I've installed a few. They can be quite noisy if mounted wrong. It's best to mount them as far forward of the passenger compartment as possible and also mount them on additional rubber isolators to cut down on vibration. Even then you'll still notice when they cycle on and off, but it won't be nearly as loud and annoying as a vacuum pump rigidly mounted to say the firewall.
Troy
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1969 Chevelle
Old setup: Procharged/intercooled/EFI 353 SBC, TKO, ATS/SPC/Global West suspension, C6 brakes & hydroboost.
In progress: LS2, 3.0 Whipple, T56 Magnum, torque arm & watts link, Wilwood Aero6/4 brakes, Mk60 ABS, Vaporworx, floater 9" rear, etc.
Brian Hobaugh SCCA National Tour June 2014
First Hemi 'Cuda Convertible Ever Built
Short clips: Goodguys Pleasanton autocross and pit videos
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