Tuning school

Big Bore · Jun 22, 2012

4.0l sahara said:
Does anybody know if the software will work on a mac?

If you install a Windows OS it will. That's how Curtis tunes my truck.

Vader's Fury · Jun 22, 2012

907DAVE said:
Why is the ICP dropping? is it because you are calling for more pw without a change in rpm. Therefore the inj is using more oil without the hpop spinning faster to supply it.

The problem with dropping the MFD is it will effect base SOI, and will require a bit of reworking if we were to change it.

Otherwise I like where you are going, but my questions are still unanswered.

drop pw a lil bit and you will allow the pressure to come back up and atomization will be better. No more flakes of coal.

907DAVE · Jun 23, 2012

Arrg, lets not get carried away with variables.

I am trying to get everyone to see how the PCM functions, and the purpose of these maps.

2000wa250 · Jun 23, 2012

Are you getting smoke because you're putting too much fuel into the cylinder?

Pull back MFD a bit and while there's less fuel it can burn more effectively and efficiently creating a better burn leaving less smoke but also creating hotter gasses and spooling the turbo so that that cleans up the rest of it?

You said you haven't downshifted so for me that makes me think you are "under the turbo" so to speak. You are artificially creating the issue by commanding too much fuel. Pull it back and icp goes up, fuel burns better and hotter, turbo spools faster and the extra air allows the fuel to burn more completely resulting in a small puff and you merging successfully and hang on as the turbo lights

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DocBar · Jun 23, 2012

2000wa250 said:
Are you getting smoke because you're putting too much fuel into the cylinder?

Pull back MFD a bit and while there's less fuel it can burn more effectively and efficiently creating a better burn leaving less smoke but also creating hotter gasses and spooling the turbo so that that cleans up the rest of it?

You said you haven't downshifted so for me that makes me think you are "under the turbo" so to speak. You are artificially creating the issue by commanding too much fuel. Pull it back and icp goes up, fuel burns better and hotter, turbo spools faster and the extra air allows the fuel to burn more completely resulting in a small puff and you merging successfully and hang on as the turbo lights

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I agree that without downshifting, your RPM's aren't spooling the turbo fast enough. Lot's of smoke and higher egt's.

Gearhead · Jun 23, 2012

907DAVE said:

I personally don't do much wth this table as it is simply a pedal vs mass fuel desired, just make sure it commands max at WOT. If you are using this to tune for bigger injectors etc, you are doing it wrong IMO.

Shaw · Jun 23, 2012

Matt, I think Dave is just using that to try to show people what you have to look at to figure out what to change. With out showing that map you wouldn't know what mfd is.

But like you said, i don't change that table ether.

907DAVE · Jun 23, 2012

Nope, leave that one alone other than a tiny bit in the idle and off idle area's to "soften" things up.

I think some of you guys are programmed to think that you need to cover up a certain problem with bigger oil, more air, faster downshifting, etc, when the problem will still be there.

Quit blaming your truck and start blaming your tuning. If that thing is smokey, it not cause your tires are too big, or your turbo is not the best....its cause you are injecting too much damn fuel for the condition. Yes there are things that can be done to reduce smoke like maintaining proper ICP, or fixing those boost/ drive leaks and keeping your setup as efficient as possible.

Thats not the point of this thread.

WILD_PHIL · Jun 23, 2012

Subscribed.

Big Bore · Jun 23, 2012

907DAVE said:
Quit blaming your truck and start blaming your tuning. If that thing is smokey, it not cause your tires are too big, or your turbo is not the best....its cause you are injecting too much damn fuel for the condition.

Must be quoted for posterity.

2000wa250 · Jun 23, 2012

So dave,
What's the issue that needs to be addressed to fix your hypothetical situation? Pull fuel back?

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Dieselboy. · Jun 23, 2012

2000wa250 said:
So dave,
What's the issue that needs to be addressed to fix your hypothetical situation? Pull fuel back?

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Timing, PW, ICP, MFD.

2000wa250 · Jun 23, 2012

Dieselboy. said:
Timing, PW, ICP, MFD.

Care to elaborate a bit? Retard or advance timing? I would assume shorten pulse width add some icp and pull some fuel back?

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Gearhead · Jun 23, 2012

you would be suprised how well everything takes care of itself just scaling the pw map back to account for the increased volume of fuel from a modified injector at the same pressure and pw.

Powerstroke Cowboy · Jun 23, 2012

subscribed...
This is a path I want to go down...

Shaw · Jun 23, 2012

Leave the timing part alone for Dave's question. The answer is in the tables he posted. I struggled with this for a long time and once I was able to comprehend what is going on it made it easier to understand.

We will cover the timing aspect of it later. If you cant understand what the PCM is doing then you have no hope of tuning. It really is easy but you first have to understand what is going on!

907DAVE · Jun 23, 2012

Gearhead said:
you would be suprised how well everything takes care of itself just scaling the pw map back to account for the increased volume of fuel from a modified injector at the same pressure and pw.

That is where I would like to take this discussion. I have examples if we can make it that far...lol.

Shaw said:
Leave the timing part alone for Dave's question. The answer is in the tables he posted. I struggled with this for a long time and once I was able to comprehend what is going on it made it easier to understand.

We will cover the timing aspect of it later. If you cant understand what the PCM is doing then you have no hope of tuning. It really is easy but you first have to understand what is going on!

Zactly!

907DAVE · Jun 23, 2012

For those still interested, I challenge you to go back to post #73 and tell me what the PW is in that situation.

I will give out a gold star to anyone who can tell me this, and then make a guess at what happens if we were to lower PW in that area.

Big Bore · Jun 23, 2012

907DAVE said:
For those still interested, I challenge you to go back to post #73 and tell me what the PW is in that situation.

I will give out a gold star to anyone who can tell me this, and then make a guess at what happens if we were to lower PW in that area.

The values on the ICP scale on the PW table did not make sense, or did not match anything I could correlate them to on the other two tables. My guess is 3.8 ms.

My WAG for the result of lowering PW is, since you have a mass fuel desired, if you lower the PW, the PCM will bump ICP to meet the commanded mass fuel desired? Injecting the same amount of fuel in a narrower window and higher pressure will hit the bowl better and atomize better?

Shaw · Jun 23, 2012

Big Bore said:
The values on the ICP scale on the PW table did not make sense, or did not match anything I could correlate them to on the other two tables. My guess is 3.8 ms.

My WAG for the result of lowering PW is, since you have a mass fuel desired, if you lower the PW, the PCM will bump ICP to meet the commanded mass fuel desired? Injecting the same amount of fuel in a narrower window and higher pressure will hit the bowl better and atomize better?

Use this to convert the PSI to MPa

http://www.chapelsteel.com/mpa-psi.html

All of the tables are metric but Bill does have a PSI ICP map.

Just convert the PSI over then you should be able to figure out the PW