Stage 1 + SF intake...AND no A/F problems?

[XTi24]

How many of you are stage 1 + SF and are seeing normal A/F Learning numbers?

I have a 2012 WRX flashed to Cobb Stage 1 (93 octane) + SF OTS map, with a Cobb SF intake installed. I used the Cobb Stage 1 + SF map in conjunction with an AP.
I found that my A/F was REALLY off, so I started searching and the only Stage 1 + SF threads I could find between here, iwsti, nasioc, and 2 other WRX sites are people seeing bad A/F numbers or knock with stage 1 + SF.

So I'm wondering how many of you are running the SF intake without problems and have good looking logs to prove it.

[Heide264]

I'll state the obvious, but check for any leaks. Consider cleaning the MAF possibly. Lastly, contact Cobb about it.

I wouldn't be surprised to see some A/F learning, however. Things such as temperature changes and altitude changes will change your fuel trims. At idle, they are quite touchy.

What are we talking here when you say "bad A/F numbers"?

[XTi24]

This is at idle (the value for "C" is WAY off):

A/F Learning 1: -2.3
A/F Learning 1 A: -2.5
A/F Learning 1 B: -2.1
A/F Learning 1 C: -11.4
A/F Learning 1 D: 0.0

I've already gotten the "check for boost leak" advice from Bill@COBB, but I'm not really thinking he's going to tell me "we haven't had anybody use the SF intake and get good numbers..." he's going to try to tell me how to troubleshoot (I mean no disrespect there, Bill has been very helpful thus far. Cobb is, however, a business. I doubt they'd just straight up tell me if the majority of people who bought it were having problems with their intake and their tune together.). The problem is I never see any of those troubleshooting threads end up with "found the boost leak, everything is fine now." And I definitely didn't see any threads saying "just installed Stage 1 + SF on my GR WRX and my logs look great!"

So, I'm doing a bit of my own troubleshooting as well as doing what he told me to do.

BTW, here is the log he saw that made him ask more questions...

https://docs.google.com/spreadsheet/...=sharing#gid=0

[zax]

Yeah, C is a little off (that's your primary cruise typically -- 25-50g/s). I know it's difficult to populate, but I would try to fill Column D (>50g/s). One thing to note is that stoich on winter gas is usually about 14.1:1 -- E10 which is about 4% off, so you'll notice your LTFT will adjust to compensate for this 4% by adding more fuel. Also, it's likely that the SF intake behaves just a little different from stock.

Are you using a Cobb stage 1 map?

[XTi24]

Yeah, C is a little off (that's your primary cruise typically -- 25-50g/s). I know it's difficult to populate, but I would try to fill Column D (>50g/s). One thing to note is that stoich on winter gas is usually about 14.1:1 -- E10 which is about 4% off, so you'll notice your LTFT will adjust to compensate for this 4% by adding more fuel. Also, it's likely that the SF intake behaves just a little different from stock.

Are you using a Cobb stage 1 map?

Here is a copy and paste from my original post:

"I have a 2012 WRX Stage 1 (93 octane) with SF intake installed..."

And, yes, it is a Cobb OTS stage 1 93 octane + SF map from Cobb's website.

BTW, I didn't understand half of the words in your post, lol. I know absolutely nothing about tuning cars. I just know what Bill@COBB told me when I posted my log. He said column C was extreme. He never mentioned column D...I know nothing.

[zax]

Here is a copy and paste from my original post:

"I have a 2012 WRX Stage 1 (93 octane) with SF intake installed..."

And, yes, it is a Cobb OTS stage 1 93 octane + SF map from Cobb's website.

BTW, I didn't understand half of the words in your post, lol. I know absolutely nothing about tuning cars. I just know what Bill@COBB told me when I posted my log. He said column C was extreme. He never mentioned column D...I know nothing.

Getting cranky doesn't lend to me wanting to assist you. "Stage 1" is universally used to describe a car with a tune. It's important to understand WHICH stage 1 map you've flashed, which was not stated in the initial e-mail. Given the fact that Cobb now offers separate maps for Stock airbox and SF intake leads me to believe the new GR cars respond differently to the Cobb SF intake the previous years, and would explain why another stage 1 map intended for the stock MAFv scaling is not ideal.

Good luck with your car.

[XTi24]

Getting cranky doesn't lend to me wanting to assist you. "Stage 1" is universally used to describe a car with a tune. It's important to understand WHICH stage 1 map you've flashed, which was not stated in the initial e-mail. Given the fact that Cobb now offers separate maps for Stock airbox and SF intake leads me to believe the new GR cars respond differently to the Cobb SF intake the previous years, and would explain why another stage 1 map intended for the stock MAFv scaling is not ideal.

Good luck with your car.

I actually wasn't being cranky, sorry if it sounded that way, though. It's tough to tell on the internets.

I guess ending your post with "Good luck with your car." means that you're done helping me because you think I was being a wise arse. Hopefully you're not that quick to decide, because it sounds like you know a ton more about tuning than I do.
My post wasn't meant to be cranky, I was trying to make sure you knew how ignorant I am when it comes to tuning. You have to talk dumb to me about tuning or I won't get it (not condescending, just dumb it down, lol). And you're very right, in my ignorance, I did not specify which type of tune I was using...that is very important for anyone wanting to be helpful. Thank you for pointing that out. I edited the OP to include that information.

Let's not become another statistic in the internet forum wars.

[Heide264]

There is definitely some detonation there (at least your ECU thinks so), and not in a good spot. At WOT (wide open throttle), however, your ECU has no way of knowing if your fueling is correct or not.

Try logging a longer drive (20 minutes or so) with steady throttle inputs. Don't go into wide open throttle or anything. Just driving around town and maybe a bit of high way cruising. Log your A/F Correction 1 and A/F Learning 1, as well as your MAF(V) and RPM.

The issue here is that without a wideband o2 sensor, wide open throttle becomes nearly useless in terms of troubleshooting fueling. The stock o2 sensor isn't accurate under boost pressure, and the ECU works around that by going into an open loop fueling method... with some corrections applied that it learned during normal driving.

Basically, under normal driving (very little if no boost), the car will read the air/fuel ratio and will "learn" some fueling trims (LTFT = long term fuel trim = A/F Learning, STFT = short term = A/F Correction) to bring the ratio back to around stoich (14.7 afr). This is called closed loop fueling (if you know anything about control systems, this makes a lot of sense).

Under heavy loads, where the stock sensor isn't accurate and things may be moving too quickly for it anyhow, the ECU does what it can. It reads in a MAF voltage, looks at your MAF scaling, and injects whatever fuel it thinks it should. There is no feedback to the ECU that it is correct or not (aside from any detonation). It will take into account the fuel trims that were learned during closed loop driving, however.

So basically, make a log as I explained above. Afterwards, you can add together A/F Learning and A/F Corrections in excel and plot them against MAF(V). You will be able to see if your MAF is scaled correctly or not against various MAF voltages. You can also plot the fuel trims against RPM to see if it is an RPM dependent fueling issue for example.

[EJ257]

This is at idle (the value for "C" is WAY off):

A/F Learning 1: -2.3
A/F Learning 1 A: -2.5
A/F Learning 1 B: -2.1
A/F Learning 1 C: -11.4
A/F Learning 1 D: 0.0

I've already gotten the "check for boost leak" advice from Bill@COBB, but I'm not really thinking he's going to tell me "we haven't had anybody use the SF intake and get good numbers..." he's going to try to tell me how to troubleshoot (I mean no disrespect there, Bill has been very helpful thus far. Cobb is, however, a business. I doubt they'd just straight up tell me if the majority of people who bought it were having problems with their intake and their tune together.). The problem is I never see any of those troubleshooting threads end up with "found the boost leak, everything is fine now." And I definitely didn't see any threads saying "just installed Stage 1 + SF on my GR WRX and my logs look great!"

So, I'm doing a bit of my own troubleshooting as well as doing what he told me to do.

BTW, here is the log he saw that made him ask more questions...

https://docs.google.com/spreadsheet/...=sharing#gid=0

Listen to Bill...you're not hitting target boost, and your car is having to pull fuel, which could indicate a leak. I would start by checking the TMIC/BPV.

You don't fix a mechanical issue with tuning.

As for not seeing people say "Found my boost leak, everything's great"...people will come on seeking help, get an answer, and not post back. It happens a lot on online forums, if they're not a somewhat regular member. What sucks is that it makes it difficult for people who find a thread by searching to find credibility.

[XTi24]

There is definitely some detonation there (at least your ECU thinks so), and not in a good spot. At WOT (wide open throttle), however, your ECU has no way of knowing if your fueling is correct or not.

Try logging a longer drive (20 minutes or so) with steady throttle inputs. Don't go into wide open throttle or anything. Just driving around town and maybe a bit of high way cruising. Log your A/F Correction 1 and A/F Learning 1, as well as your MAF(V) and RPM.

The issue here is that without a wideband o2 sensor, wide open throttle becomes nearly useless in terms of troubleshooting fueling. The stock o2 sensor isn't accurate under boost pressure, and the ECU works around that by going into an open loop fueling method... with some corrections applied that it learned during normal driving.

Basically, under normal driving (very little if no boost), the car will read the air/fuel ratio and will "learn" some fueling trims (LTFT = long term fuel trim = A/F Learning, STFT = short term = A/F Correction) to bring the ratio back to around stoich (14.7 afr). This is called closed loop fueling (if you know anything about control systems, this makes a lot of sense).

Under heavy loads, where the stock sensor isn't accurate and things may be moving too quickly for it anyhow, the ECU does what it can. It reads in a MAF voltage, looks at your MAF scaling, and injects whatever fuel it thinks it should. There is no feedback to the ECU that it is correct or not (aside from any detonation). It will take into account the fuel trims that were learned during closed loop driving, however.

So basically, make a log as I explained above. Afterwards, you can add together A/F Learning and A/F Corrections in excel and plot them against MAF(V). You will be able to see if your MAF is scaled correctly or not against various MAF voltages. You can also plot the fuel trims against RPM to see if it is an RPM dependent fueling issue for example.

This is exactly the kind of explanation I was hoping for. Thank you for explaining it so well. Good stuff. I know nothing about control systems, but it still makes sense to me the way you explained it.

I will log part of my 30min drive home (which includes stoplights, side roads, and highways with anywhere from 25mph to 60mph speed limits).

[Heide264]

This is exactly the kind of explanation I was hoping for. Thank you for explaining it so well. Good stuff. I know nothing about control systems, but it still makes sense to me the way you explained it.

I will log part of my 30min drive home (which includes stoplights, side roads, and highways with anywhere from 25mph to 60mph speed limits).

That being said, I do agree with EJ above. This does sound like a mechanical issue to be honest. I have a feeling ya have a boost leak somewhere along the lines. Doing the log isn't a bad idea regardless.

[XTi24]

Listen to Bill...you're not hitting target boost, and your car is having to pull fuel, which could indicate a leak. I would start by checking the TMIC/BPV.

You don't fix a mechanical issue with tuning.

As for not seeing people say "Found my boost leak, everything's great"...people will come on seeking help, get an answer, and not post back. It happens a lot on online forums, if they're not a somewhat regular member. What sucks is that it makes it difficult for people who find a thread by searching to find credibility.

I fully intend to do what Bill recommends...I'm just already planning my next move if I can't find a boost leak. I'm going to be taking the intercooler/TB coupler off tomorrow to reinstall it with a clamp instead of just the glue or whatever they put on it from the factory, since many people suggest that.

Also, I guess I should add that I did just get a report back on another forum of someone who "listened to Bill, found the leak at the intercooler/TB coupler area, fixed it, and now all is well."

So, now I have more hope in that process than I did before.

[EJ257]

I fully intend to do what Bill recommends...I'm just already planning my next move if I can't find a boost leak. I'm going to be taking the intercooler/TB coupler off tomorrow to reinstall it with a clamp instead of just the glue or whatever they put on it from the factory, since many people suggest that.

Also, I guess I should add that I did just get a report back on another forum of someone who "listened to Bill, found the leak at the intercooler/TB coupler area, fixed it, and now all is well."

So, now I have more hope in that process than I did before.

The TMIC/BPV section of the '08+ WRX has issues. Not everyone logs the base map, some people just flash and go, and would have no idea. Not everyone reaches out to Cobb about the problem. Not everyone gets to talk to Bill. Then there's the people I described before.

My $ would be on a mechanical problem. Reset the ECU when you perform that "fix" and then start logging again. In the future, disable Dynamic Adv (°); we have DAM and Ignition Timing, which is all we care about (the amount of advance isn't really important, and is wasting bandwidth).

[XTi24]

The TMIC/BPV section of the '08+ WRX has issues. Not everyone logs the base map, some people just flash and go, and would have no idea. Not everyone reaches out to Cobb about the problem. Not everyone gets to talk to Bill. Then there's the people I described before.

My $ would be on a mechanical problem. Reset the ECU when you perform that "fix" and then start logging again. In the future, disable Dynamic Adv (°); we have DAM and Ignition Timing, which is all we care about (the amount of advance isn't really important, and is wasting bandwidth).

Got it...you can call me number one, because I'm about to make it so.

[XTi24]

There is definitely some detonation there (at least your ECU thinks so), and not in a good spot. At WOT (wide open throttle), however, your ECU has no way of knowing if your fueling is correct or not.

Try logging a longer drive (20 minutes or so) with steady throttle inputs. Don't go into wide open throttle or anything. Just driving around town and maybe a bit of high way cruising. Log your A/F Correction 1 and A/F Learning 1, as well as your MAF(V) and RPM.

The issue here is that without a wideband o2 sensor, wide open throttle becomes nearly useless in terms of troubleshooting fueling. The stock o2 sensor isn't accurate under boost pressure, and the ECU works around that by going into an open loop fueling method... with some corrections applied that it learned during normal driving.

Basically, under normal driving (very little if no boost), the car will read the air/fuel ratio and will "learn" some fueling trims (LTFT = long term fuel trim = A/F Learning, STFT = short term = A/F Correction) to bring the ratio back to around stoich (14.7 afr). This is called closed loop fueling (if you know anything about control systems, this makes a lot of sense).

Under heavy loads, where the stock sensor isn't accurate and things may be moving too quickly for it anyhow, the ECU does what it can. It reads in a MAF voltage, looks at your MAF scaling, and injects whatever fuel it thinks it should. There is no feedback to the ECU that it is correct or not (aside from any detonation). It will take into account the fuel trims that were learned during closed loop driving, however.

So basically, make a log as I explained above. Afterwards, you can add together A/F Learning and A/F Corrections in excel and plot them against MAF(V). You will be able to see if your MAF is scaled correctly or not against various MAF voltages. You can also plot the fuel trims against RPM to see if it is an RPM dependent fueling issue for example.

Here is the longer log as you requested:

https://docs.google.com/file/d/0B3R4...it?usp=sharing

I will be working on the intercooler coupler tomorrow, so hopefully the results of this log will be moot in a day or two.