Muffler centre pipe investigation - Bit of a surprise!

[cpitts]

*BUMP*

More investigation performed on the centre pipe. Just had to be sure it flowed as well as I thought.
Y split examined.
Dint/bump examined.
Pipe inside reso examined.

Read the first post.

[SUB4RU]

Bringing up and old topic here...

I currently have a Phat DP and Hi Tech Mufflers and stock Y & centre pipe on my t/b STI and was looking to do the centre pipe next.

Does all this mean that a custom 3 inch centre pipe and Y pipe is not worth the money?

[tangcla]

Does all this mean that a custom 3 inch centre pipe and Y pipe is not worth the money?

I would say so - the benefit you would get would be from increase in pipe diameter.

[cpitts]

Does all this mean that a custom 3 inch centre pipe and Y pipe is not worth the money?

Depends what your goal is.

If you're looking to replace the turbo and head north of 200kW then you'll certainly get benefits from the centre pipe in terms of spool speed and peak power increase.

If you're looking to keep the stock turbo, then yes, power will hit harder, but you're peak power won't change. All you'll be doing is moving around the torque delivery and that's about it.

Is this good value for money? Well depends on your buy price. If you cna get one cheap 2nd hand, then yeah, if not...... then that's a lot of money for extra noise.

[GTSPECB STI]

Ok I have been in this position exactly.

Ran Phat Dump and stock centre and y pipes with sti quads. Performance improved dramatically with these mods and a tune.

Replaced stock centre pipe with 3"s/s pipe and hot dog resonator and retuned with again considerable gain and the exhaust note was still shite with the sti quads. I then replaced the sti's quads with the hitechs..performance improved marginally but the exhaust note improved like the difference between night and day..huge improvement.

Do the centre pipe in mild steel if you want to save a couple hundred $$ but def do the this mod.

the history of my exhaust experiences and dyno results can be found here viewtopic.php?f=11&t=969&start=60

[SUB4RU]

Thanks, just what i wanted to see.

I didn't think there would be much power gain by going 1/2 an inch bigger for a metre or 2. I might hit up TCP auto and see how much his new pipes are separately.

[GTSPECB STI]

no problem and when you see the stock centre pipe and flat resonator / baffle in the centre of it you will understand why its a restriction.

[shippy_]

Thanks mate you have put my mind at ease after your Muffler center pipe investigation and Gutting of the mufflers threads you have saved me doing it myself, now all i am concerned about is why do my headers have 3 cats, not 100% sure if it needs 3 cats Im sure 2 should be sufficent


Thanks

[cpitts]

np Matt, exactly why I do these things. It's all about knowledge.

[PHAT GT]

Thanks mate you have put my mind at ease after your Muffler center pipe investigation and Gutting of the mufflers threads you have saved me doing it myself, now all i am concerned about is why do my headers have 3 cats, not 100% sure if it needs 3 cats Im sure 2 should be sufficent


Thanks

If you own an 04-08 liberty turbo ther are no cats in the headers and up pipe

only 2 cats in the down pipe/front pipe or dump pipe (what ever you want top call it)

[smythie]

it's a 6 cylinder from his profile Phat -they do have 3 cats. One in each header and another in the mid pipe just after the junction