Is there a significant loss of low end torque by doing this? What size piping should be used if doing this, 2.25 or 2.5? Im guessing by straight piping the 3rd cat I can free up some exhuast flow.

 

first, if you head to your local exhaust/welding shop, if you ask them to cut anything, they will replace it with straight pipe that matches the diameter, cuz...thats their job. they are skilled at what they do.

2nd, removing the third cat and leaving everything else the same only results in like 2-3hp gain.

you are better off buying an aftermarket jpipe that removes the third cat.
an aftermarket jpipe has better flowing bends than the stock "crushed" pipe.
the longer jpipe gets rid of the third cat and you can expect to see around 15hp with this.

also, since the third cat is bolted on, it will be harder for you to find matching flanges. the exhaust shop will also have a hard time matching the flanges. its like a specific honda part.
might as well buy an aftermarket jpipe that has the honda flanges welded on.

 

As Justnspace said, you should really go with a aftermarket J-Pipe with a 3rd cat delete. The combination of getting rid of the third cat and replacing the exhaust J piping with smoother, larger piping will equal the most power. We have our V2 J-Pipe available for $475 not including shipping.

http://store.excelerateperformance.c.../i-494454.aspx

 

as always, Excelerate to the rescue!

 

XLR8 v2 J-pipe made a very noticeable difference, especially in the midrange on my car.

 

Would straight piping the 3rd cat cause any power loss though?

 

no, but you wont gain anything either......

very pointless to do.

thats the whole point of what I wrote and excelerate validated it

 

Rephrased;

why would you spend time and money on something that will give you very minimal gains?

 

Well my exhuast guy would charge me $30 to straight pipe it so im thinking it would give a better exhuast note and open up the exhuast a bit.

 

not even worth 30 bucks.

no sound difference

 

again, third cat is bolted on.

exhaust guy will have to find honda flanges.

unless he's just going to weld shit so that you cant ever get it offf.....

 

Really?! No sound difference? I was thinking deleting the cat would make it louder. Plus i was thinking with 140k miles that cat is probably clogged up no?

 

^no way!

lol sounds like you want to justify the purchase by any means necessary.

if you are going to get something cut off, cut the mid-muffler and resonators and replace them with straight pipe.....

the mid-muffler and resonators are not bolted on, so its a simple job for exhaust guy... cut, replace and weld.

 

the third cat is in place for extra emissions.
a civic is rated LEV (light emissions vehicle)

the TL is rated ULEV (ULTRA light emissions vehicle)

we have two main primary catalytic converters that take care of sound and emissions coming off the heads of the engine

 

Just try it and find out OP!

Butt dyno is very accurate sometimes

 

no and no

 

Yea I already have mid muffler straight piped with 2.5 and resonator replaced with dynomax. Not loud enough for me.

 

replace dynomax with straight pipe

 

I originally had a straight pipe in place of the dynomax and it sounded good except for the insane amount of rasp that would kick in at 2.5k rpm to about 3.5k rpm. Sounded really bad in those rpms unless ur flooring it.

 

If you want some performance and sound more exhaust sound...just add HFPCs and leave the rest of the piping the same

 

Does anyone know if this muffler will fit a type s bumper with aspec kit? It has a 4.5 inch tip.

http://www.amazon.com/gp/aw/d/B0086A6U3W/ref=mp_s_a_1_63?qid=1464452553&sr=8-63&pi=AC_SX236_SY340_QL65&keywords=Acura+tl+muffle r

 

My 3rd cat is rattling and I hear a muffling sound and some spongy material moving around. The flanges are rusted together so I can’t simply unscrew it out. Also not willing to spend money on sourcing a now rare item, so I’m thinking of just having straight piped. Cutting the cats off from the exhaust flanges and welding on a 2.5” pipe in place. Cheap enough for me. Any issues with this I’m unaware of?

folks said volume doesn’t increase, only clarity which I like. No reports or rasp or drone? I’m currently running a stage 3 (mid muff delete + Dynomax res 24215).

no inspections here in Ontario, Canada so don’t care about legality.

 

Update: it was the top heat shield that was rattling, so didnt need to take off the cat, but I did. Straightpiped and its as i was told.
Minimal increase in volume, but rather opens up the exhaust, giving more mid range growl and purrr that i like. Sounds more drier too (guitar players may get what i mean). Able to hear more of that rumble too. No rasp or drone for me.

It MAY have decreased low end torque as it did feel a little sluggish off the line, but dont notice it anymore.