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Discussion Starter #1
Short story I want to know what needs to be upgraded in a 2020 STI in order to get tuned. Just looking to go Stage 1+ for a while (maybe forever) while maintaining a high level of reliability.

I have seen that the newer STIs operate at the upper range of the fuel system capabilities. And most if not all tuners will require you to get an adjustable fuel pressure regulator and fuel pressure sensor regardless of what stage you want to take it to.

But there are so many options out there that I have no idea what is minimum vs what would be ideal vs what is overkill. The cobb fuel pressure regulator kit seems to list that it includes an OEM FPR... so what is it upgrading if it’s an OEM FPR? It seems like the aeromotive FPR is well liked but it’s for ‘moderate to high’ hp applications - is that more than a stage 1+ STI would make? Do I need new fuel lines to match? At this point would it be silly to not just do the fuel pump with the fuel pressure regulator and the fuel sensor? Will any aftermarket fuel pressure sensor do?

Any help understanding what exactly is needed and why would be greatly appreciated.
 

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If you're just doing an intake and tune you don't need fuel upgrades. Stock setup will be fine. Its when you add a downpipe and intake is when you need fuel upgrades
 

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Discussion Starter #3
If you're just doing an intake and tune you don't need fuel upgrades. Stock setup will be fine. Its when you add a downpipe and intake is when you need fuel upgrades
That is what I originally thought, but then here is the page for one of my local tuners and their site says any 08+ STI they wont touch without both a Cobb FPR and Cobb fuel sensor. (IAG Performance Accessport Pro Tuning Services for Maryland, PA, DE, VA Subaru WRX, STI, Forester XT, Legacy GT, Spec B, Turbo. Protuning, Access Tuner, AP tuning, COBB Tuning, MD, Baltimore, Towson, Glen Burnie, Columbia, Ellicott City, Washington D)

So is that hoo hah? Or why would they otherwise require that for ALL instead of just saying stg2 or higher requires these parts?
 

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Each tuner is going to be different and have different requirements. I would talk to whoever you're going to get tuned by to see what they require. Those mods aren't necessary but good to have.
 

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Every tuner has a different preferance. I would first decide on how far you currently want to go with modding the car. Then i would recommend you go over this with your selected protuner/shop. Some tunes may say you need it all while others will say you need bare minimum. Its really going to depend on them and how far you go with mods.
 

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Every tuner has a different preferance. I would first decide on how far you currently want to go with modding the car. Then i would recommend you go over this with your selected protuner/shop. Some tunes may say you need it all while others will say you need bare minimum. Its really going to depend on them and how far you go with mods.
Correct. Stage 1 is just a tune of the stock setup, stage 2 is a tune with aftermarket downpipe, neither (should) require fuel system upgrades unless there is something that changed from the GD's to the GR's.
 

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That is what I originally thought, but then here is the page for one of my local tuners and their site says any 08+ STI they wont touch without both a Cobb FPR and Cobb fuel sensor. (IAG Performance Accessport Pro Tuning Services for Maryland, PA, DE, VA Subaru WRX, STI, Forester XT, Legacy GT, Spec B, Turbo. Protuning, Access Tuner, AP tuning, COBB Tuning, MD, Baltimore, Towson, Glen Burnie, Columbia, Ellicott City, Washington D)

So is that hoo hah? Or why would they otherwise require that for ALL instead of just saying stg2 or higher requires these parts?
Once you start increasing the boost you will get a stumble around 2800-3200 RPM with the 08+ FPR, there are lots of threads about it. The Cobb FPR is the same as the 07 STI and doesn't
exhibit the same fuel pressure drop as the 08+. You can use any other aftermarket adjustable FPR instead of the Cobb.
 

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Discussion Starter #8
Once you start increasing the boost you will get a stumble around 2800-3200 RPM with the 08+ FPR, there are lots of threads about it.
Thanks, I've read a bunch of those threads but I guess the question I couldn't answer was how much of an increase in boost before it really matters? I'm just throwing an intake on the car and getting it tuned to open it up a little. I cant imagine boost will be more than a couple psi higher. So does that take me into FPR land?

But in any case, talked to the shop that's going to do my tuning and they recommended the sensor so it can act as a failsafe, but they didn't think the FPR was a necessary addition for what I'm trying to accomplish.
 

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If you're just doing an intake and tune you don't need fuel upgrades. Stock setup will be fine. Its when you add a downpipe and intake is when you need fuel upgrades
Thanks, I've read a bunch of those threads but I guess the question I couldn't answer was how much of an increase in boost before it really matters? I'm just throwing an intake on the car and getting it tuned to open it up a little. I cant imagine boost will be more than a couple psi higher. So does that take me into FPR land?

But in any case, talked to the shop that's going to do my tuning and they recommended the sensor so it can act as a failsafe, but they didn't think the FPR was a necessary addition for what I'm trying to accomplish.
I was trying to remember back to when I had the stumble issue. I think I was wrong when I said it's due to increased boost, it's due to increased airflow when adding intake and downpipe together, as lucid215 stated. I don't know if you'll have that problem with intake alone, sounds like you'll be fine.
 
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