Cobb Acces Port in MN

Discussion in 'Modifications And Maintenance' started by 55_MPH, Jun 21, 2019.

  1. 55_MPH
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    55_MPH Active Member

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    I'm looking to modify my stock 2017 STi. I'm starting with the Stage 1Cobb SF intake and Cobb Access Port: http://www.subispeed.com/cobb-stage-1-power-pack-2015-sti

    I was at the dealership for last minute warranty work. One of the service guys, who seemed pretty informed, warned me that the base AP map from Cobb has a tendency to make engines explode, specifically in MN (something about the temp and air moisture). In all my research I have yet to come across this nugget of information. So now I'm contemplating a custom tune. Anyone have any issues with the Stage 1 Cobb AP map in MN? Thanks
     
  2. joebush44
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    joebush44 Well-Known Member

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    LOL. I think this is a common misconception that is presumably caused by the flatbill "Subie bros" who either don't follow the guidelines on the required parts for a particular "off the shelf" map and/or just don't properly maintain their car. As long as you install the appropriate required parts, OTS maps are perfectly safe. However, by no means would an OTS map be preferred over a pro-tune if you're trying to squeeze every ounce of performance out of the car.

    If the OTS map calls for a catted turbo back exhaust, a COBB intake, and a 3 Port EBCS...you can't expect it to work the same using a manual boost controller in place of the 3 port, or using a catless DP instead of catted, or a Perrin intake instead of COBB.

    Some people think that "an intake is an intake", but that's just not true on a MAF based car. The diameter of the piping and the placement of the MAF sensor inside the pipe (whether it's near a bend or not) will most certainly effect the MAF sensor's ability to meter the air - and accurately. COBB developed the maps using a COBB branded intake - so use a COBB intake unless it's otherwise specified in the map notes.

    This is purely an example... but say COBB's intake is 2.5" diameter and that's how the map is calibrated because that's the intake they used when creating the map...now someone uses X brand intake that is a 3" pipe instead of the COBB intake - that's .5" worth of air that is passing by the MAF sensor unmetered. The MAF has to be scaled appropriately - COBB already did that, but you have to use the right intake. This is just an example of how important it is to follow the map notes.

    In short, follow the map notes and only install the mods that the map calls for...nothing more and nothing less.

    IMO, jump for a stage 2 map with a COBB EBCS and turbo back exhaust :)

    If you decide to take the pro-tune route instead, JM Auto is well respected in the community.
     
    55_MPH, GrawvyRobber, Mnelson and 2 others like this.
  3. SurlyOldManMN
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    SurlyOldManMN Omdat fok jou Staff Member

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    Protune or gtfo. It's cheap insurance if nothing else. If the expense or inconvenience of a protune is unpalatable, probably best not to mod the car at all.
     
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  4. 55_MPH
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    55_MPH Active Member

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    Thank you both. I'm going for the pro tune, I want to see this care hit 200k so a little insurance seems worth the price.