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Uwe Braun of the Porsche factory GT development team has indicated that on the Cayman GT4 you can balance the aero at the front after adjusting the rear wing for maximum down force in a matter of minutes by removing the little flap ahead of each front wheel, which are held in with two small bolts on each side. See attached picture.
Do we have anything like this in our GT3 cars?
There appears to be a similar flap piece in the GT3 but I don't think it serves the same purpose. Wondering why did they do that for the GT4 and not the GT3. Any thoughts on this. Mark
Not really sure, however It appears when you remove the flap, it opens up air channels that increase downforce on the front end. I was hoping someone here can provide more information and also wondering why not make this available to the GT3, and especially when both cars share the same front end. Mark
In the latest Chris Harris GT4 review video, AP talks about this removal flap at the end of the video. Still wondering why not have this available to our GT3 cars, considering they are supposed to have identical front end. Mark
Not really sure, however It appears when you remove the flap, it opens up an air channel that increases downforce on the front end. I was hoping someone here can provide more information and also wondering why not make this available to the GT3, and especially when both cars share the same front end. Mark
Interesting. Thanks for bringing this up. Not an expert, but I think you are correct. I am guessing that by removing this cover it opens a channel that allows air to exit from under the front splitter up over the front wheels, thus creating an area of low pressure and downforce at the front axle. Like in this diagram, and similar to effect of the louvers in the GT3 RS front fender and in many LMP cars. Recall that apparently by removing the "mesh" from inside the 991 GT3 RS louvers, one can increase the downforce even more, presumably because the mesh must slightly impede air flow through the louvers. Likewise, I'm presuming opening up this channel on the GT4 has a similar effect of increasing downforce.
AP talks about it with Chris Harris at 9:00 on this video as you stated.
I've lightened the above still image to better show the removable cover (circled).
This cover seems to exist on the GT4 and not the GT3 precisely because the former has an adjustable rear wing (adjustable from 4.5 - 7 degrees that would need greater balancing downforce on front axle when increasing wing's rear axle downforce), whereas the wing on the GT3 is fixed and therefore no need to add adjustable front axle downforce since presumably front and rear axle downforce are already optimized and balanced. [EDIT: corrected below by Zulu Alpha]
BTW, I was wondering about the "ducts" that hang down in front of the wheels in both the GT4 and the GT3. Does anyone know their purpose? (other than to crack when driving over speed bumps and the like!!) Is it to reduce tire quirt from interfering with the underbody diffuser aero?
An explanation of tire squirt: 'tyre squirt' this is when the flow that ejects from the sidewall of the tyre squirts into the path of the diffuser.
The slot/duct in front of the tyre redirects the airflow intended to hit the tyre head on minimizing the 'squirt' effect toward the diffuser.
- See more at: http://somersf1.blogspot.ca/2012/05/....aaMIW5U1.dpuf
This photo is from Elephant Racing's suspension overview and shows not only the plastic bump in front of the wheel, but also the lack of the removable cover on the GT3.
Last edited by <3mph; 03-10-2015 at 04:40 AM.
Reason: wrong about GT3 wing
BTW, do we know whether the GT3 RS rear wing will be adjustable like the GT4? From the best photos I've seen, it seems to have a similar appearance. Perhaps then GT3 RS also has adjustable front axle downforce then (other than by removing the mesh)? Anyone hear anything about this?
Thanks for sharint the info. Makes sense,and very informative but the mystery remains why the GT3 does not get one while it also has an adjustable rear wing.
One more question, comparing the pictures you posted from elephant racing of the GT3 and the picture from Chris video, I wonder if the plastic bottom that has the raised duct piece along with the plastic piece that is attached by 3 screws below the wheel mesh on the GT4 and of course the flap piece in question that is attached by 2 screws would fit our GT3. Comparing both pictures the pieces look identical or has at least same dimesions with the exception of course of the addition of the little flap piece. Wondering if it fits our GT3, it would provide some addition down force at the front wheel. Just wondering. Mark
On a second thought, my ducts are already badly cracked and missing few chunks, so I may be getting that additional airflow after all, and without the need for the additional small flap! Probably should adjust my rear wing for maximum downforce to balance the car and take advantage of the additional downforce I am generating up front from the severly cracked ducts. Mark
Most Wings are adjustable with maximum downforce usually around 10 Degrees UP varying slightly with the size of the Gurney Flap. On most tracks, additional downforce will trump additional drag for faster laptimes.
03-09-2015, 03:00 AM
Balancing Aero At The Front
