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Ask AJ Hartman - Aero Questions

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Grant 302

basic and well known psychic
AJ, thanks for making this thread! I've been following you on Instagram for a while now, great stuff! I have some suspension and safety mods to make before I can start thinking about aero, but it's in the back of my mind.

My question is- how much difference does it make where the hood louvres are in fore/aft placement on the hood? The reason I ask is my new engine is really tall at the front and pokes out of the hood. I'm going to make a bump and glass it into the hood and wanted to put some heat extraction louvres in it as well.

Here's a photo of where the engine peeks out-
View attachment 69839
This is before the hood was on it, but might give you an idea of where the tallest point falls.
View attachment 69840
Thanks!
Brad
So we have this center kit for the 99-04 mustangs which should be available shortly, it is meant to sit on top of the hoods main surface covering the entire center recessed area, blanker panel in front and rear positions louvers right behind the radiator for optimum performance, louver blades are about 1" below top surface. Hard to tell from your pics but if the throttlebody stuff is 1" or more below the top surface this would be for you, if not we could customize it. Give us a call or send us an email if interested. [email protected]

99-04 Mustang Center Kit.jpg
 
106
166
Exp. Type
HPDE
Exp. Level
Under 3 Years
Michigan
So we have this center kit for the 99-04 mustangs which should be available shortly, it is meant to sit on top of the hoods main surface covering the entire center recessed area, blanker panel in front and rear positions louvers right behind the radiator for optimum performance, louver blades are about 1" below top surface. Hard to tell from your pics but if the throttlebody stuff is 1" or more below the top surface this would be for you, if not we could customize it. Give us a call or send us an email if interested. [email protected]

View attachment 69980
Thanks. I'll have to lay something on there and see how much clearance I have below the high sections of the hood. This would be exactly what I'm looking for, though. Might be a couple months but I'll get back with you.

Brad
 
Its crunch time to get ready for the wind tunnel with this car. I think we have 38 runs planned? But anyway, like all my wind tunnel stuff, I'll post the video when we go. If you want to get caught up on previous wind tunnel stuff, heres the link. While getting parts on the car I thought this side by side was pretty cool. All our CFD was done by JKF Aero, better known as Kyle.Engineers on youtube, who worked at Mercedes F1 for a few years. We will be getting baseline runs on the car with the factory GT350R aero, and then working through our list testing all sorts of parts and setups. We will only be doing our single element wings this trip since we will only be testing our "small" splitter option at the moment.
Untitled design.png
 
43
23
Exp. Type
HPDE
Exp. Level
10-20 Years
Fresno, ca
Its crunch time to get ready for the wind tunnel with this car. I think we have 38 runs planned? But anyway, like all my wind tunnel stuff, I'll post the video when we go. If you want to get caught up on previous wind tunnel stuff, heres the link. While getting parts on the car I thought this side by side was pretty cool. All our CFD was done by JKF Aero, better known as Kyle.Engineers on youtube, who worked at Mercedes F1 for a few years. We will be getting baseline runs on the car with the factory GT350R aero, and then working through our list testing all sorts of parts and setups. We will only be doing our single element wings this trip since we will only be testing our "small" splitter option at the moment.
View attachment 70447

In for this, as I just bought a 350r for track duty. Thank you for sharing!
 
43
23
Exp. Type
HPDE
Exp. Level
10-20 Years
Fresno, ca
I'm totally geeking out on this and was fantically writing down everything until you said you would sell balanced packages lol.
I only plan to keep this car for a year or two, so looking for options I can reverse. I'm thinking a splitter with bells and whistles and a wing mounted to a separate trunk.
I do see other wings that use OEM mount points, but then there goes all that handy research.
 
I'm totally geeking out on this and was fantically writing down everything until you said you would sell balanced packages lol.
I only plan to keep this car for a year or two, so looking for options I can reverse. I'm thinking a splitter with bells and whistles and a wing mounted to a separate trunk.
I do see other wings that use OEM mount points, but then there goes all that handy research.
you gotta be careful attaching a proper wing to OEM mounting points. It will be OK up to a point, but a wing that makes a lot more Df than the R wing needs much larger footplates and to tie into the trunk it a way to handle to increased loads.
 
43
23
Exp. Type
HPDE
Exp. Level
10-20 Years
Fresno, ca
you gotta be careful attaching a proper wing to OEM mounting points. It will be OK up to a point, but a wing that makes a lot more Df than the R wing needs much larger footplates and to tie into the trunk it a way to handle to increased loads.
How does that all work with your CF trunk? I have one sitting in my garage for one of my other cars, but haven't mounted it yet because I don't know that it will hold up to the pressure from the wing LOL
 
How does that all work with your CF trunk? I have one sitting in my garage for one of my other cars, but haven't mounted it yet because I don't know that it will hold up to the pressure from the wing LOL
One of my trunks or someone elses? We lay up our carbon trunks to hold the forces of our wing. I would not put a wing on another companies composite trunk without a bunch of extra work to reinforce it.
 
43
23
Exp. Type
HPDE
Exp. Level
10-20 Years
Fresno, ca
One of my trunks or someone elses? We lay up our carbon trunks to hold the forces of our wing. I would not put a wing on another companies composite trunk without a bunch of extra work to reinforce it.


Yes, sir. I was specifically talking about yours. I think I'll go that route then.
I don't see any packages built yet, but I'm thinking the of going this route so as to preserve my OEM parts for resale.Screenshot_20220103-171018_Chrome.jpg
 
Yes, sir. I was specifically talking about yours. I think I'll go that route then.
I don't see any packages built yet, but I'm thinking the of going this route so as to preserve my OEM parts for resale.View attachment 71500
Feel free to shoot me a PM to go over any specifics but what you picked out will be a nice balanced package. Our Apex 8 will need about 5 degrees to balance out our 5" splitter with not much else on the front.
 
43
23
Exp. Type
HPDE
Exp. Level
10-20 Years
Fresno, ca
Feel free to shoot me a PM to go over any specifics but what you picked out will be a nice balanced package. Our Apex 8 will need about 5 degrees to balance out our 5" splitter with not much else on the front.
Will do. Thank you.
 
Great vid thanks for taking the time to make it AJ. Couple questions:

Do you think the drag increase from the spats would have been so great if the baseline was 305’s poking out there at 3+* camber ala a common setup?

Do you plan to offer a high DF canard for 15-17 S550’s?
 
Great vid thanks for taking the time to make it AJ. Couple questions:

Do you think the drag increase from the spats would have been so great if the baseline was 305’s poking out there at 3+* camber ala a common setup?

Do you plan to offer a high DF canard for 15-17 S550’s?
Yeah that exact question went through my mind as well. I think the way you phrased it, the total drag would be the same, but since the 305's up front would stick out more, the delta from no tire blocker to tire blocker wouldn't have been as great. But if you used larger tire blockers, the drag would be higher, but would probably see a higher Df gain. As for our 15-17 canards, we don't have any plans yet on a version 2 canard to look like our other options on 18+ and GT350's. I originally made them to resemble the GT4 canards.
 

Dave_W

Cones - not just for ice cream
984
1,277
Exp. Type
Autocross
Exp. Level
20+ Years
Connecticut
Also keep in mind that a tire sticking out in the air may have more drag than a spat of equivalent frontal area due to (wavy hands) the tread surface spinning "against" the air flow. You'd have to use a "rolling road" wind tunnel to see the real effects of this.
 

Grant 302

basic and well known psychic

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