Eagle Owners - Notice something missing?

[Seangie]

Im starting it up in a few minutes.  Ill see if I can get a video of the new loudness.

-Sean

[Seangie]

Here is the video.

Crank up your subwoofer.

https://youtu.be/DB20ZDsP8SU

[Seangie]

Here is the link to the manufacturers webpage -

http://www.aeroexhaust.com/mufflers/aero-exhaust-at5050xl-diesel-muffler.html

When I ordered the muffler Jordan (owner of the company) emailed back immediately and let me know they were out of stock and said they would have them again in 3-4 weeks.

I explained I really wanted this muffler mostly because it was the perfect size to fit in the space without too many modifications.  I also told him we needed it by may15th as we would be mobile a week later and wouldnt be able to have it shipped to us.

He said the muffler should be in stock by then but he shipped me the show model anyways so that I would have it in time.

Fantastic service.  We got a 3 hour drive to houston tomorrow and Ill post back here and ler you know how it goes as far as performance and heat.

-Sean

[Scott & Heather]

Sounds really good!


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[TomC]

It will be all telling you pull a hill with it cranked up. Sounds good though! Good Luck, TomC

[Seangie]

We made it to houston and the bus is running great.

Bus sounds awesome with the new muffler.  The low end noise coming out of the thing almost hurts your ears.

As far as performance, it has certainly improved.  Bus has more get up and go.  I drove from North San Antonio to Houston and there were quite a few smaller hills but big enough to have to downshift to get over them.  I did notice quite a bit more headroom going over the hills.

The bus seemed to be running hotter than normal.  It was about 88 degrees with 60-70% humidity yesterday and Id typically expect the bus to run at about 195 when pulling 70 down the highway in that warmer weather but it seemed to be running about 3 or 4 degrees warmer than that.  Its been 3 months since I drove the bus

On one long incline I was trying to keep the bus at 70 for as long as I could to see what would happen and the temps climbed up to about 205 and then I let off and let it cool down.

It was weird though because after that the temps dropped right back down to normal and I tried to get them to climb again but they stayed at 190-195 the whole time after that. Im thinking it may have been a stuck thermostat from the bus sitting for 3 months.  Ill keep an eye on it and report back after our next drive to Dallas tomorrow.

There was a noticeable lack of exhaust smoke coming from the tailpipe. I think the turbo is spinning up faster which helps with this reduction in smoke.

One thing that still hasnt cleared up is the soot coming out of the engine.  Without the turndown exhaust tip on it the heat and soot are blowing straightback on the van.  So Ill have to see if I can tighten up the pipeline underneath the bus and get a turndown on the end of it.

-Sean

[DoubleEagle]

Very interesting, it looks like a straight-thru glass-pak design, is it all stainless steel? Is it too noisy inside the bus at highway speed, or is it a little louder and sounds cool?

[lostagain]

Sounds good. Is it empty inside? My Donaldson resonator is the same shape and approximate size, and is empty. Fairly loud. Don't hear it from inside the bus though.

JC

[Geoff]

Kakimoto muffler for Detroit Diesels?  No thanks.  I like quiet and respect other people on the road.  Its not what you hear inside, its what others hear outside.

--Geoff

[Scott & Heather]

My bus is quiet compared to some truckers when they throw their jakes....wow. Just about the time I'm falling asleep at the wheel, a trucker has to drive by me with his jakes on and wake me up. Sheesh.


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[eagle19952]

Kakimoto muffler for Detroit Diesels?  No thanks.  I like quiet and respect other people on the road.  Its not what you hear inside, its what others hear outside.

--Geoff

Harley Davidson's sound horrible too...not.

[Geoff]

I've had several HD's, now I'm down to two after a high of 5.  My '85 FLH has a 89 inch stroker with flowed heads and I put a "Thunderheader" on it and it hauled @$#, but I couldn't take the noise.  I have a stock muffler on it now. Not as fast, but even earplugs didn't stop the Thunderheader noise.

--Geoff

[Seangie]

Hey Guys -

We got another 600 miles down on this thing and Ive got an update on how this muffler is doing.

1. Temps - The temp issues I had going out to Houston were definitely caused by a stuck thermostat or air pocket.  When I left San Antonio the reservoir was 1/2 full and when I got to Houston it took 2+ gallons of 50/50 to fill it back up.  Since then I have had no issues with heat.  Bus has been sitting right at 190 with 88 degrees of full Texas Sun.  Its climbed a little higher than that on some of the longer pulls when I am not paying attention and find myself "hot boxing" (Lugging for you Old Timers    ) But never hit 195.

2. Power - This is a hard one. Its been mostly uphill from Houston to Clovis, NM. My bus will typically run at 74mph on the flats (I95 east coast) with no problem. Here it has been a little slow to get to 70 and slower to hit 71-72 unless I'm going downhill.   This AM's drive from Abeliene to Clovis it would sit right at about 65-68 with full fuel. So I'm curious to hear if anyone else has made this run from Abeliene to Clovis on 84 with a 692 and HT40 and what you ran at.  Keep in mind we have a 10k lb toad behind us.  The bus is definitely punchier with less smoke from a full stop.  But curious if I'm losing power in the top end or if its just the hills.

3. Soot - This has been a problem since I first bought the bus. Its never gone away.  I spoke with Don Fairchild a while back and asked him about this and he said the same thing Cliff said that the current filter I have (1250 CFM) is not enough air for a turboed 6v92 with the 9F80 injectors that I currently have. He said 1500cfm would be ideal but the more air the better. So a retrofit there is on the long list of TODO's. Jimmy Clay had a intake mod where he just put a T on the intake and added a smaller truck filter inside the engine bay to get the extra air. Seemed simple enough.  I'm going to have to revisit this at some point.  But the only reason I mentioned it above was that the muffler is blowing straight back instead of out to the curb like the previous pipe was set up to do.  Because of this all the soot ends up on the toad instead of the road.  

4. Noise - Lets be real here, My engine (keep in mind there is no insulation at all in the engine bay and the aux air compressor bay is wide open) is about as loud as the exhaust unless I'm accelerating. The original muffler was pretty loud as well (Here is a video from days past to compare https://www.youtube.com/watch?v=F72-1HJ1kfc ) The new muffler is slightly louder than the old one but its certainly more pleasant to listen to. There are a bunch of reasons why I singled out this muffler -
size (32" long and only 7" at the bulge),
it is a straight through glasspack,
it has a resonator built in,
it is designed for performance (slight backpressure)
with attention to keeping the noise down.  

The manufacturer site says "The AT5050XL has a built-in resonator and patented air foil cone, which will not only increase fuel mileage, but significantly improve your horsepower and torque while decreasing noise and exhaust gas temperature"

We ran straightpipe for 4 hours coming into San Antonio in February and that was embarrassingly loud.
In researching this site and others the consensus was that 0psi back pressure would not affect a turboed 6v92s performance and you could straight pipe with no issues.  That was another factor going into a non-standard muffler.
So far I am happy with the noise, as I said above its slightly louder but sounds much nicer to listen to.  I can't hear any more noise from the drivers seat than I could with the old muffler unless your driving in a tunnel or by a wall with the windows open.

5. Fuel - Calculations showing we had 6.2mpg on our drive from Houston to Abeliene but we did run the generator during that time.  This is about the same (Maybe slightly better) than what we normally get pulling the toad.  We usually see between 6 and 7mpg.  7 on the flats and 6 in the hills so this is right in line with what I would expect to see.  Is there a fuel savings?  I couldn't say that without a computer looking at actual use.

Thats all I got!

Any questions?

JC - It is empty inside with a slight cone toward the outlet.  That cone seems to be 1" thick and adds maybe a 1/2" around to the inside of the straight through?  Im not sure, I am just going on memory from looking at it last week before I installed it.  I wish I took more pics.

Geoff - Its not a Kakimoto.

Walter - It is a combination straight through with a resonator.  I believe it is all stainless steel. Not noisy inside the bus at all.  Slightly louder, sounds cool.

-Sean

[lostagain]

I wonder what a "resonator" is. Mine is called a resonator by Donaldson. It is totally empty though. So I thought, rightly or not, that the sound waves expand in the larger diameter to take the harsh edge off the noise. And noise is a subjective matter. What is noisy to one person is music to the next. A loud DD is pleasant to a Detroit enthusiast, just like a straight piped Harley to a biker, but aggravating to other people.

And yes, more air intake will help. I have had the 1350 cfm Ecco filter that Clifford recommended. Runs much better, less smoke, cooler, etc.

JC

[Seangie]

I wonder what a "resonator" is. Mine is called a resonator by Donaldson. It is totally empty though. So I thought, rightly or not, that the sound waves expand in the larger diameter to take the harsh edge off the noise. And noise is a subjective matter. What is noisy to one person is music to the next. A loud DD is pleasant to a Detroit enthusiast, just like a straight piped Harley to a biker, but aggravating to other people.

And yes, more air intake will help. I have had the 1350 cfm Ecco filter that Clifford recommended. Runs much better, less smoke, cooler, etc.

JC

JC - do you have a part# for that filter