12HT exhaust 3" with or without muffler? Just a resonator at the tip? (1 Viewer)

[helocat]

HJ61 with a 12HT, I am going to build my own 3" exhaust for it off the turbo back. Question is with or with out a muffler? I am thinking of just using a 3" x 17" resonator at the tip and no muffler in the mid section.

Anyone else do this? I don't mind a bit more noise, but don't want to blow my ear drums out pulling a hill.

 

[pathfinder_88]

Hi there,

I had a cheap, non-mandrel bent 3" exhaust made up for my HJ61 a few years back. I didn't run a muffler and was happy with the tone. I have a preference for louder exhausts though and I recall a friend stating that it sounded "like a dump truck". It really wasn't that loud and I didn't really notice it on the highway over the tire hum. It's a tough call because everyone is different with respect to preferences. I figure you could add a muffler later if it's too loud.

I believe I have a video around somewhere revving it stationary...I'll try to post it up later tonight.

For comparison, I've got a mandrel bent 3" on my HDJ81 with a Aero muffler and I find it a little on the quiet side.

 

[blis]

I run a short (300mm I think) free-flow muffler on the end of my 3" exhaust and I imagine without it the noise would get on my nerves eventually... But then again my exhaust exits under the passenger door so if you ran it all the way to back you could probaply get away without muffler...

 

[pathfinder_88]

I run a short (300mm I think) free-flow muffler on the end of my 3" exhaust and I imagine without it the noise would get on my nerves eventually... But then again my exhaust exits under the passenger door so if you ran it all the way to back you could probaply get away without muffler...

Yeah, mine exited by the rear bumper so likely less noticeable.

 

[cruiserpilot]

I have a custom 3" mandrel exhaust on my 12ht 60, I have a muffler cause I just want my truck as quiet as possible. On highways with concrete dividers ( like all of the urban interstates ) and with a rear bumper discharge, I'm certain that without a muffler the resonance would be too much.

 

[esh]

I notice noise more puttering along slow dirt/gravel roads, and it got annoying over many hours. Going from a cherry bomb to a large flowmaster with 3" tube has made no difference in EGTs, and noise has gone to a deep tone at lower RPMs. You probably wouldn't notice much difference in a setup at highway speeds climbing a hill if you exit at the rear of the truck.

Columbia River Mandrel has nice kits for bends.

 

[Tim-HJ61]

I've just got a resonator right down the back. Noise level is fine for all occasions..

www.peoplehelp.com.au/landcruiser for my write up of various projects, including routing the exhaust outside the chassis to gain more space underneath for more fuel tanks.

Tim

 

[helocat]

I notice noise more puttering along slow dirt/gravel roads, and it got annoying over many hours. Going from a cherry bomb to a large flowmaster with 3" tube has made no difference in EGTs, and noise has gone to a deep tone at lower RPMs. You probably wouldn't notice much difference in a setup at highway speeds climbing a hill if you exit at the rear of the truck.

Columbia River Mandrel has nice kits for bends.

Thank you Ken. Columbia River Mandrel does have some great prices on 304SS too.

I've just got a resonator right down the back. Noise level is fine for all occasions..

www.peoplehelp.com.au/landcruiser for my write up of various projects, including routing the exhaust outside the chassis to gain more space underneath for more fuel tanks.

Tim

Tim, Great information on your pages there! I might just use the same route you did, going outside the frame. You tuck back in by the rear axle, do you just hug the inside of the frame then back out for the end?

Good to see I am not off track by just flagging off the turbo. I have been planning that. Just planning on a 3/8" (9mm) thick flange to handle the heat.

Resonator at the end is the plan for now. Looking forward to building it once I have my IC finished.

Mark

 

[Tim-HJ61]

Mark it's got to work around the chassis, axle movement and shock absorber, and allow for all the flexing that might go on.

I can take some other pictures of specifics if you want them and I will add them to the website write up as well as post them here. I got an exhaust shop to do it, he figured it all out. One mount has cracked and I need to get that redone as it rattles, but apart from that, I've had no issues for the several years it's been on - Maybe 4 years.

The resonator sits in the same spot the original second muffler sat. Right down the back just prior to the exit point under the rear bumper - pointing out the back of the vehicle. It'd look better to have a 4" pipe sticking out the back rather than the 3" to add to the wow factor - chrome of course.

Tim

 

[71-CRUISER]

On the 12ht 60 I built a few years ago we ran nothing but a straight 2-1/2" pipe out the back. No muffler no resonator. Nada and it was not loud at any speed nor did it have any drone on the highway. Just the stock manifold and turbo.