Mishimoto Honda Civic Si final prototype parts

8th Generation Civic Si Intake Development, Part 3: Final Product Design

Interested in purchasing our new Civic Si intake system? Check out more details on our product page linked below!

Mishimoto Honda Civic Si Performance Air Intake

Our last write-up for this Civic Si intake included our dyno testing results as well as some insight into our use of 3D printing for rapid prototyping. Since then, we’ve tweaked our design to provide flawless fitment and we’ve constructed a final prototype. The last box to check on our list is a final fitment verification and road testing. Our test vehicle owner will be putting some additional road miles on the car and will offer his opinion of the improved intake sound. Soon we will have a new addition to our line of Honda Civic Si parts!

Final Prototype

Mishimoto Honda Civic Si final prototype parts
Mishimoto Honda Civic Si final prototype parts

As we’ve mentioned previously, this kit is a drop-in replacement for the stock setup. We will include all components needed for installation.

One of the key pieces to this kit is the aluminum intake pipe. Check out a closer look at this part!

Mishimoto Civic Si intake pipe final prototype
Mishimoto Civic Si intake pipe final prototype

As you can see, we intend to offer this in two finishes, a polished aluminum and a powder-coated black pipe. This pipe incorporates a stock-style MAF housing and will accept the stock sensor without issue. The smooth mandrel bend provides ideal airflow with minimal turbulence. In addition, the port on the pipe mates with the stock CCV line, requiring no modification to your Si.

Next, we have our air filter heat shield!

Mishimoto Honda Civic intake heat shield final prototype
Mishimoto Honda Civic intake heat shield final prototype
Mishimoto Honda Civic intake heat shield final prototype
Mishimoto Honda Civic intake heat shield final prototype

The purpose of this piece is to prevent high engine-bay temperatures from heat soaking the air filter. If heat-soak occurs, typically a loss of power will result due to the high intake temperatures. Most often, intake heat-soak will occur when airflow within the engine bay is absent, such as during long idle conditions (traffic, autocross staging, etc.). Our heat shield is in place to reduce the impact this heat has on our air filter and on the air entering the intake manifold.

We’ve constructed this piece from durable steel, which has been powder-coated black for higher scratch resistance. The edges are lined with a weather-stripping material to eliminate any vibrations between surfaces. Also notice the small bracket built into the front of the shield; this is in place to accept the stock cold-air inlet duct. You will see how this fits in our installed images later in this article. The box itself features two built-in mounting brackets. A third bracket is mounted to the box with the included hardware. This bracket is shown below.

Mishimoto Honda Civic intake heat shield ancillary bracket
Mishimoto Honda Civic intake heat shield ancillary bracket

Next up, our throttle-body coupler. This component mates our Civic Si intake piping to the throttle body.

Silicone throttle-body coupler for Mishimoto Civic Si intake
Silicone throttle-body coupler for Mishimoto Civic Si intake
Silicone throttle-body coupler for Mishimoto Civic Si intake
Silicone throttle-body coupler for Mishimoto Civic Si intake

This coupler is a five-ply unit and is far more durable than a rubber counterpart in terms of longevity and resistance to heat, oil, and fuel.

What would an intake system be without a filter? Check out the filter we are including with this Honda Civic intake kit!

Mishimoto Honda Civic Si parts
Mishimoto Honda Civic Si parts

This is our high-flow oiled filter. This unit is serviceable and can be cleaned for a lifetime of repeated use. The large surface area provides improved airflow compared to the stock paper filter.

Final Kit Installed

Time to bolt our final kit into place! Check out a few shots taken during the install!

The heat shield is tucked back in the rear of the engine bay, where the filter is positioned. Below you can see the cold-air duct in place on the clip we designed for our shield.

Mishimoto Honda Civic Si parts installed
Mishimoto Honda Civic Si parts installed

The heat shield is tucked back in the rear of the engine bay, where the filter is positioned. Below you can see the cold-air duct in place on the clip we designed for our shield.

Mishimoto Civic Si intake kit installed
Mishimoto Civic Si intake kit installed

Test Drive Report

The owner of this Si is an employee here at Mishimoto, so we were able to grill him with questions after he drove with this setup for a few days. In short, he was very pleased with the package. The intake sounded great, and he did indeed feel some extra power at the top end. He also reported that during normal driving conditions, light and partial throttle, the intake sounds similar to stock. During heavy acceleration and high throttle input, the sound is quite impressive.

Heat-soak never seemed to be an issue, despite temperatures reaching the mid-90s during the testing timeframe. This is fantastic to hear.

All positive points!

Coming up!

Not much left to do with this project! We will begin working on manufacturing our first batch of Honda Civic Si intake kits. In the meantime, we will be launching a discounted pre-sale for those who followed our progress. Check back for more details on the pricing and shipping information for our Civic Si intake pre-sale!

Thanks for reading!

-John

Interested in purchasing our new Civic Si intake system? Check out more details on our product page linked below!

Mishimoto Honda Civic Si Performance Air Intake

 

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