Exhuast Question

[skyline32sup]

My skyline has a 2.5inch cat back exhuast system with a muffler just before the diff, then it turns into a 3inch straight pipe. If i was to get the Stainless steel drift pipes welded on the back 3inch inlet to a Y section into 2 3inch pipes would this affect anything but the sound? If i had the money I'd re-do the system but i don't so just wondering, thanks.

[Captain Natro]

shouldn't affect anything to drastic man you wouldn't be flowing enough now to out flow the current system so i wouldn't worry about the extra pipe being added.

as far as noise goes should make it a fair bit louder and on a natro thst system will be WAY over the legal db reading... also if your gona be fully hella flush sickness and stick them out a foot past the rear bar copas will hate you, and expect to be pulled over alot...

tldr, won't affect anything, will be louder and illegal

[skyline32sup]

Okay well, its only costing around 90 to get it welded on and have the piping moved around so thanks. As for it sticking out, I'll prob just cut more into the rear bar so it can fit out and have it pretty flush to the back of the rear bar, already got enough defects as it is.

[mad082]

it will be as loud as anything. the cops will hear you coming from miles away

[skyline32sup]

maybe x2 2inch pipes?

[Captain Natro]

its not as much about pipes as it is mufflers, one muffler in a system will always make loud regardless of pipe diameter.

think mufflers and resonators for adjusting sound, and pipe diameter as adjusting flowcapabilitys

[mad082]

pipe size will always have an effect on noise though, even after the muffler. the more restriction in an exhaust, the more effect the muffler will have. this is why with a big exhaust you often get a drone at low rpm. there isn't enough restriction to really quieten it down. also the amount of echo that you get with bigger pipes. twin 3" pipes will be mega loud. twin 2" pipes will still be pretty loud, but not as loud.

if the car is a natro (hence posting in here), and an r32 (according to your profile, then anything above 2.5" on a 2L engine is a waste of time and you may well be losing low end power. 2.25" would be more than adequate for a 2L engine unless you spend all your time on the track at high rpm.

[skyline32sup]

Okay thanks, yeah its just a rebuilt RB20DE the current 2.5inch system is what was on it so don't really want to pull it all out. Im going to sell the tips. and run a single stainless steel pipe from the muffler of 2.5 inch might make it a little better.