Checking turbo operation

http://log.malonetuning.com/chart/229349#H8KLCADCssO%2FwpJaAgNNwovDkQrCgzAMAMO%2FJcOPDcOow7BvSh%2FDqgw1w5A1wpLDhsOhw7bDtcOaCmPCj3fDh3kPT3nDjVwIwpPDisK%2BVXBDcE1mUcO%2Bw5LChQ4SFcOSaAR3KW9SQxM8MB7DnMKOw7vCicOLwoLCn8KfAsOlwrRaXyrDmV%2FDsMKPw6Bgw6whw64mdcOLbMONwo9TCCfCtzzDpifCjwAAAA%3D%3D

This is a graph I generated after adjusting the turbo actuator. I made it longer by one whole turn, since they said online that it was very sensitive, so I didn't want to go too far. The actuator is a pain in the butt to adjust BTW. Hopefully I will get faster at it.

I also tested the actuator and it does start moving around 2-4" of vacuum. It hits the stop at 18" like it is supposed to.

The graph looks about the same as the last one, so it doesn't look like this attempt helped.

Should I adjust it 2-3 full turns this time?

Looks like I am peaking at around 19 PSI, which shouldn't be too much, but the duty cycle is still in the 90s. I found some recommendations saying the duty cycle should be around 80%? Someone on this thread suggested 65%, not sure which is better?

Here is a log from my 1999.5 Jetta. It peaks at 18 PSI or so.

http://log.malonetuning.com/chart/2...wwo/DoGDDrCHDriZ1w4tsw43Cj1MIJ8K3PMOmJ8KPAAAA


Thanks!

Here is a blurb about the N75%:

The ALH and PD motors have opposite N75% readings; if the ALH N75% is at say, 15% the ECU is giving the actuator as much vacuum as it can, if the N75% is at say, 90% the ECU is trying to bleed off the vacuum as fast as possible. With the PD motor the N75%'s work the exact opposite. The place you need to check the N75% is at full throttle in third gear. IIRC, my N75% at idle is around 14%. A reading of 65% @WOT in third gear is a generally good reading for a correctly tuned motor. Do not get caught up on having 3" of vacuum when the actuator starts to move and 18" when it hits the stop, not all turbos are going to work at their optimum with these settings. Those are the general settings for a factory replacement turbo, but if your turbo is modified in any way, those numbers are basically useless.

So when my N75% is up at 93% the ECU is trying to bleed off vacuum as fast as possible because the turbo is making too much boost. So I guess that I do need to make the actuator even longer.

Did you notice how much play is between the actuator arm and a the VNT lever? They do wear out, with the spherical bushing falling apart.

The bushing kept falling out. I put the end of actuator arm in a vise to try to compress it so the bushing would stay in. There is some play for sure.

Should I get a new actuator?

mrfiat said:

This is a graph I generated after adjusting the turbo actuator. I made it longer by one whole turn, since they said online that it was very sensitive, so I didn't want to go too far. The actuator is a pain in the butt to adjust BTW. Hopefully I will get faster at it.

I also tested the actuator and it does start moving around 2-4" of vacuum. It hits the stop at 18" like it is supposed to.

The graph looks about the same as the last one, so it doesn't look like this attempt helped.

Should I adjust it 2-3 full turns this time?

Looks like I am peaking at around 19 PSI, which shouldn't be too much, but the duty cycle is still in the 90s. I found some recommendations saying the duty cycle should be around 80%? Someone on this thread suggested 65%, not sure which is better?

Here is a log from my 1999.5 Jetta. It peaks at 18 PSI or so.

Thanks!

Click to expand...

The earlier graph indicated absolute 33.43 PSI, the next one 31.36 PSI (absolute)
That's a 2 LB drop.
Try another turn on the nut.

The good news is that I'm getting faster at removing the turbo actuator.

http://log.malonetuning.com/chart/229375#H8KLCAB6TsKTWgIDTcKLw5EKwoMwDADDvyXDjw3DqMOwb0ofw6oMNcOQNcKSw4bDocO2w7XDmgpjwo93w4d5D095w41cCMKTw4rCvlVwQ3BNZlHDvsOSwoUOEhXDkmgEdylvUkMTPDAew5zCjsO7wonDi8KCwp%2FCnwLDpcK0Wl8qw5lfw7DCj8OgYMOsIcOuJnXDi2zDjcKPUwgnwrc8w6Ynwo8AAAA%3D

I went out two full turns on this graph. (3 full turns total)

Does this look better?

I think maybe I should go two more turns.

Definitely better than http://log.malonetuning.com/chart/229349
but still way over request. Veins aren't fast enough, then it's too far open up top. How's the vacuum range?

Is it hitting the stop screw at full vac?

Thanks. It was hitting the stop at 18" before I went two turns out. I haven't checked it with today's changes. Vacuum is 24" at the tee on the brake master hose. (which should be fine, I think)

I will go out two more turns and then check it with a vacuum pump tomorrow.

mrfiat said:

The bushing kept falling out. I put the end of actuator arm in a vise to try to compress it so the bushing would stay in. There is some play for sure.

Should I get a new actuator?

Click to expand...

There should not be any play.

mrfiat said:

The bushing kept falling out. I put the end of actuator arm in a vise to try to compress it so the bushing would stay in. There is some play for sure.
Should I get a new actuator?

Click to expand...

If yours holds vacuum, then just get this for $8.99
https://www.amazon.com/gp/product/B00BD9BUEC/ref=oh_aui_detailpage_o04_s00?ie=UTF8&psc=1

I adjusted the actuator out two full turns. That is as far as it can be adjusted out. It is possible the actuator is slightly compressed in with no vacuum due to the length of the rod. (it might not be, hard to tell)

I did two runs:

http://log.malonetuning.com/chart/229399#H8KLCADDssOMwpRaAgNNwovDkQrCgzAMAMO%2FJcOPDcOow7BvSh%2FDqgw1w5A1wpLDhsOhw7bDtcOaCmPCj3fDh3kPT3nDjVwIwpPDisK%2BVXBDcE1mUcO%2Bw5LChQ4SFcOSaAR3KW9SQxM8MB7DnMKOw7vCicOLwoLCn8KfAsOlwrRaXyrDmV%2FDsMKPw6Bgw6whw64mdcOLbMONwo9TCCfCtzzDpifCjwAAAA%3D%3D

http://log.malonetuning.com/chart/2...Pw6Bgw6whw64mdcOLbMONwo9TCCfCtzzDpifCjwAAAA==

The duty cycle is maxing out of 70% which seems pretty good. The car does accelerate faster now.
It seems a little laggy down at low RPMs though. Looks like the boost is peaking at 18 psi, which should be perfect, I think. I estimate I am getting 30-50% more power after I hit 2000 RPM.

What do you guys think about these graphs?

I did not have time yet to check it with a vacuum pump yet. No idea yet if it is hitting the stop at 18", but I doubt it.

If the graphs look ok, then I will get the rod end suggested above. (Thanks for that) Or if the rod being all the way extended at rest is a bad thing, then I will get a new actuator.

Thanks!

The last one shows the difference less then 3 LB, I would be happy with that.
The rod end change may help if your turbo veins are a bit sticky at the ends.
If you measure the length from the vacuum unit to the bushing you could use that length with the new bushing end.
Now that I'm doing mostly short trips (less then 10 mikes) my veins may be sticking more.
Will pull the turbo in a month or two.

mrfiat, the graphs do look significantly better. If it were me, I would order the new actuator "link" from Amazon. Every little bit of play you can remove from the actuator is a good thing, so the turbo can operate properly . As I have mentioned before the 3" and 18" setting are just a place to start when trying to reset the actuator arm. At this minute, I don't know where mine is numbers-wise, I have it adjusted to where if I peg the throttle at 1800-2000 RPM the engine doesn't "cough or stutter."

Thanks! I ordered the new actuator end. Looks like I'm good to go on the turbo. I drove it again today and it was actually pulling pretty good at low RPMs also. It feels much better.
I thought something might be wrong with the turbo which would be very $$$.

Hopefully this will help my fuel economy issues.

I guess I need to get a tune done next. That should help FE and performance.

My last tank was 38.4 mpg. (80% City) I think that I should do better than that.

Below 1800 rpm or so, my acceleration is sluggish. I just checked my turbo actuator. It starts moving at 3-4" and stops at 18" of vacuum, so it is working correctly.

mrfiat said:

My last tank was 38.4 mpg. (80% City) I think that I should do better than that.

Below 1800 rpm or so, my acceleration is sluggish. I just checked my turbo actuator. It starts moving at 3-4" and stops at 18" of vacuum, so it is working correctly.

Click to expand...

My mileage is down the dumper same as yours since I was laid off.

I have replaced my turbo actuator and adjusted it the same setting as the old one. I also have installed new 520 nozzles and gotten a tune from Kerma.

Here is my current boost graph. How does it look?

http://log.malonetuning.com/chart/2...Pw6Bgw6whw64mdcOLbMONwo9TCCfCtzzDpifCjwAAAA==

I just wondering if the boost should come on a little sooner than it does?