Hey, I have a 2.4L LE5 engine and I'm trying to figure out some turbo line logistics. I've figured out how I'm going to do the oil lines, and I bought the thermostat housing from an LHU to gain the extra port for the water return line, I'm just trying to figure where I should be getting the water feed from? I think the factory turbocharged engines get it from just above where the upper radiator hose connects but on my engine there is only a tiny M8 bolt there, and I haven't been able to find an M8 to -6AN adapter (too big of a size jump for decent flow I'd assume). I could drill this out larger but I'm trying to think of alternative places since that position is not ideal anyway. Garrett turbo recommends the feed flow into the lower port of the turbo and out from the higher (with a 20 degree tilt) so I can only assume that having the feed coming from a higher point in the system is less than ideal as well. In fact in my scenario it is the highest point in the system so any air in the system would appear there first which could be bad. I have three alternative positions in mind and I was hoping you could help in picking one or possibly suggest a 4th.

My ideal spot would be to use the drain plug on the bottom of the water pump with an adapter fitting. This positions it low and I won't have to weld or drill anything which is nice. My only concern with this is I'm not sure if this area actually sees water flow when the car is running or if it's only there as a drain. My next thought is welding a -6AN fitting to the pipe coming out of the water pump. This puts it roughly level with the return port with nice short hose routing but the feed and return are essentially coming from the same source so I don't know if water will flow well since it has a much larger path of lower resistance it can be allowed to take. My last resort is welding a fitting directly to my radiator end tank next to the upper hose outlet. It will be about the coldest source for water but the hose will be kind of an eye sore for me. A clean, professional appearance is very important to me which is why I don't just tee off the upper radiator hose as it appears many do.

Thoughts and suggestions greatly appreciated. Oh, and this setup is in a miata so I'll post a pic to help visualize things. Thanks!