pop-off valve installation incident.

[Soze911]

Greetings, while making the hole -with the appropriate hole-saw- for the pop-off valve on my 82 Targa, I unknowingly drilled past the Air box and into some part just undernneath the Air box. I have driven the car several times and I don't notice any difference. Can it be that whatever I drilled into is not affected by the hole?
thank you

[Rockafella]

I think you mean you drilled past the first layer and into another layer of plastic IN the airbox, no? If you actually went through to the other side, you would likely create a vaccum leak so large that the car wouldn't run right.

My guess is you went into one of the lower layers that act as a "manifold" of sorts to the left side runners. While not great, you should be ok to drive your car like that with no real ill affects.

[Hawks911]

Soze,

I had exactly the same experience. I couldn't believe that in all the research I did on the subject (including Wayne's 101 Project book) that no one mentioned the need to be ultra careful about the tight clearance beneath the airbox floor. I drilled into a small aluminum chamber directly beneath the larger hole created by the hole saw. I corrected the mistake by using Permatex Ultra Blue RTV to glue a small quarter sized aluminum patch over the hole created by the pilot bit in the saw. I tried to vacuum out any metal shavings and hoped for the best. Have put on about 500 miles since then with no known problems.

Good luck!

Mike

[Soze911]

Yes, Hawks911 described it much more clearly than I did. I used epoxy (the same kind I used to seal the pop-off valve to the airbox) and don't really feel any difference in performance. I too did ample research before getting the courage to do this modification myself, and no one mentioned that aluminum chamber beneath the airbox.
It doesn't sound like something that must be corrected though, right?
thanx you two.

[dlagerstrom]

I just did this this weekend as well. Although I was lucky enough not to put a hole in the thingy. It appears to be a baffle of sorts. There is a series of tubes that go to each of the 6 ports on the bottom of the airbox. I have been trying to figure out what they do exactly but don't have a clue.

[john walker's workshop]

it's a plenum to contain and direct the cold start valve spray down each runner so there's less chance of blowing the airbox. the older ones didn't have it.