stock03

Yesterday I installed a Donaldson 4” muffler. I’m not sure of the model, but it’s approximately 4’ long. I installed it right past the stock 3 ½” down pipe and then connected it to the Banks 4” muffler and out the back.

The truck is a little quieter at idle but has a deeper tone when accelerating, and it sounds more like a big moving truck. The turbo whistle is more distinct, but I don’t think it’s any louder.

When cruising at approximately 50mph on a flat surface, the motor is extremely quiet. I haven’t gone over 50mph yet, so I don’t know if the drone will be gone. I’ll be going for a drive today and driving at 65 plus. If the drone is gone, I’ll be pleased with the muffler. If not, then I’ll deal with it…

mikeh1725

2 mufflers, going assassin style

stock03

The truck is very quiet at 70 plus. The drone is pretty much too. The next test will be towing. But so far, so good.

alboy

I tried the two muffler route .not great for towing heavy, went to a resonator .4x30 from FTE DIESEL, great results,very quiet ,no drone at all.I think i would go with FTE resonator ,5 inch with reducers for quicker spool up on the bottom end.

stock03

I haven't towed yet, and I'm hoping the drone isn't bad. But so far it's much better than before.

I only have a few feet available for one more muffler/resonator. So if I decide to get one, I'll remove the Banks and move the Donaldson towards the rear axle and install the resonator close to the down pipe.

Where is your resonator, and are you using a resonator only?

mikeh1725

^^^^ Interested as well. May get have bought an fte resonator for a good price just waiting on the guy to sell it to me. May run it alone or run it with the donaldson haven't decided yet. Thing should be very quiet

stock03

My brother has a 4" system with resonaor only on his 12valve, and it's loud, but doesnt drone.


I don't know anyone with a CR with a resonator only; but if you have a resonator plus a good muffler, your truck might be "factory" quiet, which is what I'd like. I just don't want my 3" muffler on again.

mikeh1725

Yea I know what you mean. I would like to run just the resonator at the downpipe but I can only imagine trying to convince the inspection place that that is in fact my muffler and it's most efficent at the downpipe.

I would imagine the resonator and a donaldson muffler would put you close to stock sound.

stock03

Ref inspection, do you mean emissions? If so, that’s a bummer. No inspections/emissions on diesels in New Mexico.

However, when I took my gas car in for emissions the inspector didn’t conduct any sort of visual (ref exhaust system). Besides take my $20 and give me a piece of paper that read, “pass”, I don’t know what he did.

mikeh1725

Here in my part of Texas we don't get smogged, we just have to pass a "visual check". Texas law states that a muffler must be on the truck, so when you go to get a generic inspection they will ask if you have a muffler. If your truck is somewhat loud, most of the time they will crawl under the truck and look in the "traditional" location.

This is the part where I think they would give me bs, but I guess we will wait and see

stock03

If you have just as resonator after the down-pipe, I'm sure you'd be ok. Resonators look like mufflers.