Bluefin Stage 2 too much boost .. not enough fuel pressure?

[Hedge]

I would have thought your N75 would be taking care of any excess boost. 

[haithame]

Yeah I read your story with your conversation with the guy from australia on mkvgolf.

 I think my problem is a little different from yours, because when I read your story, your fuel pressure requested versus achieved was inconsistantly variable all the time, whereas mine is only inconsistantly variable on high load, in a specific series of RPM where boost is excessive (i.e. 1.43 BAR).

At anything lower than 1.4 BAR boost, my fuel pressure is perfect. I'm going to ask SC to scale back the requested boost in the danger zone, so that the car will only achieve less than 1.4 BAR boost in those areas and then I think it will be fine - I'll let you know how I get on.

my fuel pressure is inconsistent in the range of 4k rpm not all the time

[Mark_GTIV]

I would have thought your N75 would be taking care of any excess boost. 

The wastegate actuator is used to keep the turbine in it's efficiency envelope and stop it over-reving and it's controlled by the mapping - When SC tweak the boost mapping, the ECU will use the wastegate actuator to control the turbo according to the map. In other words the N75 will do whatever the map tells it to do, and right now SC are asking for 1.4 BAR... which is the issue.

[Mark_GTIV]

Yeah I read your story with your conversation with the guy from australia on mkvgolf.

 I think my problem is a little different from yours, because when I read your story, your fuel pressure requested versus achieved was inconsistantly variable all the time, whereas mine is only inconsistantly variable on high load, in a specific series of RPM where boost is excessive (i.e. 1.43 BAR).

At anything lower than 1.4 BAR boost, my fuel pressure is perfect. I'm going to ask SC to scale back the requested boost in the danger zone, so that the car will only achieve less than 1.4 BAR boost in those areas and then I think it will be fine - I'll let you know how I get on.

my fuel pressure is inconsistent in the range of 4k rpm not all the time

oh really.. what are the boost readings when the fuel pressure goes strange?

[john_o]

have you have checked that you arent due the Fuel Pressure Sensor recall (not that I think its an issue here)?

reading your comprehensive reply. Im surprised your  fuel press actual is ABOVE your requested.
forge shouldnt have an effect under WOT and you are achieving requested boost levels.
I assume you have tried going back to stage 1 (which the bluefin will allow) and the fault doesnt occur ?
FP looks ok in rest of range but have you checked your cam follower?
may also be worth changing your in tank fuel filter too?

the question in my mind would be why SC map is requesting a boost level the car (in good working order) cant achieve  
either that or dropping the boost is just a band aid to hide an issue you havent found yet...

at the end of the day vrstu's the expert

(the other contraversial option given the way the bluefin maps are uploaded , in theory you could reflash to stock and get a stage 2 REVO or APR trial and see if it exhibits the same issue))

[Mark_GTIV]

have you have checked that you arent due the Fuel Pressure Sensor recall (not that I think its an issue here)?

reading your comprehensive reply. Im surprised your  fuel press actual is ABOVE your requested.
forge shouldnt have an effect under WOT and you are achieving requested boost levels.
I assume you have tried going back to stage 1 (which the bluefin will allow) and the fault doesnt occur ?
FP looks ok in rest of range but have you checked your cam follower?
may also be worth changing your in tank fuel filter too?

the question in my mind would be why SC map is requesting a boost level the car (in good working order) cant achieve  
either that or dropping the boost is just a band aid to hide an issue you havent found yet...

at the end of the day vrstu's the expert

(the other contraversial option given the way the bluefin maps are uploaded , in theory you could reflash to stock and get a stage 2 REVO or APR trial and see if it exhibits the same issue))

Hi,

Thanks for the reply. Blimey I hope it's not hardware related. 2007 car, 26K Miles perfectly serviced and for two years pretty much only driven by my wife (prolly hardly ever hit 3K RPM) still it is still under warranty.

Actually, my fuel pressure is on or below requested. As to the the point regarding SC and why SC map is requesting a boost level the car (in good working order) cant achieve : if the car only made the level SC requested, it would be fine, but the car is making a little more boost than SC request and thats what is taking it over the edge.

Of course this is all assuming that the mapping SC sent me for stage 2 is the right one.

[vRStu]

Boost requested is often higher than actual, especially on REVO'd KO3 cars as they just ask for the maximum. 

I don't think it would be advisable to have trial software installed.

The boost levels will go a bit crazy when the fuel cut hits as the engine/ECU will 'pull back' to keep things safe.  Sort the fueling out and I think you'll have solved the problem.  IMHO you are asking too much of the OEM pump with an agressive map.

Also worth logging the timing to see how much you are pulling.

[Mark_GTIV]

Boost requested is often higher than actual, especially on REVO'd KO3 cars as they just ask for the maximum.

I don't think it would be advisable to have trial software installed.

The boost levels will go a bit crazy when the fuel cut hits as the engine/ECU will 'pull back' to keep things safe.  Sort the fueling out and I think you'll have solved the problem.  IMHO you are asking too much of the OEM pump with an agressive map.

Also worth logging the timing to see how much you are pulling.

In my case actual boost is sometimes more than requested boost. With the milltek TBE and the Carbonio the airflow on my car is better than SC were anticipating with the standard stage 2 map. The car's fuel delivery system simply cant cope with delivering enough fuel for 1.43 BAR of boost through the 2.8K to 4.3K rev range.

They've toned down the mapping and after the 3rd map that they've sent me today - the car has settled down - isn't throwing a DTC code and is able to deliver correct pressure for the amount of boost generated.

Problem is solved and car is now running 1.2 BAR of boost safely. So a big thanks to Superchips for helping to sort this out today.

[Mark_GTIV]

Further discussed here : http://www.mk5golfgti.co.uk/forum/index.php?topic=4289.msg83398#msg83398

Solved here : http://www.mk5golfgti.co.uk/forum/index.php?topic=5543.msg85303#msg85303