Not making peak boost

[DShane]

Yesterday I installed the V3 Accessport on my car (2005 LGT manual) and flashed the stage 1 91 octane map onto it. Definitely made the car run a lot smoother but I drove around for an hour or so with it and wasn't making more than 12.83 psi.

Peak boost for this map is 15 and other people with the same car and tune I've talked to say they're making between 15-16 psi.

Only mods on the car are an AVO drop in filter and an OBX (eBay) CBE.

Anyone have any ideas as to what my problem is?

Any input would be appreciated as this is my first cobb tuned car.

 

[SUBARUDE]

13-14 seems to me would be more normal for a stage one map but you could a a boost leak and it's very hard to diagnose not seeing dealing with it in person

 

[drvsdwz]

Try flashing a HWG map. Also check your a/f learning. If it's adding fuel at idle, you may have a small boost leak.

 

[DShane]

Try flashing a HWG map. Also check your a/f learning. If it's adding fuel at idle, you may have a small boost leak.

Pardon my ignorance but what is a HWG map? I haven't been looking at the a/f but I will go for a ride in a little bit and check it. 

I read that a common problem that causes this is a faulty boost control solenoid but I'm not sure how to confirm that.

 

[Matt]

I thought stage two was the 15 psi map. Make sure you have all the mods cobb requires you to have.

 

[drvsdwz]

Sorry, high waste gate map. Usually cobb makes 3 versions. A low waste gate map for cars going over peak boost, a normal one, and the high waste gate map. You can find them on the cobb website under support and then your vehicle. Also, don't check the a/f ratio sensor 1 parameter, you should be checking your a/f learning instead. That will tell you if it's adding fuel or taking it away.

 

[jojo69]

Pardon my ignorance but what is a HWG map? I haven't been looking at the a/f but I will go for a ride in a little bit and check it. 

I read that a common problem that causes this is a faulty boost control solenoid but I'm not sure how to confirm that.

HWG/LWG means High Waste Gate and Low Waste Gate. Esentially different maps that Cobb has put out for cars that either do not reach target boost (HWG) or are over target boost (LWG). It should be downloadable in the Cobb website

Have you posted any log for Cobb to review? There is a tutorial video on how to do so on the Cobb website and it certainly couldn't hurt to do some logs and post them on the forum and on nasioc to get feedback. 

Like Matt said, make sure you are using the same parts that the Map you have flashed uses. 

hahaha, drvsdwz just replied as I was making this reply

 

 

[drvsdwz]

i've been around the cobb accessport for a few years now and have a firm understanding on how to determine a boost leak or if the wastegate duty cycles are just not high enough. 

i.e. if you're not hitting peak boost, one of basically 2 things:

1. boost leak, which can be determined by looking at the a/f learning at idle. if it's 3+, chances are it's a boost leak

2. wastegate duty cycles not high enough

the most important thing is making sure that you have the proper map installed for your modifications.

 

[DShane]

I thought stage two was the 15 psi map. Make sure you have all the mods cobb requires you to have.

It says no mods are required to run the stage 1 tune. Peak boost for stage 1 and stage 2 is the same it says 15 psi for both of them.

I will check the A/F leaning and post back. 

I looked on cobb's website though and couldn't find anything for HWG maps. 

 

[Matt]

I think those are Sti maps from what I've seen as far as hwg. If the car ran fine before and won't hit target boost after the reflash try resetting the ecu and Reflashing the map again.

 

[DShane]

Is a/f leaning 1 what I want to be looking at?

If so it was at 0 when I first started the car, but as soon as the thermostat got to about 1/4 of the way up it started jumping up to 10.8, 7.8, 5.6, just randomly jumping and then once it fully heated up it staid at a constant 10.8. Guessing that means I have a pretty big boost leak somewhere?

Also I was wrong before. Stage 2 map bumps the peak boost up to 16.5 psi

I just did a short drive and datalogged it but I can't figure out how to upload it to the forum?

 

[jojo69]

I just did a short drive and datalogged it but I can't figure out how to upload it to the forum?

Have you tried using google docs to share your datalog. Make sure privacy settings are set to public so that peeps can open it/look at it.

 

[drvsdwz]

Vacuum hose probably popped off. I believe on the plastic manifolds there is a small vacuum hose that likes to pop off underneath it near the throttle body

 

[DShane]

Is there any chance that an exhaust leak between my stock downpipe and my aftermarket CBE would cause this? Because I feel like there is a pretty decent leak there since I don't have the proper adapter required to go from stock downpipe to 3" cat back

Here is the google docs link for what i datalogged today:

https://docs.google.com/spreadsheets/d/1jKdYez_3PM91IBm5y-YFtf9sb_SvKSwixmJ1Y-s69pM/edit?usp=sharing

 

[Matt]

anything after the turbo shouldn't effect boost.

 

[DShane]

Ok so where is this problematic vacuum hose so I can check that?

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[DShane]

bump

 

[drvsdwz]

ok, so i will be uploading a picture. It is hard to get at and requires removal of the intercooler. It attaches to the intake manifold at the underside near the throttle body. it is on the right side of the picture circled in purple. Sometimes that is the hose that will pop off(same as the 2008+ wrx intake manifold styles)

You will have to click on the file to make it bigger.



I hope this helps

also, MAF sensor could be dirty.

 

[DShane]

Alright I will take the inter cooler off and look this afternoon

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