Hi there, was looking in the engine bay the other day and noticed the huge like 2.5" hole at the front of the air intake box. Thinking to myself, "that doesn't look right?" I pulled up the exploded parts viewer at Atlantic British, and lo and behold I'm apparently missing that trumpet/horn/cone thing that attaches to the front.

Is it necessary? I plan on getting a snorkel down the road and figure I'll be sealing the hole off anyway.

Thanks for tolerating the newbie!

 

welcome to the forum! Your snorkel kit will come with parts that to be replaced. Everything that is there is supposed to be there.

 

Thanks for the free bump, but I'm pretty sure this is the D1 section. Any answers?

 

Are you talking about the horn looking part where it sucks air from?
If so i am pretty sure the kit will come with a block out seal for that or the snorkel will attach there.

 

Ok, yes. Thank you, that's it. I haven't found too many videos that specifically talk about (or show) sealing off the airbox. Good to know, I won't worry about it then.

I've only had the truck for about a week so I'm literally still learning about a whole new breed of vehicle at this point. Thank you all for your experience and advice!

 

The horn piece is used to reduce the noise from the intake. It doesn't restrict flow, and might actually help a tiny bit with a venturi effect but the chief purpose is prevent a loud sound wave coming off the lip of the airbox opening where the diffusion is happening. The horn is a more gentle diffuser.

 

You can have mine if you want it... I will be taking it off soon to mount a second battery.

 

Old thread, just ran across it here in 2-2020. Yes that snorkel is a restriction on the inlet side of the engine. THe 4.6 engine runs a lot better. The snorkel had a 1.615" inside diameter just behind the bell which is 2.048 sq/in of cross sectional area. Ram tubes, (velocity stacks to some) are of 1.490" diameter or 1.743 sq/in of cross sectional area. Don't forget there are eight ram tubes which equates to 13.944 sq/in total area being fed by the one 2.048 sq/in of snorkel area. 2.048 / 13.944 is 0.1468 the area, the ram tubes are 6.808 times larger in cross sectional area. Do the math. With the snorkel the 4.6 was suffering by 4,800 rpm's, not any more, pulls to the 5,900 rev limiter. Snorkel to remove intake noise, give me a break, there is no difference running without the snorkel or with it installed. Even if it made noise it's music. For a cold ram air without rain water as well up high within being practical duct through the left radiator support hole allowing access to the left headlight lamp socket. Being up high the incoming air temp is a lot cooler than sucking air from a fog light opening down in the air dam which is where the hot air rising off black asphalt especially fresh asphalt plus summer heat. The nipple stub at the air box with snorkel removed has an ID of 2.756" diameter which equates to 5.965 sq/in cross sectional area. Compare snorkel cross sectional area vs the nipple stub you have gained in area times 2.912. Three inch rubber tubing fits perfectly over that air box stub, tightens up with a hose clamp. Take two 3" diameter rubber hoses (smooth interior and exterior with molded threading) having 45 degree bends plus a 1" long piece of 3" exhaust pipe with two hose clamps you now have the perfect offset. Clamped onto the air box, the opposite end passing through the radiator support behind the left headlight. My tubing sticks forward beyond the radiator support by only 3/8" plus no rain water. Cold air ahead of the radiator passing through the grill making a 90 degree turn left and into the intake duct. Intake 45's (one each off a late 80's Ford) times two vehicles I was set. Total cost I recall under $10 back in 2000 from the wrecking yard, hose clamps and 3" tubing from my stash collection.
I installed this tubing back in 1-2000 a week after taking ownership of the 95 5 spd D1. It takes 45 seconds to remove and install the snorkel to look proper to pass the Kalifornia **** visual smog inspection before the sniff test once every two years. Oh, rotated the TPS sensor from the factory position as the securing screw holes have been elongated allowing changing the voltage signal to the ECU to spec of the Mark Adams "Tornado" chip. Damn right a block away from the smog station pull over reinstalling the cold ram air as well returning the TPS to the "Tornado" voltage spec again. This another 45 seconds alteration. Also installed a brass plug 3/4" long with a 0.040" hole drilled through it restricting the hot coolant to the plate under the throttle butterfly. This restriction installed into the small hose before installing hose onto the radiator. A 1/4" deep 10-32 thread into one end allowing removing the restriction if needed with a 10-32 screw. It was installed back in 2000 as well made an adjustable restriction installed into the IAC hose preventing that instant 2,700 rpm's cold start revving the engine. Now holds at just under 900 rpm's after the Pre-Oiler has cycled before starting.......~~=o&o>........