Low Boost 0%wgdc

Tuning discussion for all first generation Mazda 2.3 MZR DISI Turbo powered vehicles
CounterKilla
Posts: 11
Joined: April 1st, 2020, 10:50 am

Low Boost 0%wgdc

Post by CounterKilla »

Current engine mods: cobb downpipe, cat back exhaust. Sure aeros intake, hpfp.

For some strange reason my car is not making/meeting its boost targets. I am on the high load, high flow downpipe tune and I am only seeing a peak of 13-14 psi. From the logs i have seen it seems like the car is pulling wgdc for some reason. I've checked all of my vaccum lines from the stock bcs and even replaced the stock bcs, did not help. No boost leaks every hose clamp is tight. The logs indicate that the lack of boost is tune/ecu related. Here is an attached log, im not sure if the right parameters are checked. Sorry its 3rd gear.
Attachments
3rd gear wot.zip
(7.55 KiB) Downloaded 248 times
mituc
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Posts: 1324
Joined: December 17th, 2011, 2:47 pm
Location: Iasi/Romania

Re: Low Boost 0%wgdc

Post by mituc »

Your log doesn't contain essential logging items for looking at this problem such as engine RPM, load, mass air flow, throttle position - at minimum.
From the looks of it at this point you seem to have a huge boost leak post turbo. Huge as it coupler broke off of the clamps and is hanging in there.
2008 Cosmic Blue Mazda 3MPS
Built engine + WMI + GTX3071 gen2, ~509BHP @34PSI
2008 Icy Blue Mazda CX7
Stock engine and exhaust (YES!!), JBR3" + GTX2867 gen2 + Autotech HPFP, self-tuned to 330-ish BHP
CounterKilla
Posts: 11
Joined: April 1st, 2020, 10:50 am

Re: Low Boost 0%wgdc

Post by CounterKilla »

But why would the ecu be pulling wgdc instead of compensating with more, it stays at 0% virtually the whole time
mituc
VersaTuner guru
Posts: 1324
Joined: December 17th, 2011, 2:47 pm
Location: Iasi/Romania

Re: Low Boost 0%wgdc

Post by mituc »

Well, it's not 0 all the time, in your log the peak is 66% actually even if it's different than 0 only in a few cells. But because from your log there is absolutely no way to tell when the car is actually accelerating or doing something it's hard to tell what's going on.
The only indication is that when the manifold pressure increases the AFRs go rich indicating a leak. Also the fuel trims are negative meaning that the ECU is pulling fuel to compensate for measured air that isn't there any more.
2008 Cosmic Blue Mazda 3MPS
Built engine + WMI + GTX3071 gen2, ~509BHP @34PSI
2008 Icy Blue Mazda CX7
Stock engine and exhaust (YES!!), JBR3" + GTX2867 gen2 + Autotech HPFP, self-tuned to 330-ish BHP
CounterKilla
Posts: 11
Joined: April 1st, 2020, 10:50 am

Re: Low Boost 0%wgdc

Post by CounterKilla »

i will post another log with the required parameters when i get a chance
CounterKilla
Posts: 11
Joined: April 1st, 2020, 10:50 am

Re: Low Boost 0%wgdc

Post by CounterKilla »

Heres a much better log with the right parameters. Please help me figure out this issue.
Attachments
3rd gear wot 2.zip
(4.74 KiB) Downloaded 230 times
CounterKilla
Posts: 11
Joined: April 1st, 2020, 10:50 am

Re: Low Boost 0%wgdc

Post by CounterKilla »

Unless there is a masisve hole in my stock tmic, theres no boost leak, both couplers are rip and hole free and very tight. Pulled everything off yesterday to double check. Stock bpv is in working order, swapped with a buddy and had the same issue still. Car compression tests good, no smoke, no abnormal oil consumption.
mituc
VersaTuner guru
Posts: 1324
Joined: December 17th, 2011, 2:47 pm
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Re: Low Boost 0%wgdc

Post by mituc »

So two things:
1. in your last log we can see that while you still were in closed loop cruising the fuel trims were pretty big in negative numbers. This means that the ECU is pulling fuel because the MAF sensor reports that is measures more air than it actually goes into the engine. And this can be seen in that log, even at <10% APP the AFRs are even below 14 while in those situations they should be 14.7 dead.
2. the boost is barely hitting 1BAR/14.5PSI around 4k rpm, usually it's well below that. if it wasn't for the stock tune (or stock-ish tune) AFR corrections up to 2.5load you'd see now AFRs well below 8, by my estimations no more than half of the air measured by the MAF makes it into the engine. So it would be bad. If that is a 3rd gear log then you went WOT from about 60Kmph to about 100Kmph, which is what 3000-5000rpm gives. That took about 3 seconds while at the loads displayed in the log these cars would do 80-120Kmph (50-75mph) in about 2.4-2.5s.

If it wasn't for those fuel trims and the very slow 3000-5000rpm pull I would be tempted to blame your MAP sensor.
I understand that you pulled everything and put it back in, but that may not be the right way to check for leaks. The right way is to pressurize the whole intake.
This is something you can build or put together with a lot less money but just to make an idea this is how it looks like: https://turboboostleaktesters.com/mazda ... k04-turbo/
2008 Cosmic Blue Mazda 3MPS
Built engine + WMI + GTX3071 gen2, ~509BHP @34PSI
2008 Icy Blue Mazda CX7
Stock engine and exhaust (YES!!), JBR3" + GTX2867 gen2 + Autotech HPFP, self-tuned to 330-ish BHP
CounterKilla
Posts: 11
Joined: April 1st, 2020, 10:50 am

Re: Low Boost 0%wgdc

Post by CounterKilla »

Here's the thing. I have a 3inch sure aeros intake so im assuming thats why the maf numbers are off. I ran a stock intake on the same tune and the car ran like complete garbage even after a reflash. I did a pressure test and everything holds, both couplers are in superp condition. This morning i discovered that the lines to the stock bcs were reversed. I flipped them and was happy thinking it would fix my problem. I reflashed and now the car is only making spring pressure(10psi). Can a bad maf cal such as the one I have be causing all this, and if so why did the car run terrible with the stock intake.
mituc
VersaTuner guru
Posts: 1324
Joined: December 17th, 2011, 2:47 pm
Location: Iasi/Romania

Re: Low Boost 0%wgdc

Post by mituc »

If the problem was the MAF cal (and will be a big problem when you will fix the current issue) the fuel trims will be positive. In your case they are negative.
Last edited by mituc on April 8th, 2020, 11:15 pm, edited 1 time in total.
2008 Cosmic Blue Mazda 3MPS
Built engine + WMI + GTX3071 gen2, ~509BHP @34PSI
2008 Icy Blue Mazda CX7
Stock engine and exhaust (YES!!), JBR3" + GTX2867 gen2 + Autotech HPFP, self-tuned to 330-ish BHP
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