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Discussion Starter · #1 ·
I had a set of custom pipes made for my 04 2.3. they put a 9 inch muffler (cherry bomb) and 3 inch magnaflow tips. they bolt right up to the stock Y pipe at the rear of the car. Ok here's the question I can tell the car launches better off the line and climbs through the gears faster ........but at 105mph its done no more speed. stock muffler slower through the gears but higher top end speed . Why is that?
 

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Ok here it goes. My thinking is that when you opened up the exhaust you might of opened it up to much loosing some touque. I would see what kind of hp/tq number your car maked before and after the mod too see. Even if you gains hp/tq. You might have lost some where you are seeing the higher speeds at. all manufactures test thiere car for years before they go onthe market too see what the car will do in all kinds of conditions.
 

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Ok here it goes. My thinking is that when you opened up the exhaust you might of opened it up to much loosing some touque. I would see what kind of hp/tq number your car maked before and after the mod too see. Even if you gains hp/tq. You might have lost some where you are seeing the higher speeds at. all manufactures test thiere car for years before they go onthe market too see what the car will do in all kinds of conditions.
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I agree...engines love breathing room...but our little (compared with the huge domestics) engines need back pressure to function at peak efficiency...too much back pressure is a bad thing...but not enough is just as bad...you'll lose power...as you've...obviously found...so close it up just a bit...
 

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given on the 2.3 the restricion is about 6 feet before the Y, any change back there will not be doing anything. i'd guess it's something else or in your head
 

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yes that might be true but .. Have you seen a cherry bomb before??? You could piss straight though the darn thing and not hit anything is it. there is nothing to them. I do have to disagree with that "any change back there will not be doing anything."I know that our exhaust pipes are 2.25in inch diameter correct? If you increast that any bigger then say 2.5 at best ur asking for trouble of all kinds. Let alone 3 inch ...Long hauler how big is the pipe that the exhaust is constructed of? It might be just too big?
 

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the thing is, it's all AFTER the Y. so even though the piping is 2.25 stock, being 2 pipes it's an effectively 5" exhaust at that point. So even if the actual muffler is 3" (where i think he only said the tip was?) that only accounts for the last 10" of the car.

what i'm trying to say is, no, the muffler swap has nothing to do with any variances you might be having.


...and typically, "back pressure" is never something you want at the top end anyhow. that is the time when it would be great without an exhaust, if we ran 5k plus all the time. having smaller piping (what you might call backpressure) helps promote gas velocity down low, but becomes a restriction on top end as the gas doesn't have enough room to leave quick enough.
 

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But im figurering in that the exhaust is just like the intakes of our cars very very picky!!! Yes mr tea I understand that the stuff he is using bolted right up. And yes you have to have atleast something like 3 inchs of pipin(in length) to keep your engine safe.The problem im thinking is that because he is using a cherry bomp(you have seen one right? if not go to your local auto parts store. they are red in color) Might be depreseing his backpreasure eough that it is killing his hp/tq numbers enough. And the thing with backpreasure is... YOU NEED IT!!! no matter at what rpm. the basic thing is anything you add a performance part, like exhaust you are changeing your power curce.. hopefully for the better, but you could do it and cause a negitive efect.

Lets say you install a high flowing exhaust on our car. For example you go from our 2.25 in piping and increase it 2.5-3.0 inches. yes you will be alowing my gases out and you might be creatting more hp, But you will kill any tq you need. And tq is very important too have. More so then hp. Since hp is calculated by tq. This is the info i have (tq=twist force hp = pulling force) I have seen cars dynos before and after a cold air intake is installed(i know it is a exhaust we are talking about now, but it is almost identical, just on the incoming side) and the greatest hp was 32.4 at 6k and tw was 35.4 at 4k but the highest hp was at 289 at 5,500 and tq at 305 at 4250 witha baseline of hp of 266.5 hp at 5750 and tq 271.4 at 3750. This was in 50 mustangs and fast fords may 2006 pub for a 05-06 mustang v-6. the parts thaey put of the car was a CAI and a T.B. So basiclly just becuase you bolt on one part or 2 parts on the car, they will and do drastically change your power curve. when he changed tout his stock restictiing mufflers. Remember this is a street car NOT a race car. Mazda from the factory makes our car pretty peppy(heck we all have to watch out for out cel on a aftermaket intakes) He might of going with a cherry bomb muffler deristricting his exhaust might have gone too far. That why if he could dyno it before n after(especilly on custom work)You will never know what the modification will do too the power curve. Thats why the words "buyer beware!" is such a great slogan. IT might be in his head as you say but dynoing your car after you do custom work is always a good idea. But im thinking its not. Cherry bombs are great for novas and cudas but not mazda's. Please I know you have one of the highest tuned cars on here, it just means you have the cash and time to do it all. ANd the knowledge to do it. If you did it all yourself. Please remember that 105mph is FAST!!! Our cars stock are not built for that speed. We dont own bmw or mercedes which are built for speed. Those cars are built for the Germen Autobahn. When ever you take are car over highway speeds(60mph)It will be acting very different.
 

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Discussion Starter · #8 ·
yes that might be true but .. Have you seen a cherry bomb before??? You could piss straight though the darn thing and not hit anything is it. there is nothing to them. I do have to disagree with that "any change back there will not be doing anything."I know that our exhaust pipes are 2.25in inch diameter correct? If you increast that any bigger then say 2.5 at best ur asking for trouble of all kinds. Let alone 3 inch ...Long hauler how big is the pipe that the exhaust is constructed of? It might be just too big?
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the pipe its self is the same as original tips are 3 inch ,but today i stuck a peice of 1.75 into the tip and pressed the cherry bomb to half its original size and same response
 

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the pipe its self is the same as original tips are 3 inch ,but today i stuck a peice of 1.75 into the tip and pressed the cherry bomb to half its original size and same response
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maybe its just the cherry bomb muffler. If you have your stock stuff still put that back on and see if its your new cherry bomb mufflers that are causing the problem.
 

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Discussion Starter · #10 ·
maybe its just the cherry bomb muffler. If you have your stock stuff still put that back on and see if its your new cherry bomb mufflers that are causing the problem.
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I am running the stock exhaust now....what kills me is $225 in the cherry bombs and sound is great but the top end performance is messsed up driving to far to have mechanical troubles on the road .....better safe then sorry. If i need more backpressure i'm going to modifiy them next weekend and take a run in it to see if it helps.
original exhaust=slow take off high top end 120mph
custom pipes=fast take off low top end 105mph
 

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guys, you are missing something. you don't really ever want "backpressure" you want to find the balance of velocity vs flow. if you are changing the last 2 feet on each tip up another inch, it's not going to be changing anything too dramatic.

i've never seen the cherry bomb, but it doesn't matter. there is no way that something bigger than stock at the end, is going to make it faster down low. when i put on my Greddy system, i lost a lot of the low tq that was fun (even in my atx) but i was greated with top end gain. the 2.35" setup allowed for flow rather than velocity as it was bigger than stock, so the power band moved upwards. which is what i am saying, making any of the piping bigger should NOT have any ill effects on top end power, just bottom end grunt.

....in my atx, from stock to any other modification, including the larger cat-back, i had no issues playing above 110mph....don't know what's up with your setup, you never know.
 

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guys, you are missing something. you don't really ever want "backpressure" you want to find the balance of velocity vs flow. if you are changing the last 2 feet on each tip up another inch, it's not going to be changing anything too dramatic.

i've never seen the cherry bomb, but it doesn't matter. there is no way that something bigger than stock at the end, is going to make it faster down low. when i put on my Greddy system, i lost a lot of the low tq that was fun (even in my atx) but i was greated with top end gain. the 2.35" setup allowed for flow rather than velocity as it was bigger than stock, so the power band moved upwards. which is what i am saying, making any of the piping bigger should NOT have any ill effects on top end power, just bottom end grunt.

....in my atx, from stock to any other modification, including the larger cat-back, i had no issues playing above 110mph....don't know what's up with your setup, you never know.
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if you switch up the pipes and lose torque...could you clean up with the header, mid pipe combo :ninja:
 

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MR Tea you are absolutly right(with a aftermarket sytem)like the own you have on your car, but you can see straight though sheery bomp also known as a glass pack or straight pipe.
Exhaust sytems are very very triky to get right on your own without the proper know-how
mxracer it might be possible but wh has the money too test tons of parts. I know that i dont and being that longhauler bought cherry bomb mufflers. They are dirt cheep. You can buy them for about 20 bucks each. The red one is a glass pack muffler(cherry bomb)
 

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i had glasspacks on my mustang, i'm familiar with them, just never seen em on an import? but again, anything from the y back should not make any serious impacts on drivability...i've even had em off for a while.

i didn't touch the exhaust until after my header and midpipe. no matter what the powerband moves, just takes getting used to.
 

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When you buy a system like mr tea's it has already been tested to find out what kind of charactisics it will put on the car. That is why they are the best way too go. All the kinks have been worked out of them already.

Longhauler, i would think that going too your local muffler shop and asking them the info on it will help to shjow some light. I dont have the info on whta exactly is going on but they would.

i had glasspacks on my mustang, i'm familiar with them, just never seen em on an import? but again, anything from the y back should not make any serious impacts on drivability...i've even had em off for a while.

i didn't touch the exhaust until after my header and midpipe. no matter what the powerband moves, just takes getting used to.
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Yeah and a mustang's v-8 engine is like twice as big as our 4 bangers. I have never heard of anyone even using are darn things anymore due too people getting tickerts for noise. The only person I know that has ever used then was my Dad back in the 70's on one of his cars. LOL. But drivability is huge once your over 100mph. Something that does not matter at lower speeds is going to show uup at faster speeds. My 06 6i mtx is great till it hits about 60mph(yes it is stock).Till it hits 60 it feels very very fast, then when I am at 60 and downshift it feels like a freakin freight train, you know.Even down shifting into 3rd its still stinks.
 
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