I wanted to dive into the deckplate but got impatient needing to wait for a delivery and couldn't find anything at the local boat stores. So I hit one of the local hardware stores. When walking around the PVC / Irrigation / Toilet area, I found a 4" Pressure Tester (go here for info: http://www.lowes.com/pd_23521-138-33...%3D2&facetInfo=)


Parts Needed - two pieces about 5 bucks each:




Not wanting to simply insert the Oatey tester into a chopped up air box, I thought a better seal would be in order. I found a 4" adapter/fitting piece (apologies, because I cannot find a link to this guy anywhere). Find something similar, then chop off the two ends so that it kind of resembles a top hat. This will ensure it does not slip into the box, but yet has enough surface area for the Oatey tester be able to expand to do its job. Discard the two ends.



Trim and test fit the pressure tester into the newly created section.



Remove the airbox, go choppy-choppy on the 'front' side of it with the 'ol Dremel. Use the piece to get a good idea of the size hole needed. I noticed it needed to be a bit off center, closer to the outside and top. I figured this would allow easier access to the hole as well.



I then installed the trimmed piece using a plastic epoxy. It's a pretty tight fit, but I wanted to make sure it doesn't goes anywhere. Then install the Oatey pressure tester into it to get it all snugged down. I then waited to the next morning to ensure a good epoxy seal.



The next morning, all was right in the world. I cleaned up the airbox, got all the shavings and such out of it, and reinstalled. Pretty straightforward.



I tried the pressure tester piece and it too fit like a glove.



I've since gotten a K&N filter which also made a big difference after doing this. A nice project, cost about 10 bucks to build (not counting the K&N). Throttle response is much quicker and it actually gives a pretty nice growl when hitting the gas with a little authority. I rarely do this though... just my nature I guess. If/when needed, just pop the pressure tester in there, crank on the wing nut a couple times, and you're sealed up and ready to get wet. Enjoy!

-Eric

 

Nice job! I need to find one of those pressure tester thingies

 

The deckplate is great for sound, not good for power. Better off removing the elbow that goes into the fender, that will free up about 8whp.

 

I agree. I removed the elbow years ago when the deck plate mode was the craze and it made a difference.

 

It seems like you are implying that putting a hole in front of the air filter will be detrimental. Mind explaining your reasoning?

So increasing potential airflow through the front of the box in front of the air filter is bad, but increasing potential airflow through the side of the box, still in front of the air filter is good?

 

Yep, that is exactly the case.

Pulling air from the fender is nice clean cool air, air from the front of the airbox is hot, "dirty" engine bay air.

The fender port is not restrictive once the elbow is removed so putting another hole in the box will not gain you any power. The hotter air from the engine bay will cause a loss of power though.

I tested this out back to back on the dyno except I was using one of those way overpriced cold air intakes. Lost power over stock with elbow remove.

 

Once the truck is over 5mph, the air in front of the air box is practicall equal to ambient.

I agree there.

I've used sceitntifc method to disprove this in the past. No need to remove anything.

Correct.

Idle power while stuck in traffic maybe.

 

yeah, similar to a lot of "Cold Air Intakes", they actually loose power because of the hot air in the engine bay vs. relatively coler air in the fender. cold air is mo' betta... cold air = denser air; more air + more fuel = more power.

good job on the install though, looks clean!

I will be going back to the stock airbox at some point, I built my own "CAI" but even with the shield and insulation, I'm betting my intake temps are much higher with all the engine bay air. My meth injection pretty much takes care of that though...

 

I have seen dyno tests that say the elbow does free up power so I will take that over theory.

The air in front of the airbox gets no real airflow from the truck moving, it is all but sealed off. The only airflow it really gets is air coming from the radiator fan, which is not cool air I will add. I have also felt the difference and it is noticeable even when moving well over 5mph.

Deckplate mod does not make more power, it does make more sound which makes most people think it makes more power though, I feel for this as well with my cold air intake until I both dynoed it and tested it with a gtech (real world test since it measures the gforce). Both agreed that elbow removed is the best setup.

Real world dyno test, Cold air intake vs stock airbox with elbow removed:



High speed fan was setup in front of the truck to mimic airflow for cooling but it would also have the same effect on the airbox area

 

I agree that at highway speeds it may not be a huge difference but cruising between stoplights will be for certain a big difference in temps.

I've got my entire intake and isolator box wrapped in hot water heater insulation from home depot to keep as much heat from the engine bay out of the intake.

 

Your intake is flowing over 100 CFM while cruising at 2000rpm. Wrapping it is just a waste of insulation, air is not going to warm up while travelling through the intake at that speed.

Would be better off wrapping your battery. Might get a year more out of it.

 

Well said. Cool the air before the box, not the box.

Back to the original post, I love the pressure tester thingy. I have a PVC cap that I put over the deck plate mod, just prior to a water crossing. I put it inside the deckplate(between filter and mod), since I have mesh wire over the outside of the deckplate. Keeps the big stuff off the filter (i.e. leaves). You have great ideas. Thanks.

And....

I'll trust what ever Texas Ace says about the 3.4. Likely the only video you will ever see of a T4R on a dragstrip. Thanks for all the info, T.A.!

 

I can't believe they still allow threads about the deck-plate/air box/dyno/clean air/elbow mods. YotaTech needs a forum called Fight Club for this one.

Eight horsepower on the dyno:

http://www.off-road.com/trucks-4x4/t...cks-52540.html

STICK

PS: Hah hah hah hah [evil laughter]!

 

You will notice that they also removed the elbow that goes into the fender when doing the deckplate mod in that test. If they had removed the elbow before the deckplate the gains would have been nothing for the deckplate since the elbow has been proven to gain ~8whp over stock by itself.

They also had the velocity stack setup which is well known to flow better then the normal deckplate mod done here and still only equaled the elbow removal.....

 

Good point with the elbow, but it's still on there for the stack mod story. The photo on the couch is of someone else's air box that I bogarted from the interweb. I am thrilled to find another velocity stack fan, though. Cheers!
STICK

 

Did that airbox mod and the huge airbox replacement tube near the throttle body..... Then gas went off the hook.$$... ! Changed them all back !
Ks

 

I have the deck plate mod and elbow removed, i'm going to close up the deck plate and see if i feel the difference.

 

Doubtful you will feel much of a difference as with the deckplate you will be making more or less the same power as the elbow removed (give or take 2-3hp), just less consistently since it is open to engine bay heat.

The key is that the elbow is free, super simple and is consistent. The deckplate takes work, is not undoable and not as consistent.