Leave the factory intake snorkle or run the box open?

[Rot Box]

Turns out I'm too poor to afford the $90 Hypermax cowl induction kit I have a dirtbike trip planned for the very hot weekend of Labor day that will be about 5 hours round trip with lots of steep grades and I'm trying to figure out how to not melt my motor along the way. Right now I'm trying to figure out if the factory snorkel (91 F350--the one that bolts to the top of the radiator support thats sandwiched directly below the hood) is worth a crap or if I should just leave the box open until I can get the Hypermax kit. How much cool air do you think these really bring to the motor? They look pretty restricted or am I imagining things? I trimmed back some of the sound damper material to open up the inlet a little bit...

How many of you guys are still running it? And how many of you found it to be better removed? Sorry for another newbie-ish question ;p


Andrew

 

[The Warden]

I voted for convincing the wife that the Hypermax intake is mandatory, but assuming that doesn't fly with her, leave the factory intake snorkel in place. I was talking to Russ (typ4) a few months ago, and he was telling me about running first without the hose going to the snorkel, and then installing the hose...I don't remember the exact numbers, but IIRC it made a significant difference in EGT and fuel mileage readings

Good luck on your trip!!

 

[LCAM-01XA]

The factory intake setup on these trucks is indeed rather restrictive, however if you can find one off a 6.9 truck those are much better - I got one off an '87 truck and now it lives in my '90, it goes down to an opening in the firewall that is 4" tall and I forgot how wide but it's got some decent area and is unobstructed, unlike the factory setup that sandwiches under the hood. Being the 6.9 intake ducting ends behind the grille there should be a decent pressure head at its opening, maybe more than the one in front of the windshield where the Hypermax pulls from...

 

[Diesel_brad]

The factory intake setup on these trucks is indeed rather restrictive, however if you can find one off a 6.9 truck those are much better - I got one off an '87 truck and now it lives in my '90, it goes down to an opening in the firewall that is 4" tall and I forgot how wide but it's got some decent area and is unobstructed, unlike the factory setup that sandwiches under the hood. Being the 6.9 intake ducting ends behind the grille there should be a decent pressure head at its opening, maybe more than the one in front of the windshield where the Hypermax pulls from...

You mean. Radiator support not firewall.

My 86 6.9 air intakeis behind the grill and is approximately 3x4. It evenhas a piece of metal funneling air into it. I would not run NO intake hose all you will do is pull in HOT air

 

[LCAM-01XA]

Brad, yes, rad support, NOT firewall - dunno why I always get them mixed up, I think rad support but type firewall, not a single time however did I think firewall and type rad support, lol.

The bricknose rad supports don't have that metal flap you mention. But the opening is already there, and so are the hose for the screws that attach the ducting to it, so all in all it makes for a real easy install. Why Ford went away from this setup I dunno, it seems quite a bit better than the sandwich contraption that replaced it...

 

[dyoung14]

make your own for a fraction of the cost

 

[Black dawg]

run the factory snorkel and trim back the hood insulation. you can see the difference in smoke with and without.

 

[The Warden]

The bricknose rad supports don't have that metal flap you mention. But the opening is already there, and so are the hose for the screws that attach the ducting to it, so all in all it makes for a real easy install. Why Ford went away from this setup I dunno, it seems quite a bit better than the sandwich contraption that replaced it...

I'm pretty sure that metal flap's a splash guard as opposed to a funnel or anything on those lines. And, I think Ford went away from that design because it has a tendency to ingest water if you go through a moderate puddle...I found that out the hard way about 5 1/2 years ago fortunately the air cleaner stopped the water and I didn't hydrolock and bend a rod!! I learned quite a lesson that day about off-roading in mud puddles...

 

[agp23109]

make your own for a fraction of the cost

X2

I have the Hypermax kit and I'm very pleased with it. That being said, a $10 dryer vent duct from Lowes will serve nearly the same purpose. The plastic piece Hypermax gives you to attach to the firewall is nice but the vent duct could easily run strait through the wall with no ill effects.

 

[fury9]

there's some kind of mod where you use about a 4inch hole saw or sawzall, or whatever you have, etc... I THINK you cut a hole somewhere by the cowl. I don't remember exactly but I do remember hearing about it.

 

[Diesel_brad]

I'm pretty sure that metal flap's a splash guard as opposed to a funnel or anything on those lines. And, I think Ford went away from that design because it has a tendency to ingest water if you go through a moderate puddle...I found that out the hard way about 5 1/2 years ago fortunately the air cleaner stopped the water and I didn't hydrolock and bend a rod!! I learned quite a lesson that day about off-roading in mud puddles...

My truck would have to go thru a 4' puddle to get water into the intake tube. and then it would still have to go up hill and aprox 3' of tube to make it to the air filter where then the air filter would stop 95% of any water that even reached it

 

[MR.T]

I think the factory snorkel tube is fine, and has hardly any restriction.

Here's why: When I measured the total pressure drop at 3000 RPM inside the "soup bowl" above the intake manifold, including the snorkel, air deflector, air cleaner (NAPA paper element), and the complete soup bowl... [insert drum roll here] The total pressure drop was 7 inches of water. And about 5 inches of the total of 7 is the air filter (which isn't a "low restriction" type).

 

[dyoung14]

I now have a big hole cut next to my rad, and have my snorkel run threw there right behind the grille, i have drove in rain that you couldnt even see to drive in and its never done nothing to my engine,

But lately i been thinking about switching and cutting a hole in my firewall and trying it like hypermax does

 

[rhkcommander]

I ran a filter off the banks box i had, now i got a pipe from the turbo to behind the fan. works pretty well.

truck is set up for the next to rad air dam thing, but i dont feel like purchasing an inline air filter so i cant use it

 

[The Warden]

My truck would have to go thru a 4' puddle to get water into the intake tube. and then it would still have to go up hill and aprox 3' of tube to make it to the air filter where then the air filter would stop 95% of any water that even reached it

I don't know how deep the puddle I went through was, but it was deep enough to splash enough water into the snorkel to reach the air filter and all but choke the engine...I shut it down, opened up the air filter box to find dampness on the "dirty" side of the air filter, and after giving everything a few minutes to dry, I put it together and the engine ran okay afterwards.

My point is, maybe it's not likely, but it's certainly not as close to impossible as you imply, and I'm speaking from my experience...had my air filter seal been less than perfect or if there had been a weak spot in the air filter element that might have given way after getting wet with a running engine, things could have turned out much different. I got lucky, and as I said, I learned an important lesson...