Exaust for R33 GTS

[illusiVe]

imo, what does 3m of 2.5" pipe have to do with it when in the end its just into the atmo,

i mean basically having say 4" full exhaust (just to make it plane obvious) thats basically the same as the air being dumped straight into the atmo.. i dont get how it could be easier to have air "sucked out" when it all ends up in the atmo in the end.

[chicane]

illusive, ask your physics teacher lol.

[chicane]

Just opening up the exhaust is not necessarily the answer. The extreme would be to remove the exhaust system altogether but, for those of you who have experienced it, if the exhaust breaks near the manifold, all power is lost.

For a normaly aspirated (non-turbo) engine in particular it is important to retain a certain amount of back pressure. The reasons for this are all to do with exhaust scavenging which is to do with negative pressure pulses reflected back up the exhaust manifold to remove the last of the exhaust waste from the engine.

[[D4RKS1D3]]

Hi [D4RKS1D3],

How much it set you back? Which one is it from this list..

http://www.magnaflow.com/02product/shopdis...one=main&id=386  

Anyone know whats happening with that group buy?

cheers

chicane

http://www.magnaflow.com/02product/shopexd...one=main&id=764

Thats it there. cost about 450 for the muffler, and about 300 for the rest of the install. i do however have a feelin that i got a bit ripped off on the price of the muffler, but i didnt realli mind cuz the bloke rushed me thru and had it all installed in a couple of hours the following day.

The group buy has fallen thru i think. Not enough interest and communication problems with the supplier i think.

[Greg]

http://fujitsub.rsjp.net/search/prod-v.php...cnamID=00000523

it's 2.75" piping. What do you guys reckon?

worth a try- if its well designed it shouldn't be too droney.

my HKS 2.5" exhaust is almost as quiet as stock

[Eug]

my car had an HKS dual dragger when it was imported, far too big and far too loud - absolutely useless, it was more suited to a GTR or GTST...

needed to change it for compliancing so I had a stock exhaust put in (still have it today) and the stock exhaust sounds absolutely CRAP, but it definately isnt quiet.

[MearCat]

illusiVe - I've already posted a link to this site in this thread http://www.miata.net/garage/KnowYourCar/S4_Back.html Go and read it and learn all about scavenging

As for my muffler, I have a universal, large bodied, mild steel, 2.5" straight through muffler. Cost me $110 fitted and have proved (on the dyno) that it produces the same amount of power as my old TRUST muffler.

[Kor'axis]

what size is the standard NA exhaust?

[skyla]

Have spent sometime reading throught this thread, as I have been thinking of changing my current exhaust, to a more straight through system. Currently I have jasma approved system with extractors (6,2,1), 2 1/2" stainless exhaust system with no cat and two very large mufflers (not the straight through sort). I was thinking of putting in a couple of resinators and a straight through type muffler, in the hope that it might improve the flow of exhaust gasses.

A friend sent me this article which I found quite an interesting read, looking into the importance of exhaust gas flow and looks into the back pressure thing too.

[[D4RKS1D3]]

what size is the standard NA exhaust?

Mine was 2 1/4 inch from the factory i think. So basicalli you open it up 1/4 of an inch when movin to a 2.5 inch system. The onli thing that realli holds back your exhaust is the mechanical(?) muffler which is meant to baffle sound via redirecting exhaust fumes.

[Kor'axis]

so in an NA r33 the optimal is only 1/4 inch larger and the only real restriction is the muffler? Mechanical muffler? what ither sorts are there?

[[D4RKS1D3]]

i think thats what the standard muffler is called. It just has the air looping back and forth thru a series of tunnels. if that makes any sense. where as a with a straight through muffler, its just a straight tunnel.

_________________

| _______________|____

| ( __________________ <-----exhaust

|_(____________ ) |

_______________) |

|________________|

In a standard exhaust then the fumes are "baffled" through a "mechanical" eexhaust and this results in restrictions.

__________________

| |

|_________________|__

____________________ <----- exhaust

| |

|_________________|

In a straight thru exhaust their is no restrictions to exhaust

[chicane]

nice ascii work [d4rks1d3] hehe..

check http://auto.howstuffworks.com/muffler3.htm ppl.. some go around in the fashion like d4rk mentioned, some go thru a more 'inline' series of sound absortion material/chambers etc, but the gist of it is the same.

I spoke to an exhaust shop (perf exhaust in ringood) about a muffler today. I told him how I want to go to a quieter (ive got a noisy rev-flow muffler on there now, and 3" pipe from bends to the muffler) one and he said a canon style (round) won't be the ideal one. He recommended an oval style one. Also quoted about 380 for a maganaflow oval one, but im not thinking only maganflow, but any good brand (post if you can recommend) which will quiet it down a bit, but not strangle it (and have _some_ noise when on the throttle).

Cheers

chicane

[chicane]

anybody else care to reply to this thread and mention anything I should look out for when getting a new muffler on my R33?

Cheers,

chicane

------------------------------------------------------------------------------------------------

An internet forum is only as good as the quality which is contributed..

[mufro]

i just put a resinator on my exhaust...sounds a whole lot better ay...its still the same loudness but just got rid of the crappy crackling noise haha happy with results

[chicane]

i just put a resinator on my exhaust...sounds a whole lot better ay...its still the same loudness but just got rid of the crappy crackling noise haha  happy with results

hey mufro,

what muffler you got on your R33 GTS?

cheers

chicane

[mufro]

hey mufro,

what muffler you got on your R33 GTS?

cheers

chicane

i got a magnaflow muffler

[chicane]

i got a magnaflow muffler

What style of muffler/model magnaflow is it? How much you pay for it?

[mufro]

i got it with my car wen i bought it....um..im pretty sure its 1 of these...

http://www.magnaflow.com/02product/shopexd...one=main&id=782

http://www.magnaflow.com/02product/shopexd...one=main&id=786

not sure if its the 6 or 7 inch barrel...i dont really like the tip on it tho