AH64ID

Yep, and I pull my pilot at higher rpms which means I need a little more timing for the main.

Errrr.... I meant mpa. 23,206 psi = 160 mpa. VP's can push over 20K psi IIRC. I idle around 7K psi. Thats got to be the biggest difference for timing. Whats interesting is WOT timing isn't as different at higher rpms.

I know the CR's run more pressure, but I recall seeing some VP pressure numbers that don't put it as far below CR's as I originally thought. IIRC a VP is capable of 150 mpa and 03-07 only run up to 160 mpa stock. I run 155 mpa on my personal custom tunes, and even as low as 150 on some of them. I'll push to 180 mpa on a race 5.9 if needed.

When I was looking into it a while ago I decided I would run 100% water and then just winterize it in the fall. I don't tow much in the winter and with the colder temps I wouldn't have needed it anyhow. I have since steered away from that plan.

I use this guy. https://www.amazon.com/Shooting-Chrony-F-1-Chronograph-green/dp/B001BR3364/ref=sr_1_4?s=sporting-goods&ie=UTF8&qid=1504797152&sr=1-4&keywords=chrony+chronograph I'm not sure I like the idea of a bbl mounted one.

That's a very efficient load, much more efficient than I usually see on a win mag. Are you moly coating? I shoot a Rem 700 with a Lilja 26" bbl and a custom muzzle brake. I load a Swift A-Frame at 3010 fps using 75.5gr of H4831 SC. My Leupold VX-III 3.5-10 has a custom BDC dial on it that's marked for 1000 yards, which is plenty since it's a hunting rifle. Have you messed much with G1 vs G7? I see Hornady gives both sets of data. What I read about it I should be using G1 for my flat base and you should use G7 for your boat tail? G7 also appears to take different software to calculate as it's a different method. I run a .444 on my A-Frame, which is pretty good for a flat base. It's enough to keep my energy up for as long of a shot as I am comfortable with on an animal.

I guess MADS need to get us that base table info! Sounds liike a fairly easy to tow trailer, at least in terms of wind resistance.

What where your rpms? What kind of trailer? That's why I keep reading this thread. The differences in VP vs CR appear to be huge. What I find interesting is looking at the injection timing table in UDC Pro for VP trucks. It doesn't show anywhere near the timing you guys are talking about for OEM timing. For a CR example my latest tow tune has the most timing in the 40-60% load of any tune I have tried for 1800-2200 rpms. At 65 I am turning 1800 rpms in 6th, which is a bit low for heavy loads but okay on flatish gound and smaller loads. At about 25% load I would be really close to 800° as well and 2-4 psi... so very similar numbers there. At 25% load I am running 35mm3 (525us) of fuel and about 15.5K psi of rail. My timing is a whopping 5° and the pilot is 10° ahead of that. It's still a little higher because that's a low enough load I'm still in the cruise profile there. If I increase engine load to 40% which is going to happen on any grade over 1% I am down to 1.3° of main timing for a 55mm3 (772us) of fuel.

That's what I recall my M085171 is. How does the diamond eye sound with the exhaust brake on? The M085171 was ear splitting loud and the exhaust brake is the only reason I added a resonator. Did some towing thru the mountains this weekend and even when I need to rev up above 2500 rpms it's rare that I use more than 50% load and very rare to even break 80% load at those rpms, just based on required power, and that was all at 19K GCW on some 7-8% grades for many winding miles (Lowman to Idaho City for those that know the area). Long story short, I am not sure I need to be worried about full flow above 2700 rpms at 3 inHg. I also found that Cummins allows 5 inHg on our motors so if I exceed 3 inHg less than 1% of the time I'm okay with that. So that puts me back looking at the 4" mufflers a little harder. I'm looking at both the M090544 and M100466, and I am leaning towards the M090544. https://catalog.donaldson.com/productDetail/en/A/M090544?productId=14204&skuId=s16866&_requestid=26449276

I'm not sure what spec's you're looking at. I am looking for 2000 cfm of exhaust (not 900) and the muffler I'm looking at is rated for 1565-2530 (1-3 inHg). The size of the exhaust pipe before or after the muffler will have minimal impact on the attenuation capabilities of the muffler, so minimal that it's probably noticeable in a laboratory setting. The flow thru the muffler will be the same as thru the exhaust pipe. Backpressure is based on flow, of which I have plenty. I'm looking at nearly 2000 CFM of exhaust flow on my motor if I rev it up under full load. The M100580 will be giving just under 2 inHg restriction at that flow which should put it in the middle of it's attenuation rating at peak exhaust flow/volume. That's exactly what I am looking for. The attention can be much lower at cruise exhaust flow/volume as the actual volume is down. Even at moderate exhaust flow the attenuation of the M100580 is higher than my current muffler is peak. It should work quite well. The M090544 would also be a good muffler but I am not sure than 13-18db is enough attenuation for what I want.

There are 4" to 5" adapters that can get clamped or welded onto the muffler, and then it installs the same. I don't need 5" from the turbo back since 4" flows more than enough, I also don't want to deal with the notorious 5" drone while towing, we just don't have the exhaust flow to warrant a 5" exhaust. This won't effect anything in terms of flow, at least not more than the expansion/contraction that is already occurring in the muffler. You assume that the manufactures pay attention to all the specs. Recall the fuel filter issue from 8 or so years ago? The filtered pump companies had the world believe their filtration was better than OEM, when in reality it was worse in some cases. The other factor is that we are making a lot more power, which results in higher exhaust flow, than your standard industrial 5.9. The aftermarket world for industrial applications is a lot bigger than for pickups, so pickups seem to get what fits. Also, industrial applications are the ones who favor quiet exhaust while many pickup owners like the low attenuation sound. In this catalog you can find what I am talking about. https://www.donaldson.com/content/dam/donaldson/engine-hydraulics-bulk/catalogs/Exhaust/North-America/F110028-ENG/Exhaust-Product-Guide.pdf page 34 has the 4" to 5" adapters. page 67 has the style 1 muffler specs. I currently run a M085171 and will run a M100580 next. This catalog talks about exhaust flow, and common engine exhaust flow data, as well as backpressure recommendations. http://www.asia.donaldson.com/en/exhaust/support/datalibrary/1053747.pdf Here is the QSB 425@3000 rpm performance curve chart https://www.sbmar.com/docs/performance-curves/QSB 5.9 [425%2C3000%2C8732%2CHO%2CMay 10%2CM-91632].pdf and the 480@3400 http://www.american-nautics.ro/pdf/QSB5.9-480.pdf and finally the 440@3400. https://www.sbmar.com/docs/performance-curves/QSB 5.9 [440,3400,1860,HO,May 10,M-92284].pdf The 6.7 surprisingly doesn't require much more exhaust flow than the 5.9 at 480 hp. 480@3300 is 2161cfm. But it's a bit more air for the 550@3300 motor, up to 2450 cfm. Even the 550@3300 could use the 4" M085171 I have, if the attenuation was desirable. Even the 600@3000 8.3 is only 2830cfm.

I've been using published QSB5.9 data to get exhaust flow numbers. A 425hp QSB is rated at 3000 rpms and has an exhaust flow of 1825 cfm. A 480hp QSB is rated at 3400 rpms and has an exhaust flow of 2174 cfm. Those are crank horsepower numbers. On my last dyno I was ~410, which translates to ~480 based on a dyno of my stock tune on that same dyno. I don't often turn over 3000 rpms, let alone 2700 towing, which is where the 2000 cfm goal for exhaust flow came from. Donaldson also publishes some exhaust flow data. A 5.9 making 275 hp at 2500 rpms and 956° EGT is moving 1673 cfm. That's crank hp, so rwhp would be ~230 and we almost all above that number. As you can see the 4" mufflers with any descent attenuation run out of flow really quickly, especially for those of us that load the truck up often.

It's not theory, it's published data in the catalog. Did you look at the part of their catalog that shows attenuation and flow? In order to get the attenuation and flow I want I need a 5" muffler, as a 4" muffler with the proper attenuation lacks the flow required. Exhaust flow for my engine is going to be around 2000 cfm peak. I'd like a muffler that can flow at least 2000 cfm at 3" Hg of restriction. My current muffler can flow 3119 cfm at 3", so a lot more than I need and proves that a 4" muffler can do it... but it's only 8-12 db of attenuation and it wasn't nearly enough for my application which is why I had to add the OEM resonator from a MC truck. I'd like a muffler with ~20 db of attenuation. Looking at the 4" mufflers there isn't one that meets both criteria. There is a 4" in 5" out that is close but it's 15-20 db, and that just barely meets my criteria. In 5" we have the M100580. It can flow 2530 at 3" and has an attenuation rating of 19-25db. Perfect! My back-pressure should never hit 3" and I'll get great attenuation.

Mufflers with good attenuation have baffles on their straight thru design...... There is a LOT more to a muffler than just it's overall design and size. Take a look at the Donaldson catalog, it has lots of great info. It's just like saying since the air filter fits the box, or inlet tube, then it must filter and flow enough... and we all know that's not true. They do sound good! empty :-) With just my see thru Donaldson 40" muffler I loved the sound until I hooked up a trailer or ran the exhaust brake. Since I do a fair amount of towing, most of which is at 19K GCW or higher, on a fair amount of steep hills I want it quiet when towing, which means it will be nearly silent when not towing but oh well.

I didn't realize the difference until I started messing with it tonight.

Create an account and see if the price changes to 1499 for the combo. All the race me ultra stuff comes with a commod.

Not quiet enough. They would be fine a lot of the time, but the kids are in the back seat for a lot of my towing and even with 2 mufflers now it can be loud. Drone is more common with a 5" and I don't need that much. 4" flows plenty for a lot more hp than I make, it's just finding a quiet muffler with minimal back pressure that is more difficult.

After talking to a few shops about what they install I heard Flo-Pro the most. It was based on price, figment, and ease of install. I won't be using their muffler thou, but rather a 5" Donaldson that I'll weld the 4" adapters too. I cannot find a 4" muffler with adequate flow and attenuation for the flow a 400 rwhp 5.9 can produce. The 4" moves more than enough air but the quiet mufflers create more nackpressure.

The $1499 pricing includes the required dongle for custom tuning on warp. The race me without the dongle is 1299. So you "save" 340 by buying the package. I just realized you have to login and select US during checkout to get US pricing. Otherwise it looks like it's 1799 euros, since it's a European company.

Yes it's thicker than ATF, but ATF is only the DC factory fill. The OEM (MB) spec is a GL-4 fluid. There are 4 primary recommendations which range from SAE 50 to 80w gear lube, 75w-80 gear lube, or 75w-90 gear lube. So it shouldn't be too thick. The Delvac 50 just doesn't seem to work well with it, among others. ATF has similar viscosity to 80wt gear lube.

Those two seem to get some of the best reviews.

That does look like a new addition. Yeah lots of experimenting with the G56. The 50wt doesn't get the best shifting reviews, but that seems pretty common with the experimental G56 fluids.

I didn't realize MB and Aisin were the same company The valair DD I drove off and on for a year was nowhere near that quiet. It was fairly quiet when new but the rubber isolators didn't last long. It was installed about 4-5 years ago so I am not sure if they had changed anything when that video was made 3 years ago.

I had a descent amount of gear rollover in my truck until UDC Pro came out. Now with modified pilot timing my rollover is almost gone! It goes to show how whacked some of the OEM tuning is. I don't want a DD either. I haven't driven one that is quiet enough for me to consider.

At 4,000 miles a month I am surprised you're thinking about a straight pipe! My research led me to a Flo-Pro exhaust for when the time comes. I've heard nothing but good things from them and know a few shops that use them exclusively. I'll be trying to go even quieter on my next muffler.