Exhaust - let's talk about this one!

[Silver Ecstasy]

Well, here's my point to all of this:

This car lives and dies by it's turbo. So it's important to help that piece flow as much as possible. If you've opened up your Intake air flow by adding a SRI/CAI, then it only seems appropriate you help it exit just as comfortably.

Just like how people seem to add Turbo Inlets but no DP or exhaust mods. Then the turbo is unbalanced and people have complained about compressor surge or spikes were the intake side is outspinning the exhaust side, it's uneven. Don't quote me exactly on that but that's what i've spotted in a few TIP threads.

And the rule of thumb for forced induction cars is bigger is always better. If not for better flow, it's always good for lowering EGT's.

 

[Silver Ecstasy]

I'm not missing you point. I have built and tuned MANY engines in my time. I know how they work. The gains might not be in power terms but it could be spool time or the time it takes for the engine to build to max power. It could also just flatten out the torque curve some more.

In my experiences you almost always benifit from a free flowing exhaust (post turbo) on a forced induction engine

Exactly. If you read my very first post at the bottom. The link I found explains that. It will allow the turbo to spool or gain that power sooner than before. So we may not have to wait till 3,000 to start our power climb, only for it to die at 5,500 so soon. Technically, when I had my Forge, it died at 6,000 but still. If the turbo will appropriately and safely spool faster at a lower rpm, then that's all good in my book! Infact, i've already been in a MSCBE-equipped car and that thing had some pretty nice torque down low. Turbo came on quick and in a hurry. Infact, he doubted the necessity for a Forge BPV when he was running MSCAI/MSCBE and the car was doing great!

 

[mazdaspeed32007]

as far as hp goes on the exit side...post 300hp you would see better gains then under 300hp. under maybe 3-5 hp but above 300hp maybe 7-10. im not gunna lie though i think that even with that post 300hp if you still have the stock k04 turbo your not going to flow more air than the stock cbe can handle. that why i said earlier that you might see a 3-5 hp gain with a cbe. changing that down pipe on the other hand will open your turbo side right up. thats where all that pressure that slows air flow for this car is. it isnt in the cbe.

 

[camrycev6]

I just read your sig... mazdaspeed32007... It is so ridiculous I laughed and got a headache at the same time...

Back on topic...

I applaud any upgrade that offers a performance increase. I don't care if it is handling, power, efficiency, etc. I am not debating the cost versus increase argument here, as that is not within the scope of this discussion. That said, getting a CPE that adds 5-10 HP (TBD of course) seems perfectly reasonable to me. I too would like to see some data on the actual gains for JUST a CPE. Getting a CPE to make your car loud (especially extremely) is nothing but pure rice and a good reason NOT to get one. In fact, I wouldn't get a CPE that made my car louder even if it was going to add 20 HP. I would just be too embarrassed to drive it. That is just my take on it though, to each his own rice.

 

[jeff4880]

I'm sure the stock CBE is matched very well to the turbo and performance levels of the car. But the fact that it has 2 resinators and a muffler tell me that something from the aftermarket has to have some gains even if only 1-2 or 3-5 H.P. 1 horse power gain is a gain no matter how you look at it.

The real debate here is not weither there is any gain with a CBE, but is the gain worth the cost of the CBE? My personal opinion is that the money is better spent on the down pipe and test pipe.

 

[camrycev6]

I'm sure the stock CBE is matched very well to the turbo and performance levels of the car. But the fact that it has 2 resinators and a muffler tell me that something from the aftermarket has to have some gains even if only 1-2 or 3-5 H.P. 1 horse power gain is a gain no matter how you look at it.

The real debate here is not weither there is any gain with a CBE, but is the gain worth the cost of the CBE? My personal opinion is that the money is better spent on the down pipe and test pipe.

Well if that is the real issue, cost versus performance reward, I do not think a CBE is worth the money. That is exactly why I don't have one now. The gain would only be noticable via the "mental" dyno.

 

[squidmotion]

It's been my understanding that exhaust and exhaust backpressure are always a good thing to have when it comes to NA (naturally aspirated/non super/turbocharged cars). However, when it comes to our MS3's being turbo-charged, the rule should technically apply in any level that opening up our exhausts, freeing up flow on the exhaust side of an even greater scale and lowering EGT's will be a beneficial and positive addition to our cars, or ANY turbo car for that matter.

this i'm not as sure about... i feel backwards from you on this one... i always thought a slight amount of back-pressure on a turbocharged car was a good thing... the V8 turbo guys i knew talked about it giving the turbo something to push against and controlling the spool up/down of the turbo... the buick guys i knew would always run some kind of muffler, and never more than 3" exhaust....i think the exhaust/turbo kind of have to be thought of as a unit.. both kind of working together...

the least amount of back-pressure you can have on a N/A car the better... this one i can tell you is pretty much a fact....

from what i've been told, this is a very well designed exhaust system... i can see looking for more flow if you are seeking major hp gains... that is a given..

seems more hp for the money is found by working on the other end (induction)....

 

[jeff4880]

From what I have done with turbo bikes I can tell you the turbo will work at it's best with zero backpressure. In fact I usually just put a 6"-8" long, 3" diameter dump pipe after the turbo with a seperate waste gate pipe. Before the turbo is a diffrent story a small diameter tube header will help spool up the turbo faster. Much like holding your thumb over the end of a garden hose, the speed of the water will increase.

N/A motors are diffrent story. large diameter tubing could cause a decrease in exhauxt temp and slow the speed of the gases. Plus some backpressure will cause a scaveging affect in the combustion chamber drawing in the air/fuel mixture better.

 

[HOBDisease]

I don't know about you guys, but I love how the factory exhaust sounds, to me it's not worth the cost to get a cbe, a downpipe + test pipe combo will make me more than happy.

 

[MSMS3]

From what I have done with turbo bikes I can tell you the turbo will work at it's best with zero backpressure. In fact I usually just put a 6"-8" long, 3" diameter dump pipe after the turbo with a seperate waste gate pipe. Before the turbo is a diffrent story a small diameter tube header will help spool up the turbo faster. Much like holding your thumb over the end of a garden hose, the speed of the water will increase.

N/A motors are diffrent story. large diameter tubing could cause a decrease in exhauxt temp and slow the speed of the gases. Plus some backpressure will cause a scaveging affect in the combustion chamber drawing in the air/fuel mixture better.

Yes! Zero back pressure is best on turbo engines on the exhaust output side of the turbo.

But, again, please understand that if the stock CBE is flowing better (no matter how many resos or mufflers it may have) than the max rate of flow of the exhaust gas from the K04 turbocharger, then it has zero back pressure for that turbo. Power will not be gained by further increasing the size or flow rate of the exhaust.

It will take some very strong convincing evidence to show me that our CBE does not flow better than the K04 turbo sending it the gasses.

The restriction is between the K04 and the CBE -- the stock DP and cats.

 

[DaleNixon]

My Racing Beat CBE is cool but it's ultra quiet. It's like a whisper compared to stock. Has anyone gotten a resonator removed from the Racing Beat with any success? Yes, I've got purely sound in mind. One of my favorite things about a car is the noise it makes. Go ahead and call me a ricer if you like.

Maybe I'll look into getting an MSCBE. Where's the best deal on those suckers these days?

 

[Silver Ecstasy]

You damn ricer!

 

[screaminMS]

well i must really be a ricer lol. im not running any mufflers or cats 3" straight pipe. i love the sound of my car.

 

[Silver Ecstasy]

LOL naw, i'll just call you an enthusiast hehe.

But on a serious note, how did the car feel once you opened it up?

 

[NCZ13]

Might sound okay but it looks terrible...

yeah the MS3 doesnt look very good with a canister exhaust.

 

[PaPaSpeed]

I have a CP-E Catback coming tomorrow from SU Mark. They had a pretty good deal on them this week, so I sprung for one. Hope to get it installed soon, but i have a few things to work on first.
I'll report back when I get it installed.

 

[MM BOOST]

My Racing Beat CBE is cool but it's ultra quiet. It's like a whisper compared to stock. Has anyone gotten a resonator removed from the Racing Beat with any success? Yes, I've got purely sound in mind. One of my favorite things about a car is the noise it makes. Go ahead and call me a ricer if you like.

Maybe I'll look into getting an MSCBE. Where's the best deal on those suckers these days?

I am about to get the first resonator cut off very soon on my racing beat. I am telling you man, you really need to look into a test pipe and a downpipe. it sounds ******* amazing with the combo on my car, I just want it a little more audible, so I am going to get the first resonator removed and see how that does.

 

[djthom]

Yes! Zero back pressure is best on turbo engines on the exhaust output side of the turbo.

But, again, please understand that if the stock CBE is flowing better (no matter how many resos or mufflers it may have) than the max rate of flow of the exhaust gas from the K04 turbocharger, then it has zero back pressure for that turbo. Power will not be gained by further increasing the size or flow rate of the exhaust.

It will take some very strong convincing evidence to show me that our CBE does not flow better than the K04 turbo sending it the gasses.

The restriction is between the K04 and the CBE -- the stock DP and cats.

THIS!

Theory of Constraints FTW!

 

[DaleNixon]

I am about to get the first resonator cut off very soon on my racing beat. I am telling you man, you really need to look into a test pipe and a downpipe. it sounds ******* amazing with the combo on my car, I just want it a little more audible, so I am going to get the first resonator removed and see how that does.

Please report back bro! I don't want to remove either cat as I am worried that any exhaust mods before the 2nd cat can lead to smoking issues. If the resonator removal makes yours significantly louder, I'll probably look into that.

 

[MM BOOST]

I am sure it will make it louder man. however, I recommend doing at least the race pipe. Only thing it is for is volume control. I am running completely catless right now with 24k miles on my car with intake/turbo inlet as well, and I don't have any smoking issues. You won't be able to tell the difference by slapping on a test pipe in smoke issues, it will however, increase the exhaust tone. I think you would be happy.