I'm still debating whether or not to keep my 2.5" midpipe on, or put back the stock midpipe. Currently, I have a ZPI S-pipe (2.5") and a Tsudo N1 S-pipe back (2.5"). Stock header.

I've heard back and forth that 2.5" piping causes no back pressure, or in better terminology, less exhaust velocity. I've also heard that 2.5" piping is too big for N/A, especially on 4 bangers, causing loss of power.

I'm not expecting a night and day difference if switching back to the stock midpipe, but I just want the best out of my car, and if possible, best performance.

Any suggestions would be appreciated.

Thanks.

P.S. I'm staying N/A for now, and boosting later on.. if I do switch back to the stock midpipe, i'll hold on to the 2.5" midpipe for the turbo setup since I heard 2.5" is perfect for boosted applications. I'll be getting a header soon though, so keep that in mind.

 

bump

 

It's not simply that 2.5" pipes kill your performance. They increase your top end performance. Once your EGTs hit as high as they do in the tC, a 2.5" should (I only imagine) provide a relatively considerable gain. The problem is the tC was tuned for a fat powerband. Shifting the power slightly to the right is trying to force the tC to become something it's not. You'd have go big to take advantage of all 2.4 liters in the top end.

However, that's not too big of a problem for some. What are you looking for? I drive pretty leisurely so the whole i/h/e business doesn't appeal to me. If you drive around at peak power a lot, you'll notice gains with the 2.5" exhaust. If you drive in the middle of the RPM range a lot, you'll notice that your power has shifted away from you.

Pick your poison.

 

yeah, i believe you with the top end gains.. because that's when I "feel" the power. off the line is simply horrible.. the low end sucks. is there any way to balance it out? i thought that maybe putting back the stock midpipe would build up some back pressure, which is good for N/A, and would give me my mid's back.

 

anyone else wanna chime in..?

 

x2

 

keep your megan, add a resonator.... problem solved lol

 

i dont have megan. its tsudo s-pipe back.

 

untill you get a new header - dont worry about the midpipe ...keep the stock one. then when u get the header get a custom made one from a good muffler shop w/ 2 smaller resonators.

 

he can't not worry about it.... he has an s pipe back exhaust set up... just add a resonator either way, it'll help your backpressure and save you from sounding like ___ when you do get the header

 

I,ve a custom made 2,5 " s-pipe and i could feel the difference but in the case of my TC i've a lot more off mods

 

a resonator adds back pressure? i thought all it does is quiet down the rasp?

 

if thats the case do would a high flow cat work better for providing back pressure?

i also want to know how to create a little back pressure cuz i will be running the same exhaust (tsudo n1) with a CC s-pipe (2.5").

 

anything that restricts the airflow adds "backpressure"

 

a strait through perforated resonator will not slow down the air flow.. however a louvered resonator which most muffler shops use willl actually decrease performance and sound.

and to be honest with you spot.. for your mods, 2.5 is too big.. i would just run a 2.5 inch crush bent midpipe so you get some restrictions at the bends which would even it out.. or just keep the stock, as the stock already is a 2.25 inch mandrel bent system.

that is why most a/m companies are only producing axle backs, because they think that the stock midipie is adequate.

jmo

 

If you have to introduce restrictions in an effort to maintain proper exhaust velocity, the piping is too big.