Exaust for R33 GTS

[Eug]

mate, i am not taking a personal stab at you - this is a forum and issues/debates like

this is what keeps the forums going.

this is a forum of information... and i am merely stating that you are only taking a 1-sided

view as to the appropiate size for an exhaust system on a naturally aspirated car.

i NEVER said you were wrong, and i never dissed you for getting ur 3" system...

and I never said a thing about ur rims, kit or colour, so keep your posts relevant to the question.

The question is:

What exaust would you guys recommend for a r33 GTS in terms of value for money?

There are about 10 people including myself who have said a system no bigger than 2.5"

will give the most optimum airflow without hindering backpressure...

In your case you may have attained a higher MAX POWER reading on a dyno, but everyone

will know power does not necessarily equal go, and a car is driven differently on the street

as how it is on a dyno.

We do not want to give people who are unsure the wrong type of information.

[Eug]

its a simple concept and people have been experimenting with exhausts for quite

sometime now... its now such a widely known fact that people usually dont question it, very much anymore.

ever tried to blow water out of a 3" pipe?

ever tried to blow water out of a 1" pipe?

try blowing water out of a straw?

only in high revs will the volume of flow be sufficient for such a large system to have any sort of benefits.

I do not know how you drive... but I surely would not be redlining my car just to head to the shops.

Now - I tell you that you would infact be wasting money, because @ low revs it mid range where MOST people drive their car on the streets - a 2.5" system is the optimum.

[SRG33]

Blitz.. very deep sounding and not too loud..

[SRG33]

Oh yea, $800-1k for a stainless steel cat-back..

[SRW-1]

hahaha me 2 man...my car sounds poo'd ay...in 1st n 2nd i accelerate as slow as i can so the "gargling" noise dont show and in higher gears i change at about 2500...pisses me off soo bad.  i got the magnaflow muffler aswell and the 2.5"  how could i eliminate this noise???...i got to get rid of it

Haha yeah i've heard a few guys have had this same problem. I've had my stock exhaust on since i got the EPA test, but i'm thinking about adding another muffer into the system, before the cat if i do decide to put it back on. Hopefully that will eliminate the noise!! Otherwise i'm helpless, pack it up, sell it and leave the stock system on. Or buy a good reputable Jap brand like a Kakimoto, trust, a'pexi or blitz system. I did heaps of research and i was soo close to getting one of these but in the end decided to go to the local exhaust place!! Ah well what can you do!

[mufro]

yeh, if it takes a good brand exhaust then i'll do that...im gona hav this car for a while i think lol so i gota get the problem fixed...so like...yer...wat u's think the best thing to do would be...ne1 had experiance on this?

[MirKz]

i MAY be selling mine in about a month or two time, cat back 2.5inch with 2 resonators and a stainless muffler. (sounds HAWT as and loud not had trouble with cops loud though)

probably give it to ya for $650

its only been on the car for 3 months or so (im upgrading so might be getting 3inch)

but yeah, PM me if ure interested.

Oh and its made by Cypher Industies (a big performance shop over here in WA)

[r34_skyline]

if i just wanted to buy a muffler 2.5" intake and 4" tip purely for the sound, would this cause any loss of bakpressure ? im not really interested in power gain.

good muffler are around $280, + $120 for labour and piping = $400

catbak systems = $800 ?

dunno what i should put on. is the 400 worth it ?

hrmmm are catbak systems illegal in any way ? i dont want insurance giving me crap when it comes to claim time. (just in case)

sorry, im crap when it comes to cars.

[illusiVe]

if u ask me, u would want to eliminate back pressure all together rather than have "a certain amount".. just wondering how u think the engine works better when it has to push harder to have the waste disposed of.

[Eug]

if you are interested in only sound, and not power gain or driveability then by all means it doesnt really matter what diameter exhaust you put on.

but if you want to retain any decent sort of fuel economy and throttle response and harder acceleration through the rev range than I'd suggest no larger than 2.5"

[illusiVe]

i still admit i know poop compared to anyone who knows their way around an engine bay more than just oil, engine, exhaust, pod etc....but if u think about it wouldnt you want the least amount of friction so u could get the most air through, how would having a more congested pipe increase power? its just the amount of air u can fit through the pipe. i dont know how else to explain it really..feel free to correct me. so far i've just heard "naarr u want pressure"...

[MearCat]

It's at this point when I admit I'm slightly wrong about something. The other day, a rather knowledgable friend of mine remided me about fluid dynamics and how they relate to exhaust flows. I have incorrectly been talking about our NA's requiring a smaller exhaust diameter to retain some backpressure when I should have been saying that the smaller diameter is required to retain the scavenging effects from the engine.

I've looked around for a write up of sorts and read this : http://www.miata.net/garage/KnowYourCar/S4_Back.html

To quote a bit of it "So instead of going for the widest pipe possible we should be looking for the combination of the narrowest pipe that produces the least backpressure possible"

I still maintain that if you want to retain a reasonable abount of throttle response and drivability and if you're not going for outright top end power, a 2.5" exhaust is the biggest you want to go.

[r34_skyline]

ok thnx ppl. also, does the tip of the muffler matter ? say i got a 2.5" cannon with a 4" tip with a silence on. is that still ok ? or will it be better if went for a xforce dual tip muffler

[illusiVe]

i'd say most would say the tip dont matter cause once its out of the exhaust pipe its just going into a bigger container....unless u want to have an exhaust pipe which never ends=

anyway what im trying to say is no 4" tip wont matter, thats just the sound..just talking about the exhaust pipe itself. the smallest part of the exhaust will be its downfall.

[Eug]

however the airflow issue - NA's still need some degree of "flow"

for low and mid range revs...

and reading the link MearCat has posted only supports that a 2.5" exhaust system

is optimum for NA Skylines in regards to performance, drivibility, and throttle response.

[r34_skyline]

would 2.5" be the same for all N/A cars ? or just skylines specifically ?

[Kor'axis]

Just to get 1 thing clear... 2.5" = optimum or maximum or both

[illusiVe]

sounds good..but im just planing on 3inch since im going to turbo my beast

[Eug]

dyno proved that one wrong for me and my friend, i have GTS4 and he has a GTS.. both had increase in power from what was already on the cars when we got em.

umm... don't you already have a 3" system?!!

how can you back up this claim of more power and more torque on the dyno - just that

i just assumed by your findings that you were talking from personal experience.

[wilmee]

this is my stupid opinion....if you try to spend few hundrad dollars for a muffler, and only have some power gains, how about just remove the "CAT" at the exhaust and you should feel the difference when you're driving....mainly increase at mid-range power. this is more worth.