Magnum Throttle Body Hat on Holley 4160

[Sweet5ltr]

Recently purchased an entire air-intake assembly off a 5.2 Magnum.

Has anyone run these throttle body hats on a carburetor? I've seen it done plenty of times in the reverse (carb air cleaner assembly on Magnum throttle body).

I know fuel distribution can be an issue due to air turbulence, so I'll also be running a 1.5" aluminum spacer, to give the air a straight path into the carburetor. Not really a concern with TBI.

This isn't a race application, it's primarily to lower IATs in heavy traffic and decrease the risk of water ingestion on a 4-wheel drive.

 

[ckessel]

Interesting. I know the unit uses the same gasket for a 4bbl. There may be an issue if it uses the clamp around the circumference, my 94 Ram had that, instead of a stud in the center of the hat.

 

[Sweet5ltr]

Interesting. I know the unit uses the same gasket for a 4bbl. There may be an issue if it uses the clamp around the circumference, my 94 Ram had that, instead of a stud in the center of the hat.

This one has a stud, no clamp. It's interesting for sure, most people go the other way, which to me, doesn't make a lot of sense. Large round, open air filter element, under a hood, with an engine that's now ingesting 30-50* hotter IATs than ambient. Take out a temp gun, I believe many people would be VERY surprised after a short cruise. Modern vehicles, like Corvettes for example, start pulling timing after the IAT temps rise above 95*.

They would have been far better off, sticking with the OEM setup, which draws cool, dense air from the inner-fender, and running a less restrictive filter.

 

[ckessel]

Give it a whirl. As long as the hat base is flat with no notches cut out to prevent sealing and allow junk in, should be ducky. K&N made a unit called the FIPK which was a replacement package containing a large conical filter, fresh air shield and new smooth feed tube to the TB. The feed tube had an aluminum ring molded in that sat on the TB. Was 4" in diameter. Had one each on my 94 and wife's 99 Durango.

 

[Sweet5ltr]

Quick update, worked perfectly using a 1.5" aluminum spacer and a few makeshift brackets to the inner fender. Checked for air leaks with carb cleaner, none. Even has a fitting in the air hat for the factory PCV. Removed the inner divider in the TBI air hat, that's it. Not the prettiest thing, but this truck is built as a daily driver. We've put 9-10K miles on it since 2021. Has 50K original miles on it now. Drove it on an 800-mile round trip last November. I'm driving it 130-miles tomorrow. This is more roadkilled than I'd like, I may build new brackets in the future, spray the assembly with wrinkle paint, etc. but I also had to install a new radiator and losing daylight.

With the hood open, the air must be 30-40° cooler at the intake duct. Can't imagine the IAT difference with the hood shut. 44" off the ground to the bottom of the air duct, no chance for water intrusion.

This cost me $120 to build, which essentially gives me an OEM enclosed air filter housing (big plus) and a drainage system (another big plus). I planned to build a custom open air filter system, that was going to be over $300.

 

[ckessel]

Some years ago I put a CAI, highly rated one with 7 layer filter, on my 04.4 Cummins. It had a box by the rh battery but was not fully sealed. Ran that unit for several years. Later on in a diesel truck publication dealing only with Dodge/Cummins, Turbo Diesel Registry, a gent out of Colorado did a real world comparison on CAI units against the stock filter unit but with a duct installed on the bottom of the box with an intake below the bumper air dam. What he did was put a load on the truck, loaded trailer, then make runs up a long grade. He measured IAT in and out of the Intercooler, EGT's when under load and speed during. The sealed box with the added snorkel killed the competition. Turns out the CAI unit I used did get tested on a dyne but with open hood which is not real world. I got rid of mine and went back to stock with snorkel but use an aftermarket smooth hose from box to turbo. Don't care about noise dampening.

 

[Sweet5ltr]

100% correct. Gale Banks has ran similar tests.

The OEM snorkel intake assembly on this truck was pulling in superheated air, directly from the radiator. I went out with a temp gun last night, the top of the hood was 20° hotter where the OEM breather assembly was. Inlet temps are 25-30° cooler. I am going to insulate the lower filter housing, that'll be next week. I may place a small turbo blanket around the intake hose running over to the carb hat. That'll be all for this setup.

 

[ckessel]

I'm rethinking the a/f unit on my 65. Was originally planning to do old school NASCAR cowl induction. Already cut a hole in the firewall, started making a hat, then put it on the back burner due to moving homesteads in 18. Now I'm going to look at heading to the front instead. I may see if I can find one of the K&N FIPK units as a guinea pig to work with and pick up air either though enlarged signal light holes in the bumper or come in behind the headlights. Have been tossing ideas around while I've been working on the back of the car doing metal mods.

 

[furious70]

Would be interesting to Dyno test. Some of those sharp 90 carb hats kill power. Probably not on the weak OEM application though.

 

[Sweet5ltr]

Would be interesting to Dyno test. Some of those sharp 90 carb hats kill power. Probably not on the weak OEM application though.

You're correct, I've ran several carb hats, from the extreme velocity to the spectre, typically, you want the largest spacer you can between the carb hat and the throttle body or carburetor to straighten out airflow. Never run the divider, they can cause issues with fuel distribution. This hat originally came with an internal divider which I removed.

So far it's working great, just drove 260-ish miles with it this past weekend. I've insulated or provided a thermal barrier on the lower intake housing closest to the header.

This was never about horsepower, mainly low-speed airflow while in heavy traffic, while everything under hood is heat soaked. I sat in the Chick-fil-A drive through for 15-minutes yesterday, 85° ambient outside after driving 120-miles. Coolant temp went from 180° to 195°. I have a condenser pusher fan off a Toyota land cruiser on the truck, just purchased a Spal 12" to replace it, and the Land Cruiser (Condenser) fan will be used for a transmission cooler later on. New radiator works amazingly well, down to 170° within a mile of driving on the highway.