2019-2022+ Forte GT - Forte Mods and Performance Upgrades/ Tuning. First Page For Links..

ReaperGT said:

Howdy all! I just got a 2021 Forte GT and was looking at this post making a list of mods I want. For cold air intakes and blow off valves do you need a tune? Sorry if I sound dumb I've only owned NA engines in the past. Thanks!

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We all learn by asking questions

The other thing to note is the replacement blow off valve isn't something that will add more power. Its only job is to vent a portion of compressed air between the compressor in the turbo and the intake manifold under some circumstances, eg: accelerate hard, engine comes on-boost, lift off the gas quickly to slow down or change gear and there is a pressure wave that pushes back from the throttle butterfly back towards the turbo which can cause the compressor to surge (the tsu tsu tsu tsu turbo noises that most people love is the sound of that pressure wave bouncing between the throttle butterfly and the compressor). The BOV detects this and vents the pressure wave. there's a GFB video about it here:
The GT has a factory cold-air feed from behind the grill (near the GT badge) in to the engine bay. Installing something like the aFe Takeda intake will connect in to that factory cold-air feed and can make more noises, but in and of itself doesn't really increase power on its own - but it's a worthwhile supporting mod if you install a Racechip/JB4 later on

Scatter.Brain91 said:

Question, in stock configuration, the turbo will output 16-18 psi of boost correct?

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The short answer is 'it depends'.

The longer answer: The ECU is looking at a table of Torque output vs throttle pedal position - the pedal is effectively just a 'torque request' device. If you put the pedal down 20% in Eco mode, the ecu might go 'they're requesting 20% of max torque and with the eco setting i'll let the boost build gradually'.

Or you might be in sport mode and bury the pedal in to the firewall, and the ecu goes 'we need maximum allowed torque and to generate it as quickly as possible' - so the ecu starts playing around with cam and ignition timing, wastegate solenoids and so on in order to get to maximum torque output as soon as it can. Once it hits that torque output it starts backing things off to hold the output at a constant level.

I run an obd2 multi-function gauge and it'll often peak at 20-21psi of boost until it hits maximum torque, and then winds the boost back to 15-17psi to hold that torque output. The variance in boost pressure is due to air temp, air pressure, humidity and so on. On really cold nights in winter i've seen it hit 23psi before settling on 13-14 due to the denser air.