Hood and side vent info from a dude who worked on the SN95 program

[shovel]

Before anyone says it, yeah I know sometimes people cosplay as experts on the internet just for weird trolling reasons, and without proof anyone can just say anything. So make of this whatever you want.

I posted a video on Youtube about which way air flows through the hood vents on a SN95 and this guy replied to the video:




I covered his name in this screen capture just in case he later decides he has privacy concerns or something and deletes it, but I thought some folks on this forum would be interested to read what he had to say.

 

[ttocs]

seems strange an engineer would have the typo "are" for "air". I mean he didn't fat finger them he just plain misspelled it. But with that being said I know the rear vents were just for looks, but I have personally seen heat rising out of the holes while sitting at a stoplight in phoenix. A scoop type of vent is made to force air in where the vent on the hood is made to suck air out as air passes over it I thought. I could be wrong, I have been once or twice...

 

[Snorky]

seems strange an engineer would have the typo "are" for "air". I mean he didn't fat finger them he just plain misspelled it. But with that being said I know the rear vents were just for looks, but I have personally seen heat rising out of the holes while sitting at a stoplight in phoenix. A scoop type of vent is made to force air in where the vent on the hood is made to suck air out as air passes over it I thought. I could be wrong, I have been once or twice...

I have met a lot of doctors and engineers who cannot spell. Nothing would surprise me regarding people. Can you post a picture of said flapper valve? I think you are right about both statements regarding air flow. The hood portion would act like a cowl Induction which the colder low pressure zone would draw the heat to. So you're onto something.

 

[ttocs]

look up the venturi effect, pretty sure that is how it works.

 

[RAU03MACH]

as far as i know its a cosmetic thing
those holes would be larger to vent out

 

[shovel]

I tested the direction of air flow (on my 1996 V6 without those plug/valve things) by taping strips of yarn both inside and outside the hood and then driving at various highway speeds while filming with an action camera suction-cupped to the windshield. That car is stock ride height and has a reproduction stock air dam in place like how it came from the factory. The yarn from inside was fed through the hole to overcome gravity and the perforated grille was removed to allow the yarn to move freely wherever air wanted to move it. At highway speeds (40-85mph) the yarn from outside was consistently drawn into the holes, at some lower speeds it would get tossed out a little bit sometimes.


The green bit of yarn taped at the front of the hole is sucked in, the green yarn taped beside the hole is drawn in pretty much the trajectory one could guess, back and away from the center of the windshield. The longer yellow puffy yarn from inside is pulled back but the shortest yellow yarn from inside doesn't stick out & later when I cut the longer yarn shorter it all got pulled entirely back under the hood.

My uneducated guess there is the resistance of the A/C condenser and radiator along with the air dam must produce a low pressure area under the hood and all the air which comes in the front must have no difficulty exiting below the car & down the trans tunnel. I have no idea if the same is true for lowered cars or cars missing their air dam.


As for the spelling I've been in the workforce 30 years and there really doesn't seem to be any correlation between the spelling of words and the aptitude of a person in their role. I work within a team of engineers (electronics, not automotive) and there is a way of speaking - our guy in the youtube comments does pass the sniff test on that. He could still be some twerp cosplaying for whatever weird reason but the stakes are low here so I'm giving him the benefit.

 

[Mustang5L5]

I have met a lot of doctors and engineers who cannot spell.

Engineer here. My spelling is atrocious. Thank god for spell check.

Usually when I'm writing technical details i'm already thinking 3-4 sentences ahead and trying to catch up with my writing and mistakes happen. If i actually slow down i do much better

 

[Mustang5L5]

Slightly different subject matter, but I always like talking to the folks who worked on these cars.

I remember years ago I was fortunate to have a conversation with the guy who did the SN95 brake system for the 1994 Mustangs. I've always been big into the technical details regarding brake systems so I asked a lot of questions regarding design and development. One little tidbit of that was that stuck with me was master cylinder selection. Originally the 1994 cobra had the same Master cylinder as the 1993 Cobra R. 1" bore. The rear brakes changed however, as the 93 R used Lincoln rear disks with the same caliper as the standard cobra (45mm piston). A lot of folks incorrectly assumed the 93R got the same rear brakes as the 94 Cobra.

Anyway, with the smaller 38mm pistons on the 94 Cobra, it was revealed that the Cobra didn't really have great bite with cold pads. Once heated up on track, it was perfect. The Cobra has the largest brake system at the time on any Ford and I think the way he worded it was that management didn't like that the flagship brake system couldn't lock the wheels up. So what they ended up doing was a last minute change to the 15/16" MC to get some hydraulic advantage and give the system the extra stopping power it lacked.

I can't recall if it was the 1993 Cobra R, or the SN95 in general where management was totally against the larger brakes but the engineers insisted on them. It may have been the Cobra R. This one is fuzzy

I've had a couple other convos with other Ford engineers and it's funny to see the parallels between their industry and mine, and how decisions are made. I run into a lot of former engineers in my career and I've gotten details on other vehicles and such.

 

[Frank.JD.Perez]

Lol, i replied on this too

 

[Snorky]

Engineer here. My spelling is atrocious. Thank god for spell check.

Usually when I'm writing technical details i'm already thinking 3-4 sentences ahead and trying to catch up with my writing and mistakes happen. If i actually slow down i do much better

Exactly. The mind is so clouded with data and information that the communication and handwriting is trying to keep up and simply cannot. I have a similar issue, and as you mentioned the solution is to slow everything down(a challenge in itself).

 

[Methodical]

The vents are for looks and nothing else.

 

[shovel]

I think that's been established. It's just odd that they still underwent the effort to sort-of appear functional, like the flapper valves. It likely would have been cheaper to either omit the under-hood hole entirely or plug it with an off-the-shelf rubber plug than engineer and tool up a little flapper.

Same with the side vents, they're just for looks but they cut a hole in the wheel well and tooled up a grille and took the manufacturing step of riveting that in place which all cost money... not to mention the similarity with this whole structure on 4th gen Supras .





So the question is, what's sillier? A completely fake cosmetic feature that doesn't even try to pretend otherwise (like New Edge side vents & forward hood scoop thing), or a completely fake cosmetic vent that carries the ruse all the way?

 

[ttocs]

I think if they took the brake vents out it would look almost like prelude of the same era or a 2 door camery with a spoiler.

 

[Rons95GT]

Before anyone says it, yeah I know sometimes people cosplay as experts on the internet just for weird trolling reasons, and without proof anyone can just say anything. So make of this whatever you want.

I posted a video on Youtube about which way air flows through the hood vents on a SN95 and this guy replied to the video:


View attachment 35717

I covered his name in this screen capture just in case he later decides he has privacy concerns or something and deletes it, but I thought some folks on this forum would be interested to read what he had to say.

Is he saying our hoods are plastic? I remember a recall on something with the hoods a very long time ago, but I never heard they were plastic.

 

[Frank.JD.Perez]

The hoods definitely aren't plastic, theyre metal and fiberglass. Mostly fiberglass though

 

[ttocs]

Is he saying our hoods are plastic? I remember a recall on something with the hoods a very long time ago, but I never heard they were plastic.

there was a recall on the 94/95 models. They removed the hood blanket/liner and then cut two large holes at the front of the hood and put an adhesive or more resin inside the holes to keep it from separating. One the liner was back in place you would not know they were there. In all the year since I have only ever seen one mustang where the top skin separated from the bottom so it was either a minor issue or they were good about fixing them

Now the hood not being grounded causing radio reception problems I heard about when I was installing stereos. I never removed the ground and did an a-b test to prove it but I have heard that from other people.

 

[shovel]

I tend to think of fiberglass as pretty much plastic. I worked for a while at a Kenworth supplier making fiberglass molded body parts and we'd stuff big pillows of cut glass in hot molds and shoot them full of a polyester resin called Arotran or something like that... but to me it was all just plastic.