Intake Pressure Tester

[Smith, Kirby A]

Brett Dikeman and Mike Miller on the quattro list recently addressed using a
plumbing pipe cap to pressurize the intake manifold.  Mike's solution is
shown at

http://www.blackfoot.net/~hlm5860/Tester.html

I built one last weekend and tried it on my '95 S6.  I was only able to get
to 12 psi before the oil filler cap started hissing.  As this cap shouldn't
ever see significant pressure, unless blowby is truly massive, I'm not sure
I should expect it to hold to the 20 psi I would have liked to achieve to
test my 1.3 atm boost setup.  

Anyone able to comment on their experience with oil filler cap pressure
resistance?

Kirby A. Smith   New Hampshire USA 
1988 90q Titanium gray, 189 kmi 
1988 90q Stone gray, 187 kmi 
1995 S6 Pearl effect, 90 kmi, A'pexi boost controller, MTM Stage 1