Ok, so I have been playing with a couple different setups on my Saturn SW2. I started with HAI pulling from behind the exhaust manifold and then thought that maybe I should pull from the air dam and run behind the header and then in, so maybe I could get heated ram air.
I have since actually read up on ram air and how little you can expect (I think I saw something like 0.1psi at 60mph or so and 0.2psi at 120mph).
Anyway, the 'ram' was a 3" hole in my air dam through 3" heating duct past exhaust header and into a new hole in side of stock air box. Ducting taping everything liberally, but clearly not 'sealed'.
I did 1 run to/from work with HAI, then 1 with RAM and today back to HAI. I have numbers but they are not super telling:
Code:
Date of Run Direction Mins Gallons Miles MPG Idle gal/hr AVG IAT Mode IAT Max IAT AVG Boost Mode Boost Max Boost
5/2/2012 To Work HAI 60 1.002 54.6 54.49101796 0.2 122.9 122 136.4 -7.528 -10.784 0.239
5/2/2012 From Work HAI 45 0.7238 37.802 52.22713457 0.209 129.26 127.4 156.2 -7.392 -10.784 0.09385
5/3/2012 To Work RAM 45 0.825511111 38.281 46.37248304 0.22 78.46 78.8 95 -7.44 -10.639 -0.05
5/4/2012 To Work HAI 68 0.924584444 49.42 53.45103987 0.188 166.29 168.8 185 -7.6153 -10.639 0.239
All of these runs are engine on P+G from 50-60mph, although looking at the mins >60 is due to stop+go traffic for 10-20 mins everyday. My From work didn't go through from RAM, phone was spasing out, but I did have gauges for a while and it was the same thing. Clearly more vacuum and could see/feel the less MPGs. The average vacuum looks higher, but I think that's because I was pulsing longer (with less power). I can definitely feel more power with the HAI, I need to do a run with stock to confirm but it really feels like more power than stock too. I did read that cooling the exhaust header should increase power and scavenging (helping 'pull' exhaust from the cylinder to the cooled header), although I doubt my HAI is having that much of an effect, it does make me wonder what heatsinking to the hood would do :-).
Basically, I dropped MPG with the RAM Air and noticed increased vacuum probably due to colder air and longer pipe. I then thought, maybe I just need a larger scoop, information online suggests that somehow the scoop size doesn't matter, but I don't fully understand that.
So I did some before/after runs with 3" RAM and with a 4"x10-12" ducting that reduces to the same 3" pipe (I can post a picture if it doesn't make sense, looks like a vacuum cleaner).
Anyway, I have numbers for that too, but not much too see, it looks like it might have .2psi less vacuum at idle and maybe .1psi less at speed but never went positive at 65mph. Either way the HAI had less vacuum (probably due to less density).
One of the suggestions I read was pulling the ram air from behind the radiator. This might still be something I try, moving the fan just a little bit will give me 4"x10" for my 'scoop' and then I'd have warmer air, sort of 'rammed' and could still run past exhaust header. I know any gain would be super minuscule though so definitely not a top priority.
Of course it might be 'easier' to just put a small turbo and somehow resist the urge to run boost (my goal is just to decrease vacuum and warm air, turbo would do both but more money and more involved).
Anyway, thoughts, comments, suggestions?