Thread: Another open cone vs sealed box debate

I've posted this a few other places on this site but I want to hear all opinions. I've caught alot of flack from other sites about the intake I just put on my 98 gtp. Here is my setup, sorry for the bad quality pic.



Cost me $66 out the door with a $10 off coupon from advance. It's 4 inch tubing with a 45 degree bend, I tried the 22.5 degree bend but the filter was to big and was hitting I believe the cruise control. I bought one 3.5 to 4in coupler, bought a 7/8's holesaw bit for IAT, came with the grommet. K&N filter 4x9 inch very pleased. I actually saw on the butt dyno you can def feel the difference. Supercharger screams like a baby. I also had a old 45 degree elbow and since my car is a 98gtp I already had the triangle duct where the guys use the roof flashing. I attatched the 45 degree bend on the inside of the fenderwell to duct cold air right to the tip of the filter.

Now here's what another member on another site said about my intake. I don't totally agree with what was said at all, do you?"


DarkRelic » Mon May 17, 2010 10:49 am
"I hate to break it to you... although you made a free-er flowing intake, you actually failed by not making a box. It's been showed time and time again that Hot-Air Intakes are worse than the stock intake/airbox.

The radiator blows the hot engine air right into your air intake.... so instead of taking in air that is near ambient, you end up sucking in air that's usually 50-80 degrees above ambient, so when your supercharger (assuming a stock pulley) increases the air it's forcing into your intake manifold 150-200 degrees over ambient and then you add the extra ~50-80 degrees you are sucking in from the radiator you are doing more harm than good.

Yeah, stupid ricers who drive naturally aspirated cars can get away with hot air intakes. That's only because they don't have anything amplifying the temperature of the air the engine is taking in to begin with. you have a good start, now make yourself a box.

Oh and BTW, if you don't want your PCM to be bouncing around in your engine bay, get a chevy S-10 PCM tray."

Here's my response to the above post I have in quotations,

In no way shape or form was my stock air box/drop in paper filter out performing what I've got now, absolutely no way. Maybe at bringing in cooler temps but not flow, more air = more power. I'm going to brunswick tomorrow with a friends dad to dyno his supercharged prelude. You want me to take my stock air box dyno it, then put my setup on and dyno it? My filter is not even remotely in front of my radiator. The only time my setup would be sucking in those kind of temps is at a light or not moving. You ever wonder why when going over 35mph there's no need for fans to cool an engine? Same relevance here, especially with that stock junk air box being eliminated. If I relocate the coolant bottle it opens up even more air, not to mention from the reverse 45 degree elbow ducted to run air right to the filter on the inside of the fender.

I'm not debating that a box wouldn't out perform what I've got right now. Everyone knows cooler, dense air will always make more power. I'd totally agree with you if a car was NA but with a blower car it's different. Plus the stock air box eliminates the ability for air to flow thru the engine bay anyways, now it's wide open. The PCM isn't moving one centimeter the filter holds it down perfectly the way it is. I would like to have the PCM tray but in order for the PCM to lay flat I first need to buy a 99+ coolant bottle.

If I was good at fabricating I'd build a box but I'm not and I'm not spending $200-$300 on a box it is what it is.

Open cone 4x9 K&N > stock paper drop in
4inch pipe with 1 45 degree bend > 98 stock gtp airbox with 2 90 degree bends with corrugated tubing and 2 inch hole for air to flow thru
Flow > ambient temps especially on a modded car which I'm working on
$70 > $200-$350+ prices for a box

Next is headers, 1.95 roller rockers, cooler plugs, 180 thermo, aeroforce scangauge, 3.4 pulley, custom tune , when that's all done we will see where I'm at with knock retard and probably call it quites and focus my attention on suspension and brakes.

I'm welcome to any opinions good or bad. Thank you!

Originally Posted by 01GTP

If you can get on the dyno for free defiantly do the stock air box then your intake then open tb. Your intake is fine I would have went with a dry flow filter tho. Good choice on a big filter. Here is what I did.

Is that a flowable filter cover? I've got a dry flow on my type sh made by AEM. I wanted the 9 inch filter though and all the advances around here only had the aem dryflow in way smaller sizes. I could've ordered it but I opted for the now option. Plus the filter only cost me about $42 bucks.

I don't know if they'll have time to dyno my gtp tomorrow or not. My friend is in Iraq that owns the supercharged prelude and I've been working on getting the kinks out with his jackson racing setup with his dad for sometime now. He runs Hondata so it's a fully tuneable ecu, it was tuned in El Paso, TX and the car is now in Ohio with a definite elevation change.

If they say ya we will strap your gtp down and do a couple pulls for fun I'll be all over that. I've only done the intake so far so it's not going to be anything impressive but it would be nice to have somewhat of a baseline to go off of. I would put money on my new intake setup out perfoming the stock box by a landslide but some don't think so.

Originally Posted by Bio248

im anticipating this thread to try and prove some points that i have been pushing for quite some time. keep us updated.

The only bad thing is I thru my drop in filter in the trash, I'm still willing to bet that with the stock air box open with no filter on the dyno still wouldn't out perform what I've got now!

The guy that keeps giving me shi* really urks my nerves. He never rode in my car with a stock air box right? I can tell you when your wife says damn it pulls way harder it probably pulls way harder!

Anyways the dyno app is at 6pm tomorrow night we will go from there. I'd imagine they will have a couple hrs in the preludes retune so I don't know what kind of time we will be looking at. Plus I'm not paying $200 either to prove what is better than what. I know what is better, a stock air box isn't better than what I'm running now.

I would assume theres a lot more to it then just "how cold is the air". a significantly better flowing intake with slightly warmer air probably will produce more power under most conditions. Personally i'd do what I could to try and get fresh air to it.

What I am curious about (being my 3800 isnt supercharged). These cars are MUCH quieter then the old school blowers where the thing was louder then the exhaust.
Does having an open intake like this make the super charger significantly louder?

You know what I don't quite get. From what I understand on a 3800 the supercharger bolts down onto the intake and is essentially part of the intake.
How do people install intercoolers on this? If the supercharger it self is literally part of the intake.

Or is there a single large output from the supercharger to the intake which you can re-route?

the stock air box is technically "cold air" but its very restrictive. now without a box you have the highest amount of flow, but very hot air. get a box that isnt completly restrictive. or make one to prevent most of the hot air. You have to find a sweet spot between cold/hot air, and flow.

Originally Posted by colindunn

the stock air box is technically "cold air" but its very restrictive. now without a box you have the highest amount of flow, but very hot air. get a box that isnt completly restrictive. or make one to prevent most of the hot air. You have to find a sweet spot between cold/hot air, and flow.

Does it really matter after headers, rockers, intercoolers?