what in my tune makes the engine louder?

[Boost]

This isn't intended as an "idiot" question. I know that a tune that alters fuel pressure, timing, boost changes the explosions in the engine dramatically, thereby changing the noises they make. I am just looking for a better way to explain to someone why - or specifically which modification is responsible for making the engine sound louder or more old fashioned under some conditions such as light cruise. I suspect fuel pressure and vane position. But I learned at the dealer training that high fuel presssure in the Duramax is one of the things they used to quiet it. Now that I have increased the output and improved driveability, it sounds more "diesely". Is there something in the tune I could adress to smooth the sound back to stockish levels and still keep the ton of extra horsepower? Just trying to learn, have been doing lots of research, that's how I got it running good in the first place. Thanks!

B2206 "Desired Boost Levels With EGR Off (C)"
B2209 "Desired Boost Levels With EGR On (C)"
B2214 "Turbo Vane Target Position, EGR Off (C)"
B2215 "Turbo Vane Target Position, EGR On (C)"
B2224 "Turbo Vane Target Position Maximum (C)"
B2225 "Turbo Vane Target Position Minimum"
B0701 "Desired Idle Speed"
B1201 "Idle/Run mode"
B0720 "Main Injection Pulse"
B0721 "Main Injection Pulse (No Pilot)"
B0727 "Throttle Base Injection Quantity"
B0728 "Max Injected Fuel Quantity (Warm)"
B0910 "Injection Timing Base (C)"
B0929 "Injection Timing After Pilot Base (D)"
B0920 "Injection Timing Fuel Temp Multiplier"
B1101 "Peak Torque"
B1106 "Peak Torque vs RPM"
B1502 "EGR Maximum RPM"
B1503 "EGR Minimum RPM"

[bballer182]

timing- too far advanced will make it rattle and sound lounder...
boost/ vane position- when you open up the vanes or reduce boost at cruise range the exhaust will be noticeably louder...

[Boost]

Thank you! Now, having it "too far advanced" to where it rattles and sound louder - does that hurt anything. I am talking about if it drives very nice with no hiccups and makes great power, what PHYSICALLY causes the timing noise? Too much fuel in the cylinder? Fuel sloshing around? Again, I just want to learn and I really appreciate it. I understand more about the vanes since I am very familiar with turbos and their muffling effect. The timing's relation to noise and how it all behaves depending on timing is where I need more info. Thanks!!!

[bballer182]

well when you hear someone talking about "timing rattle" that is usually taken as pre-ignition, known in the gasser world as "pinging". pre-ignition is fuel burning and creating a massive cylinder pressure spike before TDC robbing power and most importantly destroying for engine.

[Boost]

Thanks, yeah I know about knock / detonation. So, in a diesel what would you log and monitor to make sure timing advance isn't causing rattle? You already mentioned power loss, which isn't felt in the tune right now, and any obviously unhealthy sounds / hesitations would also be detected. But as I log and watch knock retard and EGT say in a boosted gasser, what parameter / data would indicate mild or pending timing rattle on a diesel?

[bballer182]

your ear basically. i read a quote one time that says a "quite diesel is a happy diesel." pretty much true, the quieter the tune the likelihood of the tune being better for the engine is greater.

[Boost]

Hmm, I appreciate that, still though a more technical approach would be great. Are you saying that if my tune runs awesome and is louder than stock, the "noise" could be bad? Is is possible to monitor EGT and verify this? Should the timing be reduced in the tune until it quiets back down? Is a great power but loud tune bad? How about if it's only noisy under certain light cruise conditions. I am about to log and post this. Sorry for all the questions and thanks.

[bballer182]

This will help you out a BUNCH, it did me, and i'm sure 98% of everyone else out there.

http://www.dieselplace.com/forum/showthread.php?t=187521

[Boost]

Thank you bballer!!!

[bballer182]

No prob man