Completed my DIY intake/ram air with my stock air box on my GS4 yesterday. I bought a 3in. flexible intake tube from autozone for $19.99, drilled a hole in the air box, connected it with some sealant, and snaked the tube down to the bottom of my bumper by the passenger side fog light.

The overall fitment was tight as you can see from my pics but with some time and patience it was easily accomplished! Once completed I reset my ECU and took it for a 20 minute or so test run. The results seem AMAZING thus far ...It feels like I've gained power throughout the entire range! It feels quicker off the line and once it hits 4K RPM it really takes off and sounds a lot more aggressive too!! Oh and no CEL codes were thrown

I would put this set-up up against any intake out there for our cars!! It's unique because it still utilizes all the great things about the stock set-up but just adds a lot more air to the box because it's still drawing air through the scoop by the grill on the hood and also through the added tube down by the fog light!

Here are some pictures to give you a visual!!

If any of you are thinking of doing it you REALLY should!! It's probably the best DIY performance mod out there for the GS400!!

 

the work scene

 

tube getting sealed

 

another tube shot!

 

picture of the air box with tube and K&N Filter

 

Box installed with tube snaked down below

 

This is where the tube comes out. I used a black zip tie to hold it in place on the bumper!

 

interesting. i wonder if i can do this on GS300.

 

Got the condensation out of my fog light with a blow dryer and re-sealed it! Lol

 

Finished product

 

Can you take a far shot... not as close? If only it could be made to look oem, i'd do it (while I have my intake out already). TIA

 

You should be able to! I would just take measurements to make sure you can go as big as 3in on the tube since the air box is different on a gs300 compared to a gs400...I'm sure you would notice some gains but maybe not as much because you have a I6 instead of a V8

 

yeah you won't really see any gains, also i'd suggest this



just so you won't have the chance of getting water logged

 

You can't even see the tube inside of the bumper when standing right in front of the car. That's how stealth it is..Everything looks OEM except for the tube coming out of the intake box under the hood!

 

Very clever! Good install!! Im sure you'll notice a slight increase in power, Mostly at higher rpm vs low range due to the forced air shoved in the tube!