Is the Stock exhaust diameter 1.75" or 2.0"? Asking cause I'm replacing mine but I don't think the current y-pipe is stock.

 

I don't recall exactly but I know its some bastard size that doesn't quite fit anything. You have to finesse it a little to up or down a size.

 

Skimming around a bit, I noticed many saw no gain in exhaust upgrades and some had set backs.......any new word on this as those threads were fairly old......I need to do some exhaust work myself from the muff back that's why I ask.....

 

I ran just Y-pipes for a few months due to muffler and silencer rotting out, it was not overly loud by any means with no noticeable performance issues. Had a new (cheap)muffler put on a while back but didn't inquire as to what size. Y-pipe leaking (cracked) at left flange at manifold so now replacing entire system and in search of affordable options...

 

I just checked mine, believe to be 100% stock......measured 2 feet ahead of muffler......2 1/8" OD.


I'd like to get a single in, dual out running smaller twin pipes, no silencer, these Hookers get good write up's....
Example: Hooker Headers 21508HKR Aero Chamber Muffler

 

They're 2" nominal. The tailpipe is 2.25" but it's easy to adapt a much more common 2.5" muffler.

I've done a lot of experimenting with practical exhaust options (nothing full custom). I'm happy with the system I have now because it's quiet, it clears the suspension at full flex, doesn't heat my rear AC pipes, and won't be easy to rip off on rocks.

There's no useful gain in power to be had from the exhaust unless your catalytic converters are broken, molten and plugged, which is quite likely if they're original. Top-end gains have no purpose on a Land Rover since we do not drive around at high rpm, and the noise is annoying, especially when there's not even 200 hp for all of it, so just save yourself the absurdity.

I am using a large chambered style muffler in the center, and a medium-sized laminar flow style muffler in the rear. I tried several different styles of center muffler. I believe the largest chambered type is better than the packed type, but a large laminar flow muffler seemed to work just as well.

In the rear, I found that small mufflers like the little bullet packed or spiral flow mufflers are ineffective. Even with a 2-chamber, I wasn't able to notice a difference with them versus a straight pipe. I was able to get a larger, but still compact Hushpower laminar flow type on there which is noticeably quieter.

I prefer to use two different types of muffler which is why I didn't use a hushpower in the center. With two fairly large, high performance aftermarket mufflers, neither of which are "straight through," I absolutely have plenty of "flow," probably a lot more than stock. I can also have a conversation with my passengers in a normal voice.

With my exhaust working well, and the mud tires swapped out for something more AT-like, the loudest noise I had was the gears. I put some fresh 85w-140 in the diffs and now everything is nice and mild.

 

I just did a new y-pipe and I think I remember the diameter being 2.25 up to the center muffler and then 2 inches after.

I used the Part #: DAV17072
DAVICO - OE REPLACEMENT CATALYTIC CONVERTERS (48-STATE LEGAL - NO CA, NO NY)

Under $380.00 shipped. It fit up fairly easily. Had to do a little bending.

 

Because it's metric