I reached under/behind my front bumper last night and noticed that the factory air intake was made to be very close to some structure,totally shrouding the airflow.
After removing the aircleaner/airflow meter,I removed the snorkel from the tight confines of the nose and snipped away from the bottom side of the plastic part two strips about 2"X4".(basically the bottom side of each runner,back about 4")
I noticed a nice improvement in responce/driveability/ smoothness,as well as flat out performance;a little bit louder as well,but not by much.
The power increase was about the same as the difference between using regular or premium gas,maybe a little more;pretty much what the aftermarket intakes advertise I'm just thinking.
I'll have to check sometime and see if any rain water gets on the filter,but I have a pretty good feeling that it's ok since the snorkel is up pretty high above the grill opening,out of the direct path anyways.

 

was thinking about doing the same thing also... also had the idea to cut a piece of aluminum and with a type of L bend to ramp up the air to the cut out piece of the snorkel. the aluminum piece could be screwed to the part right under the snokel and the side of the L bend could be bent up to form a rectangular funnel.

but i had reservations about the aluminum thing because it rains here quite often and rain could ramp up into the air intake at freeway speeds. but just the snorkel cut out should be safe from any water.

 

My ECM has been learning the new improved airflow and really making a difference in the way it runs.
The rain thing has kept me from doing that also;might not make any difference either,as it's already in a high pressure zone.

 

Can yo post any photos of this mod. I would love to do this mod myself. Is getting the airbox out difficult?

Thank

Raj

 

SCV8,

Would you advise against removing the snorkel all together?

Without the snorkel the airflow should be even greater than with the modified one.

Thanks,

Chris K.
95 SC400

 

That would leave just a hole that would draw air from the hot engine compartment,not the high pressure area behind the bumper/outside air.
A new snorkel with a large,radiused opening would be neat to try,as you noticed,the factory one isn't very smooth.
Not much room to work in,so I was glad to have just gotten it back in there!
It is a bit louder too.

 

just yank the whole box and make an enclosement for the filter that seals it off from the engine... it will flow MUCH MUCH better than simply trimming the snorkel or removing it

 

Yeah,I messed with that a bit,but got a hesitation,stalling from not enough fuel shot initially,it hissed like crazy,and the car wasn't any faster on the freeway,so I put it all back and made the best of the factory plastic stuff.
I saw a factory ram-air setup from an old camaro,but it wouldn't fit in our cars,might make one though if I get time.

 

I have just finished testing a larger hole in the airbox with some big 6 inch convoluted rubber wire spiral wound ducting - results are very positive - pictures etc will be up next week. You can see other cold air intake tests, panel filter tests, make your own cold air intake etc here;

http://www.users.bigpond.com/pgscott/

 

Was thinking something like that also;the snorkel under there just is restrictive by it's shape alone(sharp edges,small opening).Have been looking around at a way to add a duct that'll go across the radiator opening like the guy(can't recall the name) in England has,connected by some large tubing like you described.
Soon the new paint will be done,and I can play around some more.
Wow,just looked at the link you posted;maybe the best move would be to first find out where the high pressure points on the car are,then try and take advantage of the existing aerodynamics.
When I worked at Ford,the wind tunnel guys were telling me about how the placement of scoops can make all the difference.

 

6 inch duct connected to airbox will fit under headlight. Have since made hole bigger again - have removed just about the entire front section of airbox.

 

the elephant snorkel

 

i'd replace that "elephant trunk" with something a bit straighter, those ridges on that pipe are going to cause A LOT of turbulence

 

My car's in the bodyshop,so,I can't go look under the hood;I remember that the opening in the core-support is smaller,is this right?
Just wondering where you were going to put that thing(no pun intended).
Has anyone gone through the fender,then down with an intake on these cars?

 

The snorkel stopped under the headlight. Pressure loss tests showed the elephant snorkel to surpass the standard snorkel by miles. Smooth bore pipe flows better but is a real pain to work with.
The foam mold, the stormwater inlet, the headlight scoop, the elephant snorkel and all the testing has led to this latest intake.
I am finally happy with the BFI (Big Intake). Immediately after I had applied the finishing touches I tested it with the manometer of truth (the manometer of truth doesn't care how much money you've spent, how you feel, how much time you've put in, the placebo effect, what your mates say, what the advertising said, what you've read, your seat of the pants feel, how it looks or the brand name. - All these things are for humans and the manometer doesn't care for them) we went out and did some testing.
Wow!
The standard test wouldn't record a vacuum no matter what - the other cold intakes had a -4cm of water vacuum where the all new BFI had a +1 cm of water pressure! Time to abandon the old conservative controlled test conditions and put the hammer down, all gears, sudden opening and closing of the throttle, screaming to 160 km/hr, overtaking - I could not out suck the BFI - it always washed the filter with more cold air than it could handle.
So I then plumbed in behind the filter to see what difference it was making there. The standard filter has a maximum pressure drop of -2.5 cm of water (pretty good - the K&N was -1.2cm). The maximum vacuum behind the standard filter now was -1.5 cm of water no matter how hard I drove. This means the BFI is not only providing the filter with enough air, it has effectively boosted the standard airbox into pod territory for outright flow under wide open throttle, with no hot air hassles, better filtration and positive boost under normal driving conditions.
Anything else besides wide open throttle conditions and the intake system was positively boosted (+2cm or water) the whole time. Not much boost but it means that under normal driving it's as if there is no air filter and no Air Flow Meter resulting in better fuel economy.
And it looks great - just by looking at it you can tell that it flows.
The whole thing cost $8.
(I had some plywood lying around).
Three main parts.
1. The standard filter box
- front vertical face cut out completely leaving a 5 mm vertical rim around the hole. EVA closed cell foam to seal edges of box to car surfaces above, below and to sides. (3.5 cm gap above airbox lid to bonnet when closed! - I though it would be much closer).
2. Under the headlight
Why stick a pipe under here to introduce more friction losses and make fitting a pain? - just use the bottom of the headlight as the roof and insert a piece of plywood below. Cut strip of EVA foam to smoothly direct air around. The strip has to be quite high to reach headlight. This gives maximum volume under headlight and minimises losses.
3. Chamber between the high beams.
No use fitting a pipe into here through the trianglular hole - just makes it smaller and flows less and delivers sand and bugs and water to filter. The chamber separates water, bugs and dirt from the airstream if left alone. It is nice and big - holds a big store of pressurised air ready for stomping on the throttle. All you need to do is lower the leading edge - the easiest and quickest part of the whole operation. The metal strip bars are removed and refitted once the leading edge is down. I had to relocate a denso sensor on the air filter side (what is that thing? -a temperature probe? - doesn't display temp any where inside - any one else got one there? - looks like a black cigarette sticking out) to above the leading edge instead of below it -easy. I supported the edge downwards with a column of foam strips in the middle. The left hand leading edge is now down to the centre horizontal bar (half way). The right hand side gradually returns to original postion.
Used hot glue gun to attach foam everywhere - easy and quick.
That's it.
One BFI that does everything;
- High flow
- Cold air
- Pressurised normal driving for economy
- max filtration
- no water, bug or grit problems
- Cheap DIY
- Fabulous acceleration
- sexy good looks (haha)
Could tune it for maximum boost by juggling leading edge and sealing headlight opening near battery but she'll be right for now.