I got more power out of my 70

[lumpy70]

I recently was fiddling to get a turbo on my '85 BJ70 but in the end the design didn't fit properly and it turned out to be an elaborate test fit.

However, in the process I cut off all of my exhaust sytstem to run a straight pipe for the turbo. When the turbo project got put on hold I kept the new exhaust on.

Wow! What a difference. I am now running stock manifold (temporary until the turbo) adapting into a 2.5" pipe and going thru a 2.25" baffled flow-thru muffler (sometimes called a resonator). All of this dumps out at a 45 degree angle just before the right rear tire. This is so much less constrictive than the stock setup where it goes up and around the frame then back out the back thru another muffler.

While slightly (and I do mean just slightly) louder than stock, the performance difference is impressive. I get better throttle response and more power up some hills without gearing down.

Now don't get me wrong, it's still not a turbo, but there is a noticable improvement which I am very happy with.

Craig.

 

[Stone]

Interesting, I've been thinking about straight pipes for my BJ74...but my stock exhaust is still in really good shape and I'm not in the position to dump money into the Cruiser right now if it's not absolutely necessary. I think Sheldon put straight pipes in his BJ71 before he sold it and was also happy with the results.

 

[Greg_B]

I have 2.5" on my BJ42, with a high flow muffler. It really fraps at one RPM (loud with the soft-top) however is quite pepping too!

gb

 

[Deny]

I had the same set up with a glass pack on my 42, but the noise was too much, especially with the pass. window rolled down, so I had a baffle pack style muffler put on by the local exhaust shop, and am now happy, but can notice a drop in power from when I had just the glass pack on.
Cheers,
Deny

 

[sandcruiser]

anyone know how much of a difference a larger exhaust would make on a 2H? my stock exhaust is rusting out and if I could get better power/mileage, I'd be happy to upgrade it sooner than later

 

[cruiser_guy]

anyone know how much of a difference a larger exhaust would make on a 2H? my stock exhaust is rusting out and if I could get better power/mileage, I'd be happy to upgrade it sooner than later

Bigger, less restrictive exhaust is ALWAYS a good thing. I have 2 1/2" pipe on my BJ60 with an AXT turbo but I do NOT use any type of muffler at all! It's slightly noisier (mostly noticeable next to building or walls) than the stock non-turbo setup.

If you go larger make sure the shop uses mandrel bent pipe and not simply corrigated pipe which seems to be so common here in Central America. The corrigated pipe is likely cheaper but will be much more restrictive.

 

[Syzygy]

i'm starting to look at exhaust on my 70 series bundera.

the current design is hopeless, probably the same as lumpy's. Must have about 10 bends in it...

Trying to decide if theres enough room to quieten it enough if i take it out infront of the rear wheel...

 

[HZJ60 Guy]

You dont need a muffler if your diesel is turbo'd.



Ive got two without mufflers.



TB

 

[brownbear]

You dont need a muffler if your diesel is turbo'd.


TB

Why is that only with the turbo? Does the turbo absorb so much of the energy that it makes less noise?

 

[cruiser_guy]

Why is that only with the turbo? Does the turbo absorb so much of the energy that it makes less noise?

The turbo does deaden the noise but not the same way as a muffler does. My '82 BJ60 also has 2 1/2" pipe and NO muffler. I was running a 100% stock exhaust before turboing the truck and the noise level is only slightly higher. Personally I sort of like the sound it gives off now. Idling sounds like a diesel inboard on a boat! Running you don't even notice it more unless you're up next to a divider or wall with the window open.

 

[Island Moose]

While slightly (and I do mean just slightly) louder than stock, the performance difference is impressive. I get better throttle response and more power up some hills without gearing down.

Craig.

I just cut out the muffler as well, and I will agree that the engine spools up faster and climbs hills much easier.

HOWEVER...I started it up, sounded perhaps a bit deeper than before, took off in 1st, maybe a bit more of a snarl, pushed the clutch in to shift into 2nd.....BWAAAAAAAAAAAAAARRRRRRRRGGGGGGRRRRRRRRR!!!!!!!!! ...and into 2nd...

Then on the way down a steep hill, I downshifted from 4th into 3rd.....BWWWAAAAAAAAAAAAAAAAGGGGRRRRRRRR!!!!!!!...

It is louder than a big rid with engine retarder in full swing....it's F-ing LOUD!

Am I going to put the muffler back on?....don't be ridiculous.

 

[Stone]

Lol, Moose. We're going to have to put smoke stacks coming up next to your A-pillar for you.

 

[jzilla]

Yes nice sound going downhill with mine as well. Sounds like a big rig.

 

[crushers]

you can also add a resonator to help cut out the noise, one man's music is another man's racket...

 

[tlcruiserman]

Moose,

they sound even better if you actually put a turbo on it ;p

I just cut out the muffler as well, and I will agree that the engine spools up faster and climbs hills much easier.

HOWEVER...I started it up, sounded perhaps a bit deeper than before, took off in 1st, maybe a bit more of a snarl, pushed the clutch in to shift into 2nd.....BWAAAAAAAAAAAAAARRRRRRRRGGGGGGRRRRRRRRR!!!!!!!!! ...and into 2nd...

Then on the way down a steep hill, I downshifted from 4th into 3rd.....BWWWAAAAAAAAAAAAAAAAGGGGRRRRRRRR!!!!!!!...

It is louder than a big rid with engine retarder in full swing....it's F-ing LOUD!

Am I going to put the muffler back on?....don't be ridiculous.

 

[Diesel Dude]

I turbo'd my BJ-42 and ran a two foot pipe straight down, I drove it that way for months. It was slightly louder than stock but not bad, I now run 2 1/2" pipe out the back.

 

[dieseldog]

DOT rules specifically exempt turbo-equipped diesels from requiring a muffler. The reason for this is that the turbo itself qualifies as a "sound-deadening device". As far as I am aware, this USDOT rule has an equivalent expression in Canadian law as well.

 

[tlcruiserman]

US DOT rules vary from state to state. However the only state I have every seen that does NOT have a muffler rule is Indiana. I will say that most states that require the muffler do not inspect for muffler at time of annual inspection, with the exception of New York. It is usually a matter of if you get stopped because you are really load and they PO checks and you do not have a muffler then you are going to get a ticket. I have no problem running a 3B in California without muffler as long as it has turbo it is not too load, without turbo I think I it is too load (depending on length of pip) and could get me a ticket. Just my 2 cents here.

Michael