g60karmann 0 Posted October 15, 2008 been doing my research on turbos recently and was wondering when we will see foil bearing turbos move from the aircraft to automotive applications, has it already happened :shrug: I was thinking it seemed like the best way to move forward, with friction reduced to nothing once spinning up fast enough, the temperature of the bearing would be reduced enough to not need oil / water being fed to it? plus with no friction (contact friction anyway) the lag would be reduced as well? I know there are plenty of experienced engineers on here so wanted to hear what you all thought, is it a cost issue? Quote Share this post Link to post Share on other sites
Kevin Bacon 5 Posted October 15, 2008 I've not heard of foil bearings before so I had to Google it - http://en.wikipedia.org/wiki/Foil_bearing Seems like an Interesting technology and doing away with water and oil would be a god send in car applications! I'm not sure it would spin fast enough at idle though, cause I'm guessing it acts a bit like a hover craft? Quote Share this post Link to post Share on other sites
boost monkey 0 Posted October 15, 2008 ditto that, I hadn't heard of them before. Brand names seem to use a highly durable low friction coating on the bearings instead of oil. I'm sure someone who is more Aero / Mech Engineering will be able to shed more light on the matter. Quote Share this post Link to post Share on other sites
g60karmann 0 Posted October 15, 2008 yeah from the looks of things the foil design creates trubulance between the foil plates to push them away from each other not sure what speeds this would need to be but i guess this can be tailored per bearing size and application. Could wastegate adjustment solve this i.e. let the turbo spin faster by closing the wastegate more at idle? according to http://en.wikipedia.org/wiki/Garrett_Systems Garrett have been making foil bearing turbos for the US Military which have been standard equipment for their aircraft since the 1960's!!! there must be some reason why this hasn't moved over to cars yet Quote Share this post Link to post Share on other sites
boost monkey 0 Posted October 15, 2008 cost perhaps Quote Share this post Link to post Share on other sites
Kevin Bacon 5 Posted October 15, 2008 Yeah, military budgets make F1 budgets look like small change, but the military usually take durable and long lasting in preference to cutting edge. And car parts, as we know, are deliberately engineered with a limited lifespan. I bet those foil turbos in tanks and things are still the original ones from the 60s! :D I suspect foil turbos aren't particularly fast spoolers in auto applications. Tanks and planes with vast engines don't have such a problem with spool up. Just a guess? Quote Share this post Link to post Share on other sites