[phil400]

If the scoop is opened up does it flow enough air to be the only air source to the carb?

I picked up an air filter bowl cheap that was hacked up and eliminated the snorkel, I like the look and thought maybe a benefit to have the engine draw cooler air from out side the engine compartment but now wonder if it provided enough air for it to breathe, my original is hanging on the wall so I can always put it back on.

[Formulas]

Ebay the words Dude Scoop
And a interesting test would be the use of Tufts to observe airflow while driving google tuft aeronautics

[Joe's Garage]

The logic behind that ill-fated decision was that the cooler air from the scoop versus the underhood heated air would be better for power.

100% wrong!

Took it out to play at the LVMS dragstrip. You could definitely feel it nose over above ~4k RPMs.

Below that, there MAY have been a little more power because of the cooler air charge.

Pulled the tape back off and made another couple of passes. Better overall power. Pulled to 5k like always.

ET dropped 3 tenths, from 14.1 to 13.8 and MPH picked up almost 4MPH.

With the shifter in 'D"rive, letting the transmission work as designed.

Factory shift point at ~4800RPMs.

Our 'non-scientific' conclusion was (and is) that the factory scoop opening is too small to handle the airflow without the additional air from the air cleaner snorkel added in.

Your mileage may vary.....

[PAUL K]

My test results were similar to Joe's garage. We sealed everything so the only air was coming from the open scoop on the 80 TA and tried to make a pass. The car just bucked and jerked each time I tried to put my foot to the floor. Put the open element filter back on and went 11.3 @ 118.... Never tried it again.

[steve25]

I am looking at these results a different way.

Let put some thought into this.

Motors don't buck at high throttle openings from lack of air, they do such from lack of fuel,

Now if a Carb is not getting air when at a steady rpm it's darn well not going to run rich as some are inferring here.

When I opened up the scoop on my 78 TA I also went several thousands richer on the secondary Rods in the Q-jet and the power difference above 40 mph due to high pressure air getting in was very apparent and had no transitional response issues.

Ask yourself this, the 71 and 72 TAs had a vacuum controlled flap on the shaker, so if that in and of its self had made a performance issue would the engineers have let the car go into production running like that?

Go back and look at the Car & Driver road test of these cars.
Their was no issue with them and the performance of the TAs with the 455HO options was impressive.

This type of stuff is a real petpeave of mine, like all magazine test over the decades of swapping different Intake Manifolds on while using the same Carb with the same jetting and with no dam way to monitor the air to fuel ratio or even the Exh temp of each cylinder.
There's been a ton of useless BS published over the years!

[steve25]

Phil please note, a engine does not draw in air in as you posted, that suggests a Vacuum.

The pistions descending in there Bore on the Intake stroke create a void that air rushes in to fill, it's that simple.

Only once a motor at wide open throttle reaches the rpm where whatever its peak VE level is attained does a vacuum start to be produced under the Carb

[Formulajones]

Ive never tested a ta scoop so that's interesting results. Maybe something to do with it's location facing backwards? Not close enough to the base of the windshield high pressure area?

We run dad's 69 GTO with 724 HP through the factory GTO scoops only, everything else closed off and it runs fine that way, 10.60's @ 128 mph.
My 70 RA Formula uses only the scoops and it actually runs fastest that way, if I try an open element air cleaner and ignore the RA setup the car slows way down.
These are forward facing scoops however.
I have 3 other cars with cowl induction. One is pulling air just from the base of the windshield with a factory drop base that I welded shut snorkels on.
The other 2 still have their snorkels but if you've seen a cowl induction base the snorkels aren't much to speak of with a tiny round opening the size of a silver dollar.
Those cars are raced that way, one with 786 HP and it seems to be an ample amount of air supply, they all run fine. But those rear facing factory setups are right at the base of the windshield.

On a side note one of the cowl induction setups I monitor air intake temps and it will follow the outside ambient temps within a digit or two. Way better than I thought it would be. When I want to know outside temperature I just look at my iat's lol

[PAUL K]

Originally Posted by steve25

I am looking at these results a different way.

Let put some thought into this.

Motors don't buck at high throttle openings from lack of air, they do such from lack of fuel,

They do buck and jerk when there is no air flow to pull fuel out of the boosters..... Ask me how I know

[phil400]

Alright then, I'll put the original back on, and maybe mess with making some openings in the other one, thanks for the info

[PAUL K]

Originally Posted by steve25

Ask yourself this, the 71 and 72 TAs had a vacuum controlled flap on the shaker, so if that in and of its self had made a performance issue would the engineers have let the car go into production running like that?

Go back and look at the Car & Driver road test of these cars.
Their was no issue with them and the performance of the TAs with the 455HO options was impressive.

Originally Posted by Formulajones

Ive never tested a ta scoop so that's interesting results. Maybe something to do with it's location facing backwards? Not close enough to the base of the windshield high pressure area?

We run dad's 69 GTO with 724 HP through the factory GTO scoops only, everything else closed off and it runs fine that way, 10.60's @ 128 mph.
My 70 RA Formula uses only the scoops and it actually runs fastest that way, if I try an open element air cleaner and ignore the RA setup the car slows way down.
These are forward facing scoops however.
I have 3 other cars with cowl induction. One is pulling air just from the base of the windshield with a factory drop base that I welded shut snorkels on.
The other 2 still have their snorkels but if you've seen a cowl induction base the snorkels aren't much to speak of with a tiny round opening the size of a silver dollar.

I was always entertained when I would drive my 70 TA after a rain and there were beads of water on the hood scoop. First chance I had I would floor the car and watch the beads of water fly off the top of the scoop and get sucked into the open flap leading to the air cleaner ..... IMO that proved to me the rear facing scoop did something.

Few things to think about in no particular order:

Pontiac added a second snorkel on the RAIV TA

Your closer to stock Formula hood works well "as delivered" from Pontiac on an engine that is fairly stock.

My brother's Formula which has an engine with a lot more power showed positive improvement with every modification done to improve air flow for the factory ram air set up. Removing the flaps in the snorkel. Enlarging the feed holes, raising that factory lid, replacing the the factory lid with a 14" lid.... Every modification helped the car accelerate down the track faster.

Interesting about GTO Jones car. If I recall that engine made 700 plus horsepower on the BES dyno and ran low elevens first outing at track. That amount of power is usually good for bottom tens in a heavy street car.... One might wonder if the factory RA set up wasn't as efficient as the set up on the dyno.

Zero Super Stocks run with a complete factory air cleaner set up.

We always have atmospheric pressure but I know for positive that is not enough to flow fuel through a carburetor. In order to drain the fuel I always end up pulling a bowl screw out or holding it upside down.

Nunzi and H-O made a crap ton of money selling carburetor kits to recalibrate the A/F mixture. Why did these kits work.

Our time to go to the track is limited. Every time we go out #1 goal is to come back safely and with the car in the same condition we left. #2 goal is to make a good pass off the trailer. #3 is to try and make faster passes.... By no means was my test scientific. We made a wood spacer with a seal on it that replaced the 14x2 air filter I normally used. I made a baseline run, then installed the spacer that only allowed air to be feed by the opening in the hood scoop. The burn out seemed fine but as soon as I launched the car it bucked and jerked and I had to lift. I attempted full throttle two more times driving down the track and the same thing happened. I replaced the wood spacer with the filter element I normally use and it went 11.3 again. Steve is correct without a doubt that carburetor could've been tuned to run right, I seriously doubt an improvement would be found. It's very hard to fall back a hundred steps and end up with a lead.

[PAUL K]

Originally Posted by phil400

Alright then, I'll put the original back on, and maybe mess with making some openings in the other one, thanks for the info

I'd try it since you have it. Most likely it will sound different driving around and you might like that. You might want to try and find a couple of air cleaners you could remove the snorkels from and attach them to this base.... Btw is looks like you have a fantastic TA!

[sdbob]

Interesting Information. I've just ran stock stk cleaner on my SD stocker. I did notice a difference when I took secondary rods and machine them down at the end to as thin as I could, very thin. Talking to John Herslow about his SD stocker. The fastest mph he went is when by accident they left the secondary completely out. The response was bad he said but mph was the highest he ever had

[jhein]

Take a look at post #9 in this thread:

https://forums.maxperformanceinc.com...d.php?t=874048

That made me go look at my setup. Indeed the top edge of the air cleaner lid is very close to the rim of the shaker leaving just a tiny gap around the rear where the shaker opening is. Toward the front it gets even worse. So If I were to block off my snorkel, I would have very little air flow through just the shaker. I haven't tried but I bet it would choke the motor pretty bad.

As an example, right now my shaker flap is not connected to the solenoids mechanism. It just hangs from the hinges. When I go to WOT, it doesn't do anything, it doesn't open up. So it appears that it's not pulling any significant extra air at all.

I was looking at air filters and I found that many air filter manufacturers have a different part # for RA vs non-RA cars. The RA elements are about 1/2" shorter than the non-RA. So I just got a new K&N filter that is about 1/2" shorter that I'm gonna try. I know a shorter filter may also be a restriction so we'll see how that goes. I think I'll do some Dragy tests first, then switch to the shorter filter and repeat.

[Formulajones]

Originally Posted by PAUL K

I was always entertained when I would drive my 70 TA after a rain and there were beads of water on the hood scoop. First chance I had I would floor the car and watch the beads of water fly off the top of the scoop and get sucked into the open flap leading to the air cleaner ..... IMO that proved to me the rear facing scoop did something.

Few things to think about in no particular order:

Pontiac added a second snorkel on the RAIV TA

Your closer to stock Formula hood works well "as delivered" from Pontiac on an engine that is fairly stock.

My brother's Formula which has an engine with a lot more power showed positive improvement with every modification done to improve air flow for the factory ram air set up. Removing the flaps in the snorkel. Enlarging the feed holes, raising that factory lid, replacing the the factory lid with a 14" lid.... Every modification helped the car accelerate down the track faster.

Interesting about GTO Jones car. If I recall that engine made 700 plus horsepower on the BES dyno and ran low elevens first outing at track. That amount of power is usually good for bottom tens in a heavy street car.... One might wonder if the factory RA set up wasn't as efficient as the set up on the dyno.

Zero Super Stocks run with a complete factory air cleaner set up.

We always have atmospheric pressure but I know for positive that is not enough to flow fuel through a carburetor. In order to drain the fuel I always end up pulling a bowl screw out or holding it upside down.

Nunzi and H-O made a crap ton of money selling carburetor kits to recalibrate the A/F mixture. Why did these kits work.

Our time to go to the track is limited. Every time we go out #1 goal is to come back safely and with the car in the same condition we left. #2 goal is to make a good pass off the trailer. #3 is to try and make faster passes.... By no means was my test scientific. We made a wood spacer with a seal on it that replaced the 14x2 air filter I normally used. I made a baseline run, then installed the spacer that only allowed air to be feed by the opening in the hood scoop. The burn out seemed fine but as soon as I launched the car it bucked and jerked and I had to lift. I attempted full throttle two more times driving down the track and the same thing happened. I replaced the wood spacer with the filter element I normally use and it went 11.3 again. Steve is correct without a doubt that carburetor could've been tuned to run right, I seriously doubt an improvement would be found. It's very hard to fall back a hundred steps and end up with a lead.

Yes dad's car made 724 on Tony's dyno, that was with a full exhaust and dad's headers used in the car but it had no air cleaner of any type. Maybe a dyno hat but I'd have to go back and look.

Anyway, it doesn't matter too much as we run the cars as we drive them in the street so the air cleaner setup stays. I know it does a good job pulling air in because the iat's are as cool as outside air. Is it enough air?
Don't know. I don't think the car would ever go low 10's with any air cleaner because we keep the gear mild with 3.42's, I nice snug converter that drives really well, the stock suspension setup with tweaks and a small drag radial. It 60 foots in The 1.40's but haven't put a pass together with that 60 foot. The 10.60 pass was a 1.7-something. but it mphs out the back well enough, for a street car that gets 10,000 miles a year he's happy with it, and it runs on 91 and gets almost 16 mpg.

[rolling money pits]

Non RA, single snorkel birds, seemed to run OK with an opening a medium sized lemon could plug.

There was another thread discussing T/A shakers and air flow. Maybe it’s not the volume, rather the airflow path?

[unruhjonny]

Originally Posted by steve25

I am looking at these results a different way.

Let put some thought into this.

Motors don't buck at high throttle openings from lack of air, they do such from lack of fuel,

I am posting before reading the remaining replies;
I had thought the airflow directly affects how much fuel is pulled through the carb.
While my logic could be bad;
more airflow = more fuel pulled

If this was a throttlebody (akin to a TBI engine) I think you could have fuel delivery being based on throttle position - because airflow through the throttlebody has no effect on how much fuel is pulled.

[unruhjonny]

Originally Posted by jhein

... I was looking at air filters and I found that many air filter manufacturers have a different part # for RA vs non-RA cars. The RA elements are about 1/2" shorter than the non-RA. So I just got a new K&N filter that is about 1/2" shorter that I'm gonna try. I know a shorter filter may also be a restriction so we'll see how that goes. I think I'll do some Dragy tests first, then switch to the shorter filter and repeat.

I believe that the "ram air" label for those filters is a misapplied label;
IIRC that "ram air" application is for the Trans Am's.

[mike76]

I wonder about all this. Larry Navarro's WFO package that he developed speaks against this idea. I recall him testing his setup against no air cleaner at all and the result was negligible. I don't know but this would seem to indicate that airflow through the scoop is sufficient even on the 550+ hp 472 he ran at the time. Maybe Larry can chime in on this. Mike

[PAUL K]

Originally Posted by jhein

I was looking at air filters and I found that many air filter manufacturers have a different part # for RA vs non-RA cars. The RA elements are about 1/2" shorter than the non-RA. So I just got a new K&N filter that is about 1/2" shorter that I'm gonna try. I know a shorter filter may also be a restriction so we'll see how that goes. I think I'll do some Dragy tests first, then switch to the shorter filter and repeat.

It's interesting your scoop door pulled open when the engine required additional flow. My 70 with the original engine would only pull it open about half way. I recently noticed my 70 will accept a 3" tall filter. My 74 will not. I haven't had a chance to figure out what the differences are. I'd certainly think additional space you can get between the lid and base would be a win.

Originally Posted by Formulajones

Yes dad's car made 724 on Tony's dyno, that was with a full exhaust and dad's headers used in the car but it had no air cleaner of any type. Maybe a dyno hat but I'd have to go back and look.

Anyway, it doesn't matter too much as we run the cars as we drive them in the street so the air cleaner setup stays. I know it does a good job pulling air in because the iat's are as cool as outside air. Is it enough air?
Don't know. I don't think the car would ever go low 10's with any air cleaner because we keep the gear mild with 3.42's, I nice snug converter that drives really well, the stock suspension setup with tweaks and a small drag radial. It 60 foots in The 1.40's but haven't put a pass together with that 60 foot. The 10.60 pass was a 1.7-something. but it mphs out the back well enough, for a street car that gets 10,000 miles a year he's happy with it, and it runs on 91 and gets almost 16 mpg.

I think what you guys do is quite impressive. A lot of Brand X guys have to be scratching their heads to see a couple of stock looking Pontiacs drive in, click off impressive times and drive home. Mid tens out of a street driven car isn't easy.... Along with the 16 mpg

[Formulajones]

I've found it to be sufficient enough for over 700hp on cowl induction stuff but again that's at the base of the windshield where a rear facing scoop should be. I've been racing the cowl induction stuff for decades and haven't really found anything that improves it without hacking the car.
I do know just putting an open element filter setup on the car so it's not limited to just the hood and should induce more airflow if the engine is looking for it actually slows the car down.