irocbirdbuilder

Seeing as how i went form the stock hood to the 4" cowl i have a huge amount of room to play with. Before i had a 14x3 k+n open element so my dad had a 14x4" purolator from pep boys that he has for the ram air on his truck, I threw it on and put up a longer stud. Still have a ton of room underneath. Runs alot better low end is a slight better but when you are jsut cruisin and get on it it really pulls harder. So heres some pics for your enjoyment.


Can i put on a 14x5" filter or will the 5" tall one bog the motor down any. I have the room.

THis sounds so much better nice and loud.

irocbirdbuilder

nice and big

irocbirdbuilder

Underside of the harwood 4" cowl.

So anyone got a 5" filter????

25THRSS

I'de bet it's all in your head. You're not gonna gain much or lose anything from changing filter heights. If you really want to you can invest in an Xstream filter top to take advantage of the cowl hood.

Dewey316

is already getting everything he will out of the cowl. the only way for more, is to make a sealed filter housing, and make it true cowl induction.

I agree with it being in your head. a 3" paper element will flow enough air for TBI, what good does getting more through the filter do, if it can't get through the TB.

25THRSS

Not really, if you look at the second pic, the top of the filter is level with the very bottom of the hood, and is taking in all it's air from the sides which is below the hood, so basically the cowl hood isn't doing much, if anything right now. If he was to use an xstream filter top he would be able to pull some air in from the top where the cowl would be providing cooler air. Or he could just get a high rise manifold with a thick spacer and then he might actually need the hood. Either way, the placibo effect is going on here big time. BTW, where did you get the longer stud from?

ShiftyCapone

iTrader: (7)

Ditto on the placebo effect. If anything you are feeling a difference from a lighter front end from that hood. Even if you made a true cowl induction you can only get so much air into the TBI unit as dewey described. The only way to get more in is through forced induction.

irocbirdbuilder

The stud was from my dads 91 suburban becasue he got a new one when he put the ram air on. It sits up just inside the cowl when the hoods closed not much into it jsut a tad. I figure a spacer and the xstream lid to get up into the cowl and i also want to do the injector spacer. Anyone have the weight of the stock hood on these things? I know the hood is nice and light but i drove around with it for two days with the 3" filter. It might be in my head i got some weird stuff that goes on in there

However i am a example of publik edumacation so can some one elaborate on teh placebo affect. I think i know what it means but wanna double check.lol

ShiftyCapone

iTrader: (7)

It comes from various old medical tests where they had two sets of patients with the same ailments. They gave half the group "real" medicine and the other half sugar pills. Both groups showed equal improvement because they "thought" they were being mediciated but in fact they were. The mind is a powerful tool.

Dewey316

It is a medical term, when testing drugs, they give out 'placebo' pills (sugar pills) and also real pills. they do this to determine if the effects seen by the patients are in their head, or the medication.

Poncho Villa

In my humble opinion, a huge filter is the next best thing to no filter--so a taller element is going to allow more air. My open air element makes a very loud induction sound at high rpm, almost whistling, and it's just a paper filter--definitely helped. I plan to use a K&N filter next, because it's cloth and flows better. Not only that, but the ECM will add fuel to compensate for the increased airflow. So I'd be willing to bet this man is experiencing some real gain, if only a small gain. Plus the burly induction noise is nice.

My open air element made a huge diff. These motors are just begging for higher flow in all departments. For those about to rock their TBI, I salute you. Mine already snorts pretty good, and it's stock.

Oh yeah, totally agree on fabbing an airbox to take advantage of the cowl hood. There are some cool ones on these threads.

Rock on with your huge filter dude! And fab up an airbox for cold air, that's supposed to really boost performance as well.:rockon:

Dewey316

only so much air can go through the throttle body, no matter how big the filter is.

its like a funnel, not matter how large the top is, only so much can go through the bottom, no matter how much larger you make opening at the top, it doesn't it make it get through the bottom faster.

and the ECM does not correct at WOT.

ShiftyCapone

iTrader: (7)

Well said. In additon, any "noise" change you hear due to a larger filter is just that, a noise change. The air will be entering the filter over a larger surface area and will in turn have a lower velocity and will resonate differently and therefore produce a different sound.

25THRSS

I wasn't saying to get the top for more air flow, simply for cooler air because it's closer to the cowl where it might be able to take advantage of it.

ShiftyCapone

iTrader: (7)

I gottcha now. I think that because of the injector pod location the majority of the air will be drawn in from the sides. It would be neat to see a flow demonstration with that wind tunnel smoke to see how the air actually behaves around the TBI. After all, we can only assume which way air enters into the unit with different open element combos. We could all be right or wrong for all we know.

25THRSS

You're probably right, but it's in the every little bit helps catagory, besides the Xstream top just looks so damn cool, lol. A little off topic, but is the plastic piece infront of the radiator, surrounding the hood latch, needed? I always use it to put all my tools on, but does it actually serve a purpose?

ShiftyCapone

iTrader: (7)

Yea it holds the radiator in place. If you look under it you will see two rubber mounts that fit over the top of it. When you unbolt that piece those mounts come out. It is the perfect tool shelf.

25THRSS

No, not the piece that holds the radiator in place, that's the shroud. The plastic piece I am talking about is directly in front of it. The lower hood latch is directly in the middle of it. The only thing I can think is it might have something to do with cooling, but I don't think it has a purpose besides looks. Anybody know?

EDIT: This piece

https://www.thirdgen.org/techbb2/sho...diator+plastic

BronYrAur

iTrader: (1)

Well, that's where the TPI ducts go because there are two filters on each side of the latch. I'm going to guess that since the TBI cars didn't utilize that kind of intake system they just covered up the wholes with a flat black plastic piece.

25THRSS

right, but does it actually serve a purpose besides looks?

BronYrAur

iTrader: (1)

I don't think so. I think just to cover it up so there's no gaping hole there. Unless there's some kind of airflow that goes up in front of the radiator in that space and that plastic kind of "holds" the air in there. Just a thought.

Dewey316

no it doesn't serve a purpose. firebirds don't even have one.

ShiftyCapone

iTrader: (7)

Ok I gottcha now. Pics speak a million words I thought we were talking about the shroud. That peice serves no purpose but to sorta dress up the gapping holes exposing the connections of the front end.

25THRSS

Firebirds don't have one, but they have sheetmetal in place. The only thing I could think of is it may have something to do with air flow as mentioned before. I didn't mean to hijack this thread so I apologize.

ShiftyCapone

iTrader: (7)

It could be but it seems like it would be more of a hinderance since the air dam is forcing air up in that direction. That plastic thing seems like it would trap it. My geuss is that it keeps road dust and funk out of the bay and air intake path that the air dam sucks off the road. It is the mystery plate.

Dewey316

I think it was purely apperance related. i doubt it serves any functional purpose.

ShiftyCapone

iTrader: (7)

You are probably right. They put it there saying "let them figure this one out, they will discuss it to death." They were right

steve8586iroc

I hate to let you all down but it does serve a purpose. Just like the dam on the bottom of the radiator this plastic cover makes sure all air moves thru the radiator. As most of us know we need all the air we can get thru the radiator and thats still not enough. I would not remove it unless to replace it with something else.

Steve

irocbirdbuilder

I've considered making up a nice smooth stainless steel plate for that littel cover to clean it up a littel then maybe have my buddy etch like camaro or rs or something into for somethign real unique.

I think it does help direct teh air flow through the radiator

ShiftyCapone

iTrader: (7)

Aha, I knew someone knew I guess it makes sense now. If the air dam forces the air over the radiator face and that plastic peice keeps it from merely traveling right out of that space, then the air is forced to go through the radiator due to a little high pressure zone.

Dewey316

the hood closes so tight in there, i doubt it makes any significat diffrence. the holes in the one on my car, have got to let as much air through, and the small gave between the hood and the core support.

ShiftyCapone

iTrader: (7)

The hood is slightly domed though and that might be enough to allow the air to go through without passing through the ribs of the rad if that piece was not there. We deffinatly need to get off this plane since we highjacked it so bad. We may be discussing the most pointless part ever on a 3rd gen, haha.

Dewey316

come on, next we can talk about the light under the dash, that shines on the ashtray. thats always fun.

ShiftyCapone

iTrader: (7)

I never thought about that....[me scratching chin]

What about the 3 screws that hold on the stereo face plate and the mystery ghost fourth screw that is conveinently tucked under the gage cluster part of the dash? We really need to get back on topic here

irocbirdbuilder

Yes man why in the hell do they even put the fourth one there. Mine was gone when i bought it the nice thing is it takes more to get teh cd player out on my bird the cover plate just snapped ontop of everythign atleast the camaros are screwed in lol

I'm working on some plans to fab up a functional box to make this hood really work.