Ideas for my exhaust, opinions req'd

[GPXXX]

If i use single a 3" exhaust piping from the turbo, will there be any backpressure issues if i used 2x mufflers that only has a 2.5" inlet each??

...and with having 2 mufflers for a single exhaust piping, does that theoretically mean it will muffle the noise better (since the outgoing exhaust gases are divided into two sections hence each muffler is getting less gas passing through it)?

for example, here's a pic of what i'm trying to achieve:



essentially the same setup, except the piping from the turbo dump pipe will be in single 3" (past the cat and resonator) and ending in twin mufflers.

my only concern is possible backpressure caused by turbulence at the point which the exhaust gases are split into two inlets for the individual muffler(s).

any thoughts?

[Astro]

Here are some pics of my car.






First setup…This setup consists of a straight 65mm pipe from the cat splitting in two just after the fuel tank feeding the two straight mufflers. This gave good performance increase and sometimes I also had some minor backfires.

At high RPM the car sounded great. My friends compared the noise to a racer motorbike speeding . The problem was at low rpm when cruising on high gears. The sound was so low pitched that the noise would rattle the entire car and it was very annoying to hear too. So I moved to second setup.

Second setup…. Same as first setup but added a so called twister. This is a small straight muffler which twists the gas so it will reduce the level of noise. This was installed just after the cat. At low rpm noise reduced and even the rattling but is still noticeable. Back fires reduced also. And I didn’t see any lack of performance.

I was told that when the two pipes coming down from the extractors are joint to one pipe (original setup) and then splitting them again to 2 pipes to feed my 2 mufflers, will reduce the performance. So If I am planning to go for a non turbo setup, eventually i'll change the setup again and will feed each muffler with a straight pipe directly from each extractor. So I’ll have two pipes running from front to back. Probably I’ll have to put two ‘twisters’ to reduce the noise levels.

Hope this helps.

[lal]

i don't really have a technical answer for you, but i just wanted to let you know that when I bought my FTO, it had that exact layout and specs from the pic... 3" pipe then down to 2x 2.5"

honestly, can't really tell you whether it was better or not.. but i do miss it.
I now have a custom 2.5" with cannon... thanks to the EPA
who thought that because there was two muffler that it was loud (it was only loud during back off)... anyways... the cannon i have now is much much louder than those 2 mufflers...

i better stop before i get going about the EPA again

[payaya]

with a twin system usually you get a louder exhuast note.

Why dont you try a muffler with twin intakes? Look at some V8's usually they are a twin system but is hidden with just the use of one muffler. Check out the exhuast on the American GTO (Monaro)

[GPXXX]

well it looks like this won't be going ahead... spoke to a mechanic the other day about the proposed design for the cat back system and i was told it is illegal to run an exhaust system directly beneath the fuel tank(!) Confirmed this with a contact from TMU as well...

BUGGER!!

[payaya]

a few bends will sort that out!

[GPXXX]

yes but they will create even more backpressure and I will have ground clearance issues...

[payaya]

i was joking dude!

[Supplanter]

You could always borrow the exhaust from Eric (MADFTO's) bike.

[ruchi]

I'd prefer the one off his GPvR, it sounds MADDDDDDDDDDD!!!!!

[GPXXX]

somebody remind me to bring earplugs along for next weekend LoL!

[FTO338]

How about u get some really loud speakers before next wkend instead?? heehehehhe