Swiss Cheese Mod

[chauncey0337]

Here's a write up and pics and a different version of the swiss cheese mod-
http://tahoeyukonforum.com/forum/showthread.php?t=14022&highlight=swiss+cheese+mod

 

[DenaliAK]

I like the way my truck sounds with the swiss cheese mod and K&N filter. It has a nice whistle when you accelerate, similar to a turbocharger spooling up. Sounds cool to me.

 

[mharders]

I have also done this mod with the k&n drop in. I did notice I little more throttle response. I do like the sound it provides. I used a unibit instead of the hole saw and drilled in between all the ridged in the airbox, Much easier and are able to drill more holes because you can control the size of the holes(if that makes any sense)

 

[M3PO]

Thanks ezdaar. sounds like a simple mod.

Why would GMC choose to restrict airflow when a simple straight hose would increase performance

I don't think they would. My guess is, the sound tells the "butt dyno" there was a HP gain. I believe baffles are used not only to reduce noise, but in some cases manipulate airflow. A restriction can increase low RPM air speed, much like turning a garden hose nozzle to a fine spray. This increased air speed (not FLOW) can improve throttle response and low speed torque. This same airflow restriction can lower high engine speed HP, because it is after all a restriction. At the end of the day, it is a tuning device, much like an intake manifold. To each there own, I view it as "robbing Peter to pay Paul", unless you are getting power where you want/need, or simply the sound you want.

 

[bankswood]

Now I'm confused. My man ezdaar says cut the bottom out but the write up says drill one inch holes into the dirty side.

 

[chauncey0337]

You can do either or but if you cut out the bottom you also have to cut the metal plate that attaches the box to the truck. If you drill holes, that's it, mod is complete.

 

[bankswood]

Thanks. Going to drill holes in the dirty side.

 

[DenaliAK]

I drilled about a million small holes in mine. Not for any purpose other than I didn't have a bigger bit. So I made up for it by making A LOT of holes....lol. There was a noticeable difference in throttle response. I don't know if I'm making any more power, but you feel it faster and it pulls better up hills.

 

[My01yuk]

I did this mod, with a K&N drop in, and a Airaid M.I.T intake tube. I absolutley love the sound. Can't say i have seen an MPG increase though, but the sound is sweet. My wife comments that my truck doesn't sound right when i get on it. I laugh because she never said that before i did all of these mods.

 

[bankswood]

remove airbox completly, remove metal plate from under air box.
2 methods toopening airbox.

Cut out entire bottom leaving just the mounting boss's
OR
use a bigass hole saw bit to cut out four 4" holes in bottom of airbox.

Best method? cut out entire bottom.
Buy 4" pipe and silicone adapaters and make your own tube from MAF to TB.
Not you have a HDR (Home Depot Racing) CAI, it works very well for the 40$ you will spend on pvc and silicone adapters.

Remember, theres NOTHING different between a K&N, AEM, Specter, etcetc TUBE! They are simply TUBES
Its where you get the air thats the biggest issue. Stock airbox with no bottom is absolutly the best, in terms of cost VS performance.

My AIT's run 199 @ idle with specter, buddie runs the HDR setup above, his IAT's are 178.. I knw this by my predator programmers real time diagnostics setting.

I can't quite see how to fit a 4" PVC pipe from the MAFS to the throttle body. Itlooks like it will ride over the top of the fan shroud creating problems closing the hood.

as stated earlier I would really like to see a photo of this mod