BJ 74 Exhaust time

[Phil in BC]

The exhaust on my 74 has finally rotted right through so it's time to have it replaced. A few years ago, the muffler rotter out so I just removed it and ran a strait pipe in its place. It did make it a bit louder, but really not too much. The neighbors have never complained about it.... But now that I'm running all new, should I be putting a muffler back in? Other than noise level, any advantages of putting one in, or leaving it out? If putting one in, any recommendations?

I've asked to have it replaced with 2 1/2" pipe. The guy that doing this for me wasnt sure if he could get a flex pipe that size. Since some of you are running 3" pipe, what have you guys used? He was also bitching about the tight bends going up and over the drive shaft, and and the larger pipe was going to make it difficult. Any thoughts on this?

Thanks
Phil

 

[crushers]

yes you can get the flex in 2.5"
yes, i would suggest sticking a muffler back in
yes, it is tight but a decent shop can do the work properly. if he is bitching then maybe time to shop for a different shop...

 

[Phil in BC]

Thanks Wayne.

Limited options in this town for people who do decent work at a fair price. The guys at the chain muffler shops are even more useless than I am at this, and its too far to go to the coast, so better to work with the evil I know. We'll see how he does tomorrow.

Phil

 

[crushers]

understood
or
you could do it yourself if you have the time ...

 

[Hulsty]

Maybe investigate alternate routing, I run my 3'' system between the gearbox and chassis (would be very difficult if you had a vacuum transfer case though. I dont run a flex either, the original system didnt and I have had no problems, built the system myself, once I got the hand of it, not to hard.

 

[jzilla]

I just did a 3 inch side dump exit in front of the rear tire on the drivers side, on my friends BJ71, turned out awesome!
Made a new flange and dump off the turbo with a flex pipe as well as a brace after the flex pipe. Added a resonator from a 2007 Tundra (it was free, walker also makes a small muffler that would probably work as well) that is 3 inch inside diameter.
Was planning to post pics here https://forum.ih8mud.com/70-series-tech/556253-bj74-3-exhaust.html when I have a chance.
We might consider making this set-up for people in the lower mainland if there is interest.
J

 

[Phil in BC]

Exhaust is all in now, looks and sounds good. They had no trouble with the 2 1/2" pipe, run in the same location as original. The neighbors will be happy now!

 

[fireball]

I'd like to bump this thread and get some input on a new exhaust for my 74. There's a hole behind the muffler so it won't pass inspection as-is. I figured it was a sign to upgrade!

I'd like to bump the boost maybe just a bit to something sensible like 12# or so, nothing too exciting just a little nudge. 2.5" or 3"? I've been doing some reading and the consensus seems mixed. Any advice?

Thanks!

 

[AussieHJCruza]

I run a 2H with an externally wastegated t3 and 3 inch straight from the turbo following the stock routing (except to avoid the long range tank) to out the left behind the rear tyre. It has a nice growl with a bit of a bark, but isn't unpleasant or offensive at all.

 

[Gun Runner 5]

I'd like to bump this thread and get some input on a new exhaust for my 74. There's a hole behind the muffler so it won't pass inspection as-is. I figured it was a sign to upgrade!

I'd like to bump the boost maybe just a bit to something sensible like 12# or so, nothing too exciting just a little nudge. 2.5" or 3"? I've been doing some reading and the consensus seems mixed. Any advice?

Thanks!

Recently installed a 2-1/2" exhaust on the my BJ74 at the same time the turbo boost was increased. Satisfied with the results.

 

[crushers]

2.5 is more than adequate, easier to run, cheaper.

 

[fireball]

Thanks everyone, sounds like the consensus is becoming more clear! 2.5" it will be.

@1978HJ45 any details on how much and how you modified boost levels?

 

[Gun Runner 5]

Thanks everyone, sounds like the consensus is becoming more clear! 2.5" it will be.

@1978HJ45 any details on how much and how you modified boost levels?

P.M. (Conversation) Sent.