Notices
Dodge Challenger R/T Threads specific to the Dodge Challenger R/T should be placed here.

Why don't automatic R/T's have functional hood scoops?

Thread Tools
 
Old 01-07-2009, 09:08 AM
  #1  
Junior Member
Thread Starter
 
sworn's Avatar
 
Join Date: Jan 2009
Location:
Posts: 24
Likes: 0
Received 0 Likes on 0 Posts
Default Why don't automatic R/T's have functional hood scoops?

Everything I've read states that auto R/T's don't have functional hood scoops like the standard trans. I think I also heard that the stick has more of a free flowing exhaust as well. Anybody know why the auto didn't get the same setup? (I only ask because the car I ordered is going to be an automatic.) BTW I also understand that the hood scoops are not true ram air as they just direct air over the exhaust manifolds.
Old 01-07-2009, 09:22 AM
  #2  
Member
 
robertg74's Avatar
 
Join Date: Dec 2008
Location:
Posts: 30
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Why don't automatic R/T's have functional hood scoops?

I have a an 09 R/T 6-speed and I do know that the exhaust is more "free flowing" than and auto, but I don't know why they did it that way (not that I am complaining ). I don't know if I have functional hood scoops or not. I looked at mine and they done appear to be "open" but I do have two square slots in the under side of the hood that would allow air to be directed over the manifolds. that is the only outlet I see that would go with the hood scoops.
Old 01-07-2009, 09:37 AM
  #3  
Senior Member
 
brentmannrt09's Avatar
 
Join Date: Nov 2008
Location:
Posts: 246
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Why don't automatic R/T's have functional hood scoops?

I do believe the 6 speed R/T has a free er flowing exhaust. I know my hood scoop vents are NOT open. I doubt any of the R/T hood are functional.
Old 01-07-2009, 12:03 PM
  #4  
Junior Member
Thread Starter
 
sworn's Avatar
 
Join Date: Jan 2009
Location:
Posts: 24
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Why don't automatic R/T's have functional hood scoops?

I know my hood scoop vents are NOT open. I doubt any of the R/T hood are functional.
I thought I read they were on the six speed cars.....Hmmmm

I believe you can order them, I've seen them on e-bay for $80 or $90.....
Old 01-07-2009, 12:26 PM
  #5  
Senior Member
 
brentmannrt09's Avatar
 
Join Date: Nov 2008
Location:
Posts: 246
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Why don't automatic R/T's have functional hood scoops?

I dont know who been spreadin that rumour but My 6 speed R/T hood scoops are decorative only! I'm sure you could make them ahem "functional" but they are not from the factory-Case closed
Old 01-07-2009, 04:28 PM
  #6  
Senior Member
 
BLK 6050's Avatar
 
Join Date: Sep 2008
Location: Mesa, Arizona
Posts: 1,449
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Why don't automatic R/T's have functional hood scoops?

None of the Challenger hoods, be it SRT or RT (or even SEs) have truly functional hood scoops. Yes the SRT's (and perhaps RTs) have scoops that funnel air into the engine compartment...they do nothing for perfomance (Dodge says that they help with the coolong).
The scoops as they are designed, are both to small and to close to the hood surface to be truly effective. And if you don't believe that, just read the performance studies that Chrysler themselves wrote back in the 70's. They tested all their scoops from the shaker to the 6-pak type..including after market tunnel ram scoops...they find that the scoop opening had to be at least several inches off the hood surface to truly work as intended. (Cann't remember the idea size opening or height). The only scoop that worked close to the hood was the cowl induction type, which took in air from the low-pressure area at the base of the windshield (Chevy and NASCAR designs).
Old 01-07-2009, 06:04 PM
  #7  
Junior Member
 
DDC RT's Avatar
 
Join Date: Jan 2009
Location:
Posts: 25
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Why don't automatic R/T's have functional hood scoops?

Correct,

The only way to even have the "Nostrils" as I call them to even be somewhat functional is to order the SRT inserts. The R/T doesnt regularly come that way Man or Auto. I can get them for about 35 a side, but unfortunately they are an SRT package which means SRT price. I though about ordering just to give even a little cool down effect to the engine but not for 70+ dollars for the set.
Old 01-08-2009, 06:05 PM
  #8  
Senior Member
 
BkChallenger09R/T's Avatar
 
Join Date: Nov 2008
Location:
Posts: 297
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Why don't automatic R/T's have functional hood scoops?

I have a 09 R/T with 6 speed Track Pack . I think the scoops may let a little air through . But doubt if it does much . Maybe a little cooler under the hood . Could let hot air out instead of cool air coming in . Don't know. The Automatic car has the MDS engine . Which doesn't have the VVT . And not sure if it has the upgraded head's . Have never read that it does. It may have the more restricted exhaust as that match's the set up in the 300C with that engine. I drove one and it felt just like my 300C . And they didn't want to have to certify it all over for the gov. Just a guess . A little less exhaust make's better torque . Unless you change the converter or make alot more hp on top end. The 6 speed makes more use of the power . But hard to tell if it is quicker if it had the MDS engine. Does anyone know if the MDS got the head's . I doubt it since it isn't VVT .
Old 01-08-2009, 07:39 PM
  #9  
Senior Member
 
whylee's Avatar
 
Join Date: Dec 2008
Location:
Posts: 109
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Why don't automatic R/T's have functional hood scoops?

I installed the SRT vents on my R/T. I know they do not let in much air, but its better than none. I also noticed that when you shut the engine off, you can really feel the heat exiting through the vents.
I think you would be surprised at how much air can get in there to keep the underhood temps down some.
Old 01-08-2009, 08:41 PM
  #10  
Senior Member
 
epegasus's Avatar
 
Join Date: Dec 2008
Location:
Posts: 245
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Why don't automatic R/T's have functional hood scoops?

Aerodynamics is complicated stuff. Ram air is easy and striaght forward but usually isn't what happens with production cars. Top fuel dragsters, Yes. Production grocery getters, No. What is important when talking about production cars is air flow and aerodynamics. A plane's wing generates lift by diverting air over the top of the wing faster than the air trapped under the wing thus creating a vacuum. The vacuum under the wing pulls air upward creating a lifting force which lifts the plane. The same happens with a car moving along the road. Air rapidly travels over the car and potentially can create vacuums under the car causing unwanted lifting. Designers add wings, splitters and spoilers to counteract this lift. Another technique is to smooth the flow of air under the car to cause a vacuum condition along the car's surface which is the oposite of how planes fly. When a car's shape creates down force an opening on the surface that has a clear path to the underside of the car will literally suck air from above the car and exhaust it underneath. This is a benefit of the hood venting on the SRT. Air rapidly traveling under the car draws air through the vents which also pulls heat out of the engine bay lowing the temporature around the air intake and cooling the air going into the motor.

I read a review of the SRT where they complained that the hood vents were too small compared to the large car. It could be argued that if the vents were made too large they would allow too much flow from above to beneath the car cancelling the vacuum affect which aids downforce. I can't say this is the definitely the case but cost cutting would have reduced the vent to just holes in the hood. That's not what we have. We have intricate ducting that purposely directs and smoothly guides air through specific routes. Took a lot of expensive engineering and design work to do that and it wasn't purely for looks, either.


Quick Reply: Why don't automatic R/T's have functional hood scoops?



All times are GMT -8. The time now is 11:47 AM.