Hey guys, new to the forum but spend bit of time at Sportsmobile Forum. I have a serious issue with my exhaust on the van I was hoping to get some tips from.

I recently had a very reputable exhaust shop here in Oceanside CA do a 4" stainless turbo back exhaust. I have a 98 Club Wagon HD with a 7.3 PSD in it. The guy really helped me out by welding flanges into the new exhaust and mirrored that flange onto my old cat converter. This way when I need to pass Smog here in CA I can unbolt the section of straight exhaust pipe and reinstall my cat for inspection. Then back to cat free after I pass! Pretty psyched about that. I am really happy with the quality of his work.

The thing I am not happy about is how freaking loud it is in the van. The guys at the shop tell me its not a drone but I'm not sure I agree with that. It's like all the exhaust sound is coming right into the cabin of the van. Is this just a downfall I wasn't expecting and have to live with. Or are there were solutions, I hope there is!!!! I primarily do long road trips with the van and do not want to hear that much constant noise cruising through Utah in the middle of the night.

I tried doing sound deadened in the cab. Cut out a little (emphasis on little) engine noise but NO extra exhaust noise.

The seal of the dog house was my first thing. I'm good there.

Jim at Warners has put the van on the lift and walked me through the entire system. His guys used all the factory mounts and maintained the rubber isolators. Anywhere they added supports they used 3/4"x1" rubber strips as hangers so I'm confident its not vibrating through the vehicle. He suggested adding another muffler. I asked him about a resonator which he said is the same thing, just a fancier name.

What he believes the sound is, is the material and shape of the van amplifying the noise. Not exhaust drone, but drone through the body. My van is a Chateau model so its got full trim, carpet, 4 bucket seats and a bench, etc.

I am wondering if adding sound deadening mat will help. Considering one of the nice Mass Loaded Vinyl Barriers (MLV) stuff. What do you all think, is the MLV stuff going to help?

I've had it on for 2 months and I am completely frustrated with the noise level inside the van after doing this. I have to figure something out because I do not have fun any more driving the van. I have also done the following.

- Installed Rockford Fosgate deadskin throughout the floor of the van, inside the 2 front doors, and up 18" on the side walls behind the main cabin.
- Installed the FTE resonator and kept the full through muffler (Diamond Eye). The FTE had OK results from 1400 RPM down. Not really a difference above that level though.
- Changed the exhaust location to the rear passenger corner. Cut down the noise a little, not much though.
- Removed the tip so its just 4" pipe and nothing to create a "megaphone" situation. Did this at the same time as moving the tip location.

The van is VERY loud from 1750-2100 RPMs. It is not comfortable for myself or any passenger now. I've had 4 others in the van at once and each said it is WAY too loud. I would say it is 8-10x as loud as stock.

I took the owner of the shop for a ride and he says its just exhaust noise and recommends adding another muffler to it and removing the FTE resonator. I am not completely sold on this idea. The noise level outside the van is not really much louder than stock. I thought it might be the mounts but all the hangers have rubber isolators like stock. Any hangers they added are thick rubber strap. The noise comes from the back of the van. Most of the miles I put on this are highway miles with the cruise set at 70. You have to talk very loud to be able to converse with the passenger.

Something is going on here and I'm about to lose it.

What I am thinking my next move will be...
- Maybe they installed the muffler backwards? Have them take a look
- Maybe swap it out with a different brand. It is currently a Diamond Eye, I am thinking a 30" Magnaflow.

Other than that I am stuck. I am really bummed out. Is anyone in San Diego or Orange County and could recommend someone to check it out. Or want to meet up and see what you think?

I am so bummed as I was REALLY looking forward to the benefits of this upgrade. Please help.

Thank you everyone.

Nick

 

Does it make the same noise with the cat installed? Friend of mine put a free flow muffler on his dodge and it make the inside almost intollerable. His wife complains. What muffler did you use? I put a gibson turbo back on my PSD and it is still quiet. My friends wife enjoyed her ride with us once when we were travelling. Said she wished her truck was as quiet AND comfortable as ours. You may need to replace the muffler with one that is quiet (er).

or you may need to run the vehicle for a while to let the muffler burn in. I had a magna flow put on my ranger and it was loud but after a while it quieted down, sounds good outside, not obtrusive inside.

 

where does your tailpipe point? if straight out the side try putting a short 45 degree tip on it. changing the flow direction will change the noise. if the angle change helps get you exhaust guy redoo the tail with a similar outlet angle.


that's is a huge passenger compartment , works just like a big sub box.


I put a straight pipe on my new 96 F250 in front of the cat , but it was too loud so I put the cat back on and ran no muffler. the cat was enough muffling and exhaust still had a real big sound under acceleration.


did your fuel economy drop after the cat was removed?

 

Thanks for the tips Hank. Right now there is a Diamond Eye 24" muffler on it. I am thinking of swapping it out with a 30" Magnaflow. I have put a couple thousand miles on it so it should be burned in by now right?

That was my first thought too 68Mercury250Ranger. The initial install was located right out the side behind the rear wheel with a 5" tip on it. I had them remove the tip and change the exit location to the rear corner. It helped a little, but did not solve the problem. Right now the end of the 4" pipe is cut at a 45 toward the ground.
My fuel economy stayed the same after I did the swap. It should have increased in my mind. Doesn't the CAT inhibit straight through flow, thus decreasing MPG? I am going to try and run it with the CAT bolted back in to see how that sounds.

Thanks for the replies guys, keep em coming!

 

my old clubwagon has a 2003 7.3powerstroke/4R100 in it with a superchip on towsafe. I am amazed at its empty or loaded acceleration and towing power, and I do not baby it! I never found the stock cat was any source of restriction unless it was clogged, towing a trailer with a load for a while looks after that.


I think the cat reinstall may fix your noise issue, I like a loud exhaust but have not even considered it on my clubwagon because of the cavernous body. my clubwagon is now mostly a work/towing vehicle, still on the stock original exhaust at 445,000 km . cat definitely isn't clogged and isn't much restriction. I love passing cars on a 2 lane, empty acceration is awesome even in the 7000lb plus form.


I only kept the second row 3 seater and the aft axle 4 seater. if we didn't have salt and calcium chloride on our roads, my clubwagon would be around to 1,000,000 km .

 

Don't own a diesel anything, couldn't give me one BUT.......some past experience with a '97 E250 5.4 gas motor previous owner had eliminated the cat converter.........

There was a noticeable drone inside even with an otherwise stock-type exhaust system. Adding a 3/4" plywood floor did just a little to soften or reduce the drone but it was still very apparent.

My trust exhaust shop told me the cat converter acts as a resonator of sorts, without it I would experience what we've both encountered. As tough as it is sometimes the factory does a good job designing things. While the factory exhaust system for your motor may benefit from a bit of tweaking huge changes occasionally result in better performance at the expense of another parameter that presents itself only after the fact.

 

I am running a 24" straight thru 4"in/out muffler AND a FTE resonator.

FTE Resonator 4" Stainless Steel - Resonators / Mufflers

I am thinking of changing the 24" muffler to a 30" Magnaflow but hesitant because there is so much noise reduction that would have to happen for it to be acceptable.