The owner of Lakeland Dragstrip was gracious enough to let me go to the track today while it was closed and do all the testing I wanted. My neighbor with the Firebird went with me since he works there and has all the keys. There were no timers and the track was slipery but I didn't go to see how fast the car would go. I went to make sure the electronics, cooling sys, brakes, trans and engine were ok and there were no leaks. I made a couple of soft passes to check the trans, brakes and cooling sys. Everything seemed ok, oil pressure, fuel pressure was good, the temperature stayed below 180, the trans shifted good and all the electronics worked. The traction was non existant so I had to feather the car out and get on it gradually. When it got to about 5000 RPM it felt like it was starving for fuel although the fuel pressure was a steady 9 lbs. I went back to my pit area and check the fuel bowl levels, and were ok. I thought it might be a problem with my stutter box and high end chip so I disconnected the stutter box from the MSD and installed the high end chip back on the MSD. I left the hood off and made another run. It went through the gears smoothly up to 5500 without any problems although I could only give it about half throttle before the tires would brake loose even in third gear. But it felt very strong. I went back to the pits installed the hood and made another run. The problem returned! I then turned my attention to the stub stack on the carburator and the cold air system through the scoop. I took the stub stack off, put the hood on and made another run. It was better but it still layed down a bit after 5300 rpm. I then removed the sealing plate for the cold air from the carburator, no sealing plate and no stub stack but with the hood installed. Another run, went trough the gears up to 5800 rpm with no problem except for traction and would brake the tires loose after half throttle. If I had to guess at the et for that pass I would guess it ran somewhere between a 6.40 to 6.50. I say this cause the car use to run 6.60@105 mph and I never had a problem stoping it at Lakeland. Today I had to lay on the brakes hard to stop it, the seat of the pants was stronger even though I could not give it full throttle and the rpm seem to come up very quickly. Getting back to the problem I would say that there was not enough space between the carburator and the hood scoop plus the sealing plate did not let the air turn into the carb quick enough. I'll either have to run it without the cold air or use a drop plate air cleaner bottom with a dome to direct the incoming air into the carb. I guess there is a third option and thats to install a taller scoop which I really don't want to do. The next time I take it out again, it's going to be on a day when I could expect to hook it up and see what it will do. I'm guessing low 6's to high 5's. We'll see!

67 428 Mustang Fastback Super Pro Drag Car
92 F150 P/U Trk
2002 BMW 3.0i Z3 Roadster
90 Acura Integra

Mike, I've posted the latest pics before. I haven't painted the car yet so there's nothing new to show. If you still want to see the same pics let me know and I'll post a link to my photobucket album. George

67 428 Mustang Fastback Super Pro Drag Car
92 F150 P/U Trk
2002 BMW 3.0i Z3 Roadster
90 Acura Integra

Here ya go mike, I hope it works



http://s108.photobucket.com/albums/n36/GeorgeVega>/

67 428 Mustang Fastback Super Pro Drag Car

92 F150 P/U Trk

2002 BMW 3.0i Z3 Roadster

90 Acura Integra

Sounds like it is lean to me. When you seal it to the hoodscoop you get a cooler, better charge of air causing it to lean the mixture. I dealt with this when I first sealed my scoop to the carbs. It would actually run better without the airpan until I jetted up.

Jody Aberts
Troublemaker2
1966 Fairlane 427
AA/NSS
9:49@141
1964 Galaxie 500XL
390 p-code 4spd.
1966 F-100
390-C6

It could be going lean like Jody said, or just flat out not enough air. My car runs almost identical with or without the airpan. MPH may even hurt by 1 or 2 with it on. If the scoop is too low and most of the air is going over it, then the airpan won't help. Had to feel good just getting some seat time though and nice of that guy to loan you the track.

Dale, I'm using the 68.5 scoop. I don't think it's the scoop but rather the way I sealed it. When the hood is on the carb is almost flush with the inside of the scoop. I also only cut a hole slightly larger than the carb opening. I'm going to try a larger drop base and see what happens. And yes, it was great to get back in the saddle. I can't wait to try it on a day when the track is preped. It's going to haul a$$. I can feel it.

67 428 Mustang Fastback Super Pro Drag Car
92 F150 P/U Trk
2002 BMW 3.0i Z3 Roadster
90 Acura Integra

It has a 950HP carb. There seems to be a problem in how the air goes thru the scoop and into the carb. Look at the pics in the link of the previous post. I think that the way I sealed it is the problem. I used foam on the hood toseal on a flat round pan place around the carb. I thought the air would just come in the scoop and straight down the carb but apparantly it doesn't. All I know is that it runs great without the pan in place.

67 428 Mustang Fastback Super Pro Drag Car
92 F150 P/U Trk
2002 BMW 3.0i Z3 Roadster
90 Acura Integra

I can't remember what scoop you have? If there isn't enough airflow and the carb is too close you will definitely choke it. I know some (Mustang) S/S guys don't seal the scoop because it won't get enough air.

What did the plugs look like? If you are making more power you will need more jet with the same carb. It sounds like it has much more HP and it is going to fly on a good day at a good track.

Since we have 2 and a half feet of snow here and right around zero degrees.... I am jealous that you made some runs at a "private" strip. However I am happy for you. I know how much work you have gone done on your car.

68 Cougar XR7 street and strip car, 428 4-speed, 3560# of fun, new best 10.43@131.2 1.47 60 ft

Yeah, the carb almost comes out the hood. It's actually flush with the hood. I think the rushing air into the scoop goes past the carb and actually tries to pull the gas out of it instead of pushing it into the carb. Hey, move to Florida and you too could be at the track in December.

67 428 Mustang Fastback Super Pro Drag Car
92 F150 P/U Trk
2002 BMW 3.0i Z3 Roadster
90 Acura Integra

George I have no idea what might be affecting your car but I enjoy hearing about anyone getting a run in this time of year.

I think Tom P described to me how his Thunderbolt carb hat help prevent air from rushing past his carbs in a harmful way, that it help calm the supply and prevented fuel from getting drawn out backwards (but I can't remember for certain what he said).

Gary B

That's exactly what I think is happening. I know what you are talking about. The guys with the big scoops install what they call a tongue at the back area of the carb inside the scoop. This prevents the air from going past the carb and trying to draw the gas out of it. It's actualy a pan the curves up behind the carb creating a wall. I'm going to increase the hole size on the hood form about 6 inches to about 14 and use a drop base with foam around the edge that will seal to the hood. I just didn't want to cut my new fiberglass hood any more than I had to.

67 428 Mustang Fastback Super Pro Drag Car
92 F150 P/U Trk
2002 BMW 3.0i Z3 Roadster
90 Acura Integra

to catch any air at speed. Hopefully someone will confirm this, but I read a long time ago about a simple test. Tape a couple small ribbons on the hood in front of the scoop. If the air is going in, they will lay flat, if it's going over, they will fly in the breeze.

go right around the scoop. The stock GT scoop does not get positive pressure at speed. The cowel would work better, or t-bolt style ram air.




************************************

1967 FE 390GT engine: 416 CID 233/238* @ 0.050 Solid Lifter w/ 4 spd TL.
1968 GT/CS Mustang. 289/c4
1995 Mercedes e320 I6 DOHC, 216 HP wagon.
2003 Tundra SR5, 4.7 DOHC, 4x4.
Another Galaxie (one day.)

Oh and a Bicycle - daily driver to save gas for the 'F'un 'E'xcursions.

Low scoops gave impetus to the design of the '70 T/A Challenger's raised scoop. However, I have a '69 drag test of a Torino that claims that closing off the scoop whacked 2 mph off the top end. I see a lot of Stock class guys using their scoops, so it must be better.

It made no differnce on my car with or without the airpan. No hood or even the old snorkel hood scoop. I want to get a boss 429 scoop and see what it looks like on the car.












My boss run his shaker scoop on his car. I guess you just have to make changes to see what works and what doesn't




Even on his old stocker had a stock style hood.




http://www.fquick.com/garages/viewvehicle.php?id=8822 Streetcar 90 Coupe. Stock 69 351W C6 trans 8.8 rear with 3.73, Strange 31 spline axles and spool


http://www.fquick.com/garages/viewvehicle.php?id=8820 Racecar 68 Falcon. Full Cage and FE 487ci PowerGlide trans. 9'rear with 4.56 with 33 spline axles and spool

I have a Car & Driver road test on a 69 428CJ Mach 1, and they had a similar result, about 2 tenths slower with the scoop taped up. However, in the case of the Torino, the scoop is sealed to the hood, and the Mustangs Shaker is attatched directly to the air cleaner base, so by taping up the opening, any air going into the carb would have to get in thru the smallish single air cleaner snorkle tube. Frankly, I`m suprised the cars wouldn`t slow down by more than that. It would be like you breathing with your nose partially plugged. In my opinion, not a very valid way to test the efficency of either scoop setup. I think that a better way to defeat the scoop for testing purposes would run the cars with no aircleaner assembly at all, or in the case of the Torino, leave off the flapper base and seal, which just lifts off. On my Shaker equipped Mustangs, I always either had a taller intake or carb spacer to push the Shaker acoop higher thru the hole in the hood, putting the opening about 2"`s above the hood. I always thought that they looked better that way as well. When racing, I would run without the air filter element and lid, so that the air could go directly into the carb, rather than just dumping on top of the basically flat lid. THAT was worth a couple of tenths on all my Shaker cars, even my mostly stock 70 351C 4v car.

428 powered Fairmont drag car, Best ET:10.03@132.11MPH, best 60 ft: 1.29
59 Meteor 2 dr. sedan 332, Ford O Matic
74 F350 ramp truck 390 4speed

The discussion about the 6375 Hookers not fitting intermediates got me thinking about using one of my '69 Mustangs instead (I have a set of the early 6375's, never used). I considered getting a repro scoop and just attaching it to the hood to make it sit up, as you just described. I dunno. Would rather do the Montego.

Boss 9 cars first started to run right, one of the things they found was that the factory scoop didn't work. You'll have seen the 2"-3" higher versions that're available. That's what it took not to starve the engine.
KS

for any ram air effect. I was just trying to get colder air from outside the underhood area. I may go with the system that looks like the Thunderbolt setup but uses chrome pre-bent pipes held together with blue rubber connectors and uses a hat at the carburator. I can catch air at the radiator support or the headlight area. That's something I can work with later on. My next goal is to finish the bodywork and get it painted. I've always had black race cars and this one will not be any different. Thanks for all the comments and advice. It's always appreciated. George

67 428 Mustang Fastback Super Pro Drag Car
92 F150 P/U Trk
2002 BMW 3.0i Z3 Roadster
90 Acura Integra

I've long read as well that the shaker and the low mustang/fairlane scoop were too low to grab air.

But, the 429 boss scoop I ran on my 70 Torino would visibly lift off the hood at high speed, the scoop was fiberglass and a 1/16 - 1/8 gap would open up as it tried to lift off the hood, so I think plenty of air was trying to get in there.

You can use clear plastic tube and make a pretty simple water manometer to see if the pressure is positive or negative (and how much) just inside the scoop, along with Dale P's ribbon trick. I've used this to check airflow into radiators.

Or, you could get a super sensitive $300 pressure gage and do the same thing.

Is that and a Stud Finder something women use in bars?


As long as the carb fits under the hood there is a way to get air into it without some silly huge scoop. A drop air cleaner base like they use in Nascar or a stock or aftermarket Corvette base will work and the sides and back can be sealed to the hood leaving the whole front open to draw air from under the hood as well as the bit that sucked through the scoop (not blown in).

67 428 Mustang Fastback Super Pro Drag Car
92 F150 P/U Trk
2002 BMW 3.0i Z3 Roadster
90 Acura Integra

george i had a similar experence with a 351 pinto. like you the carb fit pretty much level with the hood. i had a 71 mercury comet gt hood scoop.that only left about 2 inches to the top of scoop. at test an tune it was slower with the hood on as to having the hood on. i bought repo boss 9 scoop that made the airgap aroune 3 3/4 between the carb and hoood ran fine. you talked about a dropped base air cleaner base. i don't think this will work because the carb is flush with the hood sheatmetal.i think the problem lies with the relationship of the carb inlet to top of scoop measurement.i would try removing the scoop and run the car with a velocity stack. think the references these guys are making to the mustang and torino cars with the same scoop arrangement is one flaw. the carbs well below the hood sheet metal so they would not suffer this air starvation effect. if you need a stack to try i'll loan the one i have just let me know......gopher

although I agree with your logic. Have a look at this SS/AA Hemi car. It's one of the fastest in the country, but most are the same. You couldn't get the carb any closer to the scoop without poking a hole in it. It is up in the air though and the Hemi scoop is fairly tall.

i see what you are talking about but also consider the volume of air that the hemi scoop has. i would bet if you narrowed it down to the same width of a stock cj type scoop with the height it alrady has it would have the same problem. but thats only a theory. the good thing is george can experiment with different things till he finds a combo that works without spending a any money.just time. just relating what might be a possible fix.......gopher