Well you already have a vented bonnet so there isn't much more you can do unless you install some vacuum fans in there to suck the air out without adding weight. You won't get much ram air effect on a sloping radiator, so if it keeps the engine cool while you rev it out, then it works. Using a sloping radiator with air moving below it at speed, you might even get negative suction if the air moving across the face of the radiator is fast enough. Hanging some kind of louver to redirect the airflow through instead of under the radiator is going to catch every bit of road crap and smash it through your radiator. Someone already mentioned stone chip problem. Use your rotating wheels to suck air from behind the radiator through the wheel arch and out the sides? ** vented nose versus smooth nose panel, put a catflap on it, operate from a lever in the cabin :rolleyes2: maybe you could make it work? what about this
Could very well be the case that the car'll cook at speed, yes. System will have no problem at idle that much I'm certain of - bigger surface area, twin pass flow and same CFM. At speed is the big question. I'm not interested in the idea because I'm afraid of a lag issue - more to the point of that if the system did work, it would be very efficient in the sense of having as short a piping system as possible. If I decide to pull the plug on this idea (likely) then the intercooler will be front mounted in the regular position with a custom rad behind it on top of the rad support. I'd simply prefer this idea if it would work but no real harm done if it doesn't. Bingo There's no way I would go ahead with this set up if I determine that it'll cook at speed. What a waste of money! That's actually something I'm looking into - a rubber lip that hangs down in underneath the front bumper in front of the radiator alone. Preliminary research states that it'll help create a pressure drop behind it which is a good idea - but to be honest, people get degrees studying this stuff. I can't judge completely so quickly. Thanks for the extra input Graham. That set up looks very similar to others around with the intercooler also mounted on a big angle. The air is of course sucked out through the negative pressure area at the front of the bonnet. There are plenty of set ups out there with both the radiator as well as the intercooler are heavily angled - the logic follows something along the lines of "the air has no path of less resistance". So it goes through both cores more equally. I toyed with the idea here but honestly it would send the piping haywire and probably defeat the purpose over going with two regular vertical mounted cores. Would be great if I was employing a single in/out cooler! The air needs to go through the mouth and exit under the car, after having traveled through the radiator. Venting air into the radiator from underneath the car is the opposite of what I need! The vented bonnet honestly isn't going to help the situation at all; my forward facing vent could only lend to pressurising the bay further, where the IC needs to vent to. The wheel wells are unfortunately high pressure areas, so I won't be able to vent the rad there. Would be great if I could.
Can you think of any tidy ways to vent through the front quater panels? Will be tricky achieve without messing with the body lines but fairly popular with supercar manufacturer types. Maybe some extra exhaust fans? Could be going too far...
OK so the louvres should be on top of the radiator (you'll have some mesh to stop cats curling up in there and repel road grit and bugs anyway) to help ram more air through the radiator than the E fan at highway speeds. You will know if it will work, after you build it
Anti - heat rises so you want to leverage off this. From your original drawing move the cooler down as far as it can go and tilt it back 30 degrees. Mount the rad on top and utilise some bonnet vents with a slight lip similar to an evo 9 to create the neg pressure zone to help airflow through the rad. You will retain a short inlet tract and gain better cooling. I am sure race cars have the rad bottom mounted and the cooler on top because they are travelling at sustained road speeds. For a road car you need it to be functional and running cool when stationary.
I'd rather stick with a traditional set up than modify the bodywork to support the set up. Looking more and more like a traditional set up will be the way to go.
I'm looking at it from an environmental perspective. With the e-fans so low what about water damage from water on the road? The other problem would be rocks from other traffic (passing or following) With the radiator at that angle and the thinness of the capillaries would lead to a very easy puncture of the radiator. Deformed road surface or debris would be a major hazard to the radiator and the e-fan.
Nah I don't buy that sorry. The radiator is set at an angle much closer to the trajectory a rock would have to travel on to make it's way through the "mouth" of the bar, making it much more likely to ricochet off of the radiator. Like skipping stones. A regular upright radiator would cop the full force. That's my story and I'm sticking to it... FMIC users don't have an issue either. Radiator fan motors have to be waterproof or they'd kick the bucket every time you had a spill topping up your cooling system. Good money maker for the supplier but I don't think they'd be too popular
More or less looking beyond this idea at this stage. Still not 100% conclusive on what sort of pressure would exist under the front end of my car but if anyone can point me in the direction of some technical information conclusively stating it'll negative I'd really appreciate it. Otherwise, I've spent quite some time measuring and mapping out a more traditional alternative - custom rad mounted on a custom rad support (always wanted to get rid of mine, previous owner bent it ) with the FMIC just in front, between the frame rails. Special thanks to member Newz for helping me out with the planning of this at about 'til about midnight on Tuesday, heh.
One thing that comes to mind is installing a divider - force some of the air to go through the radiator; funnel it in with no opportunity to pass over it. Roughing out the CFM after measuring the cross sectional open area would serve as a great way to guide where to place the duct.
yo anti if it helps i have used a balometer from work on a working clutch fan when i had the shroud in place and without to prove something, was 1250 lps without a fan shroud and 1390 with it inplace
Wow yeah that would be hugely helpful. Can you elaborate on that a bit? How new was the fan clutch? How conclusively accurate is the test? That comes to about 3000 CFM. While researching people seemed to think it pulled 3-4000 CFM but nobody actually had a source. Sounded completely fabricated.
clutch fan was a older unit but i had never had or since then have had any cooling issues car has always run perfect temps. when i put the balometer on their i left it for about 5 mins, it did vary but not by much the figures i gave where a digital average over the time it was setup cfm is only a volume of air, i used a balometer with some cardboard ducting to find out the lps witch u convert to cfm
Yes I know what CFM is but you really need to know pressure etc as well to come up with comparable figures. SPAL and high end manufacturers generally provide info re what pressure the fan was tested at, and flow characteristics as pressure increases.
