Hello fellow s40 owners, I am considering getting a more performance oriented intake system for my T4 1.9L. I will probably be opting for a ram intake with a heat shield. I was wondering if anyone has done something similar, what filters you've used and your results? Any ups and downs?

And please, don't give the usual "performance intakes ruin your engine" comments, because they don't. They filter 98-99% of particles compared to stock, so by the time you get any filter related issues the car will probably be at the junkyard already.

 

there are two things to consider when tuning the intake 1) avoiding pulling in warm air that's under the hood 2) consider other bottlenecks in the air flow when setting priorities I have not looked at the 1.9s air box but on the 850Ts, the factory box was actually pretty good. I did not notice any difference between a paper filter and a K&N but wound up going back to paper just to avoid any hint of oil coming off the filter that could soil a MAF. You can shop around for various tuners to see what they carry but my take is the intake is not a priority for a turbo engine unless you are looking to get into the 350+ HP range. Since you have a turbo engine, assuming you are looking to also do an ECU tune, then dealing with the extra heat is where I'd put my focus. My personal order or enhancement: ECU tune, bigger downpipe, bigger intercooler then air box mods. Really a lot here depends on your target HP range. Gettting over 300 HP may also mean bigger injectors, bigger turbo (ie 18T or more), better air tubing, cat back exhaust but like an audiophile stereo system, there's the laws of diminishing return applies here. As a guide you may want to look at the tuner sites to see what they suggest for a stage 0, stage 1, stage 2 etc set up.