Ok, I'm going RB Header~> RB Presilencer ~> Custom Pipe~> Corksport Muffler.

The RB Presilencer Is 2.5 Inches I.D. and the Corksport Muffler has a 2.5 Inch Inlet. Should I just make the custom cat-back pipe 2.5? Is there any gain to be had from enlargine it to 3 Inches? THX





It's not my fault I'm stupid. I blame the education system.

 

Its my opinion that the 3" pipe will flow better at high rpm but you sacrafice velocity at normal driving rpm's which are usually under 4500rpm. I'm going to use a 2.5" on mine. The numbers show that you don't really need 3" pipe untill you go over 250HP. Check out the technical support section on www.dynomax.com. It has a neat chart for comparing engine displacement to expected HP and the size tubing you need.

 

i'm going for a 3" y-pipe to 2.5" collectors and mufflers hoping it will scavange a bit better but well see

james

 

Anyone else have an opinion on a full 2.5in exhaust? SP, Intake, and some performance mods. I'm looking to push about a stock TII's HP @ the rear wheels. Will a 2.5 support it?

 

i just got mine installed... i took the y-pipe off and had a muffler shop take it down to one pipe... i used 2.5 inch and it feels great and i love how i have my muffler set up!! i love my single

 

I just went singal too.

got a straight through muffler and 2.25" piping from the main cat. I can really feel the difference, and it sounds a lot better than the stock exhaust.

 

My single setup is in the mail. RB Header (actually in my garage), RB Presilencer (backordered ), and N1 single. All 2.5 inch. I vote for 2.5 inch. It is too much of a hassle to do the 2.5"-3", and I think it is pretty pointless, IMO.

 

Someone was saying that making the exhaust larger as it goes through makes more power, like a megaphone. Don't ask me how though........

 

I was told that if the exhaust is all the same size, the high pressure air is kept flowing and uninterrupted as it flows. This is especially important because the Turbo is forcing air through at very fast speeds. Picture a river being small and then having a large wide part, in my opinion, it is better to stay all the same size all the way through.

 

I agree with that. IMO, even a ported N/A motor (unless extreme BP/PP, with extensive airflow modifications), will not warrant the use of a full 3 inch. IMO, there is not enough airflow at these power levels to keep the exhaust velocity high enough. I would recommend against anything larger than a 2.5".

 

This is the BEST POST EVER! All it's doing is giving me an ego because I finally selected the RIGHT COMBO!!!

I hate to suggest bringing me down, but does anyone see any problems with running 2.5" all the way back?

 

Invest in a loud stereo and/or earplugs, even with the presilencer that straight through muffler is going to be pretty loud.

 

I SAID PROBLEMS, that's just another plus. Everyone will know when I come to their house, no need to knock. J/P How many times LOUDER than stock with the above mentioned setup be? And, heaven forbid, if I decide to quiet it down, how would I go about doing it? (I downloaded the video from Mazdatrix, and that didn't seem to be TOO loud fer' me) Anyone know how to make a silencer-insert? Will the Apex'i fit? Etc. Etc. Etc.

 

I dont think it will be annoying loud. I have RB header, presilencer, and hks exhaust and the sound levels are good. Inside the cabin is pretty quiet, even in WOT. A single setup shouldnt be that loud. Just get thick pipes. The thicker the walls of the pipe, the quiter it will sound.

 

I think the RB's 1/8 or 3/16 thick, Whatever the RB stuff is, will be how thick the cat-back pipe is.