Reviewed: INJEN Air Intake for Fiesta ST

Discussion in 'Fiesta ST Engine Upgrades' started by BlueBomber, Feb 27, 2014.

  1. BlueBomber

    BlueBomber Active Member

    The full review can be found at the link above.


    Welcome to another Expert Review – We at ModBargains got the word from Injen that their new SP Tuned Intake System for 2014 Ford Fiesta ST was now out of the prototype stage and that the final production part is ready- and now available at ModBargains. We got our hands on one of the first intake systems for Fiesta ST and had to give it a try for ourselves.


    I've previously discussed the different types of Air Intake Upgrades – this particular intake for Fiesta ST is a “Short Ram” type that adds a conical filter just ahead of the mass air sensor, but also replaces the entire intake tract rear of the MAF sensor to the turbocharger inlet. The OEM Fiesta ST Intake System, while a true ram-air type system, it’s restrictive and the integrated silencer baffles keep you from enjoying the happy spool of your turbo.

    As an enthusiast myself, I have been waiting to upgrade my intake system as nothing up until now was an appealing option – the few competing systems on the market now require cutting or modifying the EGR/PCV system and even modifying the harness.

    Injen‘s Intake System for the Fiesta ST is the first one available that is a true plug-n-play type upgrade. Given how many Fiesta ST owners are concerned about their warranties, the idea of a system that required no modification to other systems and left the EGR/PCV system intact was particularly attractive. California ST Owners take note, because I know you want to know: This intake does not yet carry a CARB number – It may in the future.

    With a few basic hand tools (7, 8, 10, 12 and 13mm deep sockets + T20 torx), I was able to install the intake system myself in my carport in about forty minutes. I found that having a set of really wide pliers was especially valuable to pop the vacuum connections off their retainers without destroying their retainer clips. I found that the most difficult part of the installation was actually removing the old intake tube that connects the inlet to the junction by the battery. This tube is secured by the 12mm ball stud that the engine cover mounts to (save this and reinstall it) and a 10mm nut. Remove the nut then remove the grommet liners, then remove the grommets. This makes it much, much easier to rotate the intake tube so you can actually get it off. Aside from this minor snag, everything installed quickly and the experience was not at all frustrating.

    I’ve been driving the car for a few days now with the Injen intake, and here are my findings. Before you even get out of your driveway the first time, you will immediately notice how much more you hear your turbocharger. This is not to say it is overly loud or drones, but rather, you actually hear the turbo spooling – and you can hear the system let off excess pressure – giving you that cool “PSSHHH” sound most people buy a blow-off valve to get.
    (Protip: The Ford Fiesta ST and Ford Focus ST do not need a Blow-Off Valve or Upgraded Wastegate Actuator – There is no performance gain for BOVs)
    So, if nothing else, you will love the improved intake tone. I have been having a hard time keeping my foot out of it! In addition to now being able to actually hear your turbo doing its thing, I notice that throttle response is improved and the car definitely feels like it has a little more gusto on the ol’ butt-dyno. (Dyno figures from us coming soon…)

    When we picked up our intake, we got the chance to see the intakes being produced, right here in California – in the USA , as opposed to being imported. What’s more, we got the chance to talk to Injen’s Intake Engineers about the system for the Fiesta ST.
    “We designed the system so you don’t have to cut any of your EGR or PCV lines,” said one Engineer, “While we were designing the intake for the Fiesta ST, we tried several different size intake tubes – 3″ was too large for the motor, but 2.5″ hit the sweet spot and that’s what we went with for final production.” Injen specializes in “Tuned” intake systems (different from ECU tuning), which tailor the air flow characteristics of the intake for maximum power and torque gains. So, what is the power gain of the tuned intake system?


    Injen reports that on an otherwise Stock Ford Fiesta ST, the Injen Air Intake got +8.71 more Horsepower and +9.15 more lb/ft of torque at the front wheels on the dyno, hitting a peak of almost 180hp at the front wheels (stock baseline is around +-170) with a stock tune and this cold air intake. Given that my own Fiesta ST is running a Cobb Stage I 91 Octane map, my gains are likely a little higher because the factory computer’s torque truncation in 1st and 2nd is disabled by the tune. If you’re running an ECU Tune like I am, you can probably expect similarly improved gains. While an enhanced intake system also can improve fuel economy, I’ve not yet noticed any change in economy – neither improved nor decreased (I will update this if I do).

    In closing, if you want a little more fun out of your Fiesta ST, this Injen Intake will definitely deliver. You’ll feel the added power, but you’ll hear the difference with every shift, and having that spool and blow off valve sound really does makes every drive a little more fun. If you’ve got a little cash burning a hole in your pocket, picking up one of these intake systems is a fantastic idea and delivers real, tangible wheel-horsepower increases (many upgrade “gain” figures are Crankshaft HP, not Wheel HP). I hate to use this phrase, but you really do get “more smiles per mile”, as it’s certainly left me grinning. Availble at ModBargains for just $250.80, the price is also hard to beat for actual wheel horsepower gains.

    Check back soon for a short video clip so you can hear this intake for yourself.

    newest video, best sound

    Story & Photos Blue Bomber
    Last edited: Mar 21, 2014
    LotusZX3 likes this.
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  3. chr0n0phage

    chr0n0phage New Member

    I wish these intakes had some type of "coldbox". Unless I see data that shows that extended high ambient temp runs won't completely heat-soak it turning it into a "hot air" intake, i'm going to hold off. I know there's always the old argument of "it's got an intercooler to cool off the intake charge...", etc..

    Sorry, I still don't want to ingest hot engine bay air.
  4. BlueBomber

    BlueBomber Active Member

    Those are good points, and things I considered myself. There is a heat shield in place. I have an AP and have been watching my intake air temps - it doesn't seem to actually be any different temp wise than the OEM unit - there doesn't seem to have been a change, unless it's reading the air temp somewhere besides the MAF.

    I will let you know how it goes, but I am considering figuring out a way to add additional shielding as well.

    Unrelated: Is that the RE Amiya (spelling?) Lotus Europa in your avvie there?
    Last edited: Feb 27, 2014
  5. chr0n0phage

    chr0n0phage New Member

    Haha yes, it is. A bad croping of the image from Speedhunters at that. Nice eye!

    I had an Injen intake on my RX-8 for a bit before it was dyno proven to actually decrease power so I'm hesitant but this is slight cheaper then other alternatives so I won't write it off completely. I may just wait till more people jump on it to get a better idea how it performs.
  6. BlueBomber

    BlueBomber Active Member

    Was that car ever a member of the "Midnight Club" that ran on the Tokyo Bay line back in the day?
    I built a car exactly like that in Tokyo Xtreme Racer 3 - a Europa with a Rotary swap. Lightest car you could possibly build.

    On a related note, I will be giving the Cobb intake a try whenever that's released and will report on what I find to be better. For now, in my opinion, it's the cleanest looking option but performance wise I think they're more or less about the same +-1hp. But an RX-8 is a different animal than a FiST, for a variety of reasons (Forced Induction vs NA, Piston vs Rotary...) and I think the intakes designed for modern cars are way nicer than the intakes of even just 5 years ago - in general the quality of parts coming from the aftermarket has improved greatly.

    also I revised the blog entry to include Injen's dyno sheet
    Last edited: Feb 27, 2014
  7. D1JL

    D1JL Well-Known Member

    I am not going to say that there is anything bad about this intake.
    Ingen has always made good things.

    However dyno test are usually done with the hood open because even the massive high speed fans can't assimilate real driving air flow.
    With the hood open the hot engine compartment air does not accumulate around the filter as it will under real use.
    So unfortunately dyno results, although may be impressive, may not be an accurate comparison.

    Firesail likes this.
  8. BlueBomber

    BlueBomber Active Member

    Good points, Dave, but I wouldn't exactly consider 8hp impressive - real world I feel like it has just a little bit more gusto but not much, the sound is the biggest thing you notice.

    That, and I think the wrinkle black does look handsome in there
  9. psylentknight22

    psylentknight22 New Member

    I'm just wondering why the fswerks intake isn't considered a plug and play...I didn't do any modification when I installed mine...but maybe I did it wrong!!
  10. BlueBomber

    BlueBomber Active Member

    About that, I was told the other intake required you to cut the green connector off the pcv hose, which would make it impossible to return to stock.
    Hence that terminology
    Did you have to cut that line to install yours?
  11. stuntdoogie

    stuntdoogie Active Member

    Does this intake come with a dry or oiled filter?

    Sent from my SPH-D710 using Tapatalk
  12. D1JL

    D1JL Well-Known Member

    That being said.
    It is true that most add on or aftermarket parts are purchased based on sight and sound over actual performance.

    stuntdoogie likes this.
  13. STGarage

    STGarage New Member

    why are you guys getting so hung up on heat soak? I'll be needing my 9 ft/lbs on corner exit.
  14. D1JL

    D1JL Well-Known Member

    Because after you reach heat soak the 9 lbs won't be there.

    Firesail likes this.
  15. STGarage

    STGarage New Member

    I guess it would depend on the event. Sitting at an autocross, or DragStrip, probably.
  16. D1JL

    D1JL Well-Known Member

    Now that is a more proper way to think.

  17. BlueBomber

    BlueBomber Active Member


    Regarding the heat soak issues, I started seeing that like you were saying when at low throttle inputs and when stuck at stoplights.

    The good news is, I was able to fix this - the fix was easy and inexpensive. I added $5 worth of self adhesive high density foam weatherstrip to seal off the intake heat shield a little more from the rest of the engine bay. After doing this, the intake temperature at idle and at low throttle inputs stabilized and low-throttle cruising intake temps stayed stable right where they were with the stock box, which is about 5-10*F over ambient.

    I talked to Injen and they'll be adding taller, fatter weatherstrip in with future kits. Just properly sealing the box off from the rest of the engine bay made a huge difference in intake temperatures and thus you'll have that +8hp +9tq consistently.
  18. D1JL

    D1JL Well-Known Member

    The shielding is good of course.
    However it is best if you can bring in extra air from outside the engine bay.

    Personally I have never seen that much HP from this kind of system.
    But if you like the way it works and the way it sounds, that is what is important.

  19. BlueBomber

    BlueBomber Active Member

    Considering the heat shield is perfectly flat on the bottom, it wouldn't be hard to put a holesaw on there and then add a duct to feed from behind the foglamp or something.
  20. D1JL

    D1JL Well-Known Member

    That is how mine is done.
    I took the duct down a little further to draw air from under the car.

  21. DaveSave

    DaveSave New Member

    Installed the Injen intake last night, and I must warn all that it will take far longer than 40 minutes to install, no matter how experienced of a mechanic you are. Mating the intake tube to the turbo with the supplied rubber connector is damn near impossible. The rubber material is just thick enough to barely stretch over the piping, while thin enough to fold and bend when you don't want it to (just be ready for a fight). Overall product quality is very good and the intake and turbo sounds are well worth listening to. No noticeable power increase or improved throttle response.

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