After looking at the Donaldson and Nelson mufflers with 4" in wouldn't it be better and probably easier if going ahead and installing a 4" downpipe? At least the trucks would have a full 4" exhaust system.

MikeyB

 

I was kind of thinking the same thing... Not sure though, My buddie might help me install it today and then I can get the downpipe at a later day.

 

O.K here is the deal, I thought it was heavy but the junk stock one was heavier!! Took us a bit to install it because we ran out of wire for the welder and took a few breaks , but it is done and I am Happy . The stock downpipe is stainless, so for now I adapted into the pipe just behind the downpipe with an adapter, 31" piece of pipe , and then the 51" Muff attached to the tailpipe. Later I'll replace the downpipe.

 

Blownaway,
Can you take some pics of your install?

Thanks

MikeyB

 

I will see what I can do, I wont have my camera until Monday, Forgot it at home. Wish I could have taken a pic. of the mufflers side by side.

 

I don't know what draebi found but the only thing I replaced is from the rear of the downpipe back and my Overhead is reading about 1 MPG higher or more after a 100 mi trip down the highway. Not scientific but it also seems to handle the higer speeds with RPM's over 2100RPM without feeling so choked up. The sound is great, Throaty when you want it but quiet for the longhauls. So might think it is too quiet but it is perfect to me. Since I don't have pics yet I'll tell you it is positioned from just behind the crossmember all the way back to where the tail-pipe flares to 4"

 

This is great stuff guys. keep it up. BTW, at my request, Holset has initiated the internal process of making the full 4" cast elbow available after market.

Doug

 

Blownaway,
Glad you liked the results as much as I did. It is hard to tell about my MPG because I put EZ on 2 days before and so the combo definetely helped with my MPG but hard to say which one and I have not calculated by hand yet to compensate for error in overhead due to EZ.
Doug,
Let us know as soon as holset releases this 4" elbow so I can get in line if price is reasonable.

 

Thanks again for the part #, I am very happy, The only downfall is that it sounds so cool under Accel. I find myself gettin on it more just to hear the sweet sound, With the windows down of course. . It is so cool that it can make such music under accel. but completely go away at cruise.

 

will do. I know they have an internal part number assigned for it, and the internal gears are turning to make it available. But I have no idea what the price will be!

I'll post something in a new thread when I find out.

 

Blownaway,

Did it get rid of the drone at 70-75mph?

Draebi said the drone was gone, hope you had the same results.

Gary

 

Blownaway,
Can you tell what type of adapter you used? Was it 3.5" ID to 4" OD? I need to start rounding up the parts for the muffler installation. I assume Fleetpride carries the exhaust accessories.

Thanks

MikeyB

 

So is it as quite as the factory exhaust at cruising speed?

 

Had mine installed Monday. The sound at idle is about the same. When under acceleration, there is a nice low rumble to it. Kind of hard to explain, but it sounds very different.

 

As for the adapter I made my own out of a 4"-4" adapter, just made 4 cuts, crimped it down and welded it so that it would mate to the 3.5" pipe.(I only did this because they were out of the adapters) It will later get replaced when I do the downpipe. As for noise, it is definately a deeper sound under accel , But I still think that it is quieter at cruise unless you take it up to 80MPH or so. I am refering to noise in the cab, If you hear what echo's off of guardrails and even cars sometimes it seems alot louder than stock. (The mufflers are straight through you know)If some of you are unsure I will be towing a 33.5' Fifth Wheel in a coouple of weeks so I will let you know noise levels towing. Hope this helps