Formula 3 cars are very high priced, high quality pieces. In Europe they are made by Dallara and Mygale. Not sure what the Japanese use. They are an all carbon tub much like an Indy or F1 car.
One benefit of the restrictor is that it acts as a sort of rev-limiter. I haven't done the math but I would surmise that 8400 RPM is going to be close to all it will achieve at 26mm. Might not even be able to get there. Another benefit of the air restrictor is that it allows a number of engines to be competitive as camshaft specs, etc are not limited within the rules, only the air and that the parts have to be "stock". I believe that the head and block have to be production castings and that all the reciprocating parts are "free" as well as cams and intake and exhaust manifolds. They are probably at least at 15:1 C:R and the cams will be as much lift as they can stand without coil binding the valve spring. The cams will be set with almost no overlap because at full RPM the air box runs at slightly negative pressure and that is when the restrictor kills the HP and the driver guy knows when to shift. I am sure that there is no vvl and maybe they have valve timing but I doubt it. Usually these type if cars operate in a 1000 to 1300 RPM window, 6 speeds and 1000# cars don't require much of a first gear. First is probably good to 60 or 70 MPH with the 1300 RPM gear splits beuond that to get to 160ish top speed.
SR20VE is going to be at a little bit of a disadvantage to some of the other 2.0L engines that are under square (longer stroke, less bore) as the restricted formula is all about getting torque as low in the rev range as possible. If the head would take it (in terms of being able to make the ports flow) a later model 2.0L engine (like the MR20DE 84x90.1) might work even better but the SR may have the advantage because of the rocker arm, allowing more valve lift. Not sure if MR have rocker or direct bucket lifter.
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Originally Posted by BenFenner 
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