Confusing boosting issue

GenpuMike

GenpuMike

Greenie N00B Member
Good evening guys, I recently put a new CST4 turbo in my car with all supporting mods, the car ran fine for the first month it was in. All of sudden, my wonderful car went from making around 18-20psi to abour 11-13psi. I ran over everything, no boost leaks, replaced my 3 port EBCS, and the turbo seems to be fine as far as shaft play goes. However, I shortened the Wastegate arm which put me back up around 15-17psi on my tune with 0 WGDC provided by Nishan. When i put it back onto the tune it was just on, I was making nearly identical boost, i've been stuck with this head ache longer than I would want to admit, any help is immensely appreciated.
 

Attachments

If you shortened the arm, you adjusted preload. That will definitely effect your boost. If your tuner did not adjust for the preload change, you will definitely see a change in boost pressures.
 
I didn't adjust it until the car abruptly dropped 6psi, I would check with nishan but hes left me hanging for 2 months now.
 
Adjusting the preload seems like a recipe for disaster. If your car was functioning properly until something happened and you increased preload, if you manage to find whatever your problem is, you'll be overboosting to the moon.

You've basically failed to diagnose the problem properly and instead, you've performed a workaround that doesn't solve the underlying issue. I would strongly recommend putting the preload back to where it was before you messed with it. Then actually ensure that the EBCS is plumbed properly, has good signal, and so forth. Right now, I see nothing in your logs that indicates a problem other than your statement that boost pressure isn't where it is supposed to be according to your map.

Moreover, the fact that you changed your preload makes it very difficult to make an apples-to-apples comparison between datalogs, as you've changed a physical parameter with unknown effect.

I don't know what kind of map you requested from Nishan, or what he told you he was going to build for you, but right now, it kind of looks like it might be a load-tuned map. If so, your boost fluctuations *could* be related to intake and boost air temperature differences (but of course, you also took the logs in different gears, so again, you've got additional variables to consider and which make the diagnosis challenging).
 
Is the Old log when the car was running as expected and the "New Log" after you did the preload adjustment? I don't see a 6psi difference like you said, I see a 2-3 psi difference. I'm assuming the car feels way slower or are you just seeing this boost number difference and assuming it's a problem?

Without knowing what your boost/load targets are set to it's hard to say what, if anything is up. Your Calculated Load values all look pretty similar and if your tune is only calling for 2.1-2.2 load, then it's not going to ask for more WGDC to make more boost. That's the benefit of a load tune, you can set it to what you want it to make and not have to worry about it using the same boost targets in the winter and the summer and having a huge difference in power/airflow. 20psi is a very different amount of airflow when you account for temperature and elevation differences, so try not to just look at boost values as your only measure of power.

You need to figure out what your load targets are set to if you're running a load based tune, which is how I'm assuming you're set up.
 
Yes the old map was the one prior to my car acting up. As for the pre-load adjustment, I will put it back to exactly how it was once i am home from work and send a log your way. Thanks for dealing with me guys.
 
  • Like
Reactions: Sho
Okay guys, I put the rod back into its normal place and ran 2 logs on it(and by normal place i mean how it was prior to me cranking it the fuck up). What is confusing me is that now, my ZERO WGDC log is showing that i am making more boost than i am on my most recent reflash from Nishan. I would like to mention I am catless, and have no CEL's.
 

Attachments

So what we've found out so far is:
  • Whether you're commanding 0 WGDC or 60ish WGDC boost is not increasing.
  • When you manually adjust your preload you're getting more boost

What that tells me is you definitely have a boost leak or a boost controller issue. You're only able to make spring pressure and when you adjust preload that increases it by a few PSI which would be expected.

You say that it just started happening out of nowhere. There weren't any changes that caused this to happen that you can think of? I had weird boost issues that were caused by splitting in the hose between my boost controller and my wastegate actuator and that also did not show on a boost leak test. I know it sounds like we're beating a dead horse, but you're absolutely positive all of the lines on your boost controller are good and you've configured it correctly? I'd also check the electrical connection for the boost controller to the harness. This honestly sounds like the boost controller just isn't plugged in or something and it's just running on spring pressure.

Check it out and report back.
 
Hi everyone, new to these forums but I was a member of MSF before it shut down. I am experiencing the same exact issue mentioned by OP. My CST4 gets up to ~13psi at 0 WGDC then starts dropping psi as I climb up to 50 WGDC where it doesn'thold more than~8psi. I've got all supporting mods (TB exhaust, hpfp, ETS TMIC, intake, bpv, boost/bypass tubes, JBR 3port ebcs, etc.) , purchased new, but haven't been able to solve the issue. Unfortunately I never got more than 13psi even after freshly installing the parts. OP.... did you ever solve your problem? If so, what was it? Really appreciate the insight.

Ps I'm currently in the tuning process with Justin @ Freekrune.
 
@Rod4893 welcome to mso! What routing are you running on your ebcs? Also is this your first map with freektune? Because if it is 13psi is close to spring pressure which makes sense that I would be that and taper off as Justin checks maf cal and timing. Meaning you'll get more boost in future revisions, what has Justin said about your logs?

Make sure your vacuum lines to ebcs are snug and not leaking.
 
Awafrican said:
@Rod4893 What routing are you running on your ebcs? Also is this your first map with freektune?... what has Justin said about your logs?Make sure your vacuum lines to ebcs are snug and not leaking.
Click to expand...

Hey man, thank you! I'm on my 3rd revision, Justin actually brought this issue to my attention and said I "might" have a wastegate problem. I'm running 3port the way JBR installation instructions directed. I will post a pic later today for feedback!
 
Hi Again, here is the image. I tried my best to color coordinate the 3 different routing to facilitate identification.
1. Red - Connects to a 'T' and is routed under a couple of wires. One side of the 'T' gets connected to the BPV, the other goes to the intake manifold.
2. Green - Connected to the Wastegate (top nipple, in the image you can see i have the other nipple plugged off).
3. Orange - Connected to the Turbo inlet

Here is the link to CST4 installation PDF (https://corksport.com/support/instructions/GEN-6-777-WEB.pdf ), page 29 shows how to route the CS EBCS, but since I used the JBR EBCS I actually referenced page 7 of the JBR link, HERE:
http://jamesbaroneracing.com/support/JBR Mazdaspeed TRU-Boost EBCS Installation Instructions.pdf
 

Attachments

  • JBR EBC 3port set up.jpg
    JBR EBC 3port set up.jpg
    269.1 KB · Views: 25
I think you have the wastegate and boost reference swapped, looking at the you posted red appears to be theft of ebcs which you said is boost ref ,(T into bpv live) JBR shows that it should be the middle port and the wastegate should on the left
@JohnnyTightlips please confirm
 

Attachments

  • Screenshot_20200821-085657.png
    Screenshot_20200821-085657.png
    952.6 KB · Views: 10
That is my fault! I had the color references mixed up in my 1st image, now revised. Apologies for wasting your time.
Red = center of EBCS, routed to the 'T'
Green = Left side of EBCS, routed to WG
Orange = Right side of EBCS, routed to TIP

After checking this out today, I noticed that one of the plugs on the turbo is actually loose and slides even with the Zip tie, but DOES NOT come off. I added a new photo about that here. Could this be the culprit? All other hoses seem to be snug in place, this is the only one that can literally slide right off.
 

Attachments

  • JBR EBC 3port set up.jpg
    JBR EBC 3port set up.jpg
    312.2 KB · Views: 25
  • Turbo notes.jpg
    Turbo notes.jpg
    115.2 KB · Views: 26
  • 3rd gear_1.xlsx
    3rd gear_1.xlsx
    72.5 KB · Views: 3
Last edited:
JohnnyTightlips said:
Use the turbo as your boost source. You will want to do 3 port...

1 to turbo inlet pipe
2 wastegate
3 turbo
Click to expand...

Hey sir, thanks a lot for the feedback! I made the change today. The line I had connected to the T I switched to the turbo instead, the other two lines I left as is. Unfortunately it did not resolve my boost issue though.
 
Simple but silly check, ebcs electronic connection is fully connected right? Past that seems like it's probably time to check for boost leaks. How are you LTFTs?
 
You must log in or register to reply here.
Back
Top