CWM for unsupported device but with same specs I have an archos 40 titanium and I'd like to install cwm (already rooted). There is no official support but on this thread they say their  instructions worked for the 45 titanium which has almost the same specifications (same processor and RAM amount ), only the screen size differ (+0.5 inch). Is it considered safe to follow the instructions for my 40ti?
When unofficially modifying your phone, nothing is safe... But if others say it worked, give it a shot.  Just keep in mind that anything can go wrong, so back up your data and have a Plan B for recovering your system.

Edit:  Plan B (how to recover your phone):

Recovery Software:  http://www.archos.com/faq/index.php?action=artikel&amp;cat=120&amp;id=301

Stock ROM:  http://update.archos.com/AFMv1/storage//files/full/a40ti/20130922.101129/OTA972121_8916_V007049.zip