I am sorry in advance coz I tried to stay away from this topic but I couldn't, must be the itch in my ass. Must go see a Doc! I think Mugen should contact you for their next project, what they could not do has been achieved by you.
"so..when you talk about the stock engine in a city..then according to POWER to WEIGHT ratio..you can get approx 267+bhp..putting in ceramic coated headers, cat-back, exhaust, cold air intake, MSD 6-AL, irridium plugs, 7-core metal wires..etc..will take me to approx 280bhp..putting in Apexi's VAFC-2 and tuning it to perfection takes another 10-15hps out of the engine..thats for the initial set-up.... over everything else ive got 75-shots of NOS..
i am getting somewhat approx 300+.."
1st of all B18c5 is rated at 200ps=197hp. Yes there is a difference between hp and Ps.
2ndly like i said I am surprised that you did not get a call from Mr Mugen himself. To get 280hp from just simple upgrades is outstanding. No matter what type of headers you try on the b18, at the most you will see a gain of 2-3hp and loose the same amount on certain rpm curves which has been proved and tested on dynos by Turbo magzine and they found the best header to be the stock one.
Catback exhaust again it has to work with the whole exhaust combination from the headers to the muffler, gains are again 2-4hp.
Cold airintake, will give you again maybe depending on the type used will give you 1-2hp gains.
MSD 6-AL, irridium plugs, 7-core metal wires.. well they will only make the engine idle and run smoother. Sorry on a N/A no noticable gains.
Apexi's VAFC-2 It is a fuel and air manipulation device and can also control vtec engagment. Again trying improve on what has already been maxed out.
So the only proper way too see big gains is forced induction, and you are using N2O 75shot yes that will give you gains. But not neccassarily 75hp more like 60hp max.
You see all these combined make a difference but not over 300hp, I think you have been misled.
As for the drag with 350z(most of them in Pak are Autos, I do not know why but they are I guess those are the cheap ones in Japan) well yes you could have beaten it easily with the B18 in the City, but you should have disspeared from the view with 300+hp. I say why don't you dyno your car and you will see what I am saying. The manufacturers of these products promise big gains, which are marketing gimicks. yes they do give gains but used with combination of other things and products, but according to the dyno you loose hp also with certain products.
As for the B18C which is a very efficient engine and has been moded max from the factory itself. Mugen itself modified the type r engines and cars. When they couldnot get more out of the engine they lightened the cars and the improved the suspension that is where they got the lower 0-100kmh numbers not only from the engine.
Hope you folks are not offended but my apologies if I have.