Thread: TD5 waste gate actuator operation

Unfortunately i didnt make such complex tests with the original actuator, i worked with the forge also i didnt have a boost gauge fitted(which i should have had for accuracy) i watched nanocom inputs fuelling comparing different setups... my tests were mainly to see which setup is better for the driveability and the best IMO is WGM + MBT and actuator a bit more ''relaxed" than the factory setting or the WGM with actuator at factory setting, the original one would be at around 15 threads left out that way, i have the original in my garage so i'll measure with a bycicle pump which has gauge where it starts opening but my presumption is that it's around 0.8 Bar then it opens more according to the load, it acts on boost like a thermostat on water temperature, progressively untill it's fully opened.... simply shortening the rod increases final boost but makes it jerky as the travel of the wastegte is reduced but with longer rod and manually controlled boost the boost curve is smoother as the wastegate's travel is more progressive.

IMO the best will be when Offtrack will work out a remap for the WGM management as to work well with "relaxed" actuator

Looks like I've got some testing to do!

onebob,
I've got some hose and pressure gauges and could rig something up to the wastegate and pump it up and measure the movement of the rod and at what pressure etc
Will also use this to test the MBC after I've done some live testing and set to max boost etc so should be able to get a ballpark pressure for initial setup of a MBC??

OffTrack,

I've sent you a PM

Cheers Lemo

Originally Posted by onebob

Thanks SF... your comments re actuator spring load brings the discussion back to my opening post on this topic.... taking MBCs and WGMS out of play at what boost pressure would the factory setting waste gate open at?

The peak boost I got with 13 threads and WGM modulator disabled but still inline was roughly 124kpa // 18psi.

Originally Posted by sierrafery

Maybe in theory it doesnt but in reality it does cos i tried both ways with drive tests and with the WGM in situ the throttle response at low revs was better and the boost built up faster than without it also with the MBT set as the final MAP reading with WGM + MBC to go up to 240 without touching the MBC just bypassing the WGM the MAP never got above 225 in the same driving conditions, i can't explain why, maybe there is a certain restriction through the fully opened WGM too...IMO the WGM does it's job the same way just that the actuation boost is lower as restricted by the MBC... i can't and i dont want to contest your research but that's how it happens i can vouch for that

what i can tell based on my drive tests is that the actuator's spring load is also very important and makes a difference even with small adjustments... at least that's obvious with the forge actuator cos all my tests were made with it

In this case I don't class increasing boost as "something useful".
After all the screw on the MBC is not just ornamental.

The reason I suggested bypassing the WGM is because of the way the WGM seems to operate when boost levels are mechanically increased.
There appears to be a tendency for boost to overshoot, then drop back to a slightly lower level as the WGM tried to control what it sees as boost higher than target. With the MBC inline before the WGM it's fairly likely you are getting this overshoot happening. If you post up a log it will be fairly easy to see

Thanks OffTrack... i can work with that and why i'm pursuing this line is that i've had two occasions where the boost gauge has climbed frightfully high when I've been cruising on the Hume Fwy, and Calder Fwy with cruise control engaged. All's good on the flat but when you encounter a long low rising section of road the CC throttle response is weird and what i can best describe feels like a "feedback loop" and a 'runaway' situation develops. My MBC has a small bleed hole so the WGA sees less line pressure than the std setup which i imagine is the issue here and what i need to do is relax the WGA spring load to allow the waste gate to actuate with the reduced WGA line pressure available to it. Mind you i'm no engineer just a crusty old printer

So as promised I did some testing, albeit rough!

So using a pressure gauge tee'd off the line and a good old bike pump

Measured WG rod is 46mm to lock nut with this being zero reference

15psi = 0mm
16psi = 0.5mm
17psi = 1mm
18psi = 1+mm moved more if I was going from 17 to 18 pumping
19psi = 1.5mm
20psi = 3mm

Method is not 100% accurate but it shows that maybe the wastegate will not open below 16psi, on mine anyway.

Cheers Lemo

Originally Posted by onebob

i've had two occasions where the boost gauge has climbed frightfully high when I've been cruising on the Hume Fwy, and Calder Fwy with cruise control engaged. All's good on the flat but when you encounter a long low rising section of road the CC throttle response is weird and what i can best describe feels like a "feedback loop" and a 'runaway' situation develops.

I remember about 12 months ago Blknight telling me the D2 cruise is a very, very basic system (about as far as you can get from those new fangled ones that stop you accelerating down hill), and you comments are entirely consistent with the limited action design. Cheers

Originally Posted by gavinwibrow

I remember about 12 months ago Blknight telling me the D2 cruise is a very, very basic system (about as far as you can get from those new fangled ones that stop you accelerating down hill), and you comments are entirely consistent with the limited action design. Cheers

It's not that basic - 6 of the engine maps are dedicated to cruise control.