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Old Apr 21, 2008, 08:36 PM
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Originally Posted by nj_08_gts
Don't know about fuel economy personally, I don't much keep track of it. When it's empty...I fill it and when Achmed swipes my card...money comes out.
That made my day man. +1 for the small sense of racism

On-topic.. Titanium or Stainless Steel better for an exhaust? I know titanium is lighter but any other benefits?
Old Apr 21, 2008, 08:42 PM
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Originally Posted by fuz_dnz
You're right about the exhaust part. My dealership told me I could modify the exhaust all I wanted, it wouldn't void any warranty. However if the exhaust would break or run into problems they would obviously not cover that part. I've installed an exhaust about a month ago but haven't gone to the dealership yet. I'm pretty sure they won't tell me anything since the first time I went I had my RRM short ram intake along with my aftermarket rims. Other mods like RRM lowering springs and RRM pulley were not that visible.
A friend of mine who works there even told me they had a guy with a huyndai tiburon come in with all sorts of mods and still get service. (I forgot what mods ) but I know it was serious mods since I was talking about my short ram intake. It definitely wasn't a turbo though.

Anyway the only reason why I go there is for an oil change and the inspection every 3000 miles. I guess as long as nothing goes wrong with my car they will keep on ignoring my mods and give me my free oil changes. But I'll know for sure what they're all about once I run into a problem.
You get free oil changes? I don't!
Old Apr 22, 2008, 07:23 AM
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The pully is a different story, although RRM hasnt had any problems with their pulley, a pully is one of those things that it has to be made perfectly. If it is off even in the slightest it can have a harmful effect on the engine. In theory a failing pulley can definately be grounds for some waranty voiding, if the damage is serious enough. a failed exhaust in comparison is still very very hard to prove. even if it is rusted out or falls off. So long as your emissions system isnt tripped. its not a problem
Old Apr 22, 2008, 07:25 AM
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Originally Posted by ChrisBond1
That made my day man. +1 for the small sense of racism

On-topic.. Titanium or Stainless Steel better for an exhaust? I know titanium is lighter but any other benefits?
if your hardcore about weight then you could go with titanium, but high grade steel is always best. I think titanium would be a bit pricey.
Old Apr 22, 2008, 11:36 AM
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Well I know that a muffler doesn't really have anything to do with the actual powertrain, but really it has a lot do do with the valves and pistons.

The back pressure a stock muffler creates keeps a bit of air in the exhaust pipes for longer than an aftermarket muffler, which is high-flow. This air results in a little bit of pressure to go back into the cylinder once the exhaust valve is opened. This pressure in the cylinder keeps the piston from moving too fast, as the piston is compressing air itself. This is why aftermarket mufflers give a bit more HP; they remove some of that back pressure, which enables the piston to travel a bit faster through the cylinder resulting in, you guessed it, more HP! With an aftermarket muffler though, or even NO muffler device at all, the piston has practically no limit to how fast it can go because of no or very little back pressure, resulting in the valves getting way too hot, and then eventually failing, or melting, unless of course you have upgraded valves to something like Titanium. SO! aftermarket muffler = *somtimes!* damaged valves.

But hey, thats just me
Old Apr 22, 2008, 02:51 PM
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Originally Posted by yitzac1990
Well I know that a muffler doesn't really have anything to do with the actual powertrain, but really it has a lot do do with the valves and pistons.

The back pressure a stock muffler creates keeps a bit of air in the exhaust pipes for longer than an aftermarket muffler, which is high-flow. This air results in a little bit of pressure to go back into the cylinder once the exhaust valve is opened. This pressure in the cylinder keeps the piston from moving too fast, as the piston is compressing air itself. This is why aftermarket mufflers give a bit more HP; they remove some of that back pressure, which enables the piston to travel a bit faster through the cylinder resulting in, you guessed it, more HP! With an aftermarket muffler though, or even NO muffler device at all, the piston has practically no limit to how fast it can go because of no or very little back pressure, resulting in the valves getting way too hot, and then eventually failing, or melting, unless of course you have upgraded valves to something like Titanium. SO! aftermarket muffler = *somtimes!* damaged valves.

But hey, thats just me
yitzac1990, there is a bit more two exhaust systems then that. Although I must admit you really do have to be an expert in exhaust systems to figure it all out. I myself couldnt claim to that expert. Most of everything I have learned has come from personal tuning and working around pros of different types and calibers. Going in reverse order of address your comment, exhaust systems namely mufflers do have effects on combustion, to some degree it is alot like plumming. But Mufflers them selves come in different designs and different configurations. Some employ rather clever tricks to produce power, or reduce sound. The failures you recently specified generally dont occur anymore due to the increase of sensors in cars today. Combusion temperaters I think and dont quote me on this should remain below 800'c, reason being spark plugs generally begin to fail at such points. I am pretty sure you will get a failure in your sparkplug before you get a failure in any valves. This is why spark plugs have temp ratings. Its amazing how much a sparkplug of a different temp can raise or lower an engines temp. Hot enough to melt the plug, or cold enough to cover it in pure crap.
I can say with confidence that regardless of what you do with your exhaust, your car will beep, and let you know before anything serious were to fail.

Moving to the actually pistons you mentioned, you are right but to a degree, since in recent years the combustion process has been refined and now almost 100% computer control. If your muffler was 2X as restrictive or lets just say smaller in diameter then the current one (just for an example to use) your engine will attempt to compensate for that change, in an attempt to compensate for what ever +/- effect it has on exhaust bi directional flow. This is even more important with the recent generation of mivec since computer can now dynamically control both intake and exhaust valves. of course the compensation will not be 100% effective, but it will work to midigate these types of situations as best it can. Anything beyond its capability I am pretty sure it would trigger some fault code. If it is serious enough you will get a engine light that is flashing continuously.

Finally commenting on backpressure. Back pressure is a difficult topic all together, I am sure I will miss something so I suggest if what I say doesnt make sense, I think I made a better case in my previous article / thread earlier located here https://www.evolutionm.net/forums/sh...d.php?t=318439

The case with back pressure and aftermarket exhausts is, there are different exhausts that can affect different things. You can design an exhaust that impacts more TQ than HP or vise versa. Piping size factors in, is there a canister? what type is it? what type of noise reduction does it use, did they use noise reduction at all. You can have a larger piping and and still come out with more backpressure then a stock exhaust. you can have again, larger piping and come out with lesss backpressure. There are so many factors its hard to count.
This is why I went thru 5 different exhaust mufflers for my dual exhaust project before I found one that was just right. the right balance of sound and power that I was looking for. All that said, you still have to review where the power is going, is it spread along the RPM curve is it targeted at peak tq / hp. In a N/A exhaust theory is very important. Not so much with a Turbo because that is more theory intensive on the intake side of things. So much more things that can go wrong, boost surges, piston or ring failure. so much!!! As I mentioned before, there is an article that is rather dated by about 8 years but it does a good enough job to get you into the theory of things for the average person out there. By no means is this the bible of exhaust theory, far from it. in some cases it goes a little to far off the track, but its enough to get you to ask the right questions. And the thing about exhausts is every one is different, every car is different, so different rules apply. So take what you read, either with my post or the article I am citing with a good grain of sale. Everyone has different thoughts. its good to ask questions.

http://www.nsxprime.com/FAQ/Miscella...austtheory.htm


oh and about powertrain the term is used in a nebulas way these days, I think I use it a little to loosely, some use it when they are refering to the transmission and engine, or when they are talking about specific things in one or both. Even wikipedia isnt specific on its definition I think. drivetrain, powertrain. terms make my head hurt
Old Apr 22, 2008, 03:06 PM
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"here is a quote from NGK about the combusion temps.

The insulator nose length is the distance from the firing tip of the insulator to the point where insulator meets the metal shell. Since the insulator tip is the hottest part of the spark plug, the tip temperature is a primary factor in pre-ignition and fouling. Whether the spark plugs are fitted in a lawnmower, boat, or a race car, the spark plug tip temperature must remain between 500C-850°C. If the tip temperature is lower than 500°C, the insulator area surrounding the center electrode will not be hot enough to burn off carbon and combustion chamber deposits. These accumulated deposits can result in spark plug fouling leading to misfire. If the tip temperature is higher than 850°C the spark plug will overheat which may cause the ceramic around the center electrode to blister and the electrodes to melt. This may lead to pre-ignition/detonation and expensive engine damage. In identical spark plug types, the difference from one heat range to the next is the ability to remove approximately 70°C to 100°C from the combustion chamber. A projected style spark plug firing tip temperature is increased by 10°C to 20°C"

http://www.ngksparkplugs.com/techinf...000&country=US
Old Apr 22, 2008, 06:38 PM
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Originally Posted by evo_soul
yitzac1990, there is a bit more two exhaust systems then that. Although I must admit you really do have to be an expert in exhaust systems to figure it all out. I myself couldnt claim to that expert. Most of everything I have learned has come from personal tuning and working around pros of different types and calibers. Going in reverse order of address your comment, exhaust systems namely mufflers do have effects on combustion, to some degree it is alot like plumming. But Mufflers them selves come in different designs and different configurations. Some employ rather clever tricks to produce power, or reduce sound. The failures you recently specified generally dont occur anymore due to the increase of sensors in cars today. Combusion temperaters I think and dont quote me on this should remain below 800'c, reason being spark plugs generally begin to fail at such points. I am pretty sure you will get a failure in your sparkplug before you get a failure in any valves. This is why spark plugs have temp ratings. Its amazing how much a sparkplug of a different temp can raise or lower an engines temp. Hot enough to melt the plug, or cold enough to cover it in pure crap.
I can say with confidence that regardless of what you do with your exhaust, your car will beep, and let you know before anything serious were to fail.

Moving to the actually pistons you mentioned, you are right but to a degree, since in recent years the combustion process has been refined and now almost 100% computer control. If your muffler was 2X as restrictive or lets just say smaller in diameter then the current one (just for an example to use) your engine will attempt to compensate for that change, in an attempt to compensate for what ever +/- effect it has on exhaust bi directional flow. This is even more important with the recent generation of mivec since computer can now dynamically control both intake and exhaust valves. of course the compensation will not be 100% effective, but it will work to midigate these types of situations as best it can. Anything beyond its capability I am pretty sure it would trigger some fault code. If it is serious enough you will get a engine light that is flashing continuously.

Finally commenting on backpressure. Back pressure is a difficult topic all together, I am sure I will miss something so I suggest if what I say doesnt make sense, I think I made a better case in my previous article / thread earlier located here https://www.evolutionm.net/forums/sh...d.php?t=318439

The case with back pressure and aftermarket exhausts is, there are different exhausts that can affect different things. You can design an exhaust that impacts more TQ than HP or vise versa. Piping size factors in, is there a canister? what type is it? what type of noise reduction does it use, did they use noise reduction at all. You can have a larger piping and and still come out with more backpressure then a stock exhaust. you can have again, larger piping and come out with lesss backpressure. There are so many factors its hard to count.
This is why I went thru 5 different exhaust mufflers for my dual exhaust project before I found one that was just right. the right balance of sound and power that I was looking for. All that said, you still have to review where the power is going, is it spread along the RPM curve is it targeted at peak tq / hp. In a N/A exhaust theory is very important. Not so much with a Turbo because that is more theory intensive on the intake side of things. So much more things that can go wrong, boost surges, piston or ring failure. so much!!! As I mentioned before, there is an article that is rather dated by about 8 years but it does a good enough job to get you into the theory of things for the average person out there. By no means is this the bible of exhaust theory, far from it. in some cases it goes a little to far off the track, but its enough to get you to ask the right questions. And the thing about exhausts is every one is different, every car is different, so different rules apply. So take what you read, either with my post or the article I am citing with a good grain of sale. Everyone has different thoughts. its good to ask questions.

http://www.nsxprime.com/FAQ/Miscella...austtheory.htm


oh and about powertrain the term is used in a nebulas way these days, I think I use it a little to loosely, some use it when they are refering to the transmission and engine, or when they are talking about specific things in one or both. Even wikipedia isnt specific on its definition I think. drivetrain, powertrain. terms make my head hurt
1. I totally agree.
2. Thank you for furthering my knowledge! lol
3. When I wrote what I said, I meant to say different mufflers can cause these problems or not, depends on the engine, pistons, muffler, everything. Im sure if someone has an old beater that barely runs, cutting the muffler off would SEVERELY damage the engine, due to old, worn parts in it already. Althought that example may seem a little extreme, It is definitely possible. I know someone with an early 90s VW passport and the whole exhaust system is completely screwed up. It is insanely loud and he has done NO modifications, except maybe bottomed out a few too many times. Something like this could over time cause severe damage to the engine and its parts.

Also, i did forget about piping size, I know that plays a big role in exhaust systems, sorry.

But again, I totally agree with you

I am going to the dealership in 2 days (Thursday) and I will actually try to get that in writing and scan it and send it to you. "The addition of any aftermarket exhaust system on the 2008 Mitsubishi Lancer will void any and all warranties having to do with the power train, i.e. engine, transmission, etc." Sound good? haha

Last edited by yitzac1990; Apr 22, 2008 at 06:44 PM.
Old Apr 22, 2008, 06:47 PM
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dont applogize, you were on the right track

and ya, get that in writing, I will post it on my wall. Its a statement that I am sure you can sue them over if they are brave enough to put it in writing. you make sure you get a manager to sign off on it.
Originally Posted by yitzac1990
1. I totally agree.
2. Thank you for furthering my knowledge! lol
3. When I wrote what I said, I meant to say different mufflers can cause these problems or not, depends on the engine, pistons, muffler, everything. Im sure if someone has an old beater that barely runs, cutting the muffler off would SEVERELY damage the engine, due to old, worn parts in it already. Althought that example may seem a little extreme, It is definitely possible. I know someone with an early 90s VW passport and the whole exhaust system is completely screwed up. It is insanely loud and he has done NO modifications, except maybe bottomed out a few too many times. Something like this could over time cause severe damage to the engine and its parts.

Also, i did forget about piping size, I know that plays a big role in exhaust systems, sorry.

But again, I totally agree with you

I am going to the dealership in 2 days (Thursday) and I will actually try to get that in writing and scan it and send it to you. "The addition of any aftermarket exhaust system on the 2008 Mitsubishi Lancer will void any and all warranties having to do with the power train, i.e. engine, transmission, etc." Sound good? haha
Old Apr 22, 2008, 06:49 PM
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ahaha alright well anyways I will try to get that paper for you to bring to HQ!
Old Apr 22, 2008, 07:08 PM
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The addition of any aftermarket exhaust system on the 2008 Mitsubishi Lancer will void any and all warranties having to do with the power train, i.e. engine, transmission, etc."

anything else you want the service manager to quote? intakes, headers, etc.?
Old Apr 22, 2008, 07:29 PM
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the exhaust is good enough. he has a point if its the INJEN one, since it messes with the emissions equipment
Old Apr 22, 2008, 07:33 PM
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ok cool, and I didn't even know Injen had one yet. I was looking into a Flowmaster 60 series myself
Old Apr 24, 2008, 07:56 PM
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Service manager is a d***!!!!

Follow up on that little warranty paper:

Like the post title says, he's a dick, first of all. I asked if he would kindly sign the paper, showing that any aftermarket exhaust would void the warranty, and he stepped back and said "I'm not signing this. I'm not setting myself up for anything..." He pisses me off! Not only has me put me through hell with all the other problems I've encountered with this car, he's rude and I think he hates me just because I want to mod my car. But anyways, yeah, no luck.....sorry evo-soul
Old Apr 24, 2008, 08:34 PM
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well, I think by company policy the techs will not do anything that will void your warranty so tell them you want them to install the exhaust. if they are serious about that claim they would refuse. I am 100% sure the manager just likes to power trip and is just bs'ing. go ahead and install the exhaust. If he pulls the void warranty thing on you, I will make the call.


Mind sharing with us who the dealer is? you dont have to.


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