following year.  But there is a fair amount of testing and racing schools that keep me busy as a coach.  Studying in real school insures I’m always busy regardless of how much racing work I do.

Hi-kick Racing: You probably travel a lot as a professional driver. Including these places and places you traveled for pleasure, what was your favorite place?
Bonilla: My favorite place is any place I can bring my girlfriend along.  Besides that, Puerto Rico has a profound effect on me, as does New York City, which is somewhat like visiting a different planet.

Hi-kick Racing: Thank you. Now could I ask you some questions about your racing career?
 

Hi-kick Racing:  How did you know that this was what you wanted to do?
Bonilla: Knowing I wanted to be a race driver was not an instant decision.  It was gradual over a period of years.  I knew I would like to be a driver, but to actually decide you want to be one, I had to be convinced it made sense.  When I got my first paycheck coaching, I knew I could make a business of it, and that’s when it really took off.  I sacrificed everything to race full-time.  It worked, up to a point.  You don’t measure success in dollars earned like normal careers.

Hi-kick Racing: Have you ever questioned yourself since then?
Bonilla: I’ve questioned what I do hundreds of times, but the answer has always been the same.  Once the answer changes, I’ll do something else. 

Hi-kick Racing: What was your favorite moment in your career? 
Bonilla: Favorite moment? That’s hard!  Winning the Skip Barber National in 2005 was very special.  Winning the first Star Mazda race in 2006 was very special.  The moment I was told I would drive the Lola Mazda LMP2 car in 2008 was VERY special!

Hi-kick Racing: Would you tell us your worst?
Bonilla: Crashing the Lola Mazda at Road Atlanta during the morning warmup before the race in 2008, taking our team out of the race.  It makes you stronger, but it was the low point of my career.

Hi-kick Racing: What was your greatest asset in financially advancing your racing career? (Note: I mistyped financially.. embarrassing!) 
Bonilla: Not sure exactly “finically”, if you meant finally or financially.  Either way, the greatest asset was people.  Networking, helping, and getting to know great people made the biggest difference.  It’s a lot like starting a new business.

Hi-kick Racing: Any tips for aspiring drivers?
Bonilla: Go to college.  Any degree is good, but a business degree is a good move.  Very few professional drivers are pure drivers earning a nice income for life on driving alone.  If you want to race for a long time, you must learn to make it a real business.  You can learn about business in school and perhaps non-traditional education like internships or mentoring.  Other than that, be prepared to make great sacrifices to make yourself fast and prepared.  Be around racing as much as you can.  Say “thank you” a lot!  Be a good person to others, no matter what. 

Hi-kick Racing: How much of your talent do you think you were born with, and how much of it do you feel that you have developed?
Bonilla: I was born with a halfway decent brain that enjoys processing enormous amounts of information.  I was born with very good eyes, ears, and a small enough body to fit in the cars I love.  But learning to make the car go fast, I thank my instructors at Skip Barber and elsewhere for teaching me.

Hi-kick Racing: A little bit about racing and the mental aspect of it

Hi-kick Racing: In Kickboxing, whatever happens in the ring is "your fault." For example, a ref might not see an opponent’s dirty techniques. You might take a low blow and become demoralized. In the end, shit happens and that is just the way it is. I feel like racing is very similar to kickboxing in that aspect. How does this effect you? Is it ever demoralizing?
Bonilla: In racing, it’s a little different.  Only about half of what happens is your fault.  We categorize it into “Things within your control” and “Things outside your control.”  In racing, there are thousands of things that happen outside your control, from the car breaking, to a driver taking you out, the weather, or an official penalizing you on a judgment call.  You learn early to blow off the stuff outside your control so there is minimal demoralization.  If you can learn to focus on what is within your control, your performance will improve significantly.

Hi-kick Racing: Do pro drivers have a lot of driving secrets?
Bonilla: Yes, but they also love to tell you how fast they are, so if you ask the right way, you can learn a lot of their secrets.  They will only hold back the really good information that cost them a lot of time and money to obtain.

Hi-kick Racing: What do you do to get ready before a race day?
Bonilla: Simulation software like iRacing, regular exercise (running, biking, weights), eating proper foods, lots of sleep, studying video and data from previous events, discussions with engineers, drivers and coaches, and lots and lots of laughing!  A positive attitude is extremely important.

Hi-kick Racing: What do you eat for breakfast on the day of? Throughout the day?
Bonilla: Breakfast varies with what’s available, but I like to get some eggs, wheat toast, plain oatmeal, fresh fruit, and quality cereals.  Throughout the day I keep things mixed up.  No fried or fatty foods, but I’ll eat pasta, chicken, rice, beans, potatoes, assorted green veggies, fish, salads, really most anything, even a good peanut butter and jelly sandwich!  If it’s close to a race, I might just eat spaghetti and fresh fruit.  Plenty of water, of course.

Hi-kick Racing: Professional drivers seem to be able to keep their cool no matter what is going on around them. How do you keep your calm and focus?
Bonilla: Keeping calm and focus is a matter of training and experience.  Unfamiliarity makes you nervous, so the more you have prepared for a race and the more years of experience you have overall, the calmer you remain.  There are other methods.  Proper sleep and food is critical.  Having an association keyword to remind yourself of a past performance that went especially well is also effective.  Having a coach is also helpful to keep your mind in a good place.

Hi-kick Racing: Do you do any fitness training? If so, I’m curious on what you do and what you feel best helps a driver.
Bonilla: There are many opinions about this.  I keep things simple; running, biking, weights, flexibility.  I’ve also added yoga recently, to keep my balance and core strength strong.  The important thing in my opinion is that you do something regularly!  Playing other sports helps too.  I’m also a big fan of stretching and flexibility, although not everyone agrees with me.  Stamina and heat resistance are also very important.

Hi-kick Racing: I noticed you provide coaching services, and it is a hugely curious topic among enthusiasts.

Hi-kick Racing: Professional athletes, for example, in football golf, or baseball, often receive coaching. In the professional level, how do you feel coaching effects a driver's improvement? What about at the youth and amateur level?
Bonilla: Coaching is effective for all levels, from beginner to pro.  A professional driver simply cannot consider all the possibilities and options for improvement.  Pride makes us blind to many areas of improvement.  An unbiased coach will make you aware of things you would never have considered.  They are worth their weight in gold.  If I could afford one, I would have a coach every single time I drive professionally.  At the youth and amateur level, a good coach adjusts his or her feedback for the level and personality of the driver. 

Hi-kick Racing: Do you think car control at a high level is something that can be taught?
Bonilla: Yes, absolutely yes.  The difference between drivers is how long it will take them to learn, and the ultimate level of achievement (some are not capable of processing the data for the highest degrees of difficulty).  Driver and coach must both have patience and unrelenting desire (and funding!) for the driver to reach his or her goals.

Hi-kick Racing: Now onto the "serious" topic. Racing technique.

Hi-kick Racing: I heard drivers breaking down corners differently. How do you break down yours?
Bonilla: In simple terms, braking, entry, apex, exit, throttle.  There is some overlap on those terms.  Within those terms, I consider what is happening with the driver, with the track, and with the car as separate influencers that could be causing problems and require corrections.

Hi-kick Racing: You once told me and other amateur drivers in a course walk that you focus on the slowest part of a corner, and when you get to that point you minimize the time you spend on it. Could you please elaborate on it?
Bonilla: It’s important to determine where the slowest part of the corner is so you can base your entry and exit around it.  It’s not necessarily to minimize the time you spend on it, but to spend all the time before and after it at faster speeds.  In a perfect world, there is one ideal best possible exit speed.  That helps you to find the slowest point of the corner, then you can arrange your braking and entry to bring you to this point, for overall efficiency.

Hi-kick Racing: How did you develop this method?
Bonilla: My brain is always thinking about efficiency.  I enjoy thinking about what the tires are doing every second in the corner, so I just wanted to understand what to do in simpler terms for my own benefit, and for the benefit of those I coach.  It occurred to me drivers waste a lot of time mid-corner at the same exact speed until they accelerate.  The math of a driving line has one point that is sharpest, or tightest, so why not think of that as the slowest part of the corner?  I didn’t think of this until I had a lot of experience in a Skip Barber car.  I reached a point where I was so relaxed in the car I could think completely outside the cockpit, and “watch” myself from above as I drove the car, making changes to what I do, thinking about what the tires are doing.  

Hi-kick Racing: We would like to know about your lifestyle. A lifestyle of a professional driver.

Hi-kick Racing: What do you do outside racing that balances your life?
Bonilla: Family, school, hobbies, eating and sleeping.  There’s not much time for anything else, but that’s okay.

Hi-kick Racing: If a child, spouse, or parent sincerely asked you to hang up your driving shoes, would you?
Bonilla: I would first ask them if they are sure.  If yes, then I would stop.  Racing is nothing compared to family.  Some drivers would say otherwise, but that’s fine.  I am completely at peace with this.

Hi-kick Racing: Do you get a lot of speeding tickets?
Bonilla: When I first got my license, I got a few!  But, the longer I was racing, the more relaxed and mellow I became on the street.  The tickets dropped way down, thankfully!  There’s just no point in going fast on the street.  Do it at the track, where it’s much safer.  Street cars are like tin foil compared to race cars.

Hi-kick Racing: Do regular sports cars do anything for you? (I'm talking about cars like a Porsche Boxter, Miata, etc.)
Bonilla: Oh yes!  I’m a huge Miata fan, and still autocross it when time allows.  A regular car has to be very lightweight to get my attention.  Sadly, manufacturers have built heavier and heavier cars over the years.  But as fuel economy becomes more important, I’m starting to see some cars start to get lighter again.  For now, I love the Mazda Miata, Porsche Cayman, and Acura NSX.  Those three are very special cars for the road.  There are lots of other great cars, of course, but the light ones win in my book.

Bonilla: I am sorry I took such a long time to reply!  I had fun writing it! It’s just hard to set aside time when work, school, and family all want my time. Thanks again, Gerardo.
 

We greatly appreciate your time Gerardo, thank you so much for taking the time to do this! I think we are all your fans now! I wish you the most success in your career.

Please check out his website by clicking on the banner below. Be sure to check out the coaching section! 

 

Photo caption and credits (Order, from top)

1. Photo of Gerardo Bonilla - photo by Craig Anderson of Mishael Abott's team in Formula Atlantic.

2. In a pro Formula Mazda (Star Mazda) in Montreal, 2006. Note F1 cars to his left. A rough day for Bonilla and many other FM drivers. Story here.

3. Bonilla wins in Sebring, 2006. Bonilla lists Sebring as a track that is very special to him. Photo by Eric McCombs.

4. Bonilla coaching Conor Daly, 2009 Anderson Racing driver.

5. Bonilla at an autograph booth as a B-K motorsports driver (BP-Mazda LMP2) in Sebring, 2009. Photo by Chuck Miller from Mazda.

Minor updates about E-bay coilover kits

In order to get the ride height I wanted, I had to have a new groove machined 50mm below the lowest groove to lower to spring perch. 6 inch springs would have worked, but I was slightly concerned with coil bind, especially if I upgrade the tophats for more travel someday.

One thing to note is that the spring perch is now very close to hitting the upper control arm. It is the inboard side that is very close to hitting the control arm. However, you can get it right up there and it won't hit it along the range of motion. If I remember correctly, at full gravity droop it was not hitting. Good enough for me!

If you live in north-central Florida, I highly recommend Stuart's Cycle to do this kind of job. They have decent machine shop equipment and are very prompt. In fact, when I took them in they were getting ready for a race that weekend. The owner told me he'll get it done in two hours, and it was done a bit before two hours. They are a motorcycle shop so they probably won't do any serious machine work on your engine, but I am sure they will take on whatever job they are reasonably able to do. 

Truth about the E-bay Coilovers

If you've been following the discussions on the Miata Ebay Coilovers you will know that they used to be about 30 dollars. If you've gone shopping for these coilovers you'll know now that they are over 70 dollars after shipping. And if you've ever looked around in ebay beyond just a cursory look, you'll notice that there are the same "ebay-style" coilovers for other cars, listed for cheaper. If you are like a lot of people, it will have crossed your mind that maybe these coilover kits are all the same. And maybe you thought you didn't want to take a risk and spend the money on kits that might not fit your vehicle. 

In this hobby, its always good to experiment and explore. That I did! I have some good news. From what I can see, the various coilover kits are identical. I ordered a set of Celica labeled kits after reading from a truck forum that their inner diameter is 2 inches. From what I've found, Celica, Accord and Civic ones are listed the cheapest. Please note, there are different coilover kits on Ebay. It is picture and vendor dependent, not car model listed dependent. You can check on various car forums too. One thing is for sure though, the Celica ones are the same size as the Miata ones.

Why would they label them differently? Well, as you may already have guessed, people probably aren't going to spend money on universal kits. Especially if they were already skeptical about the low price. People who are "car guys" as opposed to "track junkies" or racers really care a lot about their cars and want to buy only what is best for them. Kind of like spending a lot of money for gourmet cat food. Plus, it allows them to price discriminate beautifully. Perfect example of this at work is our Miata situation. We started picking up these kits fast, so the Miata labeled ones sell for over 30% more. Actually, they aren't even labeled. The listing title is the only difference.


Dimensions (Sleeve, perch, and locking ring): 
Length - Front 130mm, Rear 80mm
Inner Diameter: 50.5mm 
Weight: Front 330g Rear 245g (approx)


Truth 1 - Material
These coilovers are claimed to have been made from the same materials as most other kits. T6 series aluminum. 


Truth 2 - Threads and Machining

The machining is decent. Threads on the sleeve are pretty clean. The only part where the machining was scrappy are the holes on the bottom of the sleeves for threading in small screws to secure the sleeves. By the way, I don't think these screws and holes need to be used. This was my main area of concern; are the threads on the shock body well made? See for yourself. Good enough for me. 


Truth 3 - Fitment
If you have any 50mm diamater shock, it will fit very nicely. There is a slight amount of play, probably resulting from the approx 0.5-0.8mm difference. If it worries you so much, put a piece of paper in there. The supplied O-rings will probably work just fine with smaller shocks.


Installation steps
First, remove the C-clip from the top groove of the shock. Just spread out the ends with a pair of small screwdrivers, and then carefully slide it off the shock. Then pull out the hardware for the bumpstop/accordion shaft guard assembly. That way, you can take off the Bilstein spring perch, which is sitting on the lower C-clip on the bottom groove. Put your threaded sleeve on this groove. If this worries you, leave the spring perch and put the sleeve on top of this. You'll lose out a little bit of range though. You should be fine with it sitting on the C-clip. You will have to cut off the bit of the sleeve that is exposed over the end of the shock, or else you'll lose out in that much suspension travel. Oh precious suspension travel. Better cut that off. Just use a hacksaw. 

Thats it! If you have 50mm shocks, no adaptors, rings or anything of that sort needed. If you have an AFCO, Ground Control, Bilstein, or Koni kit that you will be willing to ship to me, please let me know. I would love to do a visual comparison of these kits.

Spring lengths

If you use the setup above, you need to use 6" springs. The more expensive springs are your only option. I took my shocks to a local motorcycle shop and had them machine a groove 50mm below the lower groove, and I was able to use 7" QA1 springs to get the ride height desired.

Here is a list of updates related to the E-bay coilover setup

Rod's update: NB Bilstein HD and Ebay Coilovers

Minor Updates (machining grooves to get correct ride height on 94 R package shocks)

Choosing a coilover setup

Technical Difficulties

So just as I was about to take finals this morning, my computer stopped working. Its only been two years since I bought it. Whats up with electronics nowadays not lasting that long? It caused a bit of trouble for me during the day today.


I am pretty sure something on my video card is wrong. It will display on my roommates LCD moniter via VGA cable, but it nothing on my laptop's display. I am also certain it has to do with overheating. 

I was going to make an update because I found a cheap source for coilovers. Yes, the "ebay-coilovers." Old news? Well, check the price. Nowadays they are 70-100 dollars after shipping, might as well buy AFCO pieces or go with your shock manufacturer's specific threaded sleeve and perch kit. The Koni ones are pretty cheap, and the Bilstein kits run about 200 for all four corners. 

Well, I'm going to take apart my laptop and try and fix it. I have a lot of racing data I recorded and I never made a backup of it. I also have a lot of digital copies of race engineering books and articles that I never backed up. Great! I may not be able to make any updates for a while. 


Good news is I am done with finals and now I am a third year law student! I have about a week of break and work starts middle of this month. O-town, here I come!

Threaded sleeve and perch kit options (AKA Coilovers)

I am upping my suspension rates again. My new setup will probably be too hard for my Bilsteins, but one day I'll be getting the revalved for even higher spring rates. An intergal part of my project is the ability to adjust ride height and use standardized spring sizes in my suspension. Threaded sleeve and perch is what I need.


Ground Control sleeve/perchs used to be the most popular kits. A lot of people don't know all the choices out there. Talk to any dirt oval guys and they'll tell you a lot of cheap, high quality options. If it is good for these guys you know it is good for us. I haven't bought any of these kits so I can't do a review on them, but I'd like to list these so we'll know that they exist. Oh, and also, coilover kit is much easier to type than threaded sleeve/perch kit, so I will just refer to them as coilover kits from now. 


1. Bilstein/Koni kits
Bilstein and Koni both make coilover kits for their shocks. Bilstein shocks for Miata are 50mm in diameter. Bilstein makes kites one for a smaller, 36 milimeter diameter shock and one that is 50mm. Bilstein coilover kit takes 2.5" springs. I believe the Koni sport shocks are 42mm in diameter. Koni makes a kit thats 42mm and 50mm.  You can probably use the 50mm Koni kit for the bilstein shocks. Bilstein kits are slightly cheaper so there is actually no reason to do that. Too bad Koni shocks for miata aren't 50mm? I think their RACE shocks are monotube and might be 50mm. If you have a set of these shocks please let me know what the diameter is and I will update this post. 


Part numbers for 50mm and 42mm kits
Bilstein: BSN-B4BOA0000117
Koni: 80-0000-1


2. AFCO Kit
AFCO has different series shocks. The ones we should be looking at are AFCO smooth-body shocks. I believe oval guys use these shocks a lot. Anyways, I have to apologize, I found out which series shocks are at the size closest to the Miata applications. If you do  some google research and find out, please let me know. AFCO makes threaded sleeves for all their smooth body shocks. The thing to do would be to get the sleeve thats very close but bigger than your shock body outer diameter, and make a sort of centering ring. Rubber o-rings, PVC pipe, etc are all options. These are cheaper than the Bilstein/Koni kits, and the sleeve material is steel. They sell each part of the kit seperately, so if you drive an NA you can probably save money by ordering just the sleeve, perch, and whatever else you need to secure the perch.


3. Mystery Ebay kit
If you go on any car forum, these kits are in hot debate right now. A lot of skepticism and optimism about them floating around. These are under 100 dollars and are by far the cheapest option. If you've noticed "economy" is a big theme in this blog. So guess which one I picked? I am going to make a seperate post goimg into detail behind the truth of these kits, so please check back!


3.5 Ebay-OBX kit
OBX, who have made sort of a brand name for themselves through their sales of decently priced medium qualify exhaust hardware and misc. parts, have started making coilever kits. As i will explain later, I can't imagine these kits being substantially higher quality than the other ones. 


Note on materials
All of these kits and the Ground Control kits are made from T6 series aluminum, with the exception of the sleeve part of the AFCO kits. They are all machined. I can't imagine any other way to make them.