Boost Or Bust - Honda S2000 Turbo Build

[JoeThaMan]

Boost Or Bust - Honda S2000 Turbo Build
Engineered with one of Hondas most refined motors from the factory, the F20C was the weapon of choice for the '00-03 Honda S2000 (AP1) in the U.S. and the '00-05 overseas. Known to spin the tachometer to the tune of 9000rpm, the high revving 2.0L engine produces the highest horsepower per liter for any naturally aspirated car currently sold on the market for less than $100,000, producing 121.9 hp per liter. Shoehorned in a rigid X-frame body with 50/50 weight distribution, the S2K showcases a roadster that possesses exceptional handling, nimble power and sporty exterior features that prove even the most macho of men can drive with its top down without looking like a complete candy ass.
While the average S2000 owner would be more than content roaming the streets in a 215hp and 153 lb-ft of torque machine in normally aspirated trim, it's not a common occurrence to see the more hardcore enthusiast bolting on numerous performance products in a quest to bump up the power. Elton Lo, owner of Raceline Development located in Temple City, Calif., led me to a possible story that involved a crippled S2K that managed to limp its way to the shop. Unknown engine conditions led us to believe that the S2K's once mighty powerplant was running on three cylinders as the constant sputtering and oil filled smoke cloud left in its wake was a good indication this motor was complete toast.
After diagnosing the problem and further discussions with the owner, Lo and I had mapped out a plan of performing a complete rebuild on the F20C while adding an amazing twist that would include the vehicle boosting 22 to 23psi on 91 octane pump gas and tuned to deliver 400 wheel hp. My initial response was simply: "Boost or bust, this should make for one hell of a story. Let's do this Elton!" With that in mind, we begin part one of a two-part series, by fortifying the once-injured F20C powerplant as we tag along with Raceline to show the ins and outs of what it takes to rebuild this 1997cc engine. Stay tuned for next our issue as we tackle the final engine drop-in and fuel management tuning as we crank up the boost and look to deliver some serious power.
Raceline recommends following the manufacturer recommendations on how much piston ring gap per bore, but depending on the type of applications, Lo says you might have to alter the specs. A prime example would be if the engine is built as a street motor running on Arias Pistons. Lo says, "Go by Arias' specs on piston-to-wall clearance, which they usually recommend three to four thousandths of an inch depending on piston size. Ask your manufacturer if the piston is 2618 forged aluminum, which has no silicone content within the piston, or a 4032 forged aluminum unit, which is a silicone content piston." Both pistons have different expansion rates where the high-silicone content piston will tend to expand more. The 4032 aluminum expands approximately 15 percent more than 2618 aluminum. The 4032 pistons have greater wear characteristics because of the silicone particulate hardening the alloy and reducing the thermal coefficient of expansion. However, a silicone aluminum alloy piston can turn brittle and become prone to fracturing when subjected to extreme stress. This is the main reason why we choose not to use a 4032 aluminum piston in our forced induced S2K, because it will be seeing a lot of cylinder pressure from the large amounts of boost we plan to run through the engine on pump gas.

Photo Gallery: Honda S2000 Turbo Build - Import Tuner Magazine



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