timming

[anarchydiesel]

I got tree'd

[DoghouseDiesel]

I got tree'd

BOOYAH!

[DoghouseDiesel]

Also, keep in mind, high timing also means high cylinder pressures.

Those of you running stock head bolts don't want to run these elevated timing numbers.

On trucks that are running stock head bolts and / or don't turn higher RPM's, I normally don't go higher than 20*.

[2007 5.9]

Also, keep in mind, high timing also means high cylinder pressures.

Those of you running stock head bolts don't want to run these elevated timing numbers.

On trucks that are running stock head bolts and / or don't turn higher RPM's, I normally don't go higher than 20*.

Unless your an idiot like me....700hp, 25*, 55psi, 4500rpms sled pulling...on STOCK bolts.

Yes Im an idiot...but I want to find the limits!! And I am positive that conservative timing in the low end has prolonged their lives.

[DoghouseDiesel]

Yeah, but you're running 25* at higher RPM's, which is just fine.

Like ya said, it's that low RPM timing that beats the crap out of the head gasket and rings.

I do the same thing on Garmon's 6.7. It's still on stock head bolts, but the pistons are cut .100". But it still has a spec'd BW466 over a BW510. Now, we just need the RPM's to wind that sucka up.

[sheldons 5.9]

I am trying to build a tune for max mpg. So I am cutting the pulse width down from stock and increasing timing in the my cruising range. I have a Gear Vendors overdrive on my 06 5.9 because I have the G56 manual. I also have a pdr cam installed and 50hp ddp nozzles. AFE Intake and Exhaust, but stock everything else including head bolts. I am targeting the Rpms for cruising which are like 1700 at 75mph.

What would be the max safe timing for the 1550 - 1800 rpm range from 10 - 45 mm3?

I have been running the timing tables from the smarty, which has pretty high low end timing. I figured that there are 1000's of people running that without any problem. I also have the 3rd event erased, so that cuts the amount of fuel. When towing 10k, my coolant temps don't go over 205.

Just wanted some input from you all. Would dyno tuning be beneficial to achieving the max possible mpg using timing and whatever other tricks there are?

[2007 5.9]

There is kind of a misnomer in the diesel world...

Diesels are MOST efficient when closest to peak TQ....I get better MPG at 21-2300rpm cruising then I do at 15-1700...the motor is lugged down that low and actually has to work harder to maintain speed then when sitting at its most efficient RPM.

These trucks cant be treated like gassers...

Sure you are running MORE rpm but if you log commanded mm3 at say 70mph in either O/D or 3rd gear...Id be willing to bet that in 3rd gear, you are actually commanding LESS mm3 than you are holding 70mph in O/D...

Difference between gassers and diesels...we can run EXTREMELY lean AFR's, up to and over 100:1...which allow very little fuel to be used at higher rpm..where with a gasser...14.7:1 is as high as its supposed to get...which means you are using fuel at all load conditions, so lower rpm is needed to actually use LESS gas.

I know its not the answer you asked for, but it can help you some.

To help in your question...I typically run my MPG timing in the 0-45mm3@1500-2000rpm zone, as high as 10*, but usually close to 7.5-8.3*

[DoghouseDiesel]

If you're building a mileage tune, I don't suggest cutting your pulsewidth. Doing that reduces engine torque. I suggest looking at your rail pressure instead.

Anyway you look at it, it will ALWAYS take XXX amount of HP to move XXX amount of weight at a given speed. If you can reduce the fuel delivered, but not make a huge dent in the torque, you'll get a bit more efficiency.

Bringing that rail pressure down in the cruising ranges will get you a little more bang for the buck than reducing duration will.

[tinman]

Rich can you comment on the theory that increased rail pressure at cruising will increase atomization and perhaps a slight increase in timing (higher pressure, more fuel sooner) to help mileage. I am running a max of 9 * of timing in the cruising range now. I played with the rail pressure a little raising it from about 17.5 to about 18.5 to 19 just to see if it would made a difference. So far I haven't demonstrated a convincing effect good or bad.