M.Bonanni Project 370Z V3.0 | Clean Slate

M.Bonanni · 09-09-2011, 10:23 PM

You may have been kidding, but you've hit the nail on the head haha. All cars are shaped like wings....the airplane kind that generate lift. Any object that has more surface area on one side vs. the other will create either lift or downforce, the side with the less surface area sees the pressure. If you flattened the surface area of the top of a car it would be much much longer than the bottom surface area which means pressure builds under the car and pushes upward creating lift. An airplane wing is designed the same way where the top half has a longer surface area than the bottom. An automotive wing is basically flipped upside down so the pressure is a downward force.

That being said, sticking the laminar air flow to the back of the car for a longer period of time actually creates more lift. So there's a trade off at some point. In one of those links they use the example of a modern VW bug which is a perfect example of aero fail despite the laminar flow of air over the rear sticking all the way to the license plate basically. As far as the rear diffuser goes, the vertical fins are basically VGs. Going back to the length of the surface area thing, rear diffusers slope upward and the fins help air stick to the surface creating a longer surface area on the bottom of the car so it better equals the top of the car basically producing negative lift, not so much downforce.

travisjb · 09-09-2011, 10:32 PM

right makes sense... in fact, I've been thinking about extending my rear diffuser out another 6" now that I don't have aero restrictions... I'm also, as I pointed out on my journal, going to try and craft an under-tray... I'm sure that will be a lot of trial & error!!

btw, I'll point out for folks that are interested in this topic, the author of the previously linked articles wrote another article three days ago... here

AutoSpeed

travisjb · 09-09-2011, 10:36 PM

hey one more thing sticking in my head... I head a world-known PhD in aerodynamics look at my car believe it or not about 1 year ago... he told me to try and minimize the boundary gap coming off the rear deck and keep it attached so that it would join the air coming off the diffuser... he said it would make the diffuser more effective... obviously runs counter to the car as upside down wing theory, but I remember he was adamant about it... brain hurts!

M.Bonanni · 09-10-2011, 04:54 PM

Quote:

Originally Posted by travisjb

hey one more thing sticking in my head... I head a world-known PhD in aerodynamics look at my car believe it or not about 1 year ago... he told me to try and minimize the boundary gap coming off the rear deck and keep it attached so that it would join the air coming off the diffuser... he said it would make the diffuser more effective... obviously runs counter to the car as upside down wing theory, but I remember he was adamant about it... brain hurts!

I am sure there is an exception to the general rule I just don't know what it is. I would go with the experts. I am guessing the benefit of doing that would outweigh the negative. If there's one thing that I have learned in my very short and very basic gathering of aerodynamic knowledge is that there aren't many things out there that don't have some sort of trade-off.

Kingbaby · 09-11-2011, 03:15 PM

Quote:

Originally Posted by travisjb

like these?

Exactly just a little smaller to not be an eye sore. Where does the air from that go?

Quote:

Originally Posted by ChipsWithDips

What are these trunk vacuum ducts you speak of?

I may have used the wrong word, but in the trunk of a 350z are two vents on either side of the trunk. I'm guessing there for cabin pressure. Not too sure but air from the rear quarter window could flow from the window to the outlet in the trunk. Creating downforce? Ferrari's do it!

Mike · 09-09-2011, 10:41 PM

Mike, when doing the actual run, how about running without the air filters?

Kingbaby · 09-09-2011, 10:42 PM

Also the rear quarter window I always wanted to have someone make a subtle duct for that area and channel it to the vaccum ducts in the trunk!

ChipsWithDips · 09-10-2011, 01:08 AM

Quote:

Originally Posted by Kingbaby

Also the rear quarter window I always wanted to have someone make a subtle duct for that area and channel it to the vaccum ducts in the trunk!

What are these trunk vacuum ducts you speak of?

travisjb · 09-09-2011, 10:49 PM

like these?

and some you can buy here
http://www.uniqueautodepot.com/Nissa...dy-p/13020.htm

travisjb · 09-11-2011, 08:22 PM

on a street car those scoops would have no functional purpose that I can think of... on a race car, they are used for rear diff cooling, driver cooling, and potentially rear brake cooling... on the car above, they cool the rear diff

M.Bonanni · 09-13-2011, 10:59 AM

Back on topic...

New sway bars just arrived from Whiteline! Very excited about these...of course they won't help at all for the standing mile, but they will for the road course!

onzedge · 09-14-2011, 10:59 PM

Quote:

Originally Posted by M.Bonanni

Back on topic...

New sway bars just arrived from Whiteline! Very excited about these...of course they won't help at all for the standing mile, but they will for the road course!

definitionxmk · 09-13-2011, 11:36 PM

M.Bonanni · 09-14-2011, 08:01 PM

Well, after all is said and done, I am not sure the Mojave Mile is going to happen for me next month. Not looking like my replacement tires will pull through in time and I don't have the cash at the moment to pony up for a brand new set of tires and the event. I am bummed, but there will be another one next spring. For now, focus shifts toward SEMA and possibly running the North American Festival of Speed Time Attack Invitational just for fun...again assuming I get some tires.

M.Bonanni · 09-26-2011, 11:41 AM

Looks like another start-up time attack series is hitting the western states. I am usually of the impression that for this type of motorsport to re-build and survive in the states we need just one organization that everyone turns to, but this one has a completely different rulebook that is more grassroots oriented. I stumbled across this link but haven't seen any official announcements from the new series. They do have their first event listed though. So far I think I might switch my focus for my 370Z build from N.A.S.A. TT to this ETA Street Class...

Extreme Time Attack

09-09-2011, 10:23 PM	#1 (permalink)
M.Bonanni The370Z.com Sponsor Join Date: Nov 2008 Location: Las Vegas Posts: 2,575 Drives: Fast Rep Power: 1322	You may have been kidding, but you've hit the nail on the head haha. All cars are shaped like wings....the airplane kind that generate lift. Any object that has more surface area on one side vs. the other will create either lift or downforce, the side with the less surface area sees the pressure. If you flattened the surface area of the top of a car it would be much much longer than the bottom surface area which means pressure builds under the car and pushes upward creating lift. An airplane wing is designed the same way where the top half has a longer surface area than the bottom. An automotive wing is basically flipped upside down so the pressure is a downward force. That being said, sticking the laminar air flow to the back of the car for a longer period of time actually creates more lift. So there's a trade off at some point. In one of those links they use the example of a modern VW bug which is a perfect example of aero fail despite the laminar flow of air over the rear sticking all the way to the license plate basically. As far as the rear diffuser goes, the vertical fins are basically VGs. Going back to the length of the surface area thing, rear diffusers slope upward and the fins help air stick to the surface creating a longer surface area on the bottom of the car so it better equals the top of the car basically producing negative lift, not so much downforce. __________________ MikeBonanni.com Twitter: http://www.twitter.com/MikeBonanni Facebook: http://www.facebook.com/MBonanni36 Function > Form

09-09-2011, 10:32 PM	#2 (permalink)
travisjb A True Z Fanatic Join Date: Jan 2009 Location: GSO Posts: 2,803 Drives: VIR Rep Power: 190	right makes sense... in fact, I've been thinking about extending my rear diffuser out another 6" now that I don't have aero restrictions... I'm also, as I pointed out on my journal, going to try and craft an under-tray... I'm sure that will be a lot of trial & error!! btw, I'll point out for folks that are interested in this topic, the author of the previously linked articles wrote another article three days ago... here AutoSpeed __________________ 2009 370Z #104 For Sale

09-09-2011, 10:36 PM	#3 (permalink)
travisjb A True Z Fanatic Join Date: Jan 2009 Location: GSO Posts: 2,803 Drives: VIR Rep Power: 190	hey one more thing sticking in my head... I head a world-known PhD in aerodynamics look at my car believe it or not about 1 year ago... he told me to try and minimize the boundary gap coming off the rear deck and keep it attached so that it would join the air coming off the diffuser... he said it would make the diffuser more effective... obviously runs counter to the car as upside down wing theory, but I remember he was adamant about it... brain hurts! __________________ 2009 370Z #104 For Sale

09-09-2011, 10:41 PM	#6 (permalink)
Mike The370Z.com Sponsor Join Date: Jun 2009 Location: Loganville, GA Posts: 5,944 Drives: 370z Rep Power: 2188	Mike, when doing the actual run, how about running without the air filters? __________________ NISSAN: 75 280Z / 86 300ZX GLL /87 Sentra SE / 03 350Z / 23 Z Porsche: 93 968 / 23 Macan GTS / 93 968

09-09-2011, 10:49 PM	#9 (permalink)
travisjb A True Z Fanatic Join Date: Jan 2009 Location: GSO Posts: 2,803 Drives: VIR Rep Power: 190	like these? and some you can buy here http://www.uniqueautodepot.com/Nissa...dy-p/13020.htm __________________ 2009 370Z #104 For Sale

09-11-2011, 08:22 PM	#10 (permalink)
travisjb A True Z Fanatic Join Date: Jan 2009 Location: GSO Posts: 2,803 Drives: VIR Rep Power: 190	on a street car those scoops would have no functional purpose that I can think of... on a race car, they are used for rear diff cooling, driver cooling, and potentially rear brake cooling... on the car above, they cool the rear diff __________________ 2009 370Z #104 For Sale

09-13-2011, 10:59 AM	#11 (permalink)
M.Bonanni The370Z.com Sponsor Join Date: Nov 2008 Location: Las Vegas Posts: 2,575 Drives: Fast Rep Power: 1322	Back on topic... New sway bars just arrived from Whiteline! Very excited about these...of course they won't help at all for the standing mile, but they will for the road course! __________________ MikeBonanni.com Twitter: http://www.twitter.com/MikeBonanni Facebook: http://www.facebook.com/MBonanni36 Function > Form

09-13-2011, 11:36 PM	#13 (permalink)
definitionxmk Track Member Join Date: Jul 2009 Location: Los Angeles CA Posts: 973 Drives: Stage 2 SC 370Z Rep Power: 19	__________________ *FALKEN . AMUSE . STANCE . INVIDIA . MINES . TOMMY KAIRA . BRIDE . VOLK RACING . GTM* Featured in DSPORT issue #137 - Follow me on Instagram: @definitionxmk

09-14-2011, 08:01 PM	#14 (permalink)
M.Bonanni The370Z.com Sponsor Join Date: Nov 2008 Location: Las Vegas Posts: 2,575 Drives: Fast Rep Power: 1322	Well, after all is said and done, I am not sure the Mojave Mile is going to happen for me next month. Not looking like my replacement tires will pull through in time and I don't have the cash at the moment to pony up for a brand new set of tires and the event. I am bummed, but there will be another one next spring. For now, focus shifts toward SEMA and possibly running the North American Festival of Speed Time Attack Invitational just for fun...again assuming I get some tires. __________________ MikeBonanni.com Twitter: http://www.twitter.com/MikeBonanni Facebook: http://www.facebook.com/MBonanni36 Function > Form

09-26-2011, 11:41 AM	#15 (permalink)
M.Bonanni The370Z.com Sponsor Join Date: Nov 2008 Location: Las Vegas Posts: 2,575 Drives: Fast Rep Power: 1322	Looks like another start-up time attack series is hitting the western states. I am usually of the impression that for this type of motorsport to re-build and survive in the states we need just one organization that everyone turns to, but this one has a completely different rulebook that is more grassroots oriented. I stumbled across this link but haven't seen any official announcements from the new series. They do have their first event listed though. So far I think I might switch my focus for my 370Z build from N.A.S.A. TT to this ETA Street Class... Extreme Time Attack __________________ MikeBonanni.com Twitter: http://www.twitter.com/MikeBonanni Facebook: http://www.facebook.com/MBonanni36 Function > Form

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