Exhaust flow question

[crobaa]

Hi guys,

I currently have a 4-1 header and stock Jdm dc2r exhaust system on my car.

I have already deleted the resonator closest to the cat, and replaced the cat with a 2.5" 100cel item.

So I am currently left with

The long barrel resonator
Mini resonator near muffler
The rear muffler

Those 3 items are still standard and I've been told I need to increase flow to suit my stage 3 head setup. I would really like to keep the car as quiet as I can whilst not restricting too much power and I'm currently thinking of deleting the 2 remaining resonators so I'm left with only the stock Jdm dc2r muffler and the 100cel cat.

Will this increase flow to the level I need and still keep the car relatively quiet compared to cars with a "sports" muffler? I believe the stock muffler flows quite well but correct me if I'm wrong

[Vvvtec]

Arnt the resonators straight through items? Surely they arnt going to hinder flow that badly? The stock muffler is probably more of a restriction that your resonators.

Remove the resonators and it will become louder.

[DreadAngel]

Like Vvvtec said, your issue here is that all the remaining parts are designed for noise reduction. Changing or eliminating them will result in noise increase.

Depending on what you think is loud, a high flowing muffler like that found on the Fujitsubo Legalis-R is the way to go for you. They aren't too loud, don't draw too much unwanted attention and shouldn't be as restrictive as the Type-R's muffler.

[mocchi]

probs better to get like 2 new straight through resonator ss lined packing for better noise reduction and swap for straight through muffler.

[crobaa]

You think the stock muffler is that restrictive? How about deleting the small res, replacing the big one with an ss lined one and new pipe?

[Vvvtec]

The oem muffler isn't straight through, its going to be restrictive

The resonators don't obstruct flow, they're there to kill noise

[crobaa]

So in theory I only need to change the rear muffler? What am I looking at with regards to max flow min noise. Especially at lower rpms like 3000 when I'm just cruising around the suburbs and people look at me like I'm hooning

[Vvvtec]

Yep you got it.

[mocchi]

stock is chambered design, shit flow but quiet
straight through best power bit more noisy
twin loop halfway noise/power

the question is

http://www.ozhonda.com/forum/customavatars/avatar30053_99.gif

[crobaa]

I refuse to ever run a twin loop in my car. I think something along the lines of a spoon street muffler would suit me well but I cant find any for sale in good condition. Any good equivilents out there?

[Vvvtec]

Find yourself a fujitsubo axle back if you can. I had a full fujitsubo catback on my b18 and it was just perfect. Was virtually as quiet as oem at low rpm, and just sang above 6000rpm. Exactly what you are looking for by the sounds of things.

[crobaa]

Ok, the legalis r one specifically?

[EKVTIR-T]

magnaflow

[crobaa]

Bwahhhh $1500+ for that legalis r! Surely my local exhaust shop will have a quiet straight through muffler. Can't justify that money for one muffler it's ridiculous

[IEVAQ8]

just to throw in the mix...
go n get a straight thru 3inch system and muffler it up to be quite....

[DreadAngel]

Bwahhhh $1500+ for that legalis r! Surely my local exhaust shop will have a quiet straight through muffler. Can't justify that money for one muffler it's ridiculous

Nobody said you need to buy for full price :p

[crobaa]

I would but my headers collector is 2.5", cat is 2.5". Thinking I'll swap the rear muffler out for a straight through one that's not stupidly expensive, if it's too loud I'll look into another resonator

[crobaa]

Even half price. It's a stupid price for an item that frankly isn't that special/unique/have so much research and development into it. Something like engine internals my budget is open as I can justify the spend, but with regards to a muffler, there's better ways to spend that cash on the car.

[DreadAngel]

Even half price. It's a stupid price for an item that frankly isn't that special/unique/have so much research and development into it. Something like engine internals my budget is open as I can justify the spend, but with regards to a muffler, there's better ways to spend that cash on the car.

I think you underestimate the quality and R&D Fujitsubo put into their products...

Anyway if Fujitsubo is too expensive, you can use theirs as a template for your own custom one...

[honda_zivic]

I would but my headers collector is 2.5", cat is 2.5". Thinking I'll swap the rear muffler out for a straight through one that's not stupidly expensive, if it's too loud I'll look into another resonator

yep thats what i did with my straight thru muffler, it was crazy loud so i added another resonator and problem solved, and then added a snail it was dead silent.lol

[crobaa]

Looks like that's what I'll be doing (except the snail part lol).

I'm sure the fujitsubo muffler is great product but for that money I just can't justify it. Maybe if it was ti I could pay 1500

[rhys.l]

I was running a pretty similar setup to you originally crobaa: JDM 4-1 header -> JDM 2.5" cat -> 98 spec JDM b pipe (3 res) -> OEM muffler. I had the same plan as you - wanting to keep things quiet and sensible but looking to extract a little more power. I actually bought Vvvtec's old Fujitsubo catback, which is a RM01A. It's probably the quietest cannon type setup you are going to find, but I still wouldn't call it exactly quiet, and I think I have the same standards as you.

I don't think putting a straight through muffler on the end of your current setup is really going to solve your dilemma either. You can bolt a Spoon N1 straight on to your current B pipe, and I bet that will be crazy loud. And putting any other cannon-type muffler on the end will probably have the same result. As I understand it, the muffler is what really decreases the outright decibel level in an exhaust setup, whereas the resonators are more about decreasing the buzzing/sort of rasping sound?

I reckon keep your current setup and try to find a freer flowing oval barrel muffler to put on the end.

[crobaa]

That's the plan exactly, gonna talk with my exhaust shop and see what they have on offer

[stndrd]

With your stage 3 head build, you will need to change your headers as well as the complete exhaust system to allow the motor to breath better. Get some toda replica's (PLM) and a 70mm exhaust with twin 15in resonators and a straight thru muffler, otherwise the head build will be pointless.

Also you need to up compression a bit more for that head setup billy

[crobaa]

I got mugen replica headers 4-1 already josh.

Compression is being increased too don't you worry about that!

[stndrd]

Mugen headers dont give as much flow as the toda

[crobaa]

For the time being there's more power to be gained by spending the cash on the engine internals, not hard to swap the header later on down the track if need be.

[crobaa]

Just to revive this thread. What are people's opinions on tail silencers? I notice spoon make the n1 muffler, and also sell a tail silencer which looks like it bolts inside the tip.

Do these silencers reduce flow that much? I like the idea of being able to easily unbolt it when need be

[stndrd]

Silencers dont really silence the car, they just alter the frequency at which it is emitted. Say a spoon n1 is on a frequency of 125hz, the silencer will change it to 100 or 90hz so it sounds different, but doesnt make it much quieter. They also make cars feel sluggish (as if the timing has been retarded) and I personally believe to be a waste of time.

You can't go and build a performance engine with massive cams etc and expect it to be quite. It just doesnt go hand in hand

[EKVTIR-T]

also sounds like shit when silencer in

[crobaa]

Not quiet, just not loud lol. At least when driving normally and not on vtec

[stndrd]

It will still be loud. Like I said it will only change the frequency. With what you are doing to your car, there is no point trying to capture the quite aspect. You should of turbocharged it if you wanted quite as the turbo acts as a muffler

[DC2-PWR]

I was running a pretty similar setup to you originally crobaa: JDM 4-1 header -> JDM 2.5" cat -> 98 spec JDM b pipe (3 res) -> OEM muffler. I had the same plan as you - wanting to keep things quiet and sensible but looking to extract a little more power. I actually bought Vvvtec's old Fujitsubo catback, which is a RM01A. It's probably the quietest cannon type setup you are going to find, but I still wouldn't call it exactly quiet, and I think I have the same standards as you.

I don't think putting a straight through muffler on the end of your current setup is really going to solve your dilemma either. You can bolt a Spoon N1 straight on to your current B pipe, and I bet that will be crazy loud. And putting any other cannon-type muffler on the end will probably have the same result. As I understand it, the muffler is what really decreases the outright decibel level in an exhaust setup, whereas the resonators are more about decreasing the buzzing/sort of rasping sound?

I reckon keep your current setup and try to find a freer flowing oval barrel muffler to put on the end.

Pretty sure Alex had the Powergetter?


It will still be loud. Like I said it will only change the frequency. With what you are doing to your car, there is no point trying to capture the quite aspect. You should of turbocharged it if you wanted quite as the turbo acts as a muffler

I had Spoon N1 with silencer, it was still loud so the only difference was it sounded fuzzy. Same with the J's Racing 60RS.

I second Alex's recommendation, if you want the best gains and really quite exhaust, you can't go past the Fujitsubo range. I mean why stuff around when there is already a product that you need (perfect & quality) that's out there... waiting for you. Just put it on the WTB section I'm sure you can pick something up for a bargain.

[rhys.l]

Pretty sure Alex had the Powergetter?

He thought he did lol :p It's definitely a RM