Now we all know if you lower an normal car the handling is greatly improved (assuming it's done right). But on a Ferrari, with the flat underbody and the venturi diffuser; when you lower it does that negatively impact the car's downforce?
Not quite, even if done right, it is not always right. Very difficult to make a blanket statement on that one. If lowered too much, as demonstrated by Mitch (where are you Mitch?) and Rob Schermerhorn, lowering such a car too much can hurt the geometry quite a bit and put the tires out of their optimum friction point by reducing the contact patch. Yes, it can. While I have not seen it, nor am I an engineer, there is still an amount of air that must be passed through the bottom of the car to allow the rear diffusor to work at its optimum performance and intended purpose.
I think lowering increases downforce. The F1 tech they interviewed on Speed (Jordan? dunno) said the lower the cars go to more downforce they can get. That's why we have barge boards.
Lowering or increasing rake will increase downforce. Period. In short Lowering will reduce the amount of air traveling under the car causing it to move faster than it normally would. Creating a lower pressure zone than at it's original ride height. Increasing rake will cause a venturi effect under the car. As far as lowering having a negative effect on traction/handling any idiot that lowers a car and doesn't reset the car to proper camber, caster, toe settings is just that. An idiot. How someone could be smart enough to earn enough money to own one of these cars but not do his homework on such a modification is beyond me. To learn more about aerodynamics on cars go here: http://www.mulsannescorner.com http://www.mulsannescorner.com/data.html Some cars are very sensitive to ride height changes though (Porsche GT3). You usually get more out of the new lower center of gravity increasing mechanical traction than with improved aerodynamics. Downforce increases usually arent that great. But they do occur. Downforce: Ferrari 360 (1999) 294 lbs. @ 150 mph, with 400 lbs. of drag 424 lbs. @ 180 mph, with 576 lbs. of drag Lift-to-drag ratio: .73:1 Coefficient of drag: .34 (factory claim) Coefficient of lift: -.25 (factory claim) Reference area: 1.9 meters square Lift: Porsche 911 (2000) 600 lbs. @ 150 mph Aero. Balance @ 150 mph: F: 228 lbs. R: 372 lbs. Yes, the 360 had Downforce while the 911 has lift....
senna21, Would lowering the car also alter the center of pressure? If the rake angle was altered, I would think that it's location could change. Not sure if the front and back are dropped the same amount, though. Probably too complex a problem for blanket statements. Just asking.
Technically yes it would. But, depending on the cars aerodynamics, how much that shift would be and how much youd feel it would depend on the car. If the front and back are dropped equally there shouldnt be any real shift. You never know where the next big aero brake will come from: http://www.dukenews.duke.edu/news/design_0504.html Could this mean that well be seeing whale flipper like wings on F1 cars? If I were an aerodynamicist Id certainly be looking into it. The 8% better lift properties would translate to the same amount in downforce with a drag reduction of 32%!!!!! Those are big numbers if you can make it work on a race car. And remember you read it here first!
I've wondered about some of the research that has been conducted on fighters and if it could be applied to cars. The upper surface of the car bodywork would have thousands of very small holes (spacing and size TBD). An internal vacuum would keep pulling the boundary layer through the body of the car, in theory reducing drag because the shear layer between the non-moving boundary layer and the ambient air is greatly reduced. At least I think that is how it worked when I read it a few years ago.
Any change in suspension will change the geometry, but if the proper methods are used the geometry can always be corrected. Therefore problem solved
