• January 15, 2009
• Category: Intake and Exhaust
• Written By: Chris
• 4 Comments

In the world of import intakes there are three major variations:

• Box intakes
• Cold Air Intakes (CAI)
• Short Ram Intakes (SRI)

All three have their key advantages and disadvantages, CAI is good for high end gain but tends to lack in the low end and can lead to hydro lock, SRI’s are good for low end response but lack in the high end and are prone to heat soak, and box style intakes sit right in the middle of the road, good low end response, better than SRI high end gain, and not as prone to hydro lock. There are plenty of each style intake on the market for Japanese autos, so in this write up I am going to focus mainly on two brands and styles, the CT (formerlly Comptech) Ice Box and the Injen SP1431 SRI/CAI intake. Both are based on results found on a 2006 Acura TSX and personal experience. I’ll also be using the “butt-dyno” as a feel for tangible response and all other dyno charts and/or graphs will be from the manufacturer.

We’ll start with the Injen SP1431.

What makes the Injen special is the fact that is a hybrid of sorts offering you either CAI or SRI applications. As shown in the picture there are two tubes and they connect together with a rubber-esc coupling. This can really make your day if you live in a wet climate and want to run a CAI in the dry season but would prefer to run SRI in the wet season to prevent hydro lock.

Injen claims that their MR technology gives you maximum performance gains all while staying within the factory safe air/fuel ratio and they back up that claim with a dyno chart showing a baseline of 162.79 horsepower compared to 169.91 horsepower equipped with the SP1431 with MR technology. The vehicle used for the test a 2005 Acura TSX six speed manual. You can view the chart by clicking here. Injen claims a full 7.12 horsepower gain over your standard OEM intake which is pretty good for an intake alone.

I ran the Injen SP1431 in SRI mode on my TSX for about 6 months and I didn’t feel a whole lot of improvement horsepower wise, I did notice some improvement with throttle response. Granted this may have been because by nature an SRI allows the air to travel less distance into the throttle body and thus the engine gets air faster, but I like to think the intake was doing it’s job. The Injen does offer that fairly loud and distinct throaty sound when you really step on it, but at cruising speed or under light driving conditions the intake is as quiet as OEM.

Install was fairly quick and painless and if you plan on leaving the intake as an SRI you don’t need to mess with removing the front bumper to get to the air resonator, simply remove the OEM intake box and tube. You will need to move some coolant lines around however and for this get some needle nose vice grips wrapped with duct tape to pinch off those coolant lines so they don’t spill. All in all to install the Injen SP1431 as an SRI should take less than an hour and most mechanics could complete the job in a half hour or less.

The CT ice box intake is exactly as it sounds, a box style intake which will re-use the bottom of your OEM intake box.

Unfortunately I was unable to find a CT Ice box dyno chart on a TSX. If you know of one with a bone stock TSX with the ice box please post it in the comments section below, thanks!

A key advantage of the CT Ice box is it’s design, in place of your OEM air resonator CT places a cone molded to have a bit of a velocity stack built in, the nice thing is that once this cone or horn as CT refers to it has passed through into the fender it makes a 90 degree turn facing the headlights. This keeps it out of most wet conditions and greatly reduces the chances of hydro lock while offering some of the benefits of sucking air outside of the engine bay. The lid on the ice box looks alot like your OEM intake lid with a few differences, one the ice box lid is taller allowing for more air volume and two the are no ridges on the inside top of the lid to make air transfer less turbulent.

With this design the ice box is able to deliver good low end response and decent high end gain, call it a compromise of sorts, you don’t get all of the benefits of an SRI or CAI but you get a good middle of the road of both SRI’s and CAI’s and a whole lot more than OEM. The ice box doesn’t offer that deep throaty sound though, there is additional sound but not a whole lot over stock, just enough for you to faintly hear it in the cabin and for the pedestrian to hear it as whine up off of the stop light.

Maintenance is a breeze since the ice box is a bigger and better OEM style intake. K&N OEM replacement filters fit the ice box easily and can be found at many local auto parts stores. To change, clean, or replace the filter simply unscrew the lid just like OEM and replace it as you typically would. Install can be a bit more tricky than an SRI, you’ll have to remove the front bumper to access the OEM air resonator and to mount the horn. The rest reuses existing parts like the OEM intake bottom and tube to the throttle body.

After driving both I prefer to ease of use with the CT Ice Box but I still lament for that throaty whale of the Injen. Which intake is better for performance? I can’t tell you that, each application is different and it depends on what you’re after. With either intake you wont regret your decision.

For more information on the Injen SP1431 click here.

For more information on the CT Ice Box click here.