HOW TO: SP20 Intake Modification

[WAR-20B]

Originally Posted by LordWorm

You can also remove the big fat bong shaped resonator.... i found a lid from a paint can, and electrical tape was perfect for plugging the hole on mine Ghetto ftw!

Not a very wise idea.

Ever heard of Helmholt resonance...?

AVOIDING this resonance is the reason why manufacturers use the resonator box.

When you remove it, you hear more induction noise. This is due to a coarser air flow into the AFM. The resonator smooths this air flow allowing more air down the pipe for its given diameter.

They are very common on NA cars especially in F1 where air speed along a pipe is critical.

Here is a web site to explain the technicalities of "that little box" > Here <

If you shorten the intake tract with (say) a pod filter, then you shift the resonant frequency up beyond the rev range so its not an issue.

However, if you keep the longer intake tract (standard pipe work) then the resonant frequency of that intake tract is lower & (usually) within the RPM range of the engine. Thus the need of the Helmholtz resonator to overcome it.

REgards