Injen

Injen

A few weeks ago, I ordered an Injen cold air intake (it also comes in black) for my car, from Club RSX. Then, of course, we got two straight weeks of on-and-off rain, so I ordered a Hydroshield. That hasn’t come in yet, but I’m impatient – so today, I finally decided to install it. The instructions that came with it were quite helpful.

Injen Cold Air Intake

Injen Cold Air Intake

From what I’ve heard, if you’ve never done this before, and have another inexperienced person helping you, you’re probably looking at 3-4 hours. Well, I got started – flying solo – at 1400, around 1600 Brian came out to help, and we got done around 1800-1830. So that was a fairly accurate estimate.

Stock airbox, with the battery removed

Stock airbox, with the battery removed

First and foremost, I had to pull out the battery – nice and simple. The first “real” step was to get the front bumper taken off. That’s where the fun began. It’s supposed to be held in by four screws on the underside, two in the wheel wells (one each), six clips underneath, and six clips on top (toward the front of the engine bay). Alright, fair enough – here’s what was really holding my bumper on. One screw in each wheel well, check; three screws underneath (one short); two clips up top, with two others being replaced by my hood lock posts, so just for fun we’ll say there were only two missing up top; and one clip on the bottom. Add it all together and that’s one missing screw and seven missing clips. Awesome.

Front of car, minus one bumper

Front of car, minus one bumper

After getting the bumper off, I noticed that there was duct tape holding the plug for the driver’s side fog light on. Equally awesome. Anyway, the next step was to get the stock windshield wiper fluid reservoir out of the car. In retrospect, this should’ve been pretty easy, but it took me a while to figure out how to get the plugs off of the washer motors – just a simple squeeze clip, but I kept thinking it’d be more complicated. So I got those off, then went to pull the hoses off – I wasn’t sure if the motors would allow any fluid through without the solenoids getting juice, so I just yanked – turns out they would. Put the hose back on, run inside for a gallon jug, and drained all the fluid out through the rear washer motor. Then I kicked the jug over while I was looking for a tool, spilling half of what I so carefully collected.

Fender well, with the holes already cut, as per the instructions

Fender well, with the holes already cut, as per the instructions

Anyway, with the motors finally disconnected, all I had to do was pull the spout out of the top and remove three 10mm bolts to get the reservoir out. Nice and simple. After that I had to cut a 4″x5″ hole in the fender well and splash guard, because that’s where the intake pipe would eventually be running. This seems like it should’ve been easy, except that I was using a very jagged-toothed handsaw intended for tree branches, and the objects I was cutting were made of rubber and probably 2-3mm thick. It was very not awesome.

Drilling out the spot welds, as per the instructions

Drilling out the spot welds, as per the instructions

The next step was to get the battery shelf out of the car, so I could drill the spot welds out of a small extraneous bracket that’s used to guide the negative chassis ground from the battery. There were only two (out of what looked like it should’ve been three) bolts on top, so that was nice and easy, but there were also two horizontally-oriented bolts on the underside that were a real pain in the ass. I was wrestling with the first one when Brian came out to help – between the two of us we were finally able to get the damn things out. But not before incurring several hand injuries trying to turn those damn two bolts.

Then we went to drill out the two spot welds, and found that the drill battery was half dead. So that was slow going – had to drill them both out just part of the way, then wrestle the thing the rest of the way off. Reinstalling the battery tray was nice and easy though; just slapped it in and screwed in the four bolts – nice and simple.

Back to the windshield wiper fluid reservoir – it was time to install the new one. First I had to get the motors out of the old one, then get the motor grommets out – the grommets were real easy, but the motors themselves were a pain in the ass. Guess they have to be though, in order to form a proper watertight seal. After getting those out, it was real simple to just put them in the new one. Then – same thing – the large spot grommet had to be moved from the stock reservoir to the new one; that was also easy.

Getting the new reservoir to mount properly, however, was a huge pain in the ass. First we didn’t realize that we were supposed to use the rubber vibra-mount in the top rear hole – so, since we only had two bolts, we had some laughs that they hadn’t shipped out enough. Then we found that it didn’t quite fit the mounting holes – the top two were about 1/8″ or so too close together on the new reservoir. So we had to shear those out a bit with the drill in order to get it to fit. Then it was just a matter of reconnecting the wires and tubes to the motors.

Stock equipment removed, Injen elbow in place

Stock equipment removed, Injen elbow in place

Once that was mounted, we needed to get all the stock tubing off the throttle body, crankcase, and brake booster, along with removing the stock airbox. That was pretty easy; just undoing a few clips and yanking on some tubes, and removing three bolts to get the airbox out. Then we had to get the elbow pipe connected to the throttle body. That was a little less simple – there’s a hose of some sort mounted right underneath the air intake portion of the throttle body, and it made getting the clamp all the way to the end of the pipe quite difficult. Once we got through that though, just tighten and done.

Feeding the intake pipe upward, as per the instructions

Feeding the intake pipe upward, as per the instructions

Next was getting the actual intake pipe mounted. First I had to make sure the transmission was in 5th, for reference as far as clearance; in 5th, it comes very close to the intake pipe, and if you don’t keep it there for reference, you might mount the pipe in such a way that you can’t use 5th gear anymore – not a great outcome to the story. Anyway, all precautions aside, it had to be fed up from the bottom, through the hole in the fender well, under the battery tray, and into the elbow we mounted to the throttle body previously.

Intake pipe as it connects to the elbow, as per the instructions; the shift linkage (A) and air temperature sensor (B) are circled

Intake pipe as it connects to the elbow, as per the instructions; the shift linkage (A) and air temperature sensor (B) are circled

Well, this was a problem, because there’s a long mounting bracket that we couldn’t seem to get past the windshield wiper fluid reservoir. Upon closer inspection, I realized that the directions were telling me to use the vibro-mount as a post to hold both the reservoir and the intake pipe in place. So we pulled the top rear bolt out of the reservoir, relocated it to the bottom, got the vibro-mount in place, and managed to finagle the intake pipe all the way in and get it clamped into the elbow and mounted with its bracket.

With the intake pipe in place, it’s looking like the home stretch. Had to mount the air temperature sensor grommet into the intake pipe, pull the sensor itself out of the old intake, and put it in the new one; then run the supplied 4mm and 17mm vacuum hoses from the intake pipe to the brake booster and crankcase, respectively. Getting the crankcase hose secured was a bit of a pain in the ass; the stock clamps are sort of stupid – but eventually we got it.

Here's everything that came out of the car - lots of extra room in the engine bay now

Here\’s everything that came out of the car – lots of extra room in the engine bay now

Then it was just a matter of double checking that everything was secured and getting the bumper reattached. That was probably the easiest part of the whole thing. Getting the fender well screws in properly was a bit difficult, but aside from that it was pretty easy getting the whole thing on. After getting the bumper on and battery connected, it was time to start it up – I’d read that it was best to let it idle for 10 minutes or so, that way the ECU could recalibrate itself to the increased oxygen entering the combustion chamber.

Immediately, I could hear the difference. The motor and coolant were cold at this point, so the idle was up high – I could clearly hear air being sucked in from in front of the driver’s side tire. After letting it idle for a little while, it was time to go for a ride. I got out onto the road, wound it up through 1st and 2nd, then heard some sort of rubbing noise. So I slowed it down, turned back into town at the next light, and pulled over. The driver’s side fender well didn’t fasten to the undercarriage properly and it was rubbing against the ground.

So I drove home, figured out how to get it on properly, and took it out for a real ride this time. The difference is huge – both in power and sound. The VTEC crossover is very clearly audible now; it’s like night and day. The advertised performance gain from stock is roughly 20hp, plus the base 200hp – 10%. On the dyno that I went to, it should show about 15-16hp gain.

Will post before/after dyno charts sometime this week – whenever I can figure out a way to enhance the scan. The line was way too thin and light on the page, so you can barely see it on the scan. I’ll figure something out though.