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Discussion Starter · #5 ·
Might be worth removing KAM fuse overnight just to reset everything as well.
But like fishy said, a tank of fuel really.
Won't this reset all the long term memory? Like setting it back to default, i would of thought this may make the learning process longer.
 

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Won't this reset all the long term memory? Like setting it back to default, i would of thought this may make the learning process longer.
But the ECU has spent ages learning what the old setup was.
You have a new setup now, so probably best to let it learn all over again.
 

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Yeah, it does, but then it will learn properly. If you run a set of mods close to what a map was written for, there is a lot less learning to do also. That's one problem with using ModX and extra mods like actuator, RS injectors etc, it has too much trim all the time.

One reason I ended up going to U412, it has less learning to do and runs good straight up from a flash.
 

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Discussion Starter · #8 ·
Yeah, it does, but then it will learn properly. If you run a set of mods close to what a map was written for, there is a lot less learning to do also. That's one problem with using ModX and extra mods like actuator, RS injectors etc, it has too much trim all the time.

One reason I ended up going to U412, it has less learning to do and runs good straight up from a flash.
What do you mean? :

it has too much trim all the time.
 

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Discussion Starter · #9 ·
But the ECU has spent ages learning what the old setup was.
You have a new setup now, so probably best to let it learn all over again.
I understand what you mean Andy, its fuse 26 isn't it?

Would reflashing Bluefin stage 2 onto the car reset the ecu back to default?
 

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What do you mean? :

it has too much trim all the time.
ModX was not written for RS injectors and whilst it will run with them, it's not necessarily optimum. The ECU take sensor readings and adjusts the delivery to what the map tells it to run at, this is trim and there is a range of trim available, so if you run in constant trim just to run normally, there is less subsequent trim available for it to use if it needs to go further when conditions change, plus it may leave areas of load or rev range not running at optimum.

A map written with the injector mapping scaled for RS injectors means it is not needing to trim for the injectors more than modx for instance would with standard injectors.

So don't ignore it and no I don't live in a dream world, this is basic stuff with mapping.

Has anyone wondered about a lot of old maps not even being able to run RS injectors?
Yes ModX runs with them, but how well really?

I think Andy is not sure so made a comment like that instead.

If you want to look at it and have an Ultra or similar, you can actually check short term and long term fuel trims. They are available from the PCM data stream off the ECU. Torque Pro also shows them.

Also, the thing with DTE being wrong when RS injectors are used on a map for stock injectors, why is that? Well, the ECU does not know you fitted bigger injectors, it just gets readings and reacts to them, but makes calculations based on the smaller injectors. So for a given fuel delivery the ECU will fire the injectors with a duty cycle, changing the injectors makes the ECU alter the duty cycle away from it's intended mapping to fall in with sensor input, it does normally do this anyway, as part of adjustments for temp, barometric pressure, boost pressure, MAF readings etc etc, so much input affects things and the bigger injectors shorten one end of the range the MAP has to work with.

Does that fill in some blanks?

Does it work for you Andy?
 

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Discussion Starter · #14 ·
ModX was not written for RS injectors and whilst it will run with them, it's not necessarily optimum. The ECU take sensor readings and adjusts the delivery to what the map tells it to run at, this is trim and there is a range of trim available, so if you run in constant trim just to run normally, there is less subsequent trim available for it to use if it needs to go further when conditions change, plus it may leave areas of load or rev range not running at optimum.

A map written with the injector mapping scaled for RS injectors means it is not needing to trim for the injectors more than modx for instance would with standard injectors.

So don't ignore it and no I don't live in a dream world, this is basic stuff with mapping.

Has anyone wondered about a lot of old maps not even being able to run RS injectors?
Yes ModX runs with them, but how well really?

I think Andy is not sure so made a comment like that instead.

If you want to look at it and have an Ultra or similar, you can actually check short term and long term fuel trims. They are available from the PCM data stream off the ECU. Torque Pro also shows them.

Also, the thing with DTE being wrong when RS injectors are used on a map for stock injectors, why is that? Well, the ECU does not know you fitted bigger injectors, it just gets readings and reacts to them, but makes calculations based on the smaller injectors. So for a given fuel delivery the ECU will fire the injectors with a duty cycle, changing the injectors makes the ECU alter the duty cycle away from it's intended mapping to fall in with sensor input, it does normally do this anyway, as part of adjustments for temp, barometric pressure, boost pressure, MAF readings etc etc, so much input affects things and the bigger injectors shorten one end of the range the MAP has to work with.

Does that fill in some blanks?

Does it work for you Andy?
Good explaination Rob and does definitely fill in the blanks, Can blow your mind all this ecu stuff.
 

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ModX was not written for RS injectors and whilst it will run with them, it's not necessarily optimum. The ECU take sensor readings and adjusts the delivery to what the map tells it to run at, this is trim and there is a range of trim available, so if you run in constant trim just to run normally, there is less subsequent trim available for it to use if it needs to go further when conditions change, plus it may leave areas of load or rev range not running at optimum.

A map written with the injector mapping scaled for RS injectors means it is not needing to trim for the injectors more than modx for instance would with standard injectors.

So don't ignore it and no I don't live in a dream world, this is basic stuff with mapping.

Has anyone wondered about a lot of old maps not even being able to run RS injectors?
Yes ModX runs with them, but how well really?

I think Andy is not sure so made a comment like that instead.

If you want to look at it and have an Ultra or similar, you can actually check short term and long term fuel trims. They are available from the PCM data stream off the ECU. Torque Pro also shows them.

Also, the thing with DTE being wrong when RS injectors are used on a map for stock injectors, why is that? Well, the ECU does not know you fitted bigger injectors, it just gets readings and reacts to them, but makes calculations based on the smaller injectors. So for a given fuel delivery the ECU will fire the injectors with a duty cycle, changing the injectors makes the ECU alter the duty cycle away from it's intended mapping to fall in with sensor input, it does normally do this anyway, as part of adjustments for temp, barometric pressure, boost pressure, MAF readings etc etc, so much input affects things and the bigger injectors shorten one end of the range the MAP has to work with.

Does that fill in some blanks?

Does it work for you Andy?
Great explanation Rob but im pretty sure that ModX runs perfectly with RS injectors over a whole different range of conditions because we ran it with no problems and were monitoring AFRs the whole time! Im a simple guy so tend not to go looking too deeply into things looking for problems if none are apparent! Alternatively you seem the kind of guy who goes looking to cure problems that might be there even though they arent apparent! Lets not forget that if youre going by the laws of physics bumblebees cant actually fly! The scientists forgot to tell the bees though!
 

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My understanding (bullet proof vest on at the ready!!) is that some maps will run either injector because there is enough range on the trim within said map to adjust the fueling back to the point where it should be when the RS injectors are installed.

Maps that have problems with the RS injectors do so because they are unable to reach the specified mixture/AFR...... with the amount of trim available to the ECU, an easy way around the problem is to give the ECU more range to play with but the fueling will still get pulled back to where it should be on standard injectors.

That to me is a problem with such a map because as the ECU learns, it will pull the fueling back to where it should be and therefore you loose most of the benefit the injectors give. The car will feel quicker when you first instal them and then gradually return to normal. We notice the initial "feeling quicker" and not so much the gradual return to normal and so feel satisfied with another successful mod!!

A purpose written map would not only have the correct fuel trim range but also a different fueling table to allow for the way the injectors deliver the juice and also the different lambda readouts the ECU will get when running them at different points in the rev range.

On that basis, I cant see how MOD X runs them correctly (or to there maximum potential)
 

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Look out, a fishy bullet will be headed your way soon


I'm glad I'm not the only one who thinks this way.......
 

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So out of all the people running RS injectors with ModX how many have had any problems?
As I said they wont have problems, there is enough head room on the duty cycle etc to get the fueling near enough to where it should be with Standard injectors.

I didn't say it would give running problems just wont give much performance increase.

Common sense says if you tell the ECU to maintain an AFR of "x" , you then add bigger injectors....the ECU will fire the bigger injectors less frequently to maintain the AFR you asked it to (if there is enough range on the trim to do so).

What you need is a specific map written for them saying go and maintain this AFR thus benefiting from the increased fueling?
 

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This is why I posted that your stock fuel pump is coping with 650cc injectors on Tigger Andy. It lowers the duty cycle on the injectors and keeps fuel pressure. If you had even more power and needed a higher duty cycle the pump would likely fall over. I'd say this is why JS fitted those injectors in the first place.
 
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