Thorin Posted May 21, 2007 Share Posted May 21, 2007 Sweet. That'll do me nicely:) Double decat on an NA is LOUD by the way Quote Link to comment Share on other sites More sharing options...
hoff Posted May 21, 2007 Share Posted May 21, 2007 Yeh I have heard that. My supe is very quiet at the moment so am looking for a bit more. Hopefull just doing the 2nd decat wont be too bad. Quote Link to comment Share on other sites More sharing options...
sipstrassi Posted May 21, 2007 Author Share Posted May 21, 2007 Sorry guys still no wiser. so if i put the decat back in. the resultant wave (back pressure) will help the engine produce more torque and horses. I had intended to purchase a manifold from Nic but will this also affect the torque and horses. pete Quote Link to comment Share on other sites More sharing options...
Dr_Doom Posted May 21, 2007 Share Posted May 21, 2007 Yeah, okay, I see my error of explanation... By changing the exhaust to a bigger bore, it would change the resonance frequency (causing the engine to breathe via the exhaust at a different time/frequency), this is required in order to time the waves at the same time the exhaust ports open, so not only does the engine push the combusted material out, but the resonance frequency would set up a wave, if timed correctly the removal wave will help pull the air out of the exhaust ports.. I assume then the intake is the opposite, utilizing the push wave at the correct time to further push in more air into the chamber. On the opposite side, the wave would also help keep the fresh air in the chamber while the exhaust valve closes. My thinking/explanation more correct now? It may be an accurate explanation but i can't make head nor tail of it .... Any chance of it in English please Will double de-catting an NA lower the performance?... When i double de-catted my NA it did feel a bit quicker. The problem was i couldn't give it a decent test because it was so bloody loud! Quote Link to comment Share on other sites More sharing options...
sipstrassi Posted May 21, 2007 Author Share Posted May 21, 2007 i was under the impression the easier the engine breathes the more power you have. stock air box is suppose to be good. bigger bore exhaust and decats. should not mean loss of torque or power. where am i going wrong? Pete Quote Link to comment Share on other sites More sharing options...
uk-rich Posted May 21, 2007 Share Posted May 21, 2007 It may be an accurate explanation but i can't make head nor tail of it .... Any chance of it in English please Will double de-catting an NA lower the performance?... When i double de-catted my NA it did feel a bit quicker. The problem was i couldn't give it a decent test because it was so bloody loud! i still want to hear it with the tubular manifold on Quote Link to comment Share on other sites More sharing options...
Ricardo Posted May 28, 2007 Share Posted May 28, 2007 I too have experienced a loss in power since replacing my stock exhaust and installing the XSPOWER system. Both my CATs are still in place and it's still noticeable, a lot less reponsive on the throttle too. Are you guy's suggesting that the ECU needs tweaking to compensate for the free'er flowing gas? Would it have been better to have left the centre sections in place and just replaced the backbox? Quote Link to comment Share on other sites More sharing options...
Thorin Posted May 28, 2007 Share Posted May 28, 2007 You should not notice a decrease in performance, in fact with both cats in place you wouldn't really notice any performance difference. Quote Link to comment Share on other sites More sharing options...
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