hoov100 Posted June 22, 2009 Share Posted June 22, 2009 Ok, what i have been seeing alot of at the junkyards, are these little flaps placed in front of each wheels, to help push air to the sides of the car and keep the air from hitting the tire. My question is this; would this have any practical application along with SDI-type side skirts for a street/weekend warrior? Quote Link to comment Share on other sites More sharing options...
johnc Posted June 22, 2009 Share Posted June 22, 2009 They reduce drag from the rotating wheel and increase the low pressure are in the front wheel well if used in conjunction with other front tray modifications. By themselves with no front tray mods they mostly add weight. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted June 22, 2009 Share Posted June 22, 2009 I disagree with John. Even with no other mods, they'll still create more low pressure at the wheel wells which will reduce pressure under the car, and as your diagram shows that is one of the places that air exits the bottom of the car. It won't be as effective as if there were ducts venting underhood pressure to the wheel well, which could then take advantage of the lower pressure, but it should still suck more pressure out even if it is from under the frame rails. I don't see any flaps on your diagram oddly... I don't think they need to be small either. EDIT--also the leading edge of the tire is a PRIME source of drag and lift. Covering it up is a good idea. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted June 22, 2009 Share Posted June 22, 2009 I looked at the picture again and saw the flaps UNDERNEATH the air dam. I thought you were talking about flaps on the side of the body covering where the wheels stick out. You don't see wheels sticking out very much anymore, and for good reason. I think your underneath flaps would be useful if you have a car that is relatively high off the ground and relatively streamlined underneath (splitter). If you don't have that, then I think John is probably right. Quote Link to comment Share on other sites More sharing options...
hoov100 Posted June 22, 2009 Author Share Posted June 22, 2009 I disagree with John. Even with no other mods, they'll still create more low pressure at the wheel wells which will reduce pressure under the car, and as your diagram shows that is one of the places that air exits the bottom of the car. It won't be as effective as if there were ducts venting underhood pressure to the wheel well, which could then take advantage of the lower pressure, but it should still suck more pressure out even if it is from under the frame rails. I don't see any flaps on your diagram oddly... I don't think they need to be small either. EDIT--also the leading edge of the tire is a PRIME source of drag and lift. Covering it up is a good idea. So basically putting vents in the wheel wells? lets assume you vent all of the air going through the radiator to the top of the hood, then assume you had the vents in the wheel well along with the flaps in front of the wheels along with the entire wheel covered, would that be a noticeable improvement as opposed to say just a regular air dam with the upper grill blocked off? Quote Link to comment Share on other sites More sharing options...
hoov100 Posted June 22, 2009 Author Share Posted June 22, 2009 basically just trying to get idea's as I'm gonna have a few months to tinker with the car, the list goes like this. seal the upper grill and make an air box, then make a hood vent and vent ALL of the air from the radiator to the top of hood. make a fiberglass belly pan the covers the entire underside of the car, minus the trans tunnel which will be where the exhaust is routed. make an air dam that covers the front wheels completely. flush mount all of the windows and seal the cowl vents, make a seal for the hood, seal off the fender wells/make smooth fender wells. vortex generators on top and a rear diffuser for the bottom. remove current spoiler and install ??? design/create engine bay vents. Am I missing anything? Quote Link to comment Share on other sites More sharing options...
JMortensen Posted June 23, 2009 Share Posted June 23, 2009 All looks good to me. I think the rear diffuser is impractical for anything other than a race car because they have to be within a couple inches of the ground to really work. I don't know which is better strictly speaking, I'm sure it would depend on how the rest of the car is set up, but I like the idea of sending the air through the radiator and then out the wheel wells. I don't see why that wouldn't work just as well as having it go up and out the top of the hood. If the airdam were designed right I think it side radiator exhausts could be more effective than top exhausts on a car with a poor aerodynamic shape in front like the Z. You could still use vents in the hood to create more downforce by dropping pressure under the hood further still as the air flows over the vents and sucks air out from underneath. Quote Link to comment Share on other sites More sharing options...
mark Posted June 23, 2009 Share Posted June 23, 2009 Ok, what i have been seeing alot of at the junkyards, are these little flaps placed in front of each wheels, to help push air to the sides of the car and keep the air from hitting the tire. My question is this; would this have any practical application along with SDI-type side skirts for a street/weekend warrior? If this is a street only car, I really don't think a ton of aero mods will make a noticable difference. For a street/weekend car check out Austin Hoke's Z. That is one of my favorite street driven Z cars on this site. Just my 2 cents worth. Quote Link to comment Share on other sites More sharing options...
hoov100 Posted June 23, 2009 Author Share Posted June 23, 2009 All looks good to me. I think the rear diffuser is impractical for anything other than a race car because they have to be within a couple inches of the ground to really work. I don't know which is better strictly speaking, I'm sure it would depend on how the rest of the car is set up, but I like the idea of sending the air through the radiator and then out the wheel wells. I don't see why that wouldn't work just as well as having it go up and out the top of the hood. If the airdam were designed right I think it side radiator exhausts could be more effective than top exhausts on a car with a poor aerodynamic shape in front like the Z. You could still use vents in the hood to create more downforce by dropping pressure under the hood further still as the air flows over the vents and sucks air out from underneath. what i want to do is tilt the radiator forward about the same angle as a z31's and utilize that air flow to be directed on top of the hood and directed to the sides of the car, with ducting the shape of a " ||/ /" as my air cleaner sticks out the center of the hood. and then sealing off the engine bay as good as i can and run vents just below/behind the center of the front strut tower. and it would just look SICK! Quote Link to comment Share on other sites More sharing options...
ZWOLF Posted June 24, 2009 Share Posted June 24, 2009 If you duct your hood to evacuate all that hot air from the radiator the last thing that you want to do is hang your carb out of the hood into that heated airstream. That goes for cowl hoods as well. Quote Link to comment Share on other sites More sharing options...
hoov100 Posted June 24, 2009 Author Share Posted June 24, 2009 If you duct your hood to evacuate all that hot air from the radiator the last thing that you want to do is hang your carb out of the hood into that heated airstream. That goes for cowl hoods as well. thats what i meant by the little doodle ||/ / something like this: what i have for an intake right now is this: http://image.superchevy.com/f/super-chevy-comments/speed-by-spectre/10766466+cr1+re0+ar1/cold-air-intake.jpg Quote Link to comment Share on other sites More sharing options...
ZWOLF Posted June 24, 2009 Share Posted June 24, 2009 That's a cool look. I'm confused at what the small scoop is in the center of the hood. Just a note for consideration. Unless you have air conditioning, ducting all that hot air across the top of the car really makes it warm inside. Quote Link to comment Share on other sites More sharing options...
hoov100 Posted June 24, 2009 Author Share Posted June 24, 2009 i have no idea what that scoop is for actually. I'm not really worried about the heat, as the car is already going to be hot as hell, but A/C is another option for another time. Quote Link to comment Share on other sites More sharing options...
ZR8ED Posted June 24, 2009 Share Posted June 24, 2009 Small "flaps" like that would be easy to install on a belly pan or incorporate them into it (cutting and bending in an angle) Attaching them using rivits would be pretty easy, and you would be able to remove them if they didin't work out well. I would not place them at a 90 degree angle to the pan, but you could put a slight angle to it. If you placed them like in the diagram, they would be at the trailing edge of the belly pan, and thus close to the wheel, so the reduction in ground clearance would be less of an effect as it would be if the whole pan was lower all the way to the nose of the car. (does that make sense?) Might work pretty good on a street car that can't run a pan lower to the ground, though Mark is right about this not being fully utilized by a street car. So what. Want to add some aero to your street car, go for it. May not pass the "bang for your buck" mods, but it sure is interesting to work on. Scott. Quote Link to comment Share on other sites More sharing options...
Roostmonkey Posted June 24, 2009 Share Posted June 24, 2009 I would make them from plastic or hard rubber, my S2000 has them and now that Its lowered, they scrape ground here and there. Quote Link to comment Share on other sites More sharing options...
hoov100 Posted June 24, 2009 Author Share Posted June 24, 2009 that's the problem with my vehicles is that they see double duty, they are driven daily on the street and driven as much as possible though canyons, autox's and the occasional track day. so any little bit will help. as long as I'm not going as far as tapping of the hood and seams to go get grocery's nothing is too much for the street for me. Quote Link to comment Share on other sites More sharing options...
Daeron Posted June 26, 2009 Share Posted June 26, 2009 the original point of the flaps on the bottomside, in front of the wheels, and the low pressure area created, is a great one. However, something makes me NOT want to duct hot engine bay air over my front brakes. Maybe I am nitpicking, but I would prefer to route the hot air back to the fender panels behind the wheel wells. there is plenty of air flowing underneath the car that did NOT pass through the radiator, that still needs to be properly evacuated, is there not? In other words, I am asking a question... isn't there more to worry about than just the hot radiator air? Or is the situation more like, I should just ignore the ~100 degrees of difference in the cooling charge for the 1900 degree brakes???? Quote Link to comment Share on other sites More sharing options...
johnc Posted June 26, 2009 Share Posted June 26, 2009 If you folks are going to all of this trouble to get a 10th of percent reduction in drag then I assume you've already ducted cool air to the brakes. If not, then you will get a much greater decrease in lap times by doing the brake ducting then adding these little flaps in front of the front wheels. Quote Link to comment Share on other sites More sharing options...
hoov100 Posted July 1, 2009 Author Share Posted July 1, 2009 If you folks are going to all of this trouble to get a 10th of percent reduction in drag then I assume you've already ducted cool air to the brakes. If not, then you will get a much greater decrease in lap times by doing the brake ducting then adding these little flaps in front of the front wheels. what speeds though? as I'm looking for stability and reduced lift at speeds great than 100MPH. (dont want to be doing a wheelie in the car when you have to turn to avoid the 300' drop) Quote Link to comment Share on other sites More sharing options...
Gollum Posted July 4, 2009 Share Posted July 4, 2009 I don't know about the 10, but the evo 8 and 9 had interesting flaps. They weren't so much for creating low pressure for the tires (the absurdly low front end for a production car did that), but more created high speed air flow for the brakes. It's probably not as effective as actual brake duct work, but I haven't seen any production cars with full brake ducts in that kind of price range. What I'm kinda getting at is that a well designed piece could do both, and if it were attached to the hub in some way you can get it as low to the ground as you want as it should never scrape unless your tire goes flat. Quote Link to comment Share on other sites More sharing options...
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