I'm sure cams can gain alot of power on a fully built motor with ITB.

 

like i said...might as well get the entire engine rebuilt...i know somebody has the funds to do it....dont let me get some money..i would have such a beast..lol

 

I still need to clarify my misconception about the exhaust diameter size.
For an F/I motor, you would need a larger diameter to keep the "forced" gasses out. N/A works somehow different. It needs back pressure to perform well without restricting the flow.

keeping the diameter sized perfectly enough to have the piping full of gas with the least restriction to create a constant stream/flow.

Too big the diameter will disrupt the flow of the exhaust
Too small will restrict the volume.


Now come on flame me

 

why would we flame you. this is your believe, and there is a lot of proof to back it up correct? I only say show me the proof of this for the S2000.

The bigger diameter may cause less increase in low end power, but it'll show better increase up top. So far I have felt no drop in bottom end performence with my 3inch system, and the car feels a lot better down low.(this is a 3inch combined with a test pipe).

While it feels great down low the biggest improvement is seen up top. The car just keeps revving, and the revs climb so smoothly. no restriction, and the car pulls hard throughout every gear. My car already fwlt good top end with my other mods, and now I can feel the improvement made by the addition of the exhaust system.

while I will agree with you and say a bigger exhaust piping(3inch) may not be good for all motor cars(unless fully built), I will only say that it may be so for cars like a civic or integra. I believe a 3inch system works very well with an NA S2K.

 

Agreed. But i am curious to why most of the japanese performance manufactures do no use the 3" exhaust.
I only know one japanese manufacturer who has a 70mm (2.75") and that is J's racing. And only recently was this developed, probably for the demand, since they used to have a 60mm without resonator in their race car.

Since the power increase is not drastically changed compared to FI, an upgraded 60mm exhaust system which would have the characteristics as follows should suffice IMO.

straight as possible
single
mendrel bents
free flowing muffer
no resonator

For example, an exhaust which is mentioned on this topic would be the T1R 70mm. what about if you had to diminish the diameter to 60mm and remove the resonator, wouldn't it have more or less the same flow ?

 

There actually are companies that make 3inch systems for the S, but they all classify them as turbo systems. I believe amuse was the first to have a 70mm exhaust system for the S2K, and even that was they called the turbo version. although many used it on there NA S's.

I am not sure about your question regarding a 60mm with those specs. Although a resonaor does not cause a decrease from the gains received from an exhaust. It's merely used to quiet one. While your suggested 60mm would show good gains, the question is will it be best suited to have with your supporting mods. While the gains between the 60-70mm exhaust system may have minimul difference when having only the exhaust. The benefits of having the 70mm show once other modification are added(header, test pipe,etc.)
The J's racing is is one of the lightest s's out there, and I believe at the time when they only had the 60mm they got rid of the resonator to loose weight. In race cars like that they strive to loose as many lbs as possible.

Obviously the weight lost by doing that was regained by using the larger 70mm exhaust system, but the benefits/gains seen through the use of the 70mm mut have been to good to pass up.

It did take sometime though for companies to start coming out with 70mm exhaust systems for the S, but once the benfits were seen more companies have started to do so.
I think all it will take is for one company to release a 3inch system showing better results, and the res will follow.

 

the back pressure theory is kinds here and there. it apply to some engines but no others. for example...

v8's hate back pressure, if you run them open header the make awesome power, on the average.

the theory is that I4 need back pressure to make hp/tq. not always true. my car runs spoon n1 with a test pipe. the only things that make exhuast not a straight pipe are the muffler and resonator. not much blockage as they are both straight through. my car makes good power like this. hell the stock exhuast it pretty wide open,not to many obstrutions. the s2k is very well designed and and flows well, it likes to have no back pressure. i predict that ruben with his 3 inch will make good power and tq.

 

 

prove me right!!

 

defenitly going to try too.