good and bad SD maps for FG Falcon

[turbotrana]

There are some FG Falcons turbos (mine was an 09 auto but the one I recently fixed was a 11 manual) that have a habit of stalling and unstable idle. There have been many posts on the forums about stalling FGs that no one so far has been able to pinpoint the reason. In my cases it seems to be due to some poor tuning at Ford leaving a critical part of the idle map that only gets visited under certain conditions being a bit lean.
This problem usually rears it head when you change to bigger injectors.
It can easily be rectified by copying a "good SD map" from another FG tune where they have the offending part of the map much richer.
I have attached an example "good" SD MAP at zero airmas and a "bad one".
The one with 14.1 at 550rpm is an example of a "good one". The SD maps do vary a bit but go thru the repository and you can get one that will give you a solid idle.

Remember with the SD maps, the higher the number the leaner. Also you got to replace both the MAP at Zero Airmass(closed) and the MAP per Airmas (closed) . They come as a pair.

I have rectified two seperate turbos with the bad maps and replaced them with good maps and have fixed the stalls and cars have solid idles. Drives much better.

So just something to bear in mind when tuning.

good SD map.png

[JETURBO]

Nice write up Terry

Did those files i uploaded help you pin point what you suspected ?

[turbotrana]

All of those that you posted were "good" SD maps and would work fine with a copy and paste. Thanks for posting, definatley helped.

The funny thing is that my 09 auto tune/strategy (the good one) is identical to a 2014 tune that Fletch89 put up (bar some minor alterations). This is the only tune where the idle airflow numbers are done differently to all other tunes. So 5 years on someone in Ford decided to use this strategy again. The way the Idle Airflow is setup does allow the revs to "hang on" a bit and I think the purpose was to minimise driveline clunk.

[JETURBO]

Yep there's head scratching differences across the FG strategy range and trying to think what they were trying to do with the changes definitely makes you think that's for sure

[hiddeous]

Great info Tony, But why is is so? Is it mechanical issue with the design of the fable FG intake or something else?

You'd like to think Ford couldn't simply fuck up a strategy that badly?

[turbotrana]

I have looked over quite a few SD maps. On different strategies Ford have tinkered alot with the part of the SD maps 1 to 1000 RPM -10 to 5 degree cam angle area. I think that is where the problem lies. Just the map tuning.
I tuned this particular E85 car from its stock virgin tune, put pretty much standard ID1000 injector data, just trimmed the low slope to get it to trim a little closer to zero.

Still stalled so I put in the two SD maps from my car which I knew drove great into this car and straight away normal behaviour.

So in my case I suspect just a little lean in a few boxes in the idle area. Even if it was mechanical (like cams a bit sticky) causing it to get into a part of the map it wouldn't normally go into, it should be tuned to allow that.

Many datalogs of the pulsewidth just before the stall also indicated very low pulsewidth (0.7ms).

Remember, this was not a constant stall, just an intermittent one. Sometimes would take a while to rear its head and can be random.

[IH8TOADS]

Nice work Tony. Just to be clear, there is distinct differences between the FG XR and FG F6 Ford airflow calibration due to mechanical differences. If you're dealing with a car with a built engine and unknown compression etc you find yourself in unknown territory also. Ford did a bloody good job with all their SD calibrations from the factory!