Ram Air vs. HAI vs. Warm Ram Air.

[Christ]

*With anticipation*:

"These pretzels are making me thirsty!"


Here's to good results!

[Tygen1]

I ate Chick-Fil-A so I'm good

Some more observations from commuting with the Cold Ram Air. IAT stays about 10 degrees above ambiant, I believe from heat soak because of the full grill block. Temps were 35-37 degrees today and the IAT was around 45 degrees. When I had to idle in ttraffic for a while the IAT rose to 55 then dropped back down to 45 when speeds picked up. While the Cold Ram Air didn't seem to hurt FE much, if at all, in the 50-60 degree temps, it seems to have a negative impact in the the 35 degree temps. Although this is all subjective right now, it "seems" to be a small negative impact. The negative impact could solely be the cold temps. MPG going to work today was 43.4, coming home was 39.2. Reallllly bad traffic tonight, but it should have been 40-41 and this morning should have been 44-45. At least that's what I'm used to seeing with the Mild HAI with IAT's in the 80-100 degree range. Can't wait to get the Wild HAI hooked up! The Heater Core I got is a bit bigger than I thought, it ought to put out plenty of heat

At 50 mph with a TPS of 21 (Idle is 17, WOT is 94):

MAF is reading around 8.00
Ignition advance is 38. This is max for my PCM.
GPH during these conditions is around 0.90
Instant MPG is around 57

(At least this is what my colesterol soaked mind remembers right now)

[Christ]

So are you going to do a variable heat control so that you can fine-tune the intake temps to figure out where you get the best economy in a given situation?

This could require alot of intense testing to find the perfect temp for each situation, but it might be worth it if you could program a circuit to control the temp based on inputs from the ECU's sensors... that would be awesome!

[Tygen1]

My plan is to run the IAT's up as high as they'll go while watching the ignition advance. When it starts to pull timing, I'll know I've crossed the line. Then I'll be able to figure out what intake temps I ought to be running. Of course I'll observe instant mpg while doing this.
Some other observations from a trip I took in July. I drove from Philly to S.Carolina overnight, pulling only underhood air. My IAT's at night were around 60-70, but when the sun rose they shot up into the 140-160 range and the FE began to rise as well. I was seeing about 10mpg gain from the higher IAT's, or at least I believe that was the cause... Anyway, this is what has lead me down this road. I was only able to get 120 degrees from my Mild HAI, so I need more heat to see if this gain I observed will return...the only way to know for sure is the A-B-A test that I hope to do this weekend.
No specific plans for a variable heat control until I know what temps I need. I really don't like messing with knobs while I drive and have no ambition to make a circuit to control this, so what ever I do will probably be fixed and be an attempt to give best results in the cold weather, when outside temps cross back over the 70 degree threashold, then I can re-evaluate the amount of cold air to bleed in...if needed.
Another fun fact: I run a full grill block summer and winter, I theorize that I spend enough time at speed that the benefit from the grill block exceeds the impact of the increased electric load from the cooling fan cycling. During the summer I just let the fan kick on to keep the temps in check. Even now in the cold it still needs to kick on fairly often to keep the engine temp under 225. So I'm kinda hoping I can pull enough hot air off this Heater core to reduce the fan cycling.

[Christ]

It would be interesting to see a graph of intake temp, instant fuel economy, and ignition timing curves plotted together. I wonder if we'd find that at certain times the max advance isn't actually optimal?

I hope the additional heater core will be sufficient to cool your fluids as well. That fan is probably hitting you pretty hard, I think.

[Tygen1]

When the fan kicks on, I can feel the car slow down, not much, but just a little more load. Instant MPG and GPH do not change at all when this happens, so I haven't really put much thought into it. I believe it is more of a sensation of slowing when the 30amp relay kicks that high speed fan on, when the amps settle down, the load becomes insignificant.
25 degrees this morning. MPG to work was 42.8.

[Christ]

So now I think capacitor to even out the load :P

[Tygen1]

Well, looks like a snow storm is gonna delay the test....

One other observation about the Cold Ram Air. I coast in neutral a lot, with the cold ram air I've noticed I don't get as good of an idle GPH on the faster coasts. For instance, I am used to coasting down a certain place at 50mph and seeing my idle gph around 0.19-0.21, this week it is 0.26-0.29, this has a large impact on the benefit gained from the coasts. This is probably due to the cold air, but I can't say that is all because the sitting still idle gph is not that much higher than it was with the Mild HAI. With the Mild HAI I was used to seeing 0.15-0.19, with the Cold Ram Air I still see that, but not as often, it's usually just a bit higher, around 0.21. So this leads me to think that the cold is causing some, but possibly the ram air effect is working by slightly presurizing the intake at higher speeds with a closed throttle. Sure wish I had a magnahelic to see what was really happening....

I guess we'll have to wait till after Christmas to get some results

[Christ]

Are you getting any kind of information from reading the MAF?

[Tygen1]

I've only just recently started watching the MAF, like Tuesday It seems to be right in line with the GPH readings, they seem to follow each other.