thrush muffler?

[Wallyman]

Sooo BTT. Is there a hanger on the backside of the muffler? I like those welded thrush mufflers. I put one on my MJ a while back with a header and all rebuilt exhaust. Dumped it right under the bed. Of course with it being an MJ the drone didnt resonate in the passenger compartment. I liked it enough though. Especially since i could set off car alarms in the college parking lot on dum-dums crappy little box-cars.

 

[GrimmJeeper]

Well mine is mainly trail rig so I'm not too concerned bout all that. Less back pressure more hp.

Wrong. A cat will have minimal effect on our engines. It will have an impact on our ability to continue wheeling legally.

along with the legal issue Darky mentioned, the second part of your statement is also not quite true. Less back pressure without the ability to take in more air will actually cause you to lose power, most noticeably torque. unless you have a way to actually pump more air through your engine an unrestricted exhaust all the way back will cause you to build less torque and therefore have less power.

 

[Darky]

Bo ran his Shelby at the drag strip both with and without a cat and saw no discernible difference between them.

 

[bails85]

wallyman... what does sooo btt mean. no there is no hanger on the back of the muffler. the cat is really short and the muffler is welded on directly to it. the rubber on the trans mount is all thats holding it there. i tried to wiggle it around to see if i would have any problems and it seemed nice and strudy. there really isnt anywhere to put a hanger at.

 

[GrimmJeeper]

btt = back to top. he's bumping your thread.

I would suggest welding a long piece of rod to the turndown and hooking it into the rubber hanger over the axle, it will bounce, and it will cause problems. first the weld will snap off of the pipe where it goes into the runner on the trans mount, then the whole thing will start moving around and bust your exhaust manifold to crap. I learned my lesson after the third time :gee:

also bails, with your pipe turned down like that you're going to A) get more exhaust fumes in the cab if you are sitting and idling in traffic, and B) the heat from the exhaust is going to go directly at the rear axle housing and steel brake line for the rear passenger wheel. Once you get it driveable take it for a spin and feel the passenger side axle tube vs the drivers side, you'll see what I mean.

Mine is turned down there too, but I change the oil in the diffs every time I change the engine oil because I know its being affected by the heat.

 

[bails85]

the picture i posted doesnt do it any justice. its not very close to the rear axle. or the tire. i rotated the offset on the muffler to the opposite side as the stock one just for that reason.
also bails, with your pipe turned down like that you're going to A) get more exhaust fumes in the cab if you are sitting and idling in traffic

i asked about that as well before i did the install. everyone said it wasnt an issue. my buddy told me he didnt have a problem with it either and he didnt even have a turn down on his. not that im doubting you but i guess it will eb something i will have to deal with if the issue occurs. thanks for your input. on a side note im pretty anal about fluid changes as well. i figure its cheap insurance and i need an excuse to get out of the house.( my wifes always in there)

 

[GrimmJeeper]

it's not the proximity to the axle, its the fact that the heat is going down while you are going forward - it blows straight back at the tube. coupled with the fact that yours does not appear to point 90° down but looks like it is slightly angled back, you are going to heat the axle up. I'll try to snap some pics of my setup and post em up in the next couple of days if I have time to get over to work on the jeep, the way i have it set up now is the only way i've been able to keep the exhaust from tearing itself apart.

I am however a bit harder on my jeep than most for someone who doesn't race it.

 

[bails85]

cool i was looking for a way to hang it but wasnt sure. pics would be great. i havent got a chance to be hard on mine yet. its been a project since ive owned it. almost. all i have to do is set the real axle and reegear the front to 4.10

 

[GrimmJeeper]

so has mine, but that's because I keep breaking things. I break something then replace it with something that won't... eventually it will be grimmproof

 

[Darky]

eventually it will be grimmproof

Impossible!

 

[GrimmJeeper]

Impossible!

so far, yes :gee:

 

[ericfx1984]

lets see if this works

that's kinda how mine is setup, I have not had any issues with fumes, well not yet... but Darky can allow more fumes into the cab... the question is how much fumes?

 

[ericfx1984]

it's not the proximity to the axle, its the fact that the heat is going down while you are going forward - it blows straight back at the tube. coupled with the fact that yours does not appear to point 90° down but looks like it is slightly angled back, you are going to heat the axle up.

you think it will really get that hot?

 

[GrimmJeeper]

whether or not it's getting hot enough to cause damage i couldn't say. I know my axle tube gets hot enough that you can't leave your hand on it, but I have a larger muffler than that little thrush one, so my turndown pipe is a bit farther back.

 

[Darky]

that's kinda how mine is setup, I have not had any issues with fumes, well not yet... but Darky can allow more fumes into the cab... the question is how much fumes?

What about me letting fumes into the cab? Explain your logic.

 

[OttawaXJ]

I run a cherry bomb glasspack in all my jeeps. I went through 3 regular mufflers in one season because they kept getting snagged on rocks, I switched to the glasspack and havent lost one yet. it looks like its been hit with an IED but it works still and still attached.

 

[Darky]

T he downside being that technically, it wouldn't be allowed in any of the areas run by the USFS and such due its lack of spark arresting abilities.

 

[bails85]

what do you mean by that darky? are you saying im not legal the way that it is? i wont know how the fumes will react. i have even got to put it on the road yet. worst case is that i have to run it out of the back. not really a big deal to me. its not hard to change it if i need to. its mainly going to be a weekend beater and back up vehicle for when it snows and such. as far as the heat goes i was always able to stand by it when the exhaust came out of the back. it didnt seem too hot but again it will be something i have to address when i get to that point.

 

[bc99xj]

I think he's talking about the glass packs.

 

[techno1154]

I think what Darky is saying is, hot exhaust particles could exit the exhaust pipe and start a brush fire. Not good in the forest.

A few years ago ( I think in 2009) a poorly maintained vehicle back fired in the Florida Everglades. It took the park rangers and the fire department days to put out that fire. The last thing I heard they were trying to get the owner of that vehicle to reimburse the moneys spent.