Peter_95

iTrader: (2)

because if you lose some backpressure, the car will lose hp.

So you deleted the center cat, the 2 resonators and the mufflers right?
kinda loud... but i know videos usually exaggerate any sound.....
if you kept your center cat, it would be quieter.

madmax98

With all due respect, not true, and it's a very common misconception.. Backpressure is bad for any engine, at anytime and any RPM area. A free flowing exhaust is what people should be after, but only in a perfect world this would be possible at all RPM areas. To explain, if one wants to achieve free flow at 6000 RPM, oone would need a 4" exhaust <for example>. Howev
er, at 2000 RPM the 4" would hurt performance. The opposite is also true, if one opts for a 2" exhaust to promote performance at 2000 RPM, performance is then hindered at 6000 RPM.
You want gases to keep on moving uniformly as fast as possible. With that in mind, in addition to fluid dynamics and physics laws, the smaller the pipe the faster the flow. But remember <it's not a perfect world> because after a certain amount of gases passing through a vessel< at high RPM for example>, the drag resistance becomes too great and actually hinders performance when it goes beyond a certain speed. The speed of exhaust many top engineers think is optimal is 0.3 MACH for exhaust and 0.4 MACH for intake IIRC. Now when people opt to go to a huge exhaust, the exhaust gases at low RPM are not moving fast anymore and the molecules start bumping int each other, thus creating "backpressure", and the engine has to work harder to push these molecules throughout the whole length of the exhaust pipes.

Believe it or not, 2.5" intake is maxed out at 600 HP, and 2.5 exhaust is maxed out at about 400, this is all according to formulas available if you search for them. Of course many things do affect these figures< bends, restrictions, engine temps, ambient temp, boost or lack of it, AFR and muffling equipment>

madmax98

From the sound clip, it sounds like an 8/10, especially when under load.

menty

Took off my mufflers today. The sound @ 2Krpm is just so drony, constantly echoing inside the car. If the sound is piped out back will it remove that drony noise?

Idle is quiet though.

madmax98

get a pair of magnaflow and come thank me after you call it a day.................

menty

I figure I may get used to it. It sounds so nice from the outside. Inside is a different story. 50kph @ 2-3k rpm is quite loud in the cabin, whereas 80kph @ 2krpm is near silent.

If I run pipes and funnel the noise to the rear will it be quieter in the cabin?