Ask AJ Hartman - Aero Questions

[ChrisM]

I guess the next question is whether a Gt hood is compatible with the Shelby hood, because I'd cut one of those up in a minute.

I was going to suggest a junkyard hood. I cannot confirm, but I do believe a stock GT hood is compatible. There's a large number of GT500 bumper conversions on GTs floating around the net that appear to show them with the stock hood. Maybe pull the hood off your "Cinderella" GT and try fitting it to the Shelby to check?

 

[blacksheep-1]

I was going to suggest a junkyard hood. I cannot confirm, but I do believe a stock GT hood is compatible. There's a large number of GT500 bumper conversions on GTs floating around the net that appear to show them with the stock hood. Maybe pull the hood off your "Cinderella" GT and try fitting it to the Shelby to check?

I've actually measured it and on paper it works,, the question seems to be the leading edge,, and when I get someone over here to help me,, I'll swap them out..

 

[AJ Hartman]

Let me guess, I prolly need an AJ Hartman custom carbon fiber hood to solve my problem.
And I'd buy one too, the cowl panel you made for my SN95 was still on the car when I sold it after 10 years

I don't make a hood for that car and probably never will. Like others have suggested, grab a junkyard GT hood if it fits, or some cheap fiberglass option from someone, and throw a set of RaceLouvers in it. Make sure the front side of the rad is ducted and you'll be all set.
And I've never made a cowl panel so must have been somebody elses.

 

[blacksheep-1]

I don't make a hood for that car and probably never will. Like others have suggested, grab a junkyard GT hood if it fits, or some cheap fiberglass option from someone, and throw a set of RaceLouvers in it. Make sure the front side of the rad is ducted and you'll be all set.
And I've never made a cowl panel so must have been somebody elses.

Really, not for the new edge,I'm sorry for the memory fade. I picked up some used vents in order to cut them up, the main issue I have is the IAT, causing the timing pull in the hot Florida summers and 130 degree asphalt temps. I've tried everything I can think of to isolate the CAI.

 

[Ewheels]

I don't make a hood for that car and probably never will. Like others have suggested, grab a junkyard GT hood if it fits, or some cheap fiberglass option from someone, and throw a set of RaceLouvers in it. Make sure the front side of the rad is ducted and you'll be all set.
And I've never made a cowl panel so must have been somebody elses.

In reference to the radiator ducting....how important is it that the ducting be sealed to the back of the bumper cover? Or as long as you have a few inches of ducting in front of the radiator to smooth out the airflow, that's good enough?

 

[Dave_W]

On a similar note, which do you think has better venting in stock form - a 2010 GT500 hood or a 2013 GT/Boss hood? I'm thinking the GT500 has more square inches of vent area, though I haven't actually measured either. Of course the other factor is air flow / pressure in the vent areas, which I'm guessing you may know from your wind tunnel testing.

 

[mavisky]

On a similar note, which do you think has better venting in stock form - a 2010 GT500 hood or a 2013 GT/Boss hood? I'm thinking the GT500 has more square inches of vent area, though I haven't actually measured either. Of course the other factor is air flow / pressure in the vent areas, which I'm guessing you may know from your wind tunnel testing.

I'm confused as the 2013 GT/Boss hood don't have any real venting at all. The 2010 GT500 hood isn't super effective but certainly an improvement.

 

[TWF]

I'm confused as the 2013 GT/Boss hood don't have any real venting at all

It has 2 grills and they are open so some air will get through even if not super effective.

 

[AJ Hartman]

In reference to the radiator ducting....how important is it that the ducting be sealed to the back of the bumper cover? Or as long as you have a few inches of ducting in front of the radiator to smooth out the airflow, that's good enough?

very important. You gotta seal it up to the high pressure zone. Otherwise a lot of that will bleed off between the gaps and lose a lot of its effectiveness.

 

[Ewheels]

very important. You gotta seal it up to the high pressure zone. Otherwise a lot of that will bleed off between the gaps and lose a lot of its effectiveness.

Glad I asked, thanks for the response!

Additionally, should I be blocking off the remainder of the grille opening that isn't going to either the radiator or the intake? See below

 

[TeeLew]

very important. You gotta seal it up to the high pressure zone.

Gaffer tape, FTW.

 

[AJ Hartman]

Glad I asked, thanks for the response!

Additionally, should I be blocking off the remainder of the grille opening that isn't going to either the radiator or the intake? See below

View attachment 80594

Yes.

 

[AJ Hartman]

Since this is an aero thread, if you like CFD and some data, this one is for you.

 

[Avalanche]

this thread is awesome. have you ever tested a ducktail spoiler on the S550? something like this.

 

[AJ Hartman]

this thread is awesome. have you ever tested a ducktail spoiler on the S550? something like this.

View attachment 80954

Not quite a duck bill, but several sizes of spoilers.

 

[5.2 liters of democracy]

Since this is an aero thread, if you like CFD and some data, this one is for you.

Fantastic and informative video as always. Saw the shoutout about the scan in the video, glad I was able to help out!

 

[TeeLew]

Not quite a duck bill, but several sizes of spoilers.

Are there any generalities that you can share? I just picked up a spare deck lid to mount my CAM spoiler. Here's the rule:

Rear spoiler may be added, but may extend no more than 10.0” from the origi-
nal body nor past the perimeter of the body. No rear wings may be added except
OE or equivalent.

Also, it can only be a flat plane spoiler. End plates or gurneys are not allowed. If they were, a spoiler off of a Modified would be a no-brainer.

My idea is to do 2 half-width piano-hinge 'stock car' spoilers which extend laterally as far as allowed and meet at a small angle in the middle. I'll cover the gap between the two with gaffer tape. The back side will be supported by strut rods and I want to have separate 'track' and 'highway' mounts which will be about 70 degrees of angle different.

It's kinda making chicken salad out of chicken $h!t. I didn't write the rules; just building to them.

 

[TeeLew]

I am looking forward to showing up and whipping out my big 10-inch, though....




(It's an Aerosmith song, young-uns)

 

[Paul McWhiskey]

I am looking forward to showing up and whipping out my big 10-inch, though....




(It's an Aerosmith song, young-uns)

Written by Fred Weismantel, first recorded by Bull Moose Jackson in 1952 on King Records.

Damn! I'm older than the old-uns! Well, probably not, just a bit of a music geek. Especially the blues.

 

[TeeLew]

Written by Fred Weismantel, first recorded by Bull Moose Jackson in 1952 on King Records.

Damn! I'm older than the old-uns! Well, probably not, just a bit of a music geek. Especially the blues.

1952? You've got me beat!