Injen CAI

[float_6969]

I just wanted to put a review up about this intake, as I was never able to find one.

The Injen Cold Air Intake for the Mazdaspeed Protoge

I recently purchased this to help cure a problem the stock MSP has. As we're all well aware, the stock intercooler is a joke, and heat soaks with normal driving. I got the joy of experiencing this last week when I was driving down a small highway at about 55 MPH. I came upon a slower car and when an opening to pass came, I took it. I down shifted to 4th and started to pass when I start to hear pre-ignition. CRAP, so I up shift to 5th and get back on it. SAME THING!!! At this point I have almost no room left, and I have to look like an idiot, hit the brakes, and get behind the slow car again. I was pissed. The car does have a SSAFC, which helped with power and smoothness a lot, and it was over 100F, but I don't think that's an excuse. As I sat there, crawling along at the speed limit, I thought about what I wanted to do to improve the situation. I know a FMIC sounds like the place to start, but I always like to modify a car in a logical manner. The issue is with intake temps being too high, and the octane rating of the fuel is too low when in boost to prevent pre-ignition. Since I'm stuck with 91 octane, the only thing I can do is make modifications to decrease intake temps, and the easiest way to do that is a Cold Air Intake. I've had Injen's before and have always been happy with them. So off to the internet I went, and a few days later it came in! I installed it last night, and here are my impressions.

Quality is, of course, very high. Injen makes great products. Installation was pretty straight forward. You have to make a couple small modifications to the coolant overflow bracket, be able to get under the car to access the clamp that holds the stock intake on the turbo, and turn the steering wheel all the way to the right to access the area in the fender to fit the filter. The instructions are plainly written, and have pictures at every step along the way.

Impressions; First off, I'm happy with it. I did notice a slight increase in power, but the real test will be passing on a hot day and seeing if the pre-ignition stops. When you come on this site, you hear about "the turkey". And how to kill the turkey. Having been around turbo'd cars for the last 10 years, I knew what this was about, but last night I got to experience it! The intake is noticeably louder. You can hear the turbo spool, and when you're in boost and you let off the gas in gear and leave it that way, you get a "whoosh" from the bypass valve opening. But, if you let off the gas and clutch in, you get the turkey! If you don't know, this sound is called compressor surge. This can be a bad thing, but at stock boost levels, it's really not that harmful. I think it's been talked about, but I think the REAL reason it happens is because in the stock setup, the wastegate line connects to the intake manifold. It should connect to either the hot pipe, or the cold pipe. When you reference it to the intake manifold and you close the throttle, it also closes the wastegate. This makes the turbo spin FASTER than it was for a few moments, which makes MORE boost, but it does it into a closed throttle plate. This overwhelms the bypass valve, and voila! You have turkey. I'm going to modify my stock cold pipe and add a barbed fitting so I can reference the wastegate from there instead of the intake manifold. I'm pretty confident this will resolve the issue and is way cheaper than another BPV/BOV.

 

[lavishauto]

I like this review. I've never owned a turbocharged car before until my MSP. So I never thought to monkey with the intake. This is the reason, when u put another intake on would you NEED to tune your car when u put the intake on or no? I had in mind that the car might be tuned to how much air is being brought in by that certain intake. And If u put on another that brings in more air
that it would make it act funny and off? And another question. When putting a BOV on a car. Do u need to tune it once you put that on too?

 

[float_6969]

The stock MSP runs REALLY rich in stock form. Because of this, my first mod was a Split Second Air Fuel Controller. This is basically a little black box (piggyback) that lies to the stock ECU and allows you to tune the amount of fuel going into the motor. They make one specific to the MSP, so if you're stock, it's basically plug-n-play.

As for needing a tune with and intake, no, you shouldn't need a tune. Because the car has a MAFS and a IATS, the computer will make any necessary alterations needed for the extra air coming in.

Another thing to note is that the stock intake isn't very restrictive. A good quality panel filter in the stock box and there is not enough restriction to cost you any power. The main reasons I went with the intake was for the cold air aspect of it, and the increase in intake noise, which is something I've always enjoyed about turbocharged vehicles.