Close-Up: The Power of K – ASLAN EF9

I’d wager that ASLAN, the Osaka based Honda outfit, is one of the leading shops in the development of K-series Honda swaps in Japan.  Following in the footsteps of America, it didn’t take long for them to capitalize on the benefits of the next generation motor.  Having no adherence to a traditional form of tuning like some shops abide by, Tani-san’s approach to building cars becomes very unique to say the least; giving each a very specific, what I can only surmise as an ‘Osaka flavor’ to them.

If you want to get a good idea of what I’m talking about, you need only take a look at Ton’s EG build to fully understand what I mean by ‘Osaka flavor’.  This EF9 is kind of a toned down version of builds that come out of their shop.  The Petronas Green, K-powered hatchback spends most of it’s time at tracks near Osaka, like Central, but recently made the journey over to Ibaraki to try it’s hand at Tsukuba.  The owner has put down a best time at Central Circuit of in the 1 minute 24 second range, and so was hoping to hit about a minute around TC2000.

The K20 makes about 230 horsepower thanks in part to a TODA ITB setup and a few other ancillary modifications.  In a car that weighs only 1700 pounds, you can imagine what 230hp feels like (it feels good).  The valve cover has been paint matched, and hey, what the hell, why not paint match the fuel rail too.  Since they’re using the stock hood, it needed to be trimmed to fit the fuel rail and as a result, it sticks up through the hood.  I guess for continuities sake, it was also painted teal green.  The rest of the exterior is pretty mild.  A Five Mart rear wing and wide front fenders are pretty much the only panels changed.    ASLAN has ties to the Kanjo team, Temple, and a few things like the obvious decals, and window netting are a tip of the hat to this relationship.

Because anything bigger on EF’s looks funky, the car is on a set of 15″ TE37’s.  225 series tires up front, and a set of 215 in the rear give the car a small bit of stagger.  Spirit coilovers handle the turns, and Spoon monoblock calipers handle the stops.

The owner was able to clock a 1’02.83 for his first time at TC2000.  It’s a long trip, but hopefully he’s back with the team again to try and best that.

Enjoy the photos from CTAC and Attack and have a great weekend.


  1. This used to be Aki’s red EF last touched by FIVE MART for Osaka Auto Messe last year before going to new owner I believe.

  2. Nick Generazio

    A 1.02 is pretty damn good, considering that was his first run at Tsukuba!

  3. Awesome chassis. I like the looks of the EG, but the EF is much easier to make fast. Although, I do have a preference for the 4-door version, because it feels better at high speed. Unfortunately, you didn’t have a coupe with the 4-door wheelbase, so that’s why I usually end up preferring the EG. I believe a coupe EG is probably ‘the best’ platform, but the EF follows in a close second.

    I was never a fan of the EK chassis look, but it certainly has a stiffer frame than the EG. For racing, those small production differences aren’t as important, because usually a cage will be added to the car.

    Also, I find it funny how inferior the DC Integra is to the little bro EG. In many respects, it’s a much better platform, especially because the rear hatch and glass on the DC.

    Basically, Honda knew they developed an awesome Civic with the EG chassis, and in later years, the ended up neutering most of it, probably because the performance of the EG was superior to the DC, and EK chassis. Of course, this closely coincidence with the start of the 30 year long economic stagnation of Japanese industry. Because of this, I am no longer surprised that the early ’90’s Honda was the peak of the value/performance ratio. At the time, Japanese manufacturers were trying to take over by producing a quality product. It is kind of ironic, that the chassis produced in that time, are STILL better than the ones that Honda makes in 2018.

    Actually, it’s kind of depressing when you think about it, because obviously, Japanese manufacturers have the expertise, but they are no longer willing to create a low-priced competitive product. There is ‘purposeful neutering’ on all the lower priced Honda vehicles now. They have horrible suspension (can you believe that the ‘successor’ to the EK Civic Si, was the totally crappy EP3. Which, I know, has plagued people trying to transform it into a racecar.

    Now, Honda keeps the double-wishbone chassis design elusively on higher priced models.

    I think, if Soichiro saw what Honda is now, he would be rolling in his grave, “What did you do to my company???” Remember, Honda was the first Japanese manufacture to build F1 cars. In all respects, Soichiro is the Japanese equivalent of Enzo Ferrari. Obviously, at a lower price point.

  4. A little surprised to see windshield wipers on this car, not to mention the washer fluid bottle and piping. For one, the entire assembly is somewhere around 10 lbs, and it is located pretty high up on the chassis. Easy to remove, and relatively painless. In the summer, I remove motor and wipers even though I am operating a street car.

    Also, there is a small aerodynamic benefit from removing the wipers. Certainly, at high speeds it becomes even more important, as it can interrupt clean airflow to the rear spoiler, or wing.

    If you are concerned about visibility, you can add anti-fog to the windshield, and either soap or ‘Rain-X’ to the exterior. Both methods were excellent at making the glass shed rainwater.

  5. Also, I can’t see any kind of ‘ram-air’ intake system. It is proven, that at high speed, you can gain anywhere from 5-10% more power from a properly designed ram-air system. It’s a lot like having a turbo, because the intake goes from negative, to positive pressure.

    Obviously, constructing a nice air-box, with a ram-air tunnel to the stagnation point on the vehicle, is a pretty big undertaking, but the benefits far out-weigh the costs.

    “A 0-1 inch of water Magnehelic pressure gauge was used to measure the pressure within the airbox. This is an extremely sensitive gauge (we’ve covered them before so to find out more, do a site search under ‘Magnehelic’) which is easily able to monitor pressure variations of this type. Testing showed that at 100 km/h, a pressure of 0.6 inches of water was present within the airbox – that is, the airbox was under positive pressure. Even at full throttle at this speed, positive pressure was maintained within the airbox – an excellent result. Positive pressure could also be measured at lower speeds – eg 0.2 – 0.4 inches of water in cruise at 60 km/h.

    These measurements showed that the two air feed supply pipes were not only providing enough air for the engine’s needs, but they were providing more than enough!”

Leave a Reply