exhaust modification - Land Rovers Only

ranger1968 · 10-08-2009, 10:20 AM

We had my 95 Classic LWB on the lift yesterday for an exhaust leak, and I determined that both cats and the muffler have a number of places where they are rotted through. All three parts look to be original, so I am not too surprised. The resonator all the way at the rear is in good shape, as is most of the pipe.

We have no emissions testing here, and I don't want to sink money into new cats, so I was planning on eliminating them, and replacing the stock rotted muffler with a Flowmaster Series 50 that I already have(a longer and slightly mellower Series 40, basically) and calling it good. A little added power and growl would be nice as well, and I figure that a little less restriction in flow is always a good thing.

I have exhaustively used the search function, but I still have a question or two.....

If I remove the cats, I can't see why the engine would run any differently, since the o2 sensors are upstream of the cats.

There is nothing attached to them in the way of sensors or lines, and there is nothing to the rear of them that would send any type of signal to the engine computer.....I see that a number of folks say that the motor will run richer, and that it will start throwing codes, but I just don't see why, since there is nothing to indicate to the engine that the cats are gone. With the untis that have o2 sensors before and after the cats, sure, I can see that, but on the older style with only the 2 sensors forward of the cats, I don't think it would be a problem....

Can you guys give me any input? Has anybody done this, and if so, how did it come out? In my search, there were a lot of " I am putting it together tonight, and I will post results tomorrow " posts, with no "tommorow" follow-up posts.....

SeattleRRC · 10-08-2009, 10:59 AM

I am in the same boat right now! Was just at the muffler shop yesterday and the guy recommended a Flowmaster 50 instead of the 40 series. I am going to replace my cats but only because we have emissions here.

Will removing the cats change exhaust flow or sound at all?
Are you going to keep your rear resonator? I'm planning to ditch mine and just throw a tip on the tailpipe where the rear resonator currently sits.

I would really appreciate pictures and even a sound clip once you've got yours together! Timing is pretty good.

ranger1968 · 10-08-2009, 11:22 AM

I think removing the cats will reduce the restriction a little, and I know that the stock muffler was fairly restictive, so the Flowmaster will defintiely be an improvement there. I am leaving the stock resonator at the back, as it is still in good shape, and does not really restrict the flow. I have Flowmaster 40's on my Bronco, and they sound good, but are a little obnoxious, which fits that truck perfectly, since it's kind of an obnoxious beast anyway. (but Soooooo much fun in the mud!) For the Rover, I would like a little growl, but not too much, and I think the 50 , along with the long pipe run and the resonator, will give it just the right tone-throaty, but not too loud. As a bonus, the 50 came in a trade I did with a guy for a bunch of stuff a couple of years ago and has just been sitting in it's box in my workshop, so it's not even costing me any $.....

As to the cats, if I can ditch them without any ill effects ( and in the older vehicle without rear o2 sensors I just don't see where there would be any) great, since they have to come out anyway, but if not, I'll get a couple of high-flows from Summit.....

ranger1968 · 10-08-2009, 11:26 AM

Hey Seattle, I really like that skidplate on the front of your Rover in the avatar pic. Where did you get that? I am thinking about ditching the front valance and mounting a winch under the bumper between the horns fer the brush guard, and that looks like it would finish it out nicely......

SeattleRRC · 10-08-2009, 12:06 PM

Got the skid plate here at AB. Probably paid too much for it.
I may be buying a parts truck next week - it has the same skid plate on it. I'll let you know if its available.

Do post pictures and see if you can post a sound clip of your exhaust!
Flowmaster has a bunch of 50 Series mufflers, which one are you putting on? I was thinking that I like the description for the 50 Series Delta Flow in stainless steel.

ranger1968 · 10-08-2009, 12:12 PM

Thanks,

The 50 I have is a Deltaflow in the aluminized steel. It's a bit bigger than the 40s but from the outside looks about the same, although I am guessing they chamber it a little differently for a quieter sound. I'll do pics, but I have no idea how to post sound clips.....

SeattleRRC · 10-08-2009, 12:18 PM

Do you have an iPhone? There is a sound recorder there, or other cell phones/digital cameras can do video? If you can't post, then maybe you could email me direct off the forum?
Thanks!

SeattleRRC · 10-08-2009, 12:30 PM

Can you post a link to the high flow cats you're thinking about using from Summit?

Parkersnell · 10-08-2009, 01:03 PM

Quote:

Originally Posted by SeattleRRC

I am in the same boat right now! Was just at the muffler shop yesterday and the guy recommended a Flowmaster 50 instead of the 40 series. I am going to replace my cats but only because we have emissions here.

Will removing the cats change exhaust flow or sound at all?
Are you going to keep your rear resonator? I'm planning to ditch mine and just throw a tip on the tailpipe where the rear resonator currently sits.

I would really appreciate pictures and even a sound clip once you've got yours together! Timing is pretty good.

HA!
Will they?.......hell yes, if you didnt have emissions you should just run straight pipes, no cats or muffler that sounds mean

ranger1968 · 10-09-2009, 09:07 AM

I was gonna get the Summit Racing cats, they have a few different models....but I don't think I'll need them.

I went to Atlantic British's site to check out that skid plate, and unfortunately it won't fit the RRC if you have a brush gaurd, so I am out on that one.....

SeattleRRC · 10-09-2009, 09:41 AM

That is funny, after I asked which cats I started researching and also decided that it wasn't worth it. Sounds like high flow cats help if you've got a high revving engine but let's be honest, these are not exactly high performance engines. Probably not worth the extra coin. I have to have cats here for emissions, but I think I'll stick with generic.

They make a skid plate that will fit RRCs with the brushguard (here). My 2 cents is ditch the cheesey factory brush guard. It looked cool in the 90s but its not very functional.

When will you put on your exhaust? I want to hear it before I make a decision on mine, which will be Monday. =)

ranger1968 · 10-09-2009, 10:54 AM

I had to order new gaskets where the y-pipe meets the manilfold, they should show up Monday, which will put me in the shop Tuesday-ish..... I am kind of excited, except for basic maintainence and a radiator, this is the first real work, and the first real mod, I have done to this vehicle, so it'll be fun.

For some reason, this thread is pretty much just you and I.

I like the brush guard, gives it the safari look, and my lights are mounted on it, so I'll keep it on. I did take off the Surco safari roof rack, and immediatley picked up 1 or 2 mpg......

I'll post pics, and if I can figure out the sound clip, I'll send that too....It's a v8, and with a Flowmaster, v-8s pretty much always sound good, especially if there's a good pipe run after it to let it mellow a bit.

RngRovaClassic · 10-10-2009, 01:34 AM

YouTube - Range Rover Classic with no exhaust

check this out. This is my 95 classic with no exhaust only the y-pipe and cats. I have a flowmaster on it now and it sounds beautiful, but in the video it sounds like a beast with no exhaust. in the video i said i chopped it off. i didn't really, i just unbolted the exhaust from the y-pipe. this is way back when i got the rover almost 2 years ago.

Jonesy · 10-10-2009, 07:54 AM

Quote:

Originally Posted by SeattleRRC

I am in the same boat right now! Was just at the muffler shop yesterday and the guy recommended a Flowmaster 50 instead of the 40 series. I am going to replace my cats but only because we have emissions here.

Will removing the cats change exhaust flow or sound at all?
Are you going to keep your rear resonator? I'm planning to ditch mine and just throw a tip on the tailpipe where the rear resonator currently sits.

I would really appreciate pictures and even a sound clip once you've got yours together! Timing is pretty good.

Dude....where you will be next year you will need to be careful on mods...they are really strict about emissions and inspections! Let me know if you want more information.

SeattleRRC · 10-10-2009, 08:33 AM

Quote:

Originally Posted by Jonesy

Dude....where you will be next year you will need to be careful on mods...they are really strict about emissions and inspections! Let me know if you want more information.

I assume that as long as I keep the cats it should be fine for inspection. No? Are there really strict with noise testing too. We can probably discuss via PM, I'll get you my email. Thanks!