[ctmazda]

My engine currently has 142k miles, without any issues whatsoever (for the most part). My worry is something going wrong, specifically with my pre cats.
I am wondering if it would be beneficial to purchase a new engine, then headers, or the other way around?

 

[aztrojans12]

A new engine is expensive, why buy a new engine if yours is still in great shape? Buy the headers and get them installed. Then, at worst case, down the road if you blow the engine, you will already have the headers. But at 142k miles you still have alot of life in the engine if you throw some headers on and keep up with monitoring your oil levels.

 

[flipper66]

what mister AZ said.

 

[ctmazda]

okay thanks for the advice , just as a rule of thumb to give me a sense; how far do these engines usually go? i know it varies by climate driving habbits oil changes etc. i am just wondering in general

 

[The Great NY]

nuthin more to say, haha

 

[aztrojans12]

okay thanks for the advice , just as a rule of thumb to give me a sense; how far do these engines usually go? i know it varies by climate driving habbits oil changes etc. i am just wondering in general

I know there are people with Mazda 6 3.0's with over 200,000 miles. But there are so many variables I don't even think anyone can really say a "general" amount. I do know that you have less than 150,000 miles, and if you have kept up with oil changes and never overheated, the engine should have another 100,000+ miles in it minimum (beyond that amount who really knows?) if you were to install headers. This assumes you never run low on oil and you never overheat. It also assumes you are willing to spend $ on the other parts of the car, like suspension, transmission, etc. etc. as they go along the way. Cars are built now days to really last a long, long time. I would throw those headers on it, keep up with oil changes and all your other fluids (brake, power steering, coolant, transmission) and you will have a long ways to go before you need to start worrying about replacing the engine.

 

[xepharo]

My best suggestion is fix as you go.
Get the most life out of your parts by doing regular maintenance such as oil change. You may assume that something is wrong, but maybe it won't happen 50k~100k later.

 

[karlt10]

Personally, I think you should replace the cover for the center console.

Damned thing could go at anytime and you'd be screwed.....

 

[SHROD]

Getting rid of the pre cats and getting headers? Is the exhaust louder , ricey ? If you leave secondary cats on ?

 

[karlt10]

Getting rid of the pre cats and getting headers? Is the exhaust louder , ricey ? If you leave secondary cats on ?

MSDS headers - into MagnaFlow cat - into factory resonator - into Racing Beat mufflers.

I was worried it was ricey because of the sound you can hit inside when really getting into it, but from outside it's not at all ricey.

And you'd have a major pain in the ass having the headers re-worked to use the secondary converters. Just do what I did.

 

[flipper66]

CPE -> high flow cats in y pipe-> magnaflow............ sound like a 92 accord with no exhaust.

so horrible.

 

[trentofdestiny]

karlt10, do you have any sounds or videos of your exhaust? I am considering headers on my wagon, but keeping the stock cat-back for now.

 

[BigAlDJ]

keeping the stock cat-back for now.

THIS IS FOR THOSE THAT ARE THINKING ABOUT CHANGING THERE EXHAUST
AS Quoted by Crossbow:
"a single 2.5 mandrel system setup, or a dual 2.0 mandrel system (Internal Diameter), work best with the 3.0 duratec system." .
"A small restrictive pipe would immediately fill with exhaust, and move at a considerable velocity, but excess gas would be left behind, which in the worst case scenario would actually remain in the combustion chamber and mix with the incoming fresh air, reducing power.
A large pipe would immediately absorb all the exhaust volume, but drop velocity to the extent that scavenging doesn't occur. Exhaust would still flow out, but would not be as efficent as it could be.
If the piping size is just right, the velocity is high enough so that it creates a suction effect at the cylinder head, and literarly sucks the exhaust out of the cylinder. This makes it easier for the piston to move up, and recovers a good amount of previously wasted energy."
"modifying the catback or mufflers will provide little or no gain, because all of the restriction is further upstream. This is verified by dyno's, as no one besides the various exhaust manufacturers have shown any gain whatsoever with any of the available catbacks on the market. (on owner dynos).
If anything, some of the catbacks are actually reducing overall power, because they're slowing down what little exhaust velocity there is, by the time it gets done going through the twists and honeycombs of doom."
FOR MORE:http://forum.mazda6club.com/engine-drivetrain/156660-exhaust-technology-sizing-velocity.html Crossbow (stickied)
Who the hell is Crossbow? If you look on the home page of this forum in the upper right hand corner in "STATS" yoo'll see he is the record holder for most posts @ 11,741. One of the great pioneers of this site.
On the Naturally aspirated 6's, replacing, or completely removing the catback, makes no appreciable power difference. Manufacturer dynos will show you an increase, but owner before/after dyno's will show no change, or a slight increase in the upper end (like 3-4) at the cost of the same amount of power in the low end. (loss of 3-4, for overall zero or slight negative gain). Always remember that it is the area under the entire power curve that is the most important, peak power contests are for dyno queens. One of these days manufacturers are going to come up with a new dyno graph which only showcases the average power gain over particular rpm ranges, and not the 5 hp between 6200 and 6700 rpm.
Also, just to mention, horsepower gains can not be added. If an intake gives you 10 hp, headers give you 20, and twowheels TB mod gives you 8, you don't end up with nearly 40 whp gain. More then likely it would be around 25-30. As you add power, it becomes more difficult to get more. (this comment not directed to anyone in particular, I just saw some members discussing crazy gains and adding numbers together)