Relationship between timing and increased Fuel

[LBZoom]

Hey guys,
I'm still fairly new to this stuff, I've been messing with it for close to a year now and I have the basics down pretty well I feel. I do have a question though in regards to increasing or decreasing injection timing based on increased fuel delivery via pulse width....is there a simple way to figure how much to adjust timing based on what percentage you increase fuel delivery by? For example, let's say I increased injector pulse in the 3,000-4,000RPM range by 30% (this would be a big tune for me because I've got a stock tranny and fuel pump)....How much should I increase timing? Or decrease?

Below 3,000 RPM's I may increase pulse by 5-15% depending on the purpose of the tune (daily driving, towing, or racing) what would be an appropriate adjustment for this kind of increase? How about for the RPM range used for cruising, would an increase in timing help fuel economy?

What would I do in the event that either the pilot or post injections were disabled?

I've experimented with increasing timing before and noticed some difference, just wondering if I'm doing it right....Thanks for the help guys!!!:cheers:

[DmaxHawk]

Thats the million dollar question. Timing is the thing that most people struggle with the most. Timing not only has to do with fuel delivery but also boost. This might give you a little step in the right direction.
http://www.dieselplace.com/forum/showthread.php?t=265723

[herculesduramax]

what you're looking for is called the 50/50 Timing rule. I'm sure someone has posted a spreadsheet on this website with these calculations. You simply copy and paste the data from your tune (factors such as rail pressure and pulse width determine the timing) into this tool and it gives you the outputs to cut and paste into the necessary timing tables. If you can't find that on this forum, go join up with the guys over at McRat racing (duramaxdiesels.com). They know they're stuff, and that's where I found the excel sheet.

[DmaxHawk]

Heres the 50/50 timing calculator

[LBZoom]

Alright good deal, I'll try it out and see! Thanks man

[killerbee]

Heres the 50/50 timing calculator

by any chance do you have an unprotected version?

[vortecfcar]

You can unprotect it yourself in excel...

Nick

[killerbee]

silly me. I just assumed...


Did you do this Nick?

[vortecfcar]

I believe JoshH built the spreadsheet. There are a few versions of it floating around.

Nick

[justin123]

i used that timing table graph system in excel and it had me take away timing but i added fuel is that right or is something wrong???? help i thought i should add timing with fuel not take away thanks for help it only took timing away at 20-30-mm3. :help2:

[LBZoom]

In some cases the calculator will remove timing...

The reason for that is because at the top of the chart you specify how much fuel you want BTDC (before top dead center crank angle) the default is 50% which means half fuel is injecting before TDC and half after....

When you first enter your data, it shows your current BTDC injection percentage with the current tables at the bottom, you'll see it goes anywhere from 0-100%, the timing calculator corrects the chart so that you get a consistent injection amount BTDC at any point on the chart....hope this helps :cheers:

[bballer182]

I have done this and just adjusted the percentage at the top of the graph (which is user definable in the V2 of the timing calc) the take certain blocks out of it and not copy the whole thing. make sense?

[justin123]

thanks yea it makes sense but when i used that timing map my truck like knocked all the time like it had too much timing which dont make sense idk ill have to keep messing around i might have over looked something somewhere else

[Nemo]

:rotflmao: :iamwithstupid: :rotflmao:



ps: im not acually calling anyone stupid... mine did same as above...

-Nemo

[joecar]

Yes, the emoticon :iamwithstupid:simply means "I agree with a previous poster" or "+1" or "x2".

[justin123]

well im glad to know im not the only one that had that i problem what i did was just put it back to stock timing and added 2 to all numbers no knocking and seems to run smooth and egts stay pretty cool so thats the way im leaving it for now until i find out for sure what i need to do. instructions or help is :welcome: thanx

[Nemo]

Yes, the emoticon :iamwithstupid:simply means "I agree with a previous poster" or "+1" or "x2".

On other forums ive had new members get all kinds of pissed at that emotion...:hihi:

-Nemo

[joecar]

On other forums ive had new members get all kinds of pissed at that emotion...:hihi:

-Nemolol... yes I've seen that...:hihi: