I think the best thing to do for upgrades when you go to a more powerful motor is do the upgrades as things break. I know this sounds like a pain and sounds like a lot of down time but you'll save money not buying a part that is strong enough. I'll be switching to a brushless in my Stampede shortly and figured a number of things would need to be upgraded to handle it but from reading on the forums, I see many people that still run a lot of the stock components and haven't broke them in a year of abuse. One thing I did do right off the bat was get an aluminum idler, the plastic ones are easy to strip with anything stronger than a stock motor. You might check the Traxxas forum for suggested upgrades though.
Welcome to the site Nick. I see your interested in the 9L and 9918 warrior - if you are going to be running 14 cells that is close to the rpm limit of the motor. You probably want to upgrade the drivetrain first - CVD's, diffs, idler gears. That is what i would start off with for now. As far as for the battery for the servo - RC-Monster offers a UBEC - so a battery is not needed for the servo - your servo would get its current from the 18 cells - It dosent use a great deal of power and it beats having to charge your receiver battery all the time also. These are a few things to think about.. Hope this answers a couple of your ?'s......
I am still confused about having a battery pack for the servo? You say I don't need one? I also read somewhere about interfernce with a brushless system and another component on the stock E-Maxx? Thanks in advance to anyone who can help me out on that one.
What sort of guarntee/warrenty do I get from a Feiago 9L and 9918?
The Feigao motors are warrantied for 2 years against defect. The controllers for six months (I think-not sure). BK is good about taking care of business, so if something happened that wasn't your fault, I doubt you will have a problem getting it serviced (haven't had any problems yet).
I am really pleased on how quickly and well you have responded, I have being trying to get answers for months on other forums, and I got them all in 1 day here! :)
I replace parts as they break or as I feel like I want the next upgrade. I finally took the plunge and got the Gorilla Max carbon chassis. It weighs over 1/2 oz less than the stock chassis. But I got it so I can lower CG and the choice of batteries is greater too.