3 ms·
Pollution concerns aside, your valves are timed and the manifold ports are shaped to work with the back pressure provided by a working cat. If you didn't compe
by noonespecial 7y ago
Pollution concerns aside, your valves are timed and the manifold ports are shaped to work with the back pressure provided by a working cat.
If you didn't compensate for this during the modification you've likely cut the working life of you head(s) by half.
- dsfyu404ed 7y ago>ports are shaped to work with the back pressure provided by a working cat. This is a 100% urban legend BS myth. There's a partial exception for two-strokes where if you tune the system right you get a resonance wave that lets you pack a little more mixture in on the intake/exhaust stroke. Literally no 4-stroke ICE benefits from back-pressure in any way. It's just that sometimes the things done to reduce back-pressure (small exhaust pipes being the primary one) seem like they would increase it and vice-versa hence the urban legend. Edit: Who the heck is downvoting this? This is how ICEs work. Google it if you don't believe me.