I have an idea that I wanna try on my SS , but Im kinda looking a knowledgeable opinion on whether Im wasting my time . Meaning if you think my idea is a waste , I wanna know why . Just trying to avoid all the opinions of people who dont know what their talking about , everyone online is a brainiack right , lol . Anyways .......I want a cat back on my SS , but Im not touching anything Ive heard on the market so far because its just to loud . My f-bodies sound good loud , to me , a loud 4 banger is just annoying . So Im at a point where I just want to build my own exhaust , which Im fully capable of doing . My idea for really getting the noise level down , and changing the pitch a little of the exhaust is instead of using a resonator , using a X-pipe . Staring with a 3" downpipe off the header I'll be using , stepping down to a dual 2.5 split , to a 2.5 X junction , then merge the 2 back into a single 3" pipe . It may sound like a would be huge , but it could be built with pretty tidy dimensions . For a muffler Im gonna use a Spintech 3" in/out . Its a AWESOME flowing muffler in the F-body world that is alot quieter than most .

I dunno , the x-pipe junction idea maybe worthless . Its just something I wanna try . On a real dual anyways , it cuts the sound level down ALOT , as well as the resonance . A plus to is it adds a pretty cool higher pitched tone . Maybe on a single exhaust , it could possibly create to much back pressure ? If I try I will definately be doing comparisons on a dyno . Probably with a stock resonator , no resonator and the fabbed x junction . Im just not too happy at all with anything I see on the market , especially the price levels there at . Looking for something different from the norm , that just might turn out to work .

 

Sorry that I cant give any quality feedback about the tech portion of your post but I too want a higher flowing exhause without the loudness.

Also Im from the fbody world too ('01 T/A w/ no cats and bullet muffler.....loud) so I know what you mean about fbody's sounding badass with loud exhaust.

 

go with a walker high flow exhaust system.

 

A) Spintech ranks right up there with Flowmaster.
B) Walker = Dynomax

If you wanted a decent sounding high flow system keeping a resonator and using a oval bodied muffler is key. Some people belive resonators on 4cyl/6cyl rob HP but they don't they are there to get rid of nasty exhaust notes most people dislike.

As for muffler chice nothing will out flow a decent straight through oval muffler like Magnaflow, Borla & Dynomax Ultra-Flo. And since they are oval there is more interior and roving material to eliminate the ricer drone most 4cyl can produce.

 

What I will be doing is getting headers and and a high flow cat on my stock exhaust

 

sorry, maybe im confused here but your gonna split the exhaust into a dual and then fab an x crossover? that doesnt make any sense. x pipes are something that works when you have 2 independant cylinder banks and the x or h is the only place they connect, wouldnt do much on a 4 banger.

also, do you happen to know the flow numbers on that spintech 3 inch?
its important to know because you only need 2.2 cfm per horsepower, any more flow than that gets you no gains what so ever, just adds noise. resonators are generally the best way to reduce noise while keeping flow numbers high so i would start my search there.


edit: this is the best article i have ever read on exhaust, very informative. most of it applies to domestic v8s but youll be able to apply alot of the info


http://popularhotrodding.com/enginem...re/0505em_exh/

" To achieve a zero-loss muffled high-performance race system we need to work with the two key exhaust system factors in total isolation from each other. These two factors are: the pressure wave tuning from length/diameter selection, and minimizing backpressure by selecting mufflers of suitable flow capacity for the application. If we do this then a quiet (street-legal noise levels) zero-loss system on a race car is totally achievable without a great deal of effort on anybody’s part. Ultimately, it boils down to nothing more than knowledgeable component selection and installation..."

"Knowing that 2.2 cfm per open-pipe hp means zero loss from backpressure allows us to determine how much muffler flow your engine needs. Just make a reasonable estimate of its open exhaust power potential and multiply by 2.2. For instance, a V-8 making 500 horsepower on open exhaust will require 500 x 2.2 = 1100 cfm. Two 550-cfm mufflers will get the job done and contain the backpressure-induced power loss to 5 horsepower or less. With mufflers rated in cfm, see how easy making an appropriate choice gets? "

in your case, id say anything that flows more than 600 cfm is a waste of money and noise.

very usefull stuff, popular hot rodding is the shizznit yo.

good luck