305 Z28

What would cutting the bottoms out of the airbox do? not the full ram air setup with the piping, just hacking most of the bottom. Those things look really restrictive. I already have K&N. I didn't see anything under search.

iroc2nv

ive noticed a little gain...not much but enough for me to leave a bit (inch or so ) of rubber going into third..with no more mods other then that at that time(does that make sense?)

all it does is makes the engine get more air hence making it breath better...breathing better =more horsies

iroc2nv

305 Z28

Is there any negative effect? Should I just drill holes or remove most of the box?
By the way Iroc, I made a custom wire grill out of stainless steel diamond grill, it gives me a body kit look. I wish I could show pics, It replaces the plastic insert, I like your front fascia, it's good to see something different for a change

Sciguyjim

Just be sure you cut the holes so the air still has to go through the filter. I've heard it's not so obvious on some cars and people were cutting holes which let the air bypass the filter completely!
Many people have open air filters in the engine bay, I did too for a few years, but people convinced me to put my filter box back on and run a pipe from the snorkle to a place where it could pick up cold air. It can make a difference compared to sucking hot under hood air. The hot air is less dense so it has less oxygen in a given volume and this reduces your HP. Conversely, sucking cold dense air helps HP. Just a 10° F change in air temp makes about a 3% change in air density, and you know the hot under hood air is more than 10° above outside air.

Perry93TransAm

Listen to what sciguyjim is saying about the holes, make sure it will not let unfiltered air into the engine, but since we know its an 85 the bottom of the box is where you cut.
Perry

Paul Riccioli Jr

iTrader: (1)

I was thinking of doing the same thing sometime in the near future with my air box. Please keep me posted on your results.

305 Z28

I drilled holes all over the bottom of the airbox and removed those plastic pieces in there. I doesn't look like a hack job though. I removed the big plastic thing directly below the airbox ,that's supposed to direct air just into the radatior, for more air flow. I didn't notice any difference, there has to be more air getting in there. I didn't hack the bottoms off of the air box, I doubt that does much anyway. So I sort of made the ram air without the tubes. I'm not wasting money on one of those stupid air intakes, like someone already said, the stock unit holds up even in drag cars, I'm not spending 100$ after I already spend 80 on those k&N

Sciguyjim

That big plastic thing is the air dam & you need it. You won't notice any difference at idle or at low speeds because the fans pull air through the radiator. At high speeds though, the fans turn off and all radiator air comes from what is scooped up by the air dam. Without the dam, airflow under the car can pull air backwards through the radiator so the hot air under the hood is going through the radiator. This makes the car run hot at expressway speeds.

See this thread on the cooling forum for a pic of the air dam:

https://www.thirdgen.org/techbb2/sho...&highlight=dam

Jim85IROC

iTrader: (2)

I cut mine right at the top of the intake vents. I used a dremmel and a cutting disk and cut all the way around. Nice and easy and doesn't let any unfiltered air in.

Jay87Z

iTrader: (2)

I can vouch for this. The 85 IROC I just bought has no air dam. I had a 4 hour highway drive home and it was running quite hot. I had to have the heat on on a 95 degree day to keep it cool. Fun drive home

BORLAZ06

After chopping my airbox Ive noticed a lilttle gain.

Runs even cooler on the highway.

jd13

BorlaZ06, that's exactly what I was planning on doing.

Do you have any problems with water getting in there or anything?

edit: Oops, it doesn't look like you still have the stock intake in there.

Scott C

Mine looks exactly like BorlaZ06. I used a jig saw to cut the bottom of the boxes off nice and clean, and also removed the large plastic air thingy directly under the air boxes. Works fine for me...no restrictions at all

dacuma

I'm pretty sure that's the stock airbox. I cut my airbox just like that and that's how you want it to look, all that you need is the lip, so that your filters can still go on there. And no, you shouldn't have any prob with water getting in there. Unless you drive through a lake. I live in florida and have had this mod done for about 3-4yrs with hurricane weather and never had a prob.

BORLAZ06

Nope, no water gets in unless you drive thru a lake....hah

I still havent used any air duct tubing to make it ram air yet...been lazy.

And the filters hang on the lip like so...

305 Z28

I left the air dam that droops under the car alone. I removed the plastic shroud above it. So air should be being directed up to the radiator, right?

Sciguyjim

I believe so but I'm not 100% sure because I have a T/A, not an IROC. I think they're set up the same way in this respect. I'm sure someone else will know for sure.

Poppa Chubby

Excellent pics Borla! Very helpful! Mine looks just like that.
I have noticed that the air filters do get dirty a little easier but that may be the crappy roads around this place . . .

jd13

Thank you two guys. That's exactly what I needed to know. I'll be gutting my air box this weekend

90Iroc-Zee

do the ram air setup, i did mine perfectly. i run about 140 degrees at speeds above 40mph. tho i can vouch at low speeds the little **** gets HOT...95 degrees with heat on full ugh i hate chicago summers.

iroc4ever

I cut my air boxes 3 weeks ago, but I left that "plastic shroud" in place...
Guess i'll have to get to it next weekend... Is it hard to get out of there??

XspyderX

Much appreciated guys, thanks.

MdFormula350

i have a firebird , i guess i should just drill a bunch of holes in that metal can of an airbox...

if i had my iroc-z still i would of made my airbox look like that...

Brian'sIROC

with the firebirds, you can cut windows out of the filter canister to get similar effects.

jmon92conv

I took two 3 in pvc 90's and hung them down behind the fog lights about an inch. I noticed a difference in the seat of your pants dyno and I have about 20 min. and $3 in it.

Jeremy

CHRISMAN2000

iTrader: (1)

I cut out the bottom of my air box.
I guess it flows better but there was no HUGE diff.
The best set up might be going with a cold air induction set up.
But that can be big bucks.

XspyderX

Thanks guys, did mine today. Very helpful and you always gotta love the free h/p.