Last track day of the year for '06 - Thunderhill (new splitter,hood vent and wing )
01-14-2007, 12:40 PM
#47
Rennlist Member
Thread Starter
funny! actually, i did tape up some 8" tufts around the hood vent area and run up to 120mph. they were pretty flat at speed with the hole sealed. with it opened, the tufts (wool yarn string) were standing up at a 45 degree angle. thats the proof that its working.
Mk
Mk
Originally Posted by jon928se
Hi Mark
Methinks as your hood vent is in the big low pressure zone and hence most likely not seeing laminar flow over the hood the only thing that will affect the amount the amount of air "sucked out" is the size of the hole. I suspect Naca ducts, venturis, leading edge flaps, wing fences - er can't think of any more aerodynamic gizmos would make very little difference. Hence your solution looks about right to me - and if it looks right it probably is.
that must have been exciting - somthing like wing walking - I can just see the next series of Jackass - """Special guest, 928 racer Mark Kibort goes hood walking""" Just kidding.
Methinks as your hood vent is in the big low pressure zone and hence most likely not seeing laminar flow over the hood the only thing that will affect the amount the amount of air "sucked out" is the size of the hole. I suspect Naca ducts, venturis, leading edge flaps, wing fences - er can't think of any more aerodynamic gizmos would make very little difference. Hence your solution looks about right to me - and if it looks right it probably is.
that must have been exciting - somthing like wing walking - I can just see the next series of Jackass - """Special guest, 928 racer Mark Kibort goes hood walking""" Just kidding.
01-17-2007, 08:03 AM
#51
Rennlist Member
Mark - we did some development with underbody panels....but theory and empirical did not match quite right and we were off on our center of pressure calc's...the instability was quite unnerving!
Learned a lot and probably can build a 928 to generate a rquired downforce with minimal drag ... might have to save that for a faster 928..maybe 258 mph?
Cheers,
Marc
Learned a lot and probably can build a 928 to generate a rquired downforce with minimal drag ... might have to save that for a faster 928..maybe 258 mph?
Cheers,
Marc
01-17-2007, 08:36 AM
#52
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Originally Posted by John Veninger
Reveived this from the UK list. Wish there was one for an S4.
01-17-2007, 11:47 AM
#54
Rennlist Member
Thread Starter
ahh, glad you asked.
I have taken pressure readings all over the hood and nose. i can take a measurement all over the car. my 30,000 dollar a day wind tunnel is hyway 85. ill have any reading you want at 100mph!
Mk
I have taken pressure readings all over the hood and nose. i can take a measurement all over the car. my 30,000 dollar a day wind tunnel is hyway 85. ill have any reading you want at 100mph!
Mk
Originally Posted by Nicole
This only applies to the center line of the car. How would you know what happens further out?
