bigwillystyle:
hi guys, i see it has been a long long time since anyone has talked about plenum!
i currently have a fvd sport exhaust and bmc filter, i am think of getting more upgrades, can anyone give me some suggestions, i am thinking of getting either an ecu upgrade or just headers with plenum (so i can keep my warranty).
thx
Hi Willy, all in my humble opinions:
Header, intake plenum, filter, air box, diverter valve, etc., are all controversial (just search for "header" on Porsche forums for example) and should be saved for later stages of modding, or maybe not at all.
The header is probably one of the most mis-used mods, probably because it is relatively inexpensive and could be installed easily. It is an advanced level mod, definitely not for stock ECU, and people would even argue you need to do a specific ECU tune when you add header. Used wrongly, it could cause power loss in certain rpm bands.
If you want to "play around" with the engine compartment, there are, at the basic level, 3 simple steps you should concentrate on (again IMHO) and ignore everything else that people are trying to sell :
a. Change exhaust to a more free flow system.
b. Tune the ECU.
c. If you want more power, then the next thing is the Intercooler, with a re-tune of the ECU if possible. Even without a re-tune, a better intercooler would still benefit (unlike the header, for example).
The following is a pretty good discussion. Go there and read about scavenging effect also; pretty cool.
>>>>>>>>>>>>>>>>
http://en.wikipedia.org/wiki/Manifold_(automotive_engineering)
Great care must be used when selecting the length and diameter of the primary tubes. Tubes that are too large will cause the exhaust gas to expand and slow down, decreasing the scavenging effect. Tubes that are too small will create backpressure against which the engine must work to expel the exhaust gas from the chamber, reducing power and leaving exhaust in the chamber to dilute the incoming intake charge. Since engines produce more exhaust gas at higher speeds, the header(s) are tuned to a particular engine speed range according to the intended application. Typically, wide primary tubes offer the best gains in power and torque at higher engine speeds, while narrow tubes offer the best gains at lower speeds.
--
Regards,
Can
997 Turbo + Bilstein Damptronic ( Review ) + GIAC ECU Tune ( Fast as a torpedo & reversible to stock - Review ) + Cargraphic Exhaust ( Oh heavenly noise! )