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FG NA tuning help


Otis
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Hi all,

Very new to the tuning side of things and would love some help starting out.

Any help pointing me in the right direction would be awesome.

Not after huge power gains but better fuel economy would be awesome.

Have a NA FG I6 with pacemakers, high flow cat with 2.5inch piping through with standard mufflers. Air intake is just a SS growler intake.

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This is more of a how do I tune, rather than a what parameter should I adjust question.

Everything can be found by searching on the internet. You can also learn to tune with hp acadamy. However, I will tell you a few things to tune a na car.

You need a wideband and you need knock ears for road tuning...

Aim for around 13:1 afr at WOT and keep it in closed loop until about 2750rpm.

Try to get 30 or so degrees of timing at WOT, 34 is great. The engine and fuel type will dictate how much timing is required.

To work out how much timing you can get into it, start the WOT afr at 12:1 and gradually increase timing. When it starts to knock, pull the timing back a couple of degrees or 3 and start to lean it out. When it starts knocking again you have found a balance. Get the timing as high as you can without going too rich... on a knock limited engine...

12:1 is much too rich for an daily street na motor and is just a starting point for setting the timing. It might be happy at 12.5:1 and it might be happy at 13.5:1. The timing will tell you where the fuel is happy and vice versa, in a road tuning scenario, within reason.

Make sure you use 98 octane fuel for best results.

For better cruise economy there is an O2 bias offset table. Play with that so you cruise at 15.5:1.

 

That is a general approach to na tuning with some falcon specific stuff in there, some cars will want more or less timing and fuel, but that info should get you in the ball park.

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6 hours ago, Roland@pcmtec said:

Why would that need to be turned off?

Because the o2 would cause a trim back to stoichiometric wouldn't it?

Therefore, it tends to over ride the afr map if it's over or below stoich?

But since you're asking, I must be wrong

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13 hours ago, Stephe said:

Because the o2 would cause a trim back to stoichiometric wouldn't it?

Therefore, it tends to over ride the afr map if it's over or below stoich?

But since you're asking, I must be wrong

I see what you are saying. You can use the bias table to adjust the stoich the narrowband trims to. Or yes if your fuel trims are within a few % max then you can disable and go entirely off the base fuel map. 

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27 minutes ago, Roland@pcmtec said:

I see what you are saying. You can use the bias table to adjust the stoich the narrowband trims to. Or yes if your fuel trims are within a few % max then you can disable and go entirely off the base fuel map. 

Yes, that's what I'm getting at.

I have read articles that advise to turn off the o2, and when happy with the fuel map, turn on the o2 and it should tweak it. Sounds good in theory i guess. Then of course open and closed loop come in it too.

Cheers

 

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12 minutes ago, Stephe said:

I have read articles that advise to turn off the o2, and when happy with the fuel map, turn on the o2

This generic advice and while true for some ecus, it doesn't apply here. Do you have a copy of pcmtec so you can see how it works?

The base fuel map in a ford pcm is literally just lambda values. There is no need to disable closed loop to dial in the base fuel table in because you can just put whatever value you want in there and the fuel will automatically change itself...providing the rest of the tune is correct.

There are other reasons for disabling closed loop on a ford pcm but this is not one of them.

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5 minutes ago, Puffwagon said:

This generic advice and while true for some ecus, it doesn't apply here. Do you have a copy of pcmtec so you can see how it works?

The base fuel map in a ford pcm is literally just lambda values. There is no need to disable closed loop to dial in the base fuel table in because you can just put whatever value you want in there and the fuel will automatically change itself...providing the rest of the tune is correct.

There are other reasons for disabling closed loop on a ford pcm but this is not one of them.

Yes, I have the Workshop version.

I have a wideband and the o2 installed. The gauge for the wideband does show the change in afr obviously, but it shows the stoich at 14.7 at idle, which is good but, the fuel map values at idle aren't at stoich, it looks like something is taking over and correcting the afr, the short and long fuel trims are active even though it's running in open loop.

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On 2/1/2022 at 8:40 PM, Puffwagon said:

 

For better cruise economy there is an O2 bias offset table. Play with that so you cruise at 15.5:1.

 

Hi Puff , @Puffwagon, Tried looking for that o2 offset table, can u post a pick or an au number please ? cant find it . Regards plumbs.

 

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