fritts

I have a hard time believing that the shear volume of exhaust coming from a 6 liter engine when properly tuned is going to be that much better. Also to this how many people right now are running around with straight pipes on the their Rams, F150s, and Sonomas. I know I am from hick country but its quite a few around here. Not to mention the Diesel trucks running around. I don't really care about legal issues or environmental. All I'm getting at is that there are much worse polluters out there than I am ever going to be. So rag on me if you want but if you want to stop pollution there are way bigger hitters than me in the line up. Let also not forget how the government is trying to put cats on all motorcycles, even though the average trip driven by a motorcycle is less than the distance usually needed for a cat to even warm up.

Quick_lude

I understand that but this is a case of "hey everyone else is doing it, why can't I?". It maybe so but that doesn't make it right for you to do it... Do you really have people running straight pipes down there? Are there NO emission laws/controls? In the end my point is that the gains realized from this mod do not outweigh the cons of polluting the environment.. Of course in the end you will do what you want. Beauty of free will vs social responsibility.

fritts

In Indiana there are the same laws that apply to almost every state, not sure about canada. Except in Indiana we do not have any type of inspection. The only thing I know that is anywhere near exhaust related that would get you in trouble would be for having an overly loud exhaust. Which is something I encounter every day on the highway or in town. I am not saying that because others do it, it is ok, I am just saying that there are other fish bigger than me to fry first.

babylou

Actually, all auto emmission test are based upon an allowed amount of emmissions per mile driven. Therefore, an SUV with 50% of the fuel efficiency does not necessarily create more pollutants. The exception is carbon dioxide emmissions, which are directly proportional to fuel efficiency, but are not considered as pollutants by many peeps.

I can guarantee that the removal of catalytic converters will make your car much dirtier than any properly functioning regulated vehicle in the last 20 years. Plus just because someone else is worse is that a reason to slack off? I think not.

fritts

How about this guys I have major quams about start up emissions. I don't think it should be required so bye airpump. But you have somewhat convinced me that I could get a high flow cat without gaining to much weight and decreasing performance. I have no Idea what the cost will be but if its not terribly cost prohibitive I'll definetly look into it. Sound better guys.

Fëakhelek

The problem is not always what cars spew the most crap either. You can't assume the your car is the only one putting out pollutants.

To get an accurate idea of how much pollution results from removed equipment you would need to take the number of antisocial irresponsible self-important ignorant sheltered spoiled American daddy-pays-for-my-stuff punk twerps and multiply that number by the amount of extra emissions produced. It is hard to say how much extra emissions there would be so I recommend using 2 cars, on modified and one not, and two ignorant fools. You put their mouths over the tail pipes and wait an hour. Then scrape their lungs and weigh the crud that comes out.

Of course I am just a jerk for saying this since everyone knows these days that you have the right to do whatever you want without thinking about or understanding the consequences and you can figure "screw anybody that doesn't like it." It's the American way.

Slickvic

Looks like this thread has been Thoroughly hi-jacked.
Lets get back to discussing the possibility of improving the exhaust in the RX-8.

We can start a virtual lynch mob for the emissions scuff-laws in a new thread, cant we?

DrKillJoY

i'm with you.. about getting the discussion back on track...

Actually , I am awaiting an email from Racing Beat about aftermarket exhaust options right now.








FWIW > if you wanna save the enviornment go ride a bike or drive a Honda Insight... I will try to keep my car within the "federal" guidelines set forth, nuff said.

Fëakhelek

I apologize for my contribution to keeping the thread off topic. I just want to say that I agree with the quoted statement. In fact the regulations might even be too restrictive. My point is simply that we are part of a community and while most of us are responsible, some of us are not. I hate to see enthusiasts get a black eye from a few people breaking the law.

Quick_lude

Well we are still talking about the exhaust. Believe I also want to extract the maximum available amount of power out of any mod but removing cats is a pet peeve of mine. Sorry.
Incidentally, why do you guys think that Mazda chose the T design for the exhaust? I'm no expert but like others commented before that 90deg turn cannot be very good for flow.. Unless they know something we don't?

zoom44

they knew people would be looking for a way to upgrade the car so gave the enthusiasts an obvious one to start with? :D

Zio

ill leave mine stock and just work with the front end, any aftermarket ones are too loud for me and I want to stay legal.

Quick_lude

I'm not sure if you can get it done where you are but in the GTA we have a custom exhaust shop, Brullen. They can make the sound tailored to your preference. A free flow exhaust does not automatically have to be loud.

rotarynews.com

Personally, the exhaust is too quiet for me. I like to be able to hear it, maybe not as ear pearsing as my FC was (that was L-O-U-D), but enough to be able to ehar it with the windows down.

I use the exhaust note as another form of input on how the engine is operating. In my FD, i can immediatly tell by the exhaust sound when something is amiss... (not that I expect anything to go wrong with the RX-8) I also use it as a shift point indicator... when i hear it reach this sound, shift.

Zio

if i can get a higher flow without failing emissions tests than I may or maybe just change for a lighter one.

SmokingClutch

On older rotaries there was a lot of power to be gained by going to a single high flow cat instead of the triple cat stock setup. Evn more can be gained by removing it altogether, though certain exhaust combinations would simply be too loud. Unless you went with Racing Beat mufflers, oftentimes a header and presilencer with a catback was too loud on an N/A FC.

In my part of the world, it's "technically" illegal to remove your emissions equipment, i.e., most shops won't do it for you but they don't make you actually have one come inspection time and many places don't do emissions tests.

Personally I think exhaust notes generally sound better without a cat, with the mufflers regulating the exhaust note - you get a purer, more vintage sound. I don't care about the "moral" ramifications, I live in a place where the thing resembling smog is when people burn their trash (yes that's legal here!) and cats don't do anything to reduce greenhouse gas (CO2) emissions. If they crack down hard enough I'll just drive cars old enough not to need to be tested (can't wait to get an RX-3!)

As for the tight bend in the exhaust, I think it's pretty simple. With only a single cat on the RX-8, and being a naturally aspirated rotary and therefore LOUD, the restrictive catback is in place to keep the car quiet in stock form. They figure most people who want a louder note will spring for an aftermarket piece, which Mazdaspeed will probably sell sooner or later.

SureShot

From what I can tell, the header and resonator are tuned to just about max.
The cat is a matter of your conscience and local enforcement.
But – Oh yeah – loose that big can in the back.
Two small straight-through’s should be about perfect.

{edit} Referring to smokingclutch's comment about loud:
It is NA, but the 4 side port arrangement gives a softer pop than a peripheral port.

quicks8

If the constriction on the exhaust on the 8 is anything close to what it was on the 2nd Gen 7's then if you are brave enough to do it, dropping the cats and running two straight pipes all the way back should make the car FLY.

I used a setup Racing Beat was providing through MazdaTrix and did that with my 89 and it was like driving a completely different car after I mod'ed it. Night and day difference, like the difference between driving a Civic and a Camaro SS. I even passed E-Check 2 years in a row, by some miracle of GOD, with no cats on the car...

I am sure they have improved the whole exhaust setup and all, but that used to be the best way to get more power out of the NA's, at least it was with the 2nd Gen. [Well that is other than being an idiot an trying to put a supercharger on that engine and wind up buying a new one every 20K miles ].

Quick

Beemer

A rotary engine is very similar in working with a two stroke engine: intake, compression and outlet. No valve's like a four stroke engine. But the exhaust mounted on a rotary engine is the same as on a four stroke engine. So I was thinking about this: a two stroke engine needs an expansion exhaust system to build up the right pressure at the right rpm's. Now I was wondering what such an exhaust would do in combination with a rotary engine...
Maybe this can gain a lot more power and torque?

O.S. Engines, a famous R/C engine manufacturer, also produces a rotary engine. It also uses an expension exhaust/muffler:

An engineering marvel
Here's another O.S. "first"-the first rotary engine for R/C models. The O.S. .30 Wankel produces tremendous horsepower for its size. In addition to being compact and highly power efficient, the .30 Wankel is smooth-running and quiet. It includes two needle bearings and one ball bearing. It's perfect for .25-.35 applications. The engine includes an expansion muffler and a glow plug.