it very much depends on what you categorize as "downhill" and what modifications you are willing to make to your bike. For true DH I would say "no effin way", but if you are talking about trail/lighter AM type riding then probably...."yea, it might go well with appropriate mods".

You do not mention the model of the bike you ride so that we can get some idea of the spec/componentry on it, but that vid posted just prior to my message is good to take note of.

shorter than XC style stem (90mm or less..ideally 70-50mm) and wide bars. That hardtail in that vid looked to have a set of Race Face Atlas FR bars..those are some wide mofo's and awesome for downhill and give you a lot of control, that partnered with a short stem to allow you to slow the steering and get back behind the saddle and lower your CG will help enormously.

Big, fat cushy DH tires for grip and traction beyond what skinnier XC tires will give. Perhaps 2.4" in the front if your forks will allow and 2.3 or 2.2" in the rear, but go as big and plush as they will allow. It will absolutely change the nature of your bike and likely make it a pain to pedal about in regular trails and suck at climbing hills as there will be a lot of rolling resistance (generally blockier-bigger tread, soft compound and low pressure) but it will pay off big time when heading down hill. Lower pressures is the norm for cush and traction and to manage as best you can from taco'ing your wheels.

Lower the seatpost to allow you to get behind it and below it and if you are agreeable to put your in all liklihood xc/trail spec'd and constructed frame thru the punishment of AM style downhill, you just might live to tell the tale. I would certainly not do anything extreme as I would presume your frame and fork are not ideal to manage that level of punishment. Remember that rocks and roots can at best break your bike and at worst break your face! Use the appropriate gear for the task at hand.

They make AM hardtails for just this task that paired with a long travel fork are quite great. As always, every eventuality is fixed by throwing cash into its resolution...