TAKE NOTE THAT THIS IS A DISCUSSION AND IF YOU SHOULD WANT TO THANK/SUGGESTION FOR ANYTHING/ ANYBODY FOR THIS INFORMATIVE THREAD (i.e: soulfly or who ever) PLEASE DO IT BY PM! THANK YOU!
Edited by: antonio_zth
Edited by: antonio_zth
Basic intake and exhaust modification guide
(for normal aspirated cars) v1.11
by soulfly
(for normal aspirated cars) v1.11
by soulfly
Introduction
This write-up is to help our car newbies in upgrading their car performance in a minimal way, and the correct way of course. No surbo, no micro compressor, no cyclone, no turbo jet, nor stromberg, heck not even stupid magnet gimmicks nor fake blow off valve! And the most important thing is, this guide will retain street drivability and very minimum noise increase (if possible).
Intake modification
The factory airbox has its own benefit such to avoid your filter from water splash as well as to reduce engine noise. Some people might think that the factory airbox is restrictive, but it is not always true since there are also aftermarket performance airbox as well. For example, the infamous Mugen air filter box (for Honda) which is actually smaller than OEM airbox. Another famous brand is ARC, which also makes intercooler, oil cooler and other performance stuffs.
1. Standard drop-in filter
If you hate engine noise, OEM filter replacement is what you would want. The standard drop in filter is actually not that bad. It is just that it has less surface area which restricts intake air suction. You can get those aftermarket performance drop-in filters such as K&N, Pipercross or HKS (just to name a few). However, I would like to remind that sponge type filter (such as HKS SPF) might have the best airflow but it's the worst in filtration. To choose a good aftermarket drop-in filter, you must make sure that it has more surface area compare to stock, else it is just no better. Performance drop-in usually does not give the best high-end power, but expect some good low end gains.
Pros : less noise, good low end power, low profile look
Cons : a little restrictive, sometimes no better than stock
2. Open-pod type filter
The airbox is removed and cone or dome/mushroom shaped filter is installed. Open-pod usually have more surface area compare to drop-ins because it has more surface area, thus more air can be sucked. However, this setup tends to suck hot air from the engine bay especially when the car is in parallel. Hot air is not good because it tend to have lower mass compare to cold air. Cold air has more mass, and more oxygen for combustion thus creates more efficient burning and more power. Somehow, this is not an issue when the car is moving especially at higher speed. Some people make heatshield to avoid hot air from the engine being sucked to the air filter area. Another good way to get cold air source is by having a cold air intake or air duct to supply air from outside of the car. Usually the air duct is placed behind the bumper. Another idea is to use custom long intake ram pipe and the air filter is positioned behind the bumper. The downside to this setup is that the airfilter can get dirty easily since our road is quite dusty and we have rain throughout the year.
There are many choices out there but most people would get K&N due to its reputation and availability. Another recommended one is the APEX'i Power Intake. This filter has one of the best filtration per performance compare to other competitors. HKS Super Power Flow is somehow not recommended for street usage due to our dusty road condition since it has poor filtration. For a user with tight budget, Simota would be a good choice if you want to try open-pod setup plus the aggressive sound of the engine.
Pros : better intake suction, more midrange to high end power
Cons : more noise, possibility of sucking hot air, can get dirty easily
3. Aftermarket intake ram pipe
Some of you might wonder whether to get aftermarket ram pipe or use the stock one. If you are getting aftermarket ones, make sure it is built with quality. If possible, avoid stainless steel ram pipes because they tend to absorb heat easily, thus increasing the intake air temperature. Iceman makes good ram pipe which is heat resistant. Size is also important. The smaller the diameter, the higher air velocity and the bigger the more air mass is allowed. Too small would be restrictive and too big is a waste. However, there is a type of ram pipe design which is fat in the middle. You can find this type of setup in some Honda. I am yet to find out the advantage, but the design is probably optimized for VTEC operation.
Pros : smoother air flow
Cons : possible heat issue
This post has been edited by antonio_zth: Feb 16 2006, 07:18 PM