madmax032
TYF Newbie
Hello! Being new to the Tahoe world and having come from a G8 GT with a Rotofab CAI, the induction silence of the Tahoe has been killing me. I don't have the budget for a good CAI at the moment but I kept on thinking-can all of the Helmholtz chambers be blocked without too much obvious hackery? 2 of those chambers also serve as passthroughs for the crankcase ventilation system so they couldn't be totally blocked off either.
Here's what the stock tube looks like inside:
Throttle Body Side:
MAF Side:
This is what I came up with. I cut slots between the chambers and the main intake tube to push in some custom cut blockoff plates:
for when the oscillating saw couldn't reach far enough, this got me the rest of the way:
I cut .8mm scrap sheet aluminum into some funny shapes to push into those slots (note the 3/8" holes for the 2 crankcase vent chambers). It was a ton of cut, check fitment, mark, cut again, check fitment, etc. to get to these shapes. I left extra metal at the top to have something to press the plates in with and remove them for trimming and sealing. The little hole at the top of the tall one is a leftover from the scrap metal's prior life and is completely outside of the port so it has no effect.
Throughout the whole process, I made sure to meticulously vacuum out cutting debris since I don't want anything getting sucked into the engine due to a silly free mod.
To make sure I didn't have any external air leaks, I globbed way too much high temp RTV on the plates before sliding them in and covered the outside edges with more RTV:
Here's what the 3 visible plates on the inside look like:
I didn't try to totally seal off the chambers (especially the crankcase vent ones that I drilled holes through)-I just got them mostly blocked off to prevent them from doing their "muffling" job. You can't see the 4th plate from the inside but in the RTV pic, you can see it slotted in. Forgive the random ugly scratches which are blind misses from 60 grit sandpaper I used to get errant plastic blobs off from the slotting process.
So, the burning question...does it work? Well, it's not a performance mod for sure-it's just blocking off the induction muffling chambers for MOAR ROAR! At part throttle, I don't notice a sound difference but the engine has a distinct new growl under heavy throttle and it sounds great. Still a bit quiet but for being a free mod that maintains the factory look (from the top) with a factory intake tube and no apparent compromises, it's a win in my book. I know that there's cheap aluminum intake pipes out there but they don't use the factory crankcase vent lines and since they are metal, they probably conduct a fair amount of heat into the intake air. Most expensive intakes are plastic/composite of some sort, probably for thermal management.
Here's what the stock tube looks like inside:
Throttle Body Side:
MAF Side:
This is what I came up with. I cut slots between the chambers and the main intake tube to push in some custom cut blockoff plates:
for when the oscillating saw couldn't reach far enough, this got me the rest of the way:
I cut .8mm scrap sheet aluminum into some funny shapes to push into those slots (note the 3/8" holes for the 2 crankcase vent chambers). It was a ton of cut, check fitment, mark, cut again, check fitment, etc. to get to these shapes. I left extra metal at the top to have something to press the plates in with and remove them for trimming and sealing. The little hole at the top of the tall one is a leftover from the scrap metal's prior life and is completely outside of the port so it has no effect.
Throughout the whole process, I made sure to meticulously vacuum out cutting debris since I don't want anything getting sucked into the engine due to a silly free mod.
To make sure I didn't have any external air leaks, I globbed way too much high temp RTV on the plates before sliding them in and covered the outside edges with more RTV:
Here's what the 3 visible plates on the inside look like:
I didn't try to totally seal off the chambers (especially the crankcase vent ones that I drilled holes through)-I just got them mostly blocked off to prevent them from doing their "muffling" job. You can't see the 4th plate from the inside but in the RTV pic, you can see it slotted in. Forgive the random ugly scratches which are blind misses from 60 grit sandpaper I used to get errant plastic blobs off from the slotting process.
So, the burning question...does it work? Well, it's not a performance mod for sure-it's just blocking off the induction muffling chambers for MOAR ROAR! At part throttle, I don't notice a sound difference but the engine has a distinct new growl under heavy throttle and it sounds great. Still a bit quiet but for being a free mod that maintains the factory look (from the top) with a factory intake tube and no apparent compromises, it's a win in my book. I know that there's cheap aluminum intake pipes out there but they don't use the factory crankcase vent lines and since they are metal, they probably conduct a fair amount of heat into the intake air. Most expensive intakes are plastic/composite of some sort, probably for thermal management.
It's just a very linear growl increase. I think if drones and moans from the intake were actually problem, aftermarket manufacturers would integrate their own helmholtz chambers but I haven't seen one yet for our vehicles or any I have owned. Higher end aftermarket exhaust manufacturers Do integrate silencing chambers (Helmholtz, tuned length secondary tubes, etc.) so the elimination of drones and moans is still a consideration for the aftermarket where it's needed.
