Flat spot at 5200rpm on 2.0T - Does yours do it?

[djhorace]

Interesting, but I would only believe anything a manufacturer claims when someone who bought it gave an unbiased opinion.

For what its worth, mine does it with the boost all the way down, and with the cat removed. I still have the damned "jingling" noise on spool point and upward - 15000 miles its been there now on and off, although its more on now than off, and its louder than ever. I have not really seen any thing "definite" posted that this could be as yet, and I know mine is not alone.

[GTIjames]

Interesting, but I would only believe anything a manufacturer claims when someone who bought it gave an unbiased opinion.

For what its worth, mine does it with the boost all the way down, and with the cat removed. I still have the damned "jingling" noise on spool point and upward - 15000 miles its been there now on and off, although its more on now than off, and its louder than ever. I have not really seen any thing "definite" posted that this could be as yet, and I know mine is not alone.

its an uprated stronger actuator than the oem one, just makes sense replacing it with the forge when you are running high levels of boost and for £120 its worth a punt.

interesting to hear you get the jingling sound on spool up, I get it too but only when the car is cold once warmed up it goes away
is it the same for you or constant?

im on the look out for a new K04 - missed one on ebay yesterday went for £250

[djhorace]

its an uprated stronger actuator than the oem one, just makes sense replacing it with the forge when you are running high levels of boost and for £120 its worth a punt.

interesting to hear you get the jingling sound on spool up, I get it too but only when the car is cold once warmed up it goes away
is it the same for you or constant?

im on the look out for a new K04 - missed one on ebay yesterday went for £250

I would consider it if someone else had the same issue, and this part "fixed" it.

My car does it when cold or hot, and its intermittent.

Out of interest, why do you need another turbo? I have a spare, but its only there incase my one goes bang.

[Poverty]

read this from mike @ forge regarding their new actuator:

could this be what we are experiencing? are oem actuator spring is failing over time and causing the issues...

"Actuators are not offered to address shortcomings with software.

They are made to address shortcomings with the OEM actuator that software does not compensate for.

Similarly to how a weak blow-off valve can leak on the pressure side of a turbocharged application, a weak wastegate can leak on the exhaust side.

The stock actuator has a soft spring in it (~ 4PSI) that doesn't effectively keep all of the exhaust gas spooling the turbo in the most efficient manner all the time. Too much exhaust gas pressure can force it open effectively causing an exhaust gas leak that limits spool and boost potential. If you figure that you are pumping 15-20 PSI into the intake side of the motor, you will have an equivalent amount of exhaust gas pressure coming out of the motor on the exhaust side.

This is a phenomenon that a lot of people experience without even realizing it. Under a high load condition, such as a wide open throttle pull in 4th, 5th, or 6th gear, boost will quickly climb to a peak value and immediately fall off and fluctuate wildly up and down and which point you will hear a fluttering effect from the engine as the ECU tries to keep actual boost in line with requested. This is far more prone to occur on a smaller turbo at higher boost levels (more air flowing through a smaller space) than a larger turbo at lower boost levels.

No amount of tuning or additional N75 duty cycle will prevent the wastehate from being blow open prematurely by exhaust gas. N75 duty cycle doesn't apply vacuum to the actuator to keep it closed. It only delays the time that pressure signal is held back until it is sent to open the actuator.

The only way to prevent this occurrence is to increase the spring tension of the actuator. Adjusting the stock unit will have a similar effect but to a lesser degree because your working with an altogether lower spring tension, and adjusting it will only limit its travel and flow potential. A replacement unit with a stiffer spring will help to spool the turbo in the most efficient manner possible by keeping all of the exhaust gas flowing over the impeller wheel."

 

where did you copy and paste this from?

[Janner_Sy]

it says mike @ forge at the top of that quote!!

[GTIjames]

Was reading about the k04 actuator over on golfmkv.com and with the logs I posted earlier which shows my boost reaching a peak and then fluctuates up and down - keiths comments I highlighted may offer an explanation

my actuator arrived today sexy bit of kit just need to get time off work and get down to jkm to fit it

 

[Janner_Sy]

have yuoou bought the same as what hudy has bought' forge actuator'  do you have links etc, had a look on forges website but couldnt find it.


also how mucg wil jkm charge to fit it.

[bacillus]

iirc the install takes about 3 hours...   

[Janner_Sy]

mint lol. so do we know if the map needs to be adjusted to make the most of it. ie for the non revo guys can it be used as a bolt on mod so with no tweakage

[GTIjames]

There we go then not cheap will cost more than the actuator...

On my phone so can't post link just go on forge website and look through the actuator section I think it's on the 4th page

120 delivered using the seat cupra discount  

[Poverty]

it says mike @ forge at the top of that quote!!

yeah I mean like what forum/thread/website?

I find the comments about the "software" odd tbh. Why should it be relevant unless a company who deals with software has asked forge to make this unit?

[KRL]

this has issue has plagued me for a fair few months now and have tried all sorts to fix it:

maf, sparks, coils, new intake (itg), replaced oem 'd' dv with forge dv, and also replaced my miltek downpipe when that blew a hole in the flexi flange

problems still remained - mainly in 4th and 5th gears and c5krpm, boost gauge suddenly drops from c20psi to 5-10psi for a second and then back to full boost

only solution i have found is too turn down the settings - i used to be b8t6f6 and am now b8t5f7

with the new settings the car does not stutter,

interestingly i noticed if I turned the timing up to 7 then the issue got worse and the stutter happended twice in the rev range

i am a vagcom beginner but this is a log i did at t7, can anyone advise what else i should be looking for

Hi James,

Your boost log looks odd to me because your specified boost is pulling back at 3880 RPM.  Also it does not look like your turbo is spooling properly.  This is a boost log from my car at stage 1.  Notice how spec'd boost remains fairly consistent and does not drop off.  Also the you can clearly see the turbo spooling at 2800RPM:


Which gear did you do your logs in and were you WOT for the entire pull?  It would be interesting to see what your N75 duty cycle is like and your fuel rail pressure.

[GTIjames]

That run was done in 4th with revo settings b8t7f6 and at wot - the graph is showing the issues I experience when running to high a timing setting.

I am now running t5 and the boost holds at 21psi upto c6500 rpm, my windows laptop is currently broken so can't get any new logs up at the mo, but went for a spin last night and did a run all the way through 4th and 5th gears watching my boost gauge and it held without any sudden drops

[KRL]

Did you check what your timing pull and timing advance were like with T7?  Maybe the ECU was pulling back which caused the strange boost log.

[Hedge]

James, take a look at this. http://www.revotechnik.com/products/pdf/SPS3_advancedUserGuide060406.pdf

Pages 8 and 11 specifically apply to you. T7 seems high unless you are running spooky high octane fuel.