Few questions about Motors, Esc’s, HDPE

[Al_]

I don't think you'll have too many issues with your 18v motors on 6s. At a full charge of 4.2V/cell, at 6s battery should be 25.2V, that's only about a 40% over voltage. Lots of people run the 12V 550 motors on 4s which is 16.8V, also about a 40% overvolt.

[Maxamuslead]

there is also 18v 550s which run at 6s no problem. It just 18000 rpm 775s which dont like 24v. 9000 rpm 775s dont mind 24v but due to them being 24v motors