Over Boosting, Questions

5036 Views 21 Replies 4 Participants Last post by drifit89, Mar 24, 2015

JS Auto Designs Jake

Discussion Starter · Aug 15, 2013

2013 STi

Turbo Back Exhaust, AEM Intake Accessport

Running the 91 Stage 2 + AEM LWG OTS tune

I was running the Normal tune but was over boosting to almost 18 in S mode

Well changed to the LWG. Still getting the same data logs. Just a little knock at tip in but clean through the pull, but got up to over 18psi.

Now it was only 51 degrees this morning so Im wondering if that is what caused it and everything is actually ok.

THoughts, concerns, help?

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1 - 20 of 22 Posts

jetpilot116

· #2 · Aug 15, 2013

For thoughts:
Under what conditions are you hitting this boost level? What gear/RPM? I know that in higher gears in a low RPM range, if you mash the throttle it is more prone to boost creep. Are you catted or catless? There are a lot of factors that are unknown here.

For concerns... get a protune. :tup:

JS Auto Designs Jake

Discussion Starter · #3 · Aug 15, 2013

i know I need to protune. Just no tuners close to this area.

Catted down pipe. All pulls in 4th gear and it was in the 5000 rpm range where I was seeing the over boost

JS Auto Designs Jake

Discussion Starter · #4 · Aug 15, 2013

i really think there is something wrong with the maps bnecause the waste gate duty cycle dropped to like 9 at like 4500 and thats where the overboosting started.

jetpilot116

· #5 · Aug 15, 2013

Probably the best thing to do is post a full log so we can see what is happening. Have you thought about an E-tune? They are becoming very popular and convenient for people in more remote locations. I'll PM you.

JS Auto Designs Jake

Discussion Starter · #6 · Aug 15, 2013

https://docs.google.com/file/d/0B-77T5xTTtP5WTNCZy1sSmpPSXc/edit?usp=sharing

COBB Tuning

· #7 · Aug 15, 2013

JS Auto Designs STi said:
i really think there is something wrong with the maps bnecause the waste gate duty cycle dropped to like 9 at like 4500 and thats where the overboosting started.

There's nothing wrong with the map - the ECU is actively dropping wastegate duty at around 4000+ RPM because you are overboosting. This is the ECU attempting to bring boost levels down (lower wgdc = less boost). However, it is having no effect which means that you have a mechanical issue that is causing the overboost condition - one that the ECU cannot control. This means that a custom tune will do you absolutely no good in this case. This really looks like a classic case of boost creep, especially if it started occurring with colder outside temperature (assuming you do not have issues with the boost control hardware). Boost creep can be solved by an external wastegate + custom tune or possibly a ported wastegate + custom tune. If you don't want to go that route, reducing airflow in or out of the motor can sometimes mitigate boost creep issues. That would be going to the stock intake or putting the stock catback on, for example.

Bill

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JS Auto Designs Jake

Discussion Starter · #8 · Aug 15, 2013

COBB Tuning said:
There's nothing wrong with the map - the ECU is actively dropping wastegate duty at around 4000+ RPM because you are overboosting. This is the ECU attempting to bring boost levels down (lower wgdc = less boost). However, it is having no effect which means that you have a mechanical issue that is causing the overboost condition - one that the ECU cannot control. This means that a custom tune will do you absolutely no good in this case. This really looks like a classic case of boost creep, especially if it started occurring with colder outside temperature (assuming you do not have issues with the boost control hardware). Boost creep can be solved by an external wastegate + custom tune or possibly a ported wastegate + custom tune. If you don't want to go that route, reducing airflow in or out of the motor can sometimes mitigate boost creep issues. That would be going to the stock intake or putting the stock catback on, for example.

Bill

Ahhh this is killing me. SO basically I wasted money on something and its hurting my motor. I havent read about this to much. Is there something seriously wrong other then what you are saying possibly?

COBB Tuning

· #9 · Aug 15, 2013

JS Auto Designs STi said:
Ahhh this is killing me. SO basically I wasted money on something and its hurting my motor. I havent read about this to much. Is there something seriously wrong other then what you are saying possibly?

Boost creep is a possibility on these cars (especially GR WRX/STi) when you go stage 2. An aftermarket intake increases the chances as well. Not everyone will see it - it also depends on conditions (colder outside temps, higher baro. pressure) which can determine the severity (or even whether it is significant or not).

The easiest potential solution to try is to put the stock intake back on (you will need to reflash the stock intake map as well). Even if as only a test to see if that improves the overboost condition (which if it does, would make it more likely to be boost creep).

Bill

JS Auto Designs Jake

Discussion Starter · #10 · Aug 15, 2013

COBB Tuning said:
Boost creep is a possibility on these cars (especially GR WRX/STi) when you go stage 2. An aftermarket intake increases the chances as well. Not everyone will see it - it also depends on conditions (colder outside temps, higher baro. pressure) which can determine the severity (or even whether it is significant or not).

The easiest potential solution to try is to put the stock intake back on (you will need to reflash the stock intake map as well). Even if as only a test to see if that improves the overboost condition (which if it does, would make it more likely to be boost creep).

Bill

I was slightly underboosting 2 days ago with the stock intake on stage 2.

New intake yesterday and plus 51 degrees when loggin and overboosting today.

COBB Tuning

· #11 · Aug 15, 2013

JS Auto Designs STi said:
I was slightly underboosting 2 days ago with the stock intake on stage 2.

New intake yesterday and plus 51 degrees when loggin and overboosting today.

Yeah, sounds a lot like boost creep - the intake increases the chances of you seeing it. Colder temps as well. There's no real way to predict if this will happen on a given car. Many will run stage 2+intake without issue. Some will only see an issue with very cold temps with that combo. Some will see an issue even at moderate temps.

Bill

JS Auto Designs Jake

Discussion Starter · #12 · Aug 15, 2013

Ok. so right now I just need to be careful with WOT and drive easy until I can get the wastegate upgraded.

Im assuming with safety I wont blow the engine as is. correct?

COBB Tuning

· #13 · Aug 15, 2013

JS Auto Designs STi said:
Ok. so right now I just need to be careful with WOT and drive easy until I can get the wastegate upgraded.

Im assuming with safety I wont blow the engine as is. correct?

If you keep any WOT runs under 4000 RPM you should be fine.

Bill

JS Auto Designs Jake

Discussion Starter · #14 · Aug 15, 2013

COBB Tuning said:
If you keep any WOT runs under 4000 RPM you should be fine.

Bill

k safety it is.

drifit89

· #15 · Aug 25, 2013

Having the same problem here. I was stage 2 with AEM CAI, with the LWG cobb map on it, was running great. Now Subaru just changed the turbo for a new one (I reinstalled stock intake and turboback). I drove home with it, tested it WOT from 2000 rpm through 6500 rpm, no problem at all. Got home, reinstalled the turboback exhaust (high-flow catted), reinstalled the AEM CAI, reflash the car with the LWG stage 2 91 octane AEM cobb map, now it boost creep from 2800 to 4500, and overboost at 16.7 psi (requesting 15.5) on S mode, and 19.9 psi on S# (requesting 18.5). Don't fu***** know what her problem is! Any idea? Thanks!

JS Auto Designs Jake

Discussion Starter · #16 · Aug 25, 2013

drifit89 said:
Having the same problem here. I was stage 2 with AEM CAI, with the LWG cobb map on it, was running great. Now Subaru just changed the turbo for a new one (I reinstalled stock intake and turboback). I drove home with it, tested it WOT from 2000 rpm through 6500 rpm, no problem at all. Got home, reinstalled the turboback exhaust (high-flow catted), reinstalled the AEM CAI, reflash the car with the LWG stage 2 91 octane AEM cobb map, now it boost creep from 2800 to 4500, and overboost at 16.7 psi (requesting 15.5) on S mode, and 19.9 psi on S# (requesting 18.5). Don't fu***** know what her problem is! Any idea? Thanks!

As of now I'm still on the same setup but we took the Cobb tune out of the mix and things are looking better.

We are pro tuning and working our way up in boost now. So far no creep. Haven't gotten to the high boost targets yet but at 16.5 right now we are hitting 16.2 peak. Perfect.

Get rid of the the Cobb map and pro tune honestly.

I know you can't usually fix boost creep with a tune but I really think there were some issues with the OTS maps that I had because I was knocking n odd spots too but that is all gone after like 3 revisions to a fresh pro tune map.

COBB Tuning

· #17 · Aug 25, 2013

JS Auto Designs STi said:
As of now I'm still on the same setup but we took the Cobb tune out of the mix and things are looking better.

We are pro tuning and working our way up in boost now. So far no creep. Haven't gotten to the high boost targets yet but at 16.5 right now we are hitting 16.2 peak. Perfect.

Get rid of the the Cobb map and pro tune honestly.

I know you can't usually fix boost creep with a tune but I really think there were some issues with the OTS maps that I had because I was knocking n odd spots too but that is all gone after like 3 revisions to a fresh pro tune map.

A good protune is a like a custom tailored suit - it will almost always fit better because it designed looking at how your exact car and local fuel quality responds to tuning changes. That doesn't mean the off-the-shelf (OTS) maps are bad - far from it, just that you will usually obtain the best results with a custom tune. There are always some portion of cars that are on the fringes (compared to average) where they will see the most advantage from a custom tune.

I would be very careful when the temps drop in your area. You were overboosting by more than 3 psi at less than 10% wgdc at higher RPM in one of your previous logs. That means the ECU has no control over boost essentially. You cannot tune around severe boost creep and the severity of it is highly dependent on conditions - might not be an issue (or still is tuneable) in warmer temps but get out of control at colder temps/higher baro. So keep your eye on it when the temps drops, even with the protune.

Bill

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COBB Tuning

· #18 · Aug 25, 2013

drifit89 said:
Having the same problem here. I was stage 2 with AEM CAI, with the LWG cobb map on it, was running great. Now Subaru just changed the turbo for a new one (I reinstalled stock intake and turboback). I drove home with it, tested it WOT from 2000 rpm through 6500 rpm, no problem at all. Got home, reinstalled the turboback exhaust (high-flow catted), reinstalled the AEM CAI, reflash the car with the LWG stage 2 91 octane AEM cobb map, now it boost creep from 2800 to 4500, and overboost at 16.7 psi (requesting 15.5) on S mode, and 19.9 psi on S# (requesting 18.5). Don't fu***** know what her problem is! Any idea? Thanks!

Any time the boost control hardware is messed with, there's the chance of introducing a problem that can cause issues. What I would do is try a short run from 2500 RPM to around 5000 RPM in 4th gear (or 3rd gear if 4th is too fast) on the fuel economy map, if you can do so safely. Get a data log of this with the default set (see our data logging video below). The fuel economy map will disable boost control - if we see evidence of overboosting or erratic boost response, then we know that there's a problem with boost hardware. An example would be if one of the wastegate vacuum lines was damaged or not securely attached.

AskCOBB - Subaru Data Logging - YouTube

Bill

JS Auto Designs Jake

Discussion Starter · #19 · Aug 25, 2013

COBB Tuning said:
A good protune is a like a custom tailored suit - it will almost always fit better because it designed looking at how your exact car and local fuel quality responds to tuning changes. That doesn't mean the off-the-shelf (OTS) maps are bad - far from it, just that you will usually obtain the best results with a custom tune. There are always some portion of cars that are on the fringes (compared to average) where they will see the most advantage from a custom tune.

I would be very careful when the temps drop in your area. You were overboosting by more than 3 psi at less than 10% wgdc at higher RPM in one of your previous logs. That means the ECU has no control over boost essentially. You cannot tune around severe boost creep and the severity of it is highly dependent on conditions - might not be an issue (or still is tuneable) in warmer temps but get out of control at colder temps/higher baro. So keep your eye on it when the temps drops, even with the protune.

Bill

I've done 2 data logs at 55 degree temps on the pro tune. No over boosting as I was getting with the OTS maps. I'm not going to get in a battle over this but the OTS maps were not working at all on my car. The more we logged. The more weird knock and over boosting we saw. Also the LWG OR HWG had no effect on my car. Boost was about the same for each one.

My suggestion to the other guys question is just do a pro tune. Even if its an etune. Most guys will charge a flat rate to do unlimited adjustments.

Contact ENDR Tuning. He will charge you a flat rate which can't be beat. Then is the most communicative guy I've had experience with that offers e tuning.

I guarantee his first OTS map to get you start, even though it will be low boost will feel amazing and you will get the picture quick

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JS Auto Designs Jake

Discussion Starter · #20 · Aug 25, 2013

I am not trying to create a debate. But my opinion is get a pro tune. The OTS maps cannot works for every car that is out there. It's just not possible. If every car was that close to the other when they came off the assembly line. Every car would also always have the same issues which is also not true. Also add in the human factor. Tune the car to your driving style and the way your car reacts.

Yes you do need to be careful in low temps. I don't plan on driving my car hard in the winter months anyway. Also I will go to an external waste gate or port my waste gate eventually to fix the boost creep issues when the time is right.

When it comes to knock. I got turned off when I was told many many times. Some knock is ok. This one is ok here that one is ok there. We were able to fix those in just a couple data logs and adjustments.

My advice is. Just don't get complacent. The second you talk yourself into some knock being ok, you might stop data logging and then you might have bad knock somewhere else and not know it.

I agree that Cobb has done an amazing thing here wi the AP and OTS tunes. Your car will always get the most out of a pro tune though as bill said. It will be custom tailored.

Also keep in kind with the pro tune especially the e tune. You will be fully involved. You will look at each log and see each tweak the tuner does. This will help you learn and see what each tweak does to fix spots in the data log and make your car run with more power but safer too. Knowledge is power as cliche as that sounds. You will feel better though knowing that everything is tailored to your car.

Cobb has given you the foundation. You or the tuner just needs to build from there.

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