If you consider the header as a "stand alone" performance piece to obtain a HP gain, the choices are easy to base on dyno charts versus budget. If you consider the header as part of an engine system you will be building later it gets a little tougher.
The Spoon header already has valves, springs, cams, injectors, pistons and an ECU purpose built to match its back pressure. Although not pictured on Kings site, Mugen has a 2200 stroker kit with an ECU to build future expansion from. Also Mugen's research clearly states that it is imparative to have a heat shield between the header and the master cylinder, which is a tested result.
I have learned from posts by UL, Cdelena, Pepe and others, just how sensitive the F20C is as a system since it was already fairly purpose built by Honda. What are members opinions about how important header matching is to future bottom and top end work?

 

This would apply to rhd drive cars. I havn't read anything about how heat sensitive the battery and other components are on that side of lhd cars like ours.

 

Yeah, didn't even think about right and left side, thanks Prolene, one post and one issue removed.

 

Cool! What makes these message boards so valuable!

 

I wonder why there's a heat shield on the stock header?

 

stock header is a heavy mild steel piece and radiates heat very well. as UL had mentioned SS has better thermal properties (in terms of keeping the heat), so if you got SS header coated like i have, the underhood temps are tolerable, though i did not think to compare temps (something i should've done) with before and after, but i do feel that the coating is worth every penny.

 

The new DC header seems to be the best bang for the buck rite now..! although there's less top end compare with spoon and mugen...

 

No doubt as a stand alone the DC price is attractive - I would just be concerned that if I had Spoon headwork and pistons in 2 years, Spoon may say the back pressure of the DC is not ideal, and if I went with a Mugen stroker in a couple years, Mugen may say the Spoon or DC is not ideal, so if you think of the header as part of the whole system (header, head and intake) you should choose the manufacturer which all components work in harmony together so you can expand later without compromising any upgrade's power potential.
It was just simpler before ECU's. You put on parts knowing they performed a function. Now, an ECU will adjust that function if it's not happy with any parts participation so they have to be well matched. Spoon and Mugen make me do this but make my wallet do this and DC makes me do this

 

Might want to eliminate the Mugen stroker kit from the equation. There are currently only three in existance (and one's on a static display) and Mugen has no plans to market the kit. According to the powers that be, the fact that the camshaft is about $5K US alone severely limits its market potential.

 

If one Mugen cam is 5K, what the hell do the oversize pistons cost? SCARY! Spoon cams are $500 each, waste valve set and springs $1000, head gasket $230, ECU $1600, header $1250 - coupled with a $125 proflow TB and your in the 5K neighborhood for the top end. Bottom end high compression pistons are 3K.
1. What kind of NA HP and torque do you think the F20C could generate from just doing the top?
2. Top & bottom?