Biggest hole for Deck plate

tmaxx13

New member
Ive been searching the forum for a person that i remember seeing I think they had a black runner that was lifted and they had a huge deck plate on it, to where the outer ring of the deck plate went over the edges of the air box, does anyone know of what size is the biggest that you can go on the deck plate?
 
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4" is plenty since you can only fit so much air down the intake tube and using a bigger deckplate won't net you better results.
 
Ive been searching the forum for a person that i remember seeing I think they had a black runner that was lifted and they had a huge deck plate on it, to where the outer ring of the deck plate went over the edges of the air box, does anyone know of what size is the biggest that you can go on the deck plate?

You are thinking of Thorrider, he had a 9" deckplate. It looks horrible.

I agree that 4" is what you want though.





Here is a pic of his...
:barf:
42290d1302401965-thorridder-build-thread-imag0155.jpg
 
i ordered a 5" last week and dont like it. I feel its too big. I already did a 5 inch hole cut out though. I just left the hole. the 4" is real clean looking.
 
4" is plenty since you can only fit so much air down the intake tube and using a bigger deckplate won't net you better results.

Yep, anything bigger than the throttle body (a little over 2") is more than enough. The engine will never pull more air than the throttle body will allow through (which is more than the engine will ever need).

Think 'funnel'. What determines how much water you can pour through a funnel - the big end or the little end? Obviously the little end, in this case the 2" throttle body (the 4" deckplate hole is the big end). If the throttle body is 2", a 4" deckplate hole won't get any more air into the motor. (In other words, the deckplate mod does nothing to increase airflow, mileage, or HP [in fact, it probably reduces HP by bringing in hot engine compartment air instead of cool fenderwell air], but makes a cool noise. :shrug:)
 
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this makes sense, i just figured after having my K&N intake where it was wide open the bigger the hole the better, but i will go with the 5" deck plate which has roughly a 4" hole, just looking for that sweet noise my old K&N used to make and maybe an extra pony!!
 
I accidently ordered a 6 inch and installed it and it fits just fine. I mean it's edge to edge but it works just like a 4 inch just more air and a different exhaust note.
 
I thought the purpose of "air box modification" was to get cool air into the intake. This Deck Plate Mod is sucking hot hot air right off the backside of the radiator. What gives? :shrug: Why is this a big deal here on T4R?
 
I thought the purpose of "air box modification" was to get cool air into the intake. This Deck Plate Mod is sucking hot hot air right off the backside of the radiator. What gives? :shrug: Why is this a big deal here on T4R?

EXACTLY!!! Why is it such a big deal here? No offense to anyone, but it's because most don't understand how engines make power (cool air = denser mixture, more power, less spark knock, longer lasting engine; hot air = less dense mixture, less power, more spark knock, shorter engine life).

The reasoning behind the deck plate mod must be 'If it makes more noise it must make more power'. Unfortunately that only works for internet tuners, not real ones.
 
Go back out and look at your truck. There are massive gaps all around the headlight that let it tons of cool air. At low speeds, yeah its mostly sucking hot air. but at less than highway speeds is when the cool air starts coming in.

I occasionally put the deckplate back in and I can really feel the loss in power. I dont notice any noise difference becuase the S/C drowns out any noise the deckplate may make.
 
Go back out and look at your truck. There are massive gaps all around the headlight that let it tons of cool air. At low speeds, yeah its mostly sucking hot air. but at less than highway speeds is when the cool air starts coming in.

I occasionally put the deckplate back in and I can really feel the loss in power. I dont notice any noise difference becuase the S/C drowns out any noise the deckplate may make.

I Hate to be disagreeable, but at speed those gaps are where air is escaping out, not entering. The air flow is compressing air into the engine compartment and it has to go somewhere. The skid plate restricts air flow. If you are looking for cool air, scavenge it from the base of the windshield where the ventilation system gets its air from. But certainly not from behind a 180 degree radiator.

In your case, the S/C needs more air than the factory inlet can supply. With a SC, you really want cold air. I would do what I could to get air from in front of the radiator.

Just saying.
 
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I made a 5'' hole. The deckplate hasn't come in yet...but I feel like i did make a difference. Little snappier, but don't expect miracles. I pressed the throttle lever thing under the hood alternatingly, like press let go press let go,and had my hand by the hole. I could feel air being sucked through the 5'' hole in big pulses. I also did the ISR mod yesterday.
 

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