I put my bottle behind the passenger seat and shortened the feed line for the reasons you mentioned. I also bought a large Speedway Motors gym bag, then cut the bottom out so that it fits over the bottle & valve. The bag also has an end compartment that zips up, I gutted the inner wall of that compartment as well so that it's zippered opening can be opened to expose the valve. Easy to open from my driver's seat, with the rear window tinting people rarely notice my nitrous system.
I have a purge system and used to use it, but it hasn't been on the car for several years. Purge system is good to have if you use a bottle warmer so you can bleed off excess pressure, but I want to use the nitrous at a moments notice without waiting for the bottle to warm up. For that reason I now calibrate for typical bottle temperatures and leave the warming blanket and purge system at home.
I also have a 50lb digital postal scale that is very handy for monitoring how full the bottles are. A nitrous pressure gauge basically only tells you the temperature of the nitrous, it won't tell you how much nitrous is in there. You need to weigh the bottle to tell how much is in there.
I also have a couple "mother bottles" that I use to keep the 10lb bottles topped off. Think I paid around $400 each for owner bottles full of nitrous. I have two because you want to get every ounce of nitrous out of the bottles that you can get, but when that bottle is empty my local welding supply store doesn't always have another full bottle in stock to swap it out. So far having two bottles has gotten me thru every supply shortage to date. Prices to swap the bottles out varies, so does the amount of nitrous that you can get out of them. Some mother bottles don't have a dip tube so you can flip them upside-down and completely empty the bottle. Others are upright bottles with dip tubes that don't always reach to the bottom. Never know which you are going to get or how long a dip tube is going to be. As a result of that, it's hard to pin down a number for nitrous cost per lb, but filling my own bottles using the freezer method I guess averages around $4 a pound. I also fill a couple friends bottles as well, what they pay me for the convenience ends up cutting my cost of nitrous down to around $2 a pound. If I had more local nitrous friends I could probably end up with free nitrous.
Grant
