VIPAIR™ Dyno Results on 99 RT 16 RWHP!!

[2002_red_gts]

PM has been sent.

What ever happened? Just interested I will have a Vipair waiting for me when i get back. Just curious

 

[Zentenk]

I have this thing called a NACA duct on my Viper! Cool air goes right in to my air filters.

 

[eucharistos]

I have this thing called a NACA duct on my Viper! Cool air goes right in to my air filters.

not that simple, dynamically, i'm told

 

[cyaford]

What ever happened? Just interested I will have a Vipair waiting for me when i get back. Just curious

I declined the kind offer by GTS-R 001 after I found out that Test and Tune in my area is completely different than just renting the track out with a large group of gearheads. I spoke to a friend who had gone to the most recent Test and Tune and he said there were so many cars that he only got in 4 runs total. I didn't want to risk the chance of not being able to properly test out the Vipair. Especially since I was going to be shipped a brand new unit for free, just to test out and post my results. Maybe someone else will do a thorough test with the following parameters I was going to go by:

3 runs with nothing,
3 runs with the Vipair added
3 runs with Vipair and a piece of clear plastic (mylar) taped over the front of the Naca to prevent air from entering or exiting

 

[GTS Bruce]

Your engine must be running on 3 cylinders. Only a 16hp gain?? I got an x-tra 160 RWHP with the WIPEAIR and I only wipe twice now after , well you know.... GTS Bruce

 

[eucharistos]

do you mean skid marks

 

[GTS-R 001]

The function of a NACA duct is to **** air out, not allow RAM Air in, once you get up to 65-80 mph the suction begins

 

[REDBLACK]

Your engine must be running on 3 cylinders. Only a 16hp gain?? I got an x-tra 160 RWHP with the WIPEAIR and I only wipe twice now after , well you know.... GTS Bruce

You are not funny.

 

[99 R/T 10]

You are not funny.

He's a lttle funny.....................

 

[ViperTony]

This thread is getting on my nerves...it just doesn't want to die. I'm going to uninstall my Vipair because of this thread.

 

[99 R/T 10]

This thread is getting on my nerves...it just doesn't want to die. I'm going to uninstall my Vipair because of this thread.

 

[VicTxV10]

The function of a NACA duct is to **** air out, not allow RAM Air in, once you get up to 65-80 mph the suction begins

Really???

NACA Ducts
NACA stands for "National Advisory Committee for Aeronautics". NACA is one of the predecessors of NASA. In the early days of aircraft design, NACA would mathematically define airfoils (example: NACA 071) and publish them in references, from which aircraft manufacturers would get specific applications

The purpose of a NACA duct is to increase the flowrate of air through it while not disturbing the boundary layer. When the cross-sectional flow area of the duct is increased, you decrease the static pressure and make the duct into a vacuum cleaner, but without the drag effects of a plain scoop. The reason why the duct is narrow, then suddenly widens in a graceful arc is to increase the cross-sectional area slowly so that airflow does separate and cause turbulence (and drag).

NACA ducts are useful when air needs to be drawn into an area which isn't exposed to the direct air flow the scoop has access to. Quite often you will see NACA ducts along the sides of a car. The NACA duct takes advantage of the Boundary layer, a layer of slow moving air that "clings" to the bodywork of the car, especially where the bodywork flattens, or does not accelerate or decelerate the air flow. Areas like the roof and side body panels are good examples. The longer the roof or body panels, the thicker the layer becomes (a source of drag that grows as the layer thickens too).

Anyway, the NACA duct scavenges this slower moving area by means of a specially shaped intake. The intake shape drops in toward the inside of the bodywork, and this draws the slow moving air into the opening at the end of the NACA duct. Vortices are also generated by the "walls" of the duct shape, aiding in the scavenging. The shape and depth change of the duct are critical for proper operation.

Typical uses for NACA ducts include engine air intakes and cooling.

 

[GTS-R 001]

Really???

NACA Ducts
NACA stands for "National Advisory Committee for Aeronautics". NACA is one of the predecessors of NASA. In the early days of aircraft design, NACA would mathematically define airfoils (example: NACA 071) and publish them in references, from which aircraft manufacturers would get specific applications

The purpose of a NACA duct is to increase the flowrate of air through it while not disturbing the boundary layer. When the cross-sectional flow area of the duct is increased, you decrease the static pressure and make the duct into a vacuum cleaner, but without the drag effects of a plain scoop. The reason why the duct is narrow, then suddenly widens in a graceful arc is to increase the cross-sectional area slowly so that airflow does separate and cause turbulence (and drag).

NACA ducts are useful when air needs to be drawn into an area which isn't exposed to the direct air flow the scoop has access to. Quite often you will see NACA ducts along the sides of a car. The NACA duct takes advantage of the Boundary layer, a layer of slow moving air that "clings" to the bodywork of the car, especially where the bodywork flattens, or does not accelerate or decelerate the air flow. Areas like the roof and side body panels are good examples. The longer the roof or body panels, the thicker the layer becomes (a source of drag that grows as the layer thickens too).

Anyway, the NACA duct scavenges this slower moving area by means of a specially shaped intake. The intake shape drops in toward the inside of the bodywork, and this draws the slow moving air into the opening at the end of the NACA duct. Vortices are also generated by the "walls" of the duct shape, aiding in the scavenging. The shape and depth change of the duct are critical for proper operation.

Typical uses for NACA ducts include engine air intakes and cooling.

Gerry Malicoat, one of the lead engineers in the GTSR race program found that the NACA duct, as it was, on the front of the Dodge Viper GTSR race car hoods caused a vaccuum and cost the car about 60 HP at speed, so they REMOVED the NACA duct from the cars from that point forward.

There are a lot of factors to have a proper NACA duct that actually feeds air versus causing a vacuum, the shape and position of the NACA on the front of the viper Gen 2 causes a vacuum at speed.

The purpose of a NACA duct is to increase the flowrate of air through it while not disturbing the boundary layer. When the cross-sectional flow area of the duct is increased, you decrease the static pressure and make the duct into a vacuum cleaner, but without the drag effects of a plain scoop. The reason why the duct is narrow, then suddenly widens in a graceful arc is to increase the cross-sectional area slowly so that airflow does separate and cause turbulence (and drag). There is a difference between feeding a cooling hose for a helmet from the side of a race car, vs feeding a 488 cubic inch engine.

 

[GTS-R 001]

From an early article on the GTS-R race cars

"
It's mid-December at Atlanta Motor Speedway, sunny but 45 degrees, and the wind is blowing briskly across the infield of the big NASCAR oval. The temperature and low humidity suggest that the big V-10 engine in the Viper coupe droning around the infield track should have no problem cranking out its rated 650 horsepower, but it isn't.
Even though air is being rammed into this Viper's NACA hood intake at speeds above 160 mph, the V-10 is gasping for air. Engineers have discovered an unacceptable pressure drop across the race-prepared engine's stock air filters. "The dyno won't tell you this stuff, which is why we're here," says Viper engine chief Jerry Mallicoat.
That "we" also includes Viper engineer Gene Martindale, test drivers Neil Hannemann (the 1994 SCCA World Challenge champion) and Tommy Archer (of Archer Brothers fame on the Trans-Am circuit), and about two dozen other technicians, engineers, and supplier and team representatives. The object of their attention is the Viper GTS-R, a pure racing version of the Viper GTS coupe that will run in three upcoming endurance races: the Rolex 24 Hours at Daytona in February, the Exxon Superflow 12 Hours of Sebring in March, and the Le Mans 24-hour race in France this June."

 

[ViperTony]

From an early article on the GTS-R race cars

"
It's mid-December at Atlanta Motor Speedway, sunny but 45 degrees, and the wind is blowing briskly across the infield of the big NASCAR oval. The temperature and low humidity suggest that the big V-10 engine in the Viper coupe droning around the infield track should have no problem cranking out its rated 650 horsepower, but it isn't.
Even though air is being rammed into this Viper's NACA hood intake at speeds above 160 mph, the V-10 is gasping for air. Engineers have discovered an unacceptable pressure drop across the race-prepared engine's stock air filters. "The dyno won't tell you this stuff, which is why we're here," says Viper engine chief Jerry Mallicoat.
That "we" also includes Viper engineer Gene Martindale, test drivers Neil Hannemann (the 1994 SCCA World Challenge champion) and Tommy Archer (of Archer Brothers fame on the Trans-Am circuit), and about two dozen other technicians, engineers, and supplier and team representatives. The object of their attention is the Viper GTS-R, a pure racing version of the Viper GTS coupe that will run in three upcoming endurance races: the Rolex 24 Hours at Daytona in February, the Exxon Superflow 12 Hours of Sebring in March, and the Le Mans 24-hour race in France this June."

I believe JonB made many posts on the subject and, at one point, had a picture of a Viper (GTSR I believe) in his avatar with the NACA duct blocked off. Some members have also done same. Search.

 

[ViperGTS]

what? at 200 mph at the autobahn you have no friends and "xx" hp does not matter because all the other cars are slower anyway...

p.s.: no, i did not read the whole thing, but it may be boring (anyway).