Exhuast

[Springie]

I know another exhaust thread /pan

I just went for the WOF and failed on noise, which I can understand is it probably is a tad too loud. Anyway, Its currently 3" from flexi, 1 resonator, and RPS resonator on the back.

I have tried another center resonator in the past and it moved the drone down the rev range and sucked power, so I want to avoid this.

What options should I look at, i've read that using some v8 style mufflers works well as they have good flow rates?

Or can i get a fujisturbo in NZ?

I want a little noise, but mainly flow.

Cheers

[bradc]

You could go with a twin setup like mine and use two mufflers which are a bit restrictive and designed to be quiet. You'll still get good flow because there is two of them

[Springie]

Have thought about it, but does it make it that much quieter?

Although, going against what I said, looks like I might redo the whole lot. I have lined up 2x 3" Resonators and a new rear, basically the same but these mufflers use ceramic packing so hopefully will be noticably quieter + the extra res.

any thoughts?

[Subaru ETA]

i got 3 inch cat back with 2 resos and RPS muffler. the RPS muffler is very droney at the best of times. ill be getting a HKS one or something soon.

at the mo i have the silener in it and i bet its under 95db now

[MarkSanne]

Under 95db... that is where I am with the Legnum I took to get it registered when I was told the car was to noisy (92db, when the max is set at 78db). And besides: my horn/claxon/whatever that thing is called in english was 4db too LOW... WHAT!!!??? well alright, the horns are easy, the full 3" exhaust is way more difficult to get down on sound, esp as orginal parts for Legnums/Galants are hard to find here and/or very high on price. So a max of 95db would be a dream for me now then I would have passed it and could've finally driven it...

[william]

I have a 3 inch system and fitted a RPS rear muffler after the original silencer developed a leak. The RPS was very droney as David said. Changed to a HKS silent and the difference was huge.

[Springie]

I have a 3 inch system and fitted a RPS rear muffler after the original silencer developed a leak. The RPS was very droney as David said. Changed to a HKS silent and the difference was huge.



where did u get the HKS?

[william]

TM. A bloke recently advertised one for $300 which is a very good price. I had a look but could not find the link. Mike (Mpau 009) had some comms with him so maybe you can PM Mike.

[Springie]

Have decided (i think) to redo the system. I am going to go


Downpipes->[flange]->Resonator->pipe->Resonator->resonator->[flange]->pipe->rear

The resonators aren't that big so hopefully it won't be over kill.

If i go with 3 ceramic packed resonators + the rear I am hoping it will keep its flow while keeping the noise down. The flanges will allow easy changes to be made in the future if need be.

[Springie]

An update:

Have spend the last two weekends on the exhaust.

Orginal

|FLEXI|=={RES}=====================||== {RPS}

factory flexi, coby and rps with 3" pipe

1st Weekend
--------------

Ripped out old system and weld new on up (all 3" mandrel ignoring bends, new flexi etc):

||FLEXI|=={RES}==========={RES}=====||== {RPS}

Results were a little bit quieter at idle and up in the revs but still quite noisy between 2000-3000RPM, but at cruising speed drone was noticably quiet. Interestingly we ran the leggie with just the two resonators and the car was quieter than with the RPS on. So with a good tip 2x resonators might be an option (although didn't drive it like this).

I though id chuck another res in to quieten it down and finish it off.

2nd Weekend
---------------

Cut middle part of pipe between 2 resonators and add new one:

|||FLEXI|=={RES}==={RES}==={RES}=====||== {RPS}

Results where WORSE! idle was maybe a bit quieter than the orginal system but louder than the one above. Basically it was back to the drone and noise of the original system (maybe like 5% better).

This weekend
---------------

Take middle res out and run with first weekends config. Although I now have a Fujitsubo rear muffler to try as well which should fix it all.

|||FLEXI|=={RES}========={RES}=====||== {RPS} or {Fujitsubo} *

* have rear flanged

Have any of you guys got a picture of a rear Fujitsubo fitted? Seems like quite a big box, and i'am wondering how well it is going to fit.

[Eurospec]

How about just put a bung in it for the test, then when its done, take it back out? Or is that sort of thing not allowed?

cheers,

Ben.

[Springie]

Its allowed, but I still want to quieten it down as there are new laws in NZ, that i can't be bothered taking the risk with and the fact, as long as it flows good i'm not concerned about having it not loud.

[Springie]

update:

exhaust is now :

|||FLEXI|=={RES}========={RES}=====||=={Fujitsubo}

i gotta say the difference is HUGE!!!, no drone at all, nice barble at idle and low revs, in fact might be a tad quiet, but still flows well. It will definably be legal now.

All i have to say is after having a JASMA stamped muffler i will never go back to anything else.

FYI

rear muffler is (top right) http://www.fujitsubo.co.jp/prod_legalisR.html

and 2x resonators are: http://xracing.co.nz/view.php?id=3&cat=21&subcat=31

I highly rate these resonators too, they are very effective. Just don't put more than two on the vr4.

[Kieran]

That's great info - Have some rep! :scholar:

I wonder why 3 resonators was louder than two though? :inquisiti

[Springie]

That's great info - Have some rep! :scholar:

I wonder why 3 resonators was louder than two though? :inquisiti

No idea, must be something to do with the frequencies the resonators are set to minimise or enhance + the length of the exhaust.

It probably depends on what resonator is used, but I also noticed that the JAP brand exhausts seem to have 1 or 2 resonators.

[MarkSanne]

I have a custom 3" exhaust on (under) the Legnum, which has 2 resonators. For getting it to lawfull standards the end silencer needed to be replaced for a standard original mitsu (or whatever EU-approved + very silent) and I did a couple of db tests with my db meter:

- with the japanese end silencer: 103-105db
- with the japanese end silencer + an extra plug-in silencer: 96-97db
- without an end silencer (!): 102-104db (no typo!)
- with the (self converted) EU Galant end silencer : 70-72db

BTW: I know, strange results. But after the legal tests I switched back to the japanese end silencer which sounds dark and GOOOD! :)