Td5 D2 engine - Turbo Wastegate (2)

ADJUSTING THE BOOST SETTING. (23/05/17)

The boost setting on the Turbo Actuator was adjusted for the second time. The initial 'feel' from the little test drive was promising, but I really need to assess it by logging data onto the Nanocom.

The intention today was to increase the MAP (Manifold Absolute Pressure) closer to the target value of 242 K/pa.

My initial fear that I had put the boost setting into 'overboost' proved unfounded and even now I'm thinking that the boost has yet more to give.

In an earlier post, I described how to adjust the onset of the boost using the knurled adjuster on the Actuator rod.

Initially, when I originally removed the Turbo Actuator from the engine, I carefully counted and wrote down the number of threads visible in front of the adjuster locknut.

This is the drawing I made detailing the initial setting of 13 threads and noting what I call the 'first adjustment' of 12 threads. It was easy to make this adjustment with the actuator removed from the engine, but it is possible to do it on the engine. The black knurled adjuster behind the locknut should turn under firm finger and thumb pressure.

First Adjustment - 12 threads

Placing a small piece of blue tape on the adjuster nut really helps to determine the movement of the nut during adjustment. The adjustment of the nut can accurately be controlled to a quarter, half, or full turn. The necessary adjustment can really be that fine.

This '12 threads' setting was combined with the install of the new MAF sensor and then road-tested with the Nanocom during the first four 'data log' sessions.(T1-T4).

Figures from those tests show a maximum developed MAP value of 219 K/pa (T4/198)

The 'target' MAP value is 242 K/pa and it was decided to get closer to that by adjusting the Actuator rod initially by one thread..

Second Adjustment - 11 threads.

It should be noted that this adjustment was carried out after the ProVent engine breather was installed. Also, a couple of weeks had passed since the first earlier adjustment in order to get a better feel for the performance.

I was very weary that this adjustment would send the engine into overboost mode and the initial test drive would produce the jittery fuel cut-off symptom at full-boost. Thankfully this did not happen.

I now need to connect the Nanocom and do another test drive/data log to determine what the maximum MAP is now. At this stage, I would expect to see an increase in the MAP figure and it should be possible to then gauge how much to turn the adjuster to get it closer to the target of 242k/pa.

Did not connect the Nanocom for a few weeks and the test run's I did (T5, T6) did not produce the results I was expecting. There was only a marginal gain in the MAP figure, but I have to say that the test conditions were not the same, so I am prepared to ignore these test runs MAP wise.

I wrote more about these tests in 'Td5 MGMT - MAP Test 4'.  Looking back on the numbers and the marginal improvement therein, I decided to revise the test route to concentrate on getting the engine to 3k rpm in 4th gear. The outcomes of which was to look for a different test route, and to adjust the Boost Setting once again!....

Third Adjustment - 10 threads

This was done on 30/06/17 and the first initial drive was encouraging. There was no overboost and the turbo pick up seemed to be starting earlier. The only way to confirm this is with the Nanocom.

Ran around with this setting for a few weeks to get a feel for it before connecting the Nanocom and recording the figures in T7.

Made use of a new test route and in general was pleased with the response of the engine, but dismayed to find the MAP figures still not climbing as I expected.

Data in T7 for the MAP shows no appreciable gain over T6 so it's back to the drawing board.

Started to pay attention to the Inlet Manifold Temp. There is a lot more data captured in these test runs then just MAP figures and I'm trying to get an idea of what the Intercooler is doing in terms of temperature drop of the charge air in a given set of conditions.

Fourth Adjustment  -  9 threads 

This was done on 20/07/17 following on from the results and experience of the previous adjustments. 

The Nanocom test on 10 threads (T7) did not produce the expected figures but that may have been due to gearing and a new test route. I elected to adjust some more and noted that the physical adjustment was a bit harder this time and I had to carefully use a wrench on the knurled adjuster.

Initial drive on the road is promising. The boost from the Turbo sure feels stronger and there is still no Overboost flutter. If the Nanocom doesn't show MAP moving up over 220kpa under boost this time I will be shocked!

13th Sept 2017 - Finally got around to another test run with the Nanocom. I have called it T8 and the results were as follows. 

The highest MAP value obtained was 223k/pa. This was achieved in 3rd gear under load at 2414rpm.

That's a gain of 3k/pa but once again it just points to more being available. ...

Fifth adjustment  -  8 threads. 

19th Sept 2017 - Did this on and having loosened the locknut, I sprayed some WD onto the threads and adjuster. This seemed to help as the knurled adjuster moved under finger pressure again. It was left at 8 threads for a Road test and the Nanocom test run.

The Nanocom test (T9) was done a few days later on 23/09/17. I drove around for a few days to get a feel for the new setting. There is no still overboost flutter, and performance when pushed feels better, but I am beginning to doubt the validity of my judgement and will look to the figures obtained under test conditions.

When analysed, the figures from T9 do not show an increase in the max MAP figure. 

The highest MAP figure obtained was 223.75k/pa (T9-170). That is .02k/pa less then that achieved on T8.  Have to admit to being a bit disappointed at that outcome, but I guess it just shows that these things aren't simply a linear progression.

I will double check the wastegate settings and consider adjusting some more..

Starting to wonder if other engine parameters are having an effect now?

Sixth adjustment  -  Seven threads 

27th Sept 2017  -  Dismayed at the 'standstill' result with the previous setting, I decided to press ahead and continue adjusting the thread length to increase the K/pa value on boost.

Once again the adjuster was turned by finger pressure after a squirt of WD40. The previously applied piece of blue tape finally came adrift, probably from WD over-spray. A new piece was quickly installed though it must be stated that it's use is just as a guide/datum mark. A close up photo is used to count the visible threads before and after adjustment.

I have driven around for a few weeks now with this setting and sure do feel a positive differrence in the driveability. I am a lot more confident moving off at road junctions and at roundabouts. Overtaking is more confidently executed. 

I have decided to continue to increase the boost and now favor an extended on-road drive-ability test against the Nanocom circui' tests. I guess that a combination of the two is the better option, but for now, I will just go ahead and adjust the Actuator rod one more time. 

..Seventh adjustment - Six threads...

20th Oct 2017  -  Recent thinking has moved towards adjusting the wastegate without testing the current setting with the Nanocom. 

This was mostly done freehand, the last quarter turn needed the wrench applied to the knurled nut. No WD40 was used. 

Like to think that I am gaining performance. The question is how much is still untapped? 

Next month is MOT time and I am already wondering if this is doing anything to the emissions..??