I already searched, honestly don't want to make a new thread but there was no specific topic for my noob questions so here it goes..

I already have a custom 63mm test pipe, custom 63mm single exit axle back (attached to a 76.2mm RS works muffler). Everything is already custom except for the stock OEM resonator and the stock pipes connected to it (the pipe after the test pipe flange and before the custom axle back flange, which is about roughly 1.5 feet long.)

I'm planning on customizing the stock mid pipes and resonator also, replacing them wit a 63mm one, but here's the thing: how long should the resonator be to provide the optimal engine performance? would a 14 inch long resonator do the job? and also, would i benefit anything if the inlet diameter of the resonator is 70mm? or should i just go wit 63mm all the way?

Thanks guys

 

It's already 60mm (2.5") then splits to 2.25" to the mufflers.

I would leave it the way it is, but the muffler is a 3", to optimize it, I would use a 60mm muffler.

Either that or replace the TP with 70mm and go already way back with 70mm.

 

Uhhhhmmmm... 60mm is 2 3/8 inches.. 63.5mm is the 2.5" you're talking about..

the stock exhaust inlet diameters of our cars is 60mm or 2 3/8 inches. and then splits into 2 inch pipes to the stock mufflers.

and sadly.. 2.75 or 70mm stainless pipes aren't available in our country, custom wise.

anyway.. i think i'm veering away already from the question at hand. How long should the resonator be to achieve the optimum performance? and would it be better to have a bigger inside diameter for the resonator
(63mm pipes->70mm resonator-> 63mm pipes) or would it only cause turbulence?

 

the difference of 3mm is also based on the gauge of the steel as well.

Since you're chopping away and don't have many options then I wouldn't be concerned about 60 or 63.5mm in terms of power.

Stay with one size if possible all the way through. or gradual step up.

HEADER - CAT/TP - RESONATOR - MUFFLER
60mm or 63.5mm - 63.5mm - 63.5mm - 63.5mm.


The longer the resonator, the more sound will be absorbed.

 

The less the better, go with 1 63mm pipe from the header to muffler if possible.

How loud do you want it to be?

 

Yup... the 63mm is the inside diameter of the pipes minus the steel walls of the pipe. i'll double check on that too, thanks for reminding me

And yep, i'll be sticking wit only one resonator, as like how they designed it from the factory, except bigger inlet diameter by 3mm. Now since its custom, i can decide on how long the resonator can be, say maybe 14 inches long, would that do the trick? i think the stock 60mm OEM resonator is only is like 12 inches long. I still have to measure it. wouldn't want to have drone but wouldn't want to lose power either.. I'm actually liking how the car sounds now, its quiet and doesn't have drone during a cruis. but once you hit VTEC, things change hella lot.
[media]http://www.youtube.com/watch?v=pKHzqOn0x14 [/media]
[media]http://www.youtube.com/watch?v=Xpw0MFcUvdo [/media]
thats me on the 2:07-2:20 mark

p.s
pardon our actions in the vid.. please dont flame me

I just want to change the mid pipes and resonator to a 63mm one so that it will be 63mm already all the way to the muffler. And hopefully, gain a few HPs wit the extra 3mm maybe

 

I good resonator really won't hurt flow at all if it has the right internal design.

 

^^ thanks for the advice. how will i be able to see or know if the resonator design is good or not? I know the typical resonator has a straight through pipe inside wit small holes in it. and some fiberglass and division inside the chamber to absorb the noise. also there's a canister type (the circle one) and the oval type. other than that, i don't know anything more in regards to resonator technology. maybe pics, instances can help.

 

Just look for one that is straight through and has a perforated core. Some have a louvered cored but those cause more turbulence and aren't as good.

This is what you DO want


This is what you DON'T want

 

Nice!!! really helpful input there. I've seen those louvered cored ones and had the feeling that its affecting the flow, have no documented evidence about it though. but i think it will make the resonator more effective? just a thought.

either way, performance > sound resonance for my application. thanks!

question though, will the perforated one be as effective in keeping the car quiet during cruising speed as the louvered one?