warm air intake is in

[lowbridescape]

The ram air effect behind a radiator fan would be marginal. They move air. They produce no perceptible pressure difference.

I thought about the original concept of putting the air inlet in the shroud behind the radiator. The result of that would be to cool the radiator with inlet air. Similar to heating inlet air with waste heat from the exhaust, but this way you reduce (slightly) the parasitic power loss of the radiator fan.

Now take that to the Xtreme. If an air/water heat exchanger (counterflow tubular h/e) were installed (mounted upstream of thermostat to get air hot faster), it would be able to heat inlet air almost to water temperature (180+ degrees F/82+ degrees C, if such was desired) and be able to calculate the heat drawn from the water at various rpm/throttle settings (heat = air volume sucked in X temp increase X specific heat of air at constant pressure) This should result in a measurable reduction in fan useage (< Whr) and possibly a smaller radiator, and a more consistent inlet air temp which would make managing the high temp air easier.

[Jay2TheRescue]

Originally Posted by lowbridescape

The ram air effect behind a radiator fan would be marginal. They move air. They produce no perceptible pressure difference.

I thought about the original concept of putting the air inlet in the shroud behind the radiator. The result of that would be to cool the radiator with inlet air. Similar to heating inlet air with waste heat from the exhaust, but this way you reduce (slightly) the parasitic power loss of the radiator fan.

Now take that to the Xtreme. If an air/water heat exchanger (counterflow tubular h/e) were installed (mounted upstream of thermostat to get air hot faster), it would be able to heat inlet air almost to water temperature (180+ degrees F/82+ degrees C, if such was desired) and be able to calculate the heat drawn from the water at various rpm/throttle settings (heat = air volume sucked in X temp increase X specific heat of air at constant pressure) This should result in a measurable reduction in fan useage (< Whr) and possibly a smaller radiator, and a more consistent inlet air temp which would make managing the high temp air easier.

I knew it would not be high pressure, but the pressure behind the radiator fan would be higher than atomspheric pressure, especially at highway speed. This is what I am thinking of ...

-Jay

[Jay2TheRescue]

Originally Posted by BEEF

on ebay they sell the fans you are talking about for power adders search "electric supercharger" the consensus on them is pretty grim though. for a small engine, you may see some gains if you can overcome the alternator draw and on larger engines they become a restriction at higher rpms because of the volume of air needed.

I still think your idea is valid when you were talkin about a passive ram air. you just won't see any gains at idle unless the fan is on. with my setup (and my grill is blocked about 80-90 percent) the fan has not come on for me since I put all of it on but I have also stopped going through drive-thrus which is where it would kick on for me. I don't think you ever want your fan to come on during normal operation. I think it is more of an "OH CRAP" device to save you from overheating. I may be wrong, all my experience is with newer cars than older anyway.

if it were me, I'd still give it a try.

I've been thinking about this... I see that these electric "superchargers" are pretty affordable. I do not want to starve the engine for air at full throttle though... I thought maybe fabricating a simple 1 way valve would do the trick. I would mount my "supercharger" inside the radiator shroud, and run a straight piece of 3" PVC pipe to the air cleaner box which on my truck is mounted on the passenger side wheelwell. I would then take a square of rubber cut from an old intertube and secure it over the hole where air normally enters the air cleaner assembly. The supercharger would supply positive pressure, and push the rubber against the hole, sealing it off. If the supercharger cannot supply as much air as the engine wants at higher RPM's the rubber will pull away from the hole, and air would rush in. At that point it would operate like a naturally aspirated engine, but at no point would I be starving the engine for air.

I love simple, low cost solutions...

-Jay

[GasSavers_BEEF]

you may also do good to go to grainger.com and see if you can find your own squirrel cage fan for cheaper. people on ebay tend to jack up the price of items after they give it a specific purpose. in the end, it is just a squirrel cage fan.

you could also monitor the flap you are talking about while someone revs the engine and maybe takes it to redline. all of this while the car is in park or neutral and see if it does reach a negative pressure situation. remeber that you are feeding this fan power through the alternator so you have to overcome those losses first.

[Jay2TheRescue]

Originally Posted by BEEF

you may also do good to go to grainger.com and see if you can find your own squirrel cage fan for cheaper. people on ebay tend to jack up the price of items after they give it a specific purpose. in the end, it is just a squirrel cage fan.

you could also monitor the flap you are talking about while someone revs the engine and maybe takes it to redline. all of this while the car is in park or neutral and see if it does reach a negative pressure situation. remeber that you are feeding this fan power through the alternator so you have to overcome those losses first.

I have a local Grainger store here, and I have an account setup with them through my business. I'm usually in there about once every 2 or 3 weeks. I have gone out the the parking lot and looked at the engine, and took some pics with my cell phone. I'll post them when I get a chance, but I'm thinking about ditching the idea of a squirrel cage fan again. I'm thinking 3" PVC into the shroud with a 4" to 3" reducer attached to it, facing the radiator. This would in effect make a funnel raising the ram pressure at highway speeds without electricity. Also, I noticed the corner of the shroud where I would be doing this would be the hottest. Right in front of where I plan to do this are the following: Radiator, External oil cooler, external transmission cooler, A/C condenser.

As I'm thinking right now I can pretty much do this all with scrap parts lying around the garage. I need about 2 feet of 3" PVC pipe, and an old intertube I can cut up. I can probably scrounge them for free. The only thing I would probably need to buy is the 4" to 3" PVC reducer to act as my funnel. How much can that cost? $2 or $3? I'll also probably need a tube of black RTV silicone, that's $2 or $3. I'm thinking this mod can most likely be done for under $10, a little more if you can't scrounge materials. I'll upload the pics I just took as soon as I can.

-Jay

[R.I.D.E.]

Jay you may want to make sure you are putting it on the hot side of the radiator. I can't tell from the photos but I think on GM the hot side is the drivers side (top hose from the thermostat to radiator is hot side).

regards
gary

[Jay2TheRescue]

Originally Posted by R.I.D.E.

Jay you may want to make sure you are putting it on the hot side of the radiator. I can't tell from the photos but I think on GM the hot side is the drivers side (top hose from the thermostat to radiator is hot side).

regards
gary

Technically it is the cool side, but I can aero mod grille block the left side. I don't want to block the right side as the oil cooler and tranny cooler are there. Plus, I would loose the benefit of a straight shot right into the air cleaner. Any bends will slow down and reduce the airflow. I'm not trying to get the air to 200 degrees or anything like that... The goal is to get warmer air than the ambient air temperature, and send it into the engine with positive pressure. I think the greatest mileage gains will be in the winter, where the air entering the engine may be 100 degrees instead of 30. I think I have a wireless digital outdoor thermometer. The kind where you put a transmitter outside, and can read the outside temp from inside the house. If I can find it I think I will put the transmitter inside the fan shroud where I propose to cut the the pipe in, and see what temps exist there. I should probably do that before I go any further with this.

-Jay

[cheapybob]

Originally Posted by BEEF

cheapybob,

the reason I am monitoring my temps so closely is because I did the grill block and the WAI during the winter/early spring. now the daily temps are getting higher and I just don't want the temps to get away from me on hot days. also, while I am riding down the road, my temps hover around the 190 point and that is engine temps. at a stop, it has gotten as high as 215 but that happened before I did all of this other stuff as well.

I do agree that it would be good to monitor other stuff but I like being able to see my water temps. I have also given thought into a second scangauge so that I can monitor 4 more parameters. I just can't justify the cost.

Just open it up a bunch so you don't need to worry about it. I tried the block off stuff as a combination aero and efficiency mod and got no added MPG from it that I could notice on my before/after 22 mi test loop, and it caused no end of problems with ignition retard everytime it went up, so I finally just opened it up again. My car isn't the same as yours, but that was the reality. Intake temp and throttle position are what are going to get results, IMO.

[cheapybob]

Originally Posted by BEEF

wait until this afternoon and see how temps get. mine are always lower in the morning. also with the heat shield, leave it on for a while and monitor it before you "swiss cheese" it. I have found myself trying to redo things that don't need to be redone so many times in the past. I have already bent up another piece of flashing for another heat shield and now my temps are right for the old one.

also for the air inlet, look into flex exhaust tubing. it worked good for me. just a thought.

The way I adjusted mine was just by bending one corner farther and farther open away from the header every time it got too hot. As long as its below 200 or so, I don't think it will ping, but to get it to stay reasonable in stop and go traffic, and have reasonable power, I found that 180f was a good number.

[R.I.D.E.]

Jay if you grille block that truck the fan clutch will sense the increased temperature and lock up more which will use more power. You probably will hear more fan noise when the cltuch engagement increases.

Consider an electric cooling fan, with thermostatic engagement that you can adjust.

regards
gary