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Discussion Starter · #1 ·
After researching modification paths for my 2013 WRX sedan for a few months, the other day I purchased a Cobb AccessPort and flashed one of their stage 1 maps. I drove for a full tank, took a couple datalogs, and I'm worried that I may be underboosting. The question is: if so, how much? And should I be worried about a possible boost leak? My hope is that some of you out there with more experience might be able to take a look at the data and offer some advice.

Here's the run-down:
* 2013 WRX
* Cobb SF Intake (with Airbox), no other mods
* Map: OTS Cobb 91 Octane Stage 1 + SF Intake

The target boost for that map is 17 PSI, but the most I've ever logged is 14.65 PSI. I hear that the 17 PSI target really has a standard variation of +/- 1 PSI, but I seem to be missing the target by more than that.

Here are two graphs I produced from my datalogging session. Both were 3rd gear pulls.

Datalog 6:
datalog 6.jpg

Datalog 7:
datalog 7.jpg

Here are links to both full datalogs that those graphs came from:
https://drive.google.com/open?id=0B4kTO_uCLNVlSmowSThTSVlmX1k
https://drive.google.com/open?id=0B4kTO_uCLNVlUE9rdVYzb3k4QTg

That said, I think this section of the first pull in datalog 6 sums it up pretty well:
Screen Shot 2016-12-29 at 9.18.37 PM.jpg

You can see that TD Boost Error never falls below 2 throughout the whole 3-4.5k RPM spectrum (WOT was hit at roughly 3.3k RPMs).

With this map, the highest peak boost I ever saw was about 14.7 PSI -- and that's peak boost... the typical level of sustained boost is more like 13.5 PSI. I should note that I also tried flashing the HWG version of Cobb's 91 Octane Stage 1 + SF Intake map. With the HWG map, I once saw peak boost hit 15.06 PSI (but never again). Using the HWG version might have helped slightly, but it still seems to me that I'm falling well short of the target.... and the fact that I continue to do so on the HWG map has me concerned that there might be a boost leak.

So... what do you guys think? Should I be content squeaking 14.7 PSI peak boost out of a Stage 1 + SF OTS Cobb map on 91 Octane? Or do I have good reason to be suspicious about a possible boost leak, since I'm still not touching that 17 PSI target?

Thanks for your input!
 

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Boost will be higher in 4th and 5th gears.. I would try doing a pull in 4th from about 3200 to 4500 rpm and see what the peak is. If it's still more than 1.5psi below target you could try using the HWG map and see if that helps. If it still can't hit target I would perform a boost leak test.
 

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Boost will be higher in 4th and 5th gears.. I would try doing a pull in 4th from about 3200 to 4500 rpm and see what the peak is. If it's still more than 1.5psi below target you could try using the HWG map and see if that helps. If it still can't hit target I would perform a boost leak test.
Not true with the CANBUS ECU Robin -- it has per-gear boost control and requested torque throttle control.

OP, what is your base elevation?

Sent from my SAMSUNG-SM-G890A using Tapatalk
 

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Discussion Starter · #4 ·
Thanks for the clarification, zax. I'm about 100 feet above sea level, and it was 35 degrees (F) when those datalogs were taken. This afternoon it was in the 40's, and I saw similar numbers.
 

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The boost error you logged is showing you how far below the target boost you are for each point in the log, so you are 2-3 psi low all the way across.

Best to start with making sure there are no leaks but that is a PITA.

You can try the alternative map they have (LWG or HWG I forget which they call it).

On the old cars we would just adjust the wastegate pre-tension a couple turns. Not sure if that is recommended any more and the map is a better solution if it works.
 

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Discussion Starter · #7 · (Edited)
I have tried the HWG version actually, and the highest peak boost I saw with that was 15.06PSI.... still well under target (even at peak!)

Anything else that might be responsible for this other than a straight-up leak? Not sure I have the tools or time to get a definitive answer from testing for a leak on my own at the moment... I do want to make sure I get this resolved though, if you guys do agree there's a problem.
 

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Ultimately the most likely reason IMO is that your particular turbo, particular actuator, particular BCS, etc. are not responding to that map the way the car it was made on did. It is a complex system and they just aren't all going to have the same exact interactions. Is it a problem - probably no. You are just losing some performance.

Yes there are other unlikely explanations that are much worse.
 

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Discussion Starter · #9 ·
That's a fair answer. At some point when I have the money, I'm planning to put in a catless up-pipe, cobb downpipe + TBE exhaust and apply their stage 2 map. What do you think the odds are that I would see a good performance boost, knowing that I'm already underperforming for stage 1?
 

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At some point when I have the money, I'm planning to put in a catless up-pipe, cobb downpipe + TBE exhaust and apply their stage 2 map. What do you think the odds are that I would see a good performance boost, knowing that I'm already underperforming for stage 1?

Your car already comes with a catless uppipe (and the stage two map was designed for cars with stock uppipe). I would expect to see relatively the same performance gain going from stage one to stage two as Cobb advertises. Personally, I would get a Protune done by a reputable tuner either way.. but that's going to cost even more.
 

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Discussion Starter · #11 ·
Your car already comes with a catless uppipe (and the stage two map was designed for cars with stock uppipe). I would expect to see relatively the same performance gain going from stage one to stage two as Cobb advertises. Personally, I would get a Protune done by a reputable tuner either way.. but that's going to cost even more.
Oh that's cool, I didn't realize the 2013 uppipes were already catless. What's your opinion on services like TorquedPerformance compared to Cobb's OTS maps?
 

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TP should be able to get you up to target boost.

On my car ('03) when I didn't hit target boost on Testes' stage II map he just had me tighten the wastegate actuator nut a couple of turns to increase the pre-tension. Then log it carefully of course to make sure it isn't spiking or overboosting. I've been running that way for 80K miles.
 

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Discussion Starter · #13 ·
Good to know. Maybe I'll wait till I'm ready to do the downpipe and TBE exhaust, then re-log and hit up TP if I'm still significantly under target. Would it be potentially unsafe for the vehicle to continue driving on it as-is until then? And also, would you recommend I get a professional boost leak check done at some point? If so, any idea how much that would cost?
 

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Oh that's cool, I didn't realize the 2013 uppipes were already catless. What's your opinion on services like TorquedPerformance compared to Cobb's OTS maps?

Yep.. only the 2L cars from 2002 to 2005 had a catalytic converter in the uppipe. I would avoid TorquedPerformance at all cost. A tune done in person is always going to be better than an e-tune.. plus to e-tune you will have to buy additional modifications to really be able to tune the car correctly (ie wide band O2 sensor). A tuner at a shop will already have their own equipment and get you squared away.


If it were me, I would save up until I had the money set aside to do everything you want.. then I would talk to JR about scheduling an appointment for a tune at Prime Motoring in Wallington, NJ (explain to him what's going on and see if he wants you to do a boost leak test or anything else prior to the tune.. if there is anything he recommends you can get it done at Prime when you go for your tune). I would also ask if he can send you a base map for all of the mods you are doing (after paying a deposit). If he can do that for you, then I would install all the parts at home a couple days before the appointment, flash the base map, then drive the four and a half hours down to Prime and let him do his magic. There are other tuners much closer to your area, but I feel like it would be worth it to make the drive and get the tune done by one of the best in the business.
 

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Discussion Starter · #15 ·
Thanks. And yeah, sometimes you definitely do get what you pay for. Do you know what the rates are like at Prime Motoring? And would the map they produce be compatible with my AccessPort so that I could still swap back and forth between maps if desired?
 

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Do you know what the rates are like at Prime Motoring? And would the map they produce be compatible with my AccessPort so that I could still swap back and forth between maps if desired?

I don't know what their hourly rates are at Prime off the top of my head. If you give them a call (201) 935-2910, or message Demetri Xanthos on Facebook I'm sure they can answer all your questions.


The map will be for the Access Port, although I don't see any reason you would want/need to switch maps in the future. Depending on the mods you do, you won't be able to safely use any of the maps that come with the AP anyways.
 

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Discussion Starter · #17 ·
Super, thanks for the contact info. Currently, the full list of mods I have in mind is .... pretty much just the typical stuff from Cobb: SF Intake + Downpipe + TBE catback exhaust. I want a combination that offers improved power throughout the RPM band, and a modest HP boost, while maintaining the long-term drivability of the vehicle. This sound like a pretty M1A1 approach to that?
 

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Currently, the full list of mods I have in mind is .... pretty much just the typical stuff from Cobb: SF Intake + Downpipe + TBE catback exhaust. I want a combination that offers improved power throughout the RPM band, and a modest HP boost, while maintaining the long-term drivability of the vehicle. This sound like a pretty M1A1 approach to that?

I would talk to the guys at the shop and see what parts they recommend.. there are cheaper options than Cobb parts which will perform just as well, and you could potentially encounter boost creep problems running both the intake and exhaust.. If you're going to get a custom tune (usually costs around $500), I would think about throwing a couple other mods while you're at it (although that's totally up to you, the more you do the more it will cost). A 3-port electronic boost controller wouldn't be bad, and those only cost around $90. Then there's also the fact that with basic stage two mods the injector duty cycle is uncomfortably high.. a set of ID1000s would give the car more overhead. You could tune for more power, fuel to each cylinder will be more even, and I would expect the car to run a little more smoothly. But then you're talking another $400 for the injectors. Stuff adds up quick, but it's something to consider.
 

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I only skimmed the log for knock correction and it appeared you are quite fine the way it is.
 
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