Td5 D2 engine - MAP test (4)

Did another test run today (16/6/17 - T5,T6) with the intent of quantifying the effect of the latest Wastegate Actuator adjustment. 

The adjustment was done weeks ago (see 'Turbo Wastegate 2' - 23/5/17 ), but with the recent coolant leak and other work I didn't get to do a test run till now. The elapsed time however since the adjustment has allowed me to trial out the engine performance and get a 'feel' for where it is now.

Generally speaking, I am happy with the improved performance. I tell myself there is a slight improvement over the first adjustment but can't say for sure without some figures in front of me. It's certainly got a faster power response when pushed. 

Obviously though, the more you get the more you want!!

Ideally, I would like the turbo to 'kick-in' at a lower RPM. I have a target of 1500 rpm to start to feel the response. At present it is around 1800. A small change, but if it is do-able it would be nice. 

Maybe I should look up the designed parameters for the Garrett turbo. Research has shown that Garrett designed the internals specifically for the Td5 engine, so there must have been some input from Land Rover on its performance parameters.

I seem to have got transfixed on the MAP target value of 242 kpa. Achieving this target is not simply a case of driving 'balls out' all the time, but rather by putting the engine under load going up a gradient or up a motorway on-ramp. In the past the highest values have been achieved thus and I recall that was in 4th at 3000 rpm. Perhaps that should be my benchmark test?  Perhaps also a new test route should be used. One that makes better use of nearby 'on-ramps' and offers repeated runs.

Well, in the end the new tests are not conclusive. T5 did not yield figures better then on T4. I put that down to the traffic flow on the test. T6 didn't do much better either. I missed a gear change at a crucial time!

The highest MAP figure obtained so far was on T6 - 287. In 4th and accelerating up the on-ramp at 2449rpm  the MAP read 220.82 which is marginally better then the 217 achieved on T4.  That T4 figure was at 3k rpm.

Whether that small gain in MAP value is the result of the wastegate adjustment is questionable and it remains inconclusive. It remains to be seen what MAP figure can be achieved now at 3k in 4th under load...

Positive outcomes are that there still appears room for improvement in getting the MAP value closer to the target of 242. I am now thinking of adjusting the Actuator rod one more turn...

On a unrelated note, studying the engine coolant temp shows the recent work on the cooling circuit was successful. It was a hot day and the cabin heater was off so Hx was relying on itself to maintain its temp range consistently and to stay in range.

Also paid attention to the inlet air temp (IAT), trying to judge the effect of the Intercooler on the intake air stream. I am now wondering what range it should have?