1997 B4V 1Z Grocery Getter Build

3 more emp videos. WOT in 3rd gear, some of might have been slight uphills, best I can do at 730 am in Los Angeles.

first one, emp gauge fitting came loose, thats the hissing at the end.
http://www.youtube.com/watch?v=MiS_3-dIZp8
this one I hit the tune limit. Looks like 1.5:1
http://www.youtube.com/watch?v=bouwME2R6yM
just another one for my logs, didn't get up that far.
http://www.youtube.com/watch?v=aaWJEUYCbKA




I will say after looking it over a couple times, the 2nd and 3rd video are pretty indicative of what my emp:imp at WOT is like.

A jump to 1.5:1, drops down to 1:1 and then the slow rise as rpms increase from 1:1 back to 1.5:1 before I let off at 6k rpms.

This is 3rd gear, and I will have to figure out 4th when I don't want to die in LA.

You car sounds sooooooooooooooooooooo quiet in those recordings Jeremy . When did you acquire the ability to record in HD btw? If you need another pair of hands to logging, I'm free tonight.

I'm done logging till we figure there is anything left to change. Not sure what to do to increase response and reduce emp. Kinda sounds like a unicorn at the moment.

I couldn't see the boost gauge in the first two video's, but on the 3rd video it looked decent relative to the EMP's - looked like you were running 28-30 psi boost to ~35 psi exhaust. The first two had EMP's in the 40-45 psi range though.

I looked at the logs/graphs you plotted in the earlier posts and nothing stood out to me (but I'm no tuner).

Keep us posted with what you try next and what you find.

Maybe try adjusting the actuator one way or another just to see what happens?

Boost pretty much jumps up to 28-30psi (my tune is set for 28) after the lag goes away. So it's pretty instant after that dreaded 1800-2200rpms. It's full boost all the way through.

Once the RPMs rise up to 4500-6k the emps start rising up too.

Both of these things make me think that the actuator is closing too far (along with the 40+psi spool up spike).

Closing the vanes helps the turbo spool up, but once it's spooled, the vanes need to get out of the way to let the turbo breathe. If the vanes close too far/too long on spool up it will be laggy with high EMP spikes. The commanded boost is still high while the EMP's are high and actual boost is low - this drives the VNT closed even further/longer (because it's not making requested boost) and it compounds the problem.

Maybe as an experiment, adjust the actuator to start moving 2-3inHg higher than it is now. This will act as an offset to the N75 table in the tune and initially close the vanes less on spool up and less at higher RPM's. It might help spool up, lower the initial EMP spike and lower the higher RPM EMP's as well. Worst case it makes it laggier - Pretty easy to do and shouldn't blow anything up (I hope ).

JFettig said:

I am waffling on my decision for a big turbo because of all this that I'm seeing. I was almost ready to grab a gtb2056vl but I have about changed my mind.

Jon

Click to expand...

Trust me, the little bit of tuning effort is very worth it. Jeremy has had a little harder time than usual getting his setup tuned in. Doesn't help that everything was brand new on the setup. I'm sure if any of us were there in person to help him, it would've been tuned in much sooner. On Ducerswld's mk5, I only had to adjust the stop screw and rod on the 2056vk once to get it within 90% of perfect.



That 3rd gear video looks great Jeremy! Lengthen the actuator rod one or two turns to get the emp spike down and it should be about perfect. I wish I could make it out there tomorrow so bad to help you get it perfect .

Mark sent me a tune with more vacuum, but it was causing emps to spike to 50! So I lengthened the rod, and opened the vanes to 1.5-2psi at idle.

Here is a 3rd gear pull I did. It's underboosting though once it gets to around 4krpms, we gotta figure that out. But look at the spool (when the emp spikes, consider the boost full 28psi). Emp drops down much more this time. Better?

3rd gear 1.5-2psi idle emp (9second mark full spool 2400rpm)
http://www.youtube.com/watch?v=6nB8sPrJsAM

I adjusted the IQ by 1.0 to get rid of some smoke. I like the reduction in smoke, although the power and some of the torque went down, but it's still torque steering so that's good.

4th gear 1.5-2psi idle emp and iq reduced 1mg (4 seconds full spool 2200rpm)
http://www.youtube.com/watch?v=XKEg0-tJBhY


*Sorry the youtube quality really eats away at the boost gauge visual, go hd*

I still had a hard time seeing the boost gauge (even in 720 HD).

3rd gear seems to have ~10 psi more EMP than the 4th gear pull. The gauge is nice and quick to respond as can be seen in the end of the 3rd gear pull so I think the slowness is "real" (not just appearing slow on the gauge). The 4th gear pull looks very nice once it spools up.

I'm not sure I'd worry about a 50 psi emp spike on spool up if it spools up quickly - might be a comprimise to make on a larger turbo? Hopefully not and you figure out what the real issue is.

I wonder if the more vacuum tune was cancelled out by re-adjusting the actuator and you're back to where you started? Maybe leave the actuator alone and put the previous tune back in and see what it does? I'm assuming that "more vacuum" is across the board and not just more on spool up and less everywhere else.

I'm really probably sticking my nose where it does not belong here so please don't take offense to anything. It's really between you and your tuner - I'm just some idiot in the peanut gallery heckling

I still had a hard time seeing the boost gauge (even in 720 HD).

Sorry, thats why I mention when it spools because of the damn vids. It's the glare/sun.

3rd gear seems to have ~10 psi more EMP than the 4th gear pull. The gauge is nice and quick to respond as can be seen in the end of the 3rd gear pull so I think the slowness is "real" (not just appearing slow on the gauge). The 4th gear pull looks very nice once it spools up.

I did change the fuel filters going to the emp gauge so it is responding with less buffer.

I'm not sure I'd worry about a 50 psi emp spike on spool up if it spools up quickly - might be a comprimise to make on a larger turbo? Hopefully not and you figure out what the real issue is.
http://www.youtube.com/watch?v=EsZ8hwDVzho my issue is it settled at 45 I've got another video where it spiked to 60psi =p I had to readjust the sucker.

I wonder if the more vacuum tune was cancelled out by re-adjusting the actuator and you're back to where you started? Maybe leave the actuator alone and put the previous tune back in and see what it does? I'm assuming that "more vacuum" is across the board and not just more on spool up and less everywhere else.
Exactly what I was thinking. I thought I had it nipped in the bud! So I tried a tune with way more vacuum tonight, thing spiked way too much and response wasn't really up. So I put the tune back to where we started in today's videos. I think the response and way its running is at the best compromise, other than wanting to remove more lag. I will try to close the vanes just a tiny tiny bit more.


I'm really probably sticking my nose where it does not belong here so please don't take offense to anything. It's really between you and your tuner - I'm just some idiot in the peanut gallery heckling. I'll take what I can get, we're kind of at a loss at the moment. That's why I hope for as many responses as I can get. I'd say you have some of the best data regarding emp anyways FUB

Jeremy, Why are you so concerned with the EMPs? I'm just curious cause they really don't seem that bad to me, or maybe I'm missing something? I noticed the "lag and not fully requested boost" this time around is a lot more like how mine is responding on occasion.

Does your car only do this when it's below 2,200 rpm or so? If so I would think it's more of a spool up issue and thus you're having such the high spike... however it settling at 45 is a bit confusing??

http://www.youtube.com/watch?v=EsZ8hwDVzho

This video makes me think whatever adjustment was done was in the wrong direction. Higher EMP's all around - both spike and steady state.

Maybe go back one more tune revision?

I assume you've checked all the vacuum components? You get at least 22inHg from the vacuum pump, the vacuum reservoir is in place, check valve is removed (thinking A4 here, don't know if B4's have them), lines and actuator are tight, no leaks and no restrictions?

FUB - thats just tune, then he made adjustments and it turned out like the videos in post 218.

Right - So leave the actuator adjusted as it is and put in the tune previous to the one used in the videos in post 218

I can try to go to the previous tune FUB but my assumption is, even less response with the less vacuum tune...

I still don't understand if a tune that adjusts vacuum or an actuator rod adjusted is the issue here, do they negate each other or is one better than the other to rely on?

B4 doesn't use much vacuum so the reservoir never seemed to make much difference. Never heard of anyone removing the vacuum check valve (a4), is yours from pump towards recirc valve? why come?


@keebler GTB shouldn't be running such high emp vs the 17/22 (in regards to data FUB made) I'm already at the point of overboosting (the extra vacuum tune with 3-4psi emp at idle equals compressor surge). Scariest **** ever. If everyone else running a GTB2260 is getting quicker response than me, why's that is my question.
Really shouldn't see this... but no one else is doing any data points of the GTB2056vk or 2260vk, especially on a rotary...

FUB to clarify if I confused you. in Post #222 video http://www.youtube.com/watch?v=EsZ8hwDVzho and http://www.youtube.com/watch?v=zpsbUPAo1R0 is PRE my latest setup that has put me at my best adjustment so far. It does not spike to 50-60psi emp anymore.

I think I have the sequence/logistics right in my head...The tune with more vacuum generated the 60 psi spikes, but then you adjusted the actuator to get what you have (the best so far) right?

When I removed my EGR valve and anti shutter valve, I removed the check valve just because it didn't seem to serve any purpose anymore. My vacuum system is very simple - Vacuum pump goes to the brake booster, Vacuum reservoir ball and the N75 valve - that's it (and the one hose from the N75 to the VNT actuator).

I'm sure the tuners here will cringe, but the way I see it, when you lay into the throttle, the requested boost increases. To achieve this higher boost pressure (mass airflow actually), the ECU commands the N75 to apply more vacuum to the vanes to close them. Closing the vanes directs the exhaust gasses at the outer tips of the exhaust wheel blades making the wheel spin faster (like blowing on the outside of the pinwheel instead of the center). Closing the vanes also increases the EMP's which accelerates the gasses faster through the vanes spinning the wheel faster as well. By this time the EGT's have risen as some additional fuel has been added which helps build EMP's as well.

Now here is where it gets interesting...Once the EMP's start to rise, boost follows and the tune keeps the vanes closed until requested boost is approached and then it starts to open the vanes to prevent overboost. As requested boost is acheived the vanes open to control boost and let the exhaust breathe again.

If you're at 1500 RPM it will initially close the vanes further than if it's at 2000 RPM or 2500 RPM since there's more airflow and energy in the exhaust at higher RPM and the turbo is already spinning faster.

When you adjust the actuator preload you keep the same shape of the curve but shift how far the vanes travel (within the physical limits of the actuator/vanes). The tune itself can change the shape of the curve as well as the magnitude.

I wonder if on this configuration that the vanes get closed further earlier to get the turbo spooling faster, but then get way out of the way to keep EMP's and boost in control. All the video's have an initial EMP spike, but then hold a relatively high EMP throughout the RPM range. If the vanes closed further initially to get a quick spool, but then opened further as/just before the turbo spools up it might improve things all around?

This is all assuming that the stop screw is properly adjusted on the turbo.

I like the idea of the vanes opening later on to reduce the emp rise, but we'd need a tuner to respond if that can be accomplished in the tune.


I mean that's what a VNT sounds like it should do. Maybe it is and it's just an overwhelming amount of gasses...

N75 map predominates for 1 to 2 sec at the moment of throttle change, after this delay, close loop pressure regulation work to correct vane to make request pressure (boost pressure map).
This is why you see step some time in pressure reaction, like under boost (n75 map)and after rise slowly (close loop) or overboost (n75 map, drop (too big action of close loop because too high) and rise (slow correct of close loop).




Dieseleux

kooyajerms - I accidently found out a bit of a half a$$ed way to maybe trouble shoot your response/EMP issues.

Tee into the line running between your N75 and VNT actuator diaphram. Run a line into the cabin with a vacuum gauge attached to it. Grab another tee and one of the little adjustable aquarium valves to create a leak. If you have a mighty vac or similar, just hook the hose T'd into the actuator to that - it has the gauge and adjustable bypass leak built into it. I have a Snap-On one like this - I'm assuming the mightyvac is similar but plastic?



With the leak fully closed, you should have the same as you had before, but be able to see what the VNT position is doing via the vacuum gauge. Crack the valve open and create a leak in the circuit. This will lower both the peak and steady state vacuum as the N75 has to flow extra air to make up for the leak. See if by adding more/less of a leak if you can get the EMP's and boost pressures under control.

I had some little critter chewing on my vacuum hose and it had a hole in it. I noticed this a couple weeks ago as my vacuum gauge wouldn't go past 15inHg (where it used to go to ~22inHg), EMP spikes were lower than I remember, response was a little slower, but not bad, etc. I've switched back/forth between tunes and just figured that I was loosing my marbles or something. Just this weekend, I had it fail completely and wasn't able to build any vacuum (or boost for that matter) at all. But right before the hose broke in half, I noticed that the boost was a little bit laggy and there was almost zero EMP spike over boost pressure.

It should be a relatively quick/easy way to do some wide range experimenting to get your tune in the ballpark.

Let us know if it works or not

kooyajerms said:

I like the idea of the vanes opening later on to reduce the emp rise, but we'd need a tuner to respond if that can be accomplished in the tune.

Click to expand...

Not a tuner, but an enthusiast .

This should help you understand how the boost control in EDC15 works.



So basically you have the N75 map with predefined values for the N75 valve. If the N75 map value applied to the valve results in boost deviation than a PIDT1 controller activates to compensate the under/over boost. The two outputs of the diagrams as stated by the document are for twin turbo setup with small and large turbo.

DT1-Gedächtnisfaktor, D-Verstärkung, P-Verstärkung, I-Verstärkung - PIDT1 controller configurations
ldmP_Lsoll - target boost
ldmP_Llin - actual boost
ldmADF - atmospheric pressure
ldmM_E - IQ input for the N75 (and some other) map.
dzmNmit - RPM
ldoTVsteu - the N75 duty cycle as determined by the N75 with applied atmospheric pressure correction and air temperature correction. The corrections are necessary because the target boost can be corrected on base of the atmospheric pressure and the air temperature
mrmVERB - fuel consumption
fgm_VzuN - current vehicle speed / RPM (factor used in some maps, like gear based torque limiter)

ldwGRminKL, ldwGRmaxKL - N75 lower and upper limiter tables
ldoGRmin, ldoGRmax - current N75 upper and lower limits

cowLDR_ARW - switch controlling the boost control behavior in the moment when the target and the actual boost get equal

ldwREG0KL, ldwREG1KL - determains weather the PIDT1 controller will activate or the control will be performed only on base of the N75 maps, generally configures the deviation that will activate the PIDT1 controller

Thanks for the info FUB, I believe that's what JFettig's been trying to get me to do.


weird cruising/steady tps
We took a trip to Portland, and first time I noticed this since we came from Ohio. If I spend any time cruising with CC or just with constant TPS (mile or so) the boost and emp start to slowly fall. At a certain point it will be almost zero emp, and maybe 1 psi of boost. Great right? Not when you hit a hill and the vanes won't close at all. The only way to regain "real" power is fully let off the TPS, or turn cruise off to build some EMP and boost. With the vanes all the way open like that power is almost nothing and it smokes. So instead of cruising, and hill climbing, I've been driving like a rabbit with on and off throttle all the way up (in Portland for the weekend). It's less prevalent in 4th, but if I drive long enough it will continue to open the vanes.

Any one experience that with their tune? It really sucks to not have any cruising ability for 1000 miles. It might make more sense if it was only related to the Cruise Control, but even with my foot steady...

What does Malone have to say about it? Maybe you should try another tuner.

I understand Jeff's (RocketChip) going to be at the San Fran GTG in September.

Maybe you should try another tune...?

df

That's not the answer one bit, we are still figuring it out.

Living in Los Angeles, I rarely get a chance to use my cruise control or drive "steady" on the highways for much time. It wasn't like this on the way from Ohio, it's a new thing we noticed.

Here are two videos of vanes slowly opening on steady 80mph driving.

http://www.youtube.com/watch?v=9-y8Fhy0Bhs

http://www.youtube.com/watch?v=g1x03BZjy_0

Hmmm - I had the opposite problem with my setup - the EMP/IMP's kept rising and rising during steady state cruising until you either leaned into the throttle (yes, more throttle, lower pressures - the vanes were commanded open) a little or let off the throttle all together. My actuator was adjusted to start movement at 0inHg and full stroke by ~12inHg. It got better at 4-17inHg, but still does it. Seems to be a function of that particular tune that in light load conditions, it commands the vanes closed, but when you lean into it they open up.

In the first video at about 1minute, when you give it some throttle, it responded pretty quickly - did you back off the throttle and then get back on it to do this?

I wonder if there is a limitation in the B4/1z ECU compared to the later A4/ALH ECUs that give some quirky operation (with wastegate and VNT being fundamentally different in control and operation).

Your dash will look like mine, but get a vacuum gauge on the VNT vacuum line in the cabin so you can see what the ECU is telling the turbo to do.

I'm sure this was asked before, but you're sure the acutator moves freely, diaphram is good, no vacuum leaks, N75 is vented correctly, etc?

At the 1 minute mark it didn't do the strange vane only open situation. I may have gone downhill at that moment and it popped the vanes closed (which it normally does). But if it's been long enough and vanes and boost are low enough, even the downhill won't pop the vane open, and if you try to blip it (without fully letting off the throttle) you won't get much emp/imp to comply and you get low increase in power and or smoke if you request enough.

actuator moves fine with the mityvac (it's used to it with the rod adjustments) Diaphragm is good I'm assuming since it holds vacuum, n75 is vented at the bottom port I believe, only one place I believe there could be a vacuum leak. Anyone confirm that the line that goes to the firewall to the fresh air flapper should hold vacuum? Was diagnosing a non recirculator valve not working.

Actuator arm should start moving at 5 inHg. If yours is opening any less, try 5.

Also, check your duty cycle. It should read no higher than 80% @ 4000 rpm in 4th gear. (I checked mine today in 4th gear, It was at 62%).

You'll need to read into the thread more, we've gone into that before.

Good luck. When you find a fix, let us know.