OK so I am spending a ton of time researching intakes for my new 17' WRX Premium. I do not want to tune it at this point in order to keep the warranty fully in place. It looks as though COBB intakes all require a tune. I found the Mishimoto intake and it says that if you run 93 octane it does not require a tune. Being as this is not my daily driver, I will definitely be running only 93 octane in it. From the product description:
"Direct fit for the 2015+ Subaru WRX
Designed in Delaware, USA and filter made in USA
Available with a polished or wrinkle black pipe finish
Mishimoto Lifetime Warranty
CARB EO #: D-759-1
Dyno-proven maximum gains of up to 33 whp and 30 wtq and peak gains of up to 28 whp and 21 wtq while maintaining safe AFRs on the stock tune (using 93 octane fuel)"
1. Why do you want an intake?
2. Do you value the factory warranty?
3. Do you believe Mishimoto's claims?
4. Do you understand why an aftermarket intake would produce additional power and torque (if at all) over the OEM airbox?
Well I guess that answers my question Going by their claim it seems like an easy bolt on 10-12 WHP that required no tune. I completely value my warranty and do not wish to do anything to void it. I also don't want to hurt the drivability. I appreciate everyone's responses.
Right off the Mishimoto site, no exception made for any octane fuel.
"Note Car must be tuned to use this intake."
Also there is 0 power to be made without tuning for the intake.
Adding the intake will probably throw fuel trims off wack in most cases making the car run overly rich and you may even just lose some performance.
Intakes like Mishimoto's make additional power by leaning out the AFR compared to the expected tabular values. OEM ECU calibration is designed to run very rich in order to increase detonation resistance and reduce NOx emissions. A leaner charge will produce more power, but also a faster and more chaotic flame front. OEMs account for a safety factor due to low quality fuel and extreme conditions (temperature, humidity, etc) and so it is generally safe to lean out the AFRs a bit more than the OEM calibration. This is where 90% of the gains are realized in an S1 map.
That being said, do you really want to invest in a product that effectively "tricks" the ECU into reducing the injector pulse width (IPW)? Think of all the other compensations that go into an ECU that scale fueling and timing for ambient conditions... the relationship between these compensations suddenly changes. I'm a firm believer that if you're going to do things, do it right. No Mishimoto for me.