This is a picture of a quad of Strombergs with air horns. I would think these air horns would be facing forward for “forced intake.” Instead, they are faced towards the driver. Any reasons why?
We have done this recently but in that picture the scoops are below the radiator shell, at speed there is no "forced air" into those frog mouths. I would venture to say that on that particular application it wouldn't really matter other than aesthetics.
I wonder if it acts like a cowl hood? Ie there’s a low pressure area and allows the carburetors to draw more air in
Do you know how fast you would need to be going for "rammed air" to be a significant factor...??? Here is the answer regarding orientation. https://myflatheadford.com/mounting-scoops-correctly/
If I remember it right, ***uming you convert ALL energy from the speed of the air (or rather, the speed of the intake through stationary air, but whatever) into a pressure increase you can get about 5% pressure increase at 200mph. At half the speed you get a quarter of the increase, so a little over 1% in the best case scenario at 100mph. In reality something designed without significant wind tunnel testing or at least computer simulation is unlikely to be close to ideal, so yeah, the results will be completely insignificant at the speeds you drive a hotrod on the roads. Another thing is that aerodynamically these "scoops" are horribly designed. For a pressure increase you want a large chamber with a small inlet and gradually increasing size, to slow the air down gradually, converting speed to pressure. These abominations, if turned facing forward, is more likely to have "too much" air enter, stop suddenly as it can't go deeper, and then have most of it turn back out again, causing turbulence and disrupting the air flow so much it is more likely to reduce power. "Scoops" of this kind are exclusively for looks. Unfortunately I tend to like the look of things that work well, so these are disqualified... but if you like them, go right ahead and put them on your car.
Well... Preferably they should face the bottom of the trash can so a proper filter can feed the carbs nice clean air, but having the opening facing backwards might be an acceptable compromise.
I was thinking this the other day , Growing up @ race track & seeing many Air inductions Racers not factory backed just woundering how many Did more harm / disadvantage performance not knowing back yrs ago even to day with out data testing BT Metter Egt / O2 on each cylinder, Spark plugs heat ranges same in each hole , to mix heat range , Stagger jet's in carb. Coolant temps just in one location To add temp gauges to balance temps a cross the combustion chambers. Many other ext . Air Induction I started taking notice of wickers on some body designs , Also land speed small openings leading to much larger , Air bells . Another 2 over time change Many FED 70 give or take Low wing , Then I think Don G showed up with Wing much higher Then other's by 3 feet or so , Or Knowing late 80's how much force out of pipes of trust not until early 2000's they started laying header's back to use a thrust propulsion acting like "power adder" Heat in clutches To much heat in tire's making them Gooey and greasy Afew personal experience on My 30 A stock top fenders & 32 Rad Shell Was caught in hard rain , No wipers 0- 40 ish mph window covered in rain Above 45 No rain . Another a 32 tag on bumper in center higher coolant temps driving Vs No tag Just thoughts for others to think about When there issues , Notes & think out side box
Always heard that forward facing frog mouths disturbed the internal workings of 97s & 94s and caused some lost performance. Figured out in ages past at the lakes? Old hot rodder tales? Who knows? Besides, they look better facing backwards.
My 2 cents: I've always believed in “backwards is better”. One, they look better and two, function better. And by function better, I mean from a debris (including rain) minimization and I also remember reading something a hundred years ago about air flow and how pulling the air from the firewall direction simply worked better. Could never understand why it worked better, but… .
Here’s a fun one. The first is an older picture of my roadster with forward facing scoops. this was taken just now in the same spot after I got home from grabbing a coffee (you want to keep people off their cell phones? Try driving a stick with manual steering while holding a cup of coffee since you didn’t build cup holders in the car). I like both versions. I recently chrome the scoops since they were too cheap to hold a decent polish. There’s is a lot less glare with them facing backwards. Performance wise? No change.
So I had to Google it, guess I didn’t remember the HRM article properly. But Google (AI) says it creates a high pressure area with a denser, cooler charge. Damn, ya’d think a guy could remember what he read 50 years ago
Just asking , I wonder if just a generic response.. I want to see actual wind tunnel for Sus specific model's . Since my pocket are not deep and I'm always talking in riddles I guess the next closest thing for me would be ball of yarn BT meter Go pro & what @RICH B mentioned I have experience this not the carbs Rich posted but other's I was working on a off-topic engine For a few hours diagnosing experimenting , end of the day ready to stop while engine was running I stuck the air cleaner On , Instant the missing and other issues went away, it was surprising. This was 20 years ago , When I started working on the engine the air cleaner was not on the engine laying in the backseat
I recall years ago as well, OT car I fired up without the air cleaner ***embly on. Idle was goofy, been so long I don’t recall exactly. But all was fine after I put the ***embly back on. Mid 80’s car, probably EFI and cpu controlled.
"Gains are generally negligible below 60 mph but can increase engine output by 1% to 5% at speeds over 120 mph."
Probably got tired of the front end lifting when they got to 600 per hour so they turned them around to let the downward drag keep the front wheels on the ground.
As others have already stated, negligible difference in performance at “normal” speeds. From Google AI:
My Olds has air scoops under the front bumper to capture cold, ram air. The air cleaner is always full of gravel, bugs, gr*** and once a snickers wrapper. Must work. The decal under the hood reminds you to clean the snow out of the scoops during winter or the car won't run. Maybe backward facing on the hood is better.
Just do the right thing, ignore ram air and run a nice big air filter. If you can't bring yourself to do that for whatever reason, put a rear facing scoop on. That should deflect all the bigger rocks and junk so they p*** right over your scoop instead of making the turn into the carb along with the air. I always thought that was the reason for having scoops rather than nothing or trumpets, slightly cleaner unrestricted air for dirt tracker engines, back when oil bath air cleaners were the only alternative.
The Jalopy Journal
