The Mustang Forum for Track & Racing Enthusiasts

Taking your Mustang to an open track/HPDE event for the first time? Do you race competitively? This forum is for you! Log in to remove most ads.

  • Welcome to the Ford Mustang forum built for owners of the Mustang GT350, BOSS 302, GT500, and all other S550, S197, SN95, Fox Body and older Mustangs set up for open track days, road racing, and/or autocross. Join our forum, interact with others, share your build, and help us strengthen this community!

My Sound Tube Delete "Cheap and Clean"

After searching and reviewing many options to delete the sound tube from my Boss, I finally settled on what I felt was the, must functional, factory looking, reversible and cost effective solution.

First was the firewall plug. I wanted a factory Ford grommet so I found this one. Many have seen it online and it works perfect. Pack of 4: $2.97+/- tax.
Boss%20Firewall%20Plug_zps6brk0tgt.jpg

Plug Installed:
Boss%20Firewall%20Plug%20Installed_zpsd7s3hkvz.jpg

Second was to find a solution for the now huge hole in the air intake tube. All the other options I had seen or found either looked cheap, out of place or just too expensive. So after much testing and researching I found this solution.

1" Copper Pipe Cap
Cost: $3.24+/-, from Lowe's. I'm sure I could of found this cheaper somewhere else, but I was tired of looking....lol.
Copper%20Plug_zps9amomah0.jpg

The copper plug is a press fit and as the inside of the sound tube port is tapered, it pressed in and sealed perfectly and will not pull through. Just for extra insurance, I did smear a very light coat of RTV around the copper plug prior to installation.

Installation Pics:
Boss%20Copper%20Plug%20Install_zpswvkqghgl.jpg

Boss%20Copper%20Plug%20Installed%202_zpsakc4jkr9.jpg

Boss%20Copper%20Plug%20Installed%201_zpsrxtpi1gb.jpg

Boss%20Sound%20Tube%20Finished%20Pic_zpsygabrml9.jpg

So for basically $4.00 and 5 minutes of work, I think I found the best solution for deleting the sound tube. I may eventually paint the inside of the copper plug, and or I found some heat shrink caps that I may install over the fitting just cause...lol. I have put several miles on it since installation. I have had zero issues with the install and am very pleased. If anyone has any questions, please feel free to ask.
 
Last edited:

ArizonaBOSS

Because racecar.
Moderator
8,574
2,445
Arizona, USA
Looks cool, too :)

My assumption is that the CTE of Copper is going to be MUCH higher than that of the plastic, so it will expand faster with heat and you won't have to worry about it becoming loose or un-seated during use.
 
Looks cool, too :)

My assumption is that the CTE of Copper is going to be MUCH higher than that of the plastic, so it will expand faster with heat and you won't have to worry about it becoming loose or un-seated during use.
That was my thought as well. Trust me, once I installed the cap, it's not going anywhere. :)
 
679
208
I use that same Ford grommet. That is the same one that comes with the Cobra Jet cold air kit now. I use the same rubber cap that was used on the Boss 302S that Watson used during the build....
 
I use that same Ford grommet. That is the same one that comes with the Cobra Jet cold air kit now. I use the same rubber cap that was used on the Boss 302S that Watson used during the build....
So I assuming you have this cap? Do you have a part number for it and or know where to purchase it? Thanks!
302S_breather.jpg
 
679
208
Yes,
that's the exact one.

https://www.mcmaster.com/#6448k39/=179lkaa

Watson had given me a spare and also provided me with the part number (6448K39). They also provided me a piece of stick on insulation that was also used in the build. It's the silver looking square you see in the picture you attached. I used the Ford Grommet because it looks neater and is "reversible".
 
Yes,
that's the exact one.

https://www.mcmaster.com/#6448k39/=179lkaa

Watson had given me a spare and also provided me with the part number (6448K39). They also provided me a piece of stick on insulation that was also used in the build. It's the silver looking square you see in the picture you attached. I used the Ford Grommet because it looks neater and is "reversible".

Awesome. Thanks for the part number. I'm sure that will help out others as well!
 

TMO Supporting Vendors

Top