best exhaust for the 4 banger?

Be retro and do glass packs.

 

I'm about to delete both my cats ✂️

 

Why would you do that?

 

I've thought about the same thing when it comes time to replace my exhaust. Since the 2.7 will never be a power house and the stock exhaust with the cats works just fine my opinion for deleting the cats is the cost. Those things aren't cheap and if you're in a state that requires no emissions testing like me it makes sense. The problem is, what happens if you move to one that does. Then you have a problem.

 

LCEngineering header opened up the top end of the revs a lot. It's a 4 into 1 long tube setup that promotes HP gains. After that, just get a full header back because the stock piping has a lot of restrictions, and is pretty small in diameter.

 

The stock exhaust is pretty nice, it's all mandrel bent, I'm not sure what restrictions you're talking about. It's my understanding that going to a larger diameter might open up the top end but at the expense of low end torque- that would not be an improvement in my eyes.

 

I have the LCE header and a 3in exhaust and have gained response everywhere in the rev range. The acceleration from off the line will always be crap but thats what you get for having a 4cyl. You won't be getting any torque benefits from anything for these motors.

The joints to the cats are tiny and with 2 cats down there you have 4 different pressure changes on the way out the exhaust.

 

Well, that's just not true. The lce header is know for boosting torque, but you may have negated that effect by losing your back pressure with the 3" exhaust.

This guy has done some dyno runs, with a few different configurations, with his main goal being to increase torque and lower the torque peak in the rpm range, the thread is worth a read:

https://www.tacomaworld.com/threads/2-7-dyno-charts.285741/

 

I know about tooter.

The nature of 4cyl is what will negate any initial off line torque. It will take a moment for enough combustion cycles happen per second to allow for adequate volumetric efficiency to be achieved. Then, the supporting mods will be utilized to their full potential. I'm in the process of putting a turbo on my motor because of the lack of bolt on torque and power for this platform.

You can dismiss whatever you want, just know that I have been through all this already, a long time ago. Just trying to help out

 

Yeah effen turbo!

 

I gained 1 to 2 mpg by swapping out the stock manifold for an LCE header.
One thing to keep in mind is, when you balance the flow with an equal length header, all cylinders get the same fuel mixture, which means no wasted fuel.
With uneven flow, the ecu (using the O2 sensor) adds fuel to all cylinders until the leanest one gets enough fuel. This leaves some with extra fuel which gets burned by the catalytic converter.
My engine also runs smoother than with the stock market exhaust. The engine will be easier on oil also.
I like quiet and it still is. The stock pipe and muffler is more than big enough.

 

@GDT I alrdy did it and it sounds beast asf. Makes my 4 banger sound like a 6

 

Cat delete with dual magnaflow

 

Stock exhaust on a yota is lame

 

I have awd eagle talon tsi..after upgrading to a bigger turbo, fuel rails ect..
I did a Cat delete and borla pipes&muffler.
It has been a chore to get inspected each year. lucky we do not have smog checks.
I have heard (rumors) that removing catalytic converter is a felony?
Is this true? I had a Mechanic a few years back that swore to me, that the police Could impound and or crush the car?

 

Flowmaster 50 Delta is what i have on my 2.7L and i think it sounds great. I ran a Thrush turbo muffler for a while and its like all the sound came into the cab (drone) and not out the pipe. The FM has very little drone and sounds sweet outside.

https://youtu.be/k1T0bFB7bkk

 

I don't know about all that, but if caught you could pay 10k in fines, I work at a muffler shop and I refuse to cut the cats out, now if you cut it off yourself and bring it to my shop I'll weld on a pipe , but I wouldn't do it to mine

 

Dang that sounds pretty good IMO,

Mind linking the exact part number, I might cut out my stock muffler or well have an exhaust shop do it and weld in one of these.

I like the way that sounds.






Speaking of cats,

years ago there was a web-site in business called www.testpipes.com, no longer there but they had a huge plethora of bolt in "test pipes" for offroad use only, you could easily remove your cat and install said "test pipe" with O2 bungs and have at it.

Lets just say an RSX-S with a DC 4-1 header, "test-pipe" O2 sim and a T1R mid-pipe and Spoon muffler could hold bumper to bumper with a WS6 on the freeway up to an undisclosed speed over the limit.



All was done on a closed section of an abandoned runway too!

 

I got mine off Amazon. Just search Flowmaster 50 Deltaflow. 2.5 in and out. I think mine was dual offset.