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Running lean on dyno


Slippery

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While attending charity event at Austec racing last weekend , i decided to put my car on the dyno.

 

My car is a facelift j spec running hybrids on 1.4 bar ,with 440 injectors, uprated fuel pump,colder plugs, hks fcd, hks double decat exhaust , hks boost controller and FMIC.

 

Ashliegh from austec racing ran it up on the dyno, But he was reluctant to run it any more as the car was running lean on the second turbo. He said that the fuel cut defender was probably on wrong setting and it should be on 8 or 9 and this should cure it.

After checking it i found it is set on 9 already. My question is can i put the fcd on 10 would this rich it up when the second turbo kicks in.

 

What other ways are there to correct this? Would fitting a Air fuel Ratio controller be the best way to go?

Dyno run march 2012.jpg

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1.4bar on 440cc injectors will see it run lean. Just not enough fuel being pushed in, and the injectors will be at their maximum so any blip in fueling or pressure and the engine is toast.

 

On hybrids I would put in 550cc injectors as a minimum.

 

Would i still need to get a Air fuel Ratio Controller to get it setup right.

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It all depends how much money you have to spend and how much labour you can afford to get the fueling right.

 

If you can find drop in 550cc injectors it will run a little rich with no other controller but not in a catastrophic way.

 

I went from an Apexi AFC to an emanage blue on my single turbo. Wish I had never bothered. The AFC is just enough if you keep within safe limits. Start fitting emanage or Syecs and the costs spiral as does the complexity.

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It all depends how much money you have to spend and how much labour you can afford to get the fueling right.

 

If you can find drop in 550cc injectors it will run a little rich with no other controller but not in a catastrophic way.

 

I went from an Apexi AFC to an emanage blue on my single turbo. Wish I had never bothered. The AFC is just enough if you keep within safe limits. Start fitting emanage or Syecs and the costs spiral as does the complexity.

 

As much as i would like a syecs not looking at spending that much. A mate i know has a Apexi SAFC and says it works well on his , which is what made me considering that option.

 

Would altering the setting fcd achieve anything?

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As much as i would like a syecs not looking at spending that much. A mate i know has a Apexi SAFC and says it works well on his , which is what made me considering that option.

 

Would altering the setting fcd achieve anything?

 

My old silver car ran quite well on SAFC (10's)

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You could also use a Kenne Bell fuel controller, it will up the voltage to the pumpits a fudge of sorts but may well do the trick.

So is it being caused by a lack of enough fuel being supplied by the pump or are the injectors not able to supply enough fuel?

Should 440 injectors be able to cope with 1.4 bar?

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So is it being caused by a lack of enough fuel being supplied by the pump or are the injectors not able to supply enough fuel?

Should 440 injectors be able to cope with 1.4 bar?

 

 

 

In theory they should, however there are a lot of variables, the std pump should also be able to cope with the fuel demand, so as others have said either drop the boost, change the injectors, and add fueling control, or use an adjustable fuel pressure reg.

 

Was the 10's referring to the FCD

 

He's referring to 10 seconds;)

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The reason its running lean is becourse the ecu is standard and fuelling and ignition trims are set up for a standard car. you can up the boost a bit hence bpu as the standard ecu map has some extra fuel . but at 1.4 bar the ecu is not supplying enough fuel . you need to turn the boost down to where its safe or get a mappable ecu and add more fuel . if you do any flat out runs or hard drive with that sort of afr will end in engine damage. adjusting the fuel cut will not help the fuelling one bit.

Rich

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The general opinion is then turn down the boost for now, look for larger injectors and a AFR controller.

Not intending to go in search of more and more bhp just want my setup to work safely.

Would uk spec injectors be ample enough for this and do they just fit straight in without adding or purchasing any additional parts.

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There is a couple of things in this that don't quite add up, firstly your run of only 379BHP with hybrid turbos and 1.4bar, i ran 369BHP on std turbos at 1.2 bar,

in theory and quite often in practice, hybrids at 1.4bar should result in around 400BHP-420BHP at least, as the std 440cc injectors should be capable of supporting 420-440BHP at 100% DC,

 

The second being that when the std ECU sees full boost or more, it will run the injectors by default at 100% DC,

Now providing the std fuel pump is in good condition it is also capable of supporting the fuel volume.

 

I also ran hybrids in TTC mode at 1.3 BAR useing EMU, and at first std 440cc injectors,and i was actually pulling fuel in order to get it out of the 9 and 10s AFR.

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Why is it a bad idea and how is it dangerous? Normally your advice is spot on but I'm struggling to work this one out!

 

Lowering boost to 1.2bar is a good idea its the 12v mod I dont like, depending which guide you follow it will leave the pump running all the time, even in the event of an accident which I wouldnt fancy if I was stuck in the car, hence my dangerous comment. Also the 12v mod only really has any affect off boost and low boost as the pump switches to full 12v when needed anyway.

 

Unless I am misunderstanding something here.

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The general opinion is then turn down the boost for now, look for larger injectors and a AFR controller.

Not intending to go in search of more and more bhp just want my setup to work safely.

Would uk spec injectors be ample enough for this and do they just fit straight in without adding or purchasing any additional parts.

 

Good idea, a resistor pack would be needed for UKs, You could get some Power Enterprise drop-ins and not bother with the resistor pack, they do some around the 550cc area ;)

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