What Would Flow Better?

[godzl1975]

In the process of deciding what to replace my rear muffler on my car so that it maintains good flow and not be an attraction to the authorities.

I do have a kakitmoto canon exhaust 3.5inch and having that on is just too noisy so decided to get a custom rear muffler (from Diff) made up and use a high flowing wide bodied muffler and that was helped with the noise n brought it down to just under the 90db.But when i had the car tuned it was running to rich and now has destroyed the packing inside of the muffler, now leads to the exhaust being smoky(grey/white) at times. When i have put the canon back on it doesnt have the smoke that comes out. Also have a new cat in there was well.

Just want to know what would have better flow (from where it bolts up at rear diff) a single 3.5 inch with a wide bodied muffler or have a twin inlet muffler that has 2.25inch pipes or there abouts and having the two pipes run into one to bolt up to the rest of the exhaust.

attached a diagram

[Bliksem]

I have a Fujitsubo exhaust like you've depicted in the top diagram. Obviously the twin 2 1/4 would flow a larger volume, but I would be skeptical as to weather it will give much of a preformance gain over your previous system. Afterall exhaust gas has already had to pass through other restrictive area's such as the cat/dump pipe which would be the first bottle necks in the system.

[FATAZZ]

id go with the 3.5"

where abouts you getting this done?

i got a muffler i need fitted.

[R31Nismoid]

Yeah, it would be based on volume.

If twin 2.25 flows more than one 3.5 - then the choice is 2.25

[godzl1975]

Yeah, it would be based on volume.

If twin 2.25 flows more than one 3.5 - then the choice is 2.25

yeah thats what i thought.... flow is prob no2 too noise that the muffler can insulate/resonate noise

and fatz...not sure yet..there is choice of couple...sureflo @ ingleburn or there is a place at padsdow that rocket industries recommended to me that stock their range of mufflers. cant rem the name the owner is a nice bloke, think wildside exhausts.

[GeeTR]

Dood, if your custom muffler burnt out, i would be taking it back to them to fix free of cost. Mufflers for piston motors shouldn't get damaged by a little rich running, thats utterally ridiculous.

Swear im not affiliated, but SMB in Sydney do custom rear cans. I personally know of a few people running them in 500-700hp rotary s which run 10-11:1 all day long... thats rich.

As for your question, you have no way of knowing which (either 2 or 1) muffler will "flow" more, as you don't know the internal construction. Slike saying a house with 4 entries and exits will have... more efficiently heating ability ? ?

If you really want to get the highest flowing legal system, custom is a sure'r bet.

PS: What ever your decision, make sure the place your gonging through guarantees the end result... otherwise instead of a can that blew out... you could end up with a illegally loud system.