Power being pulled, Turbo LQ4

[Drastius]

Hello,

Looking for some advice on what might be reducing my power in my first turbo LQ4 build.

Currently I have an LQ4 with an 80 mm VSracing turbo, I followed some of the guides on these forums for wideband VE tuning and I seem to have a decent air fuel ratio (hopefully).
The problem is now I'm looking to get into boosted regions, and power is getting pulled when I'm half throttle or more. Car feels strong with 1/4 throttle but the power drops once I add more throttle (log attached, with the tune file)

Does this look like a knock/timing issue? Or am I running into something else. I have knock retard going on, but way more power is being pulled than I expect. Once I'm past half throttle, the car feels like it has 150 hp.

Car: 87 Rx7
Trans: TR6060
Engine:
LQ4 with forged .020 over pistons
Deatchwerks fuel injectors and matching pump
AEM wideband
HPTuners 2 Bar SD OS on a red/blue PCM

Thanks in advance if you can provide any assistance.

[5FDP]

Clean up that VE table, use that smooth function more. It's way too choppy and spiky.

Your PE and BE aren't setup right and aren't helping you.

Raise the PE MAP kpa to 85kpa. Lower your pedal enable way down to like 50 or 60% throttle. Remove that 5,500rpm delay, set that to 0rpm, set the time delay to 0 seconds.

Zero out the BASE fuel spark adder table. Only use the high/low timing tables with no adder for base fuel. Zero out the EGR table too.

Disable burst knock. Set the Enable Delta Cyl Air table to 7.900.


Fix your coolant temps too. That is not helping with knock retard on pump gas. You are pushing 225-240 degrees the whole time. You need to running down around 190-200 to better help this engine.

Also if you have any pending or current knock sensor codes that will pull the max allowed timing and rob a bunch of power.

Do those changes and see where you stand.

[blindsquirrel]

What MAP sensor? Does it just happen to have the same linear/offset as the default values that get filled in when you apply the 2-bar OS, or have you not yet changed it to match the actual sensor in use?

Why is Dynamic Hi RPM Disable still set to 4,000 if there is no MAF sensor?

Engine-Torque Management-General-RPM vs Gear and Max Torque
Somehow you managed to enter values there way above the maximum limit of 640lb-ft.

ETC TPS Max somehow got set to all zeros instead of all 100s.

Brake TqMgt is still enabled.

[Drastius]

Thanks for the reply, I've done most of what you suggested.

- used the smooth feature on the VE table
- Raised PE map and lowered pedal percent
- removed PE delay
- zeroed base spark and egr spark table
- disabled burst knock

No knock sensor codes and I'll have to improve my rad airflow situation and maybe drop in a cooler thermostat to help with cooling.

Bad news is a did a pull with the new settings, and the same thing happened. What is weird is my MAP sensor is showing 60 kPA with engine off key on. Something is wrong, atmospheric here is 90 kPa.

One question, what is BE?

[Drastius]

Thanks for looking at my issue, 12516135 is the 2 bar Map sensor I'm using. From what I have read, I have the proper offset and slope.

That being said when you brought this up, I noticed my key on engine off value for the map sensor is 60 kPa, should be 90 kPa.

I'll dig into this.

Also most of these settings should be there from the 2 bar Map OS upgrade. Other than the engine torque management settings have probably been altered to help find this issue.

I'll update the tune with your suggestions after I diagnose this map sensor.

[Lakegoat]

12615136 is a GM 2 bar Map sensor. I don't know what that number is for---12516135

[Drastius]

You're right, I pulled off some dyslexia there. It is 1261536.

[Drastius]

I wasted some time diagnosing the MAP sensor, turns out the 2 Bar MAP reading doesn't work when the engine is off. It held a value of 60 after I shut the car off.
If I look at the SAE map sensor value, it correlates well with atmospheric pressure.

So back to the drawing board to figure out what the problem is. I completed most of the suggested changes and pulled off another log.
V3.30 Oct 3.hptOct 3.hpl

[5FDP]

Does the car have solid engine mounts?

With that much knock it's gotta be picking up a vibration or something. I really only see that much knock if there is a vibration or the knock sensors have issues with pending codes. Usually turning off the knock sensor codes stops the timing pull if there were codes.

[Lakegoat]

I wasted some time diagnosing the MAP sensor, turns out the 2 Bar MAP reading doesn't work when the engine is off. It held a value of 60 after I shut the car off.
If I look at the SAE map sensor value, it correlates well with atmospheric pressure.

So back to the drawing board to figure out what the problem is. I completed most of the suggested changes and pulled off another log.
V3.30 Oct 3.hptOct 3.hpl

To check the MAP sensor---With the engine off, turn the key to the on position only, start the scanner and see what the map sensor reads. Should be around 100. The offset for that map sensor is 8.00 instead of 10.

[Drastius]

Does the car have solid engine mounts?

With that much knock it's gotta be picking up a vibration or something. I really only see that much knock if there is a vibration or the knock sensors have issues with pending codes. Usually turning off the knock sensor codes stops the timing pull if there were codes.

Not solid, but very thin engine mounts that Grannys speed shop used to sell for RX7 conversions. I doubt they are good a dampening vibration.

[Drastius]

To check the MAP sensor---With the engine off, turn the key to the on position only, start the scanner and see what the map sensor reads. Should be around 100. The offset for that map sensor is 8.00 instead of 10.

That's what threw me off the first time. That trick doesn't work with the 2 Bar Map sensor channel. In my situation, the 2 Bar Map sensor will read 0 doing what you described. I can see the MAP sensor voltage and the SAE Map sensor reading with key on/engine off but not the 2 Bar map sensor reading. That only updates once the engine is running, not sure why.

[Pekka_Perkeles]

That's what threw me off the first time. That trick doesn't work with the 2 Bar Map sensor channel. In my situation, the 2 Bar Map sensor will read 0 doing what you described. I can see the MAP sensor voltage and the SAE Map sensor reading with key on/engine off but not the 2 Bar map sensor reading. That only updates once the engine is running, not sure why.

That's right, had the same issue using 2 bar. With 1 bar it works, though.

[Carlfromkerikeri]

Try turn key on, start scanning, flick key to crank starter for split second without actually starting, see if that reads map