Drop in K&N vs Cone K&N

Does anyone know what the difference is, performance wise, between a drop in replacement K&N filter and a cone K&N. A friend of mine told me that he read in a magazine that the difference wasn't noticeable. I'm wondering what you all think about them. One thing I know is the drop in over all is much cheaper. Think about it, either build or buy the new intake and everything and then buy the cone filter or just buy the drop in factory replacement K&N filter and keep the stock intake. I'm looking forward to hearing what you guys think.

Thanks,
Don
1998 white
GTP coupe

Get the conical. It has a far larger surface area, and gets air from 360 degrees. Its really not more expensive. Drop-in runs about $35, and I've gotten conicals for less then $40.

The stock airbox (drop-in) is much more restrictive than the conical. More air = more power. You can build your own Cold Air Induction for relatively cheap, or you can buy one already made. Thrasher, MSP, SLP, all make CAI's. IMHO its one of the best cheapest mods you can do for your car. And you usually get better gas mileage too, at least I did....

I did some tests.

Stock airbox + stock air filter = 14.6

Stock airbox + no fitler at all = 14.6

Removed airbox altogether = 14.3

Cone filter = 14.3

You be the judge.

YMMV.

Are those vaccuum pressure numbers Jeff? Its hard to believe that the stock filter wouldn't add any restriction at all over no filter. Kinda proves the airbox is the restriction.

I ran a best 14.5 stock.....
When I dropped a K&N Panel in, I stayed at 14.5
When I installed a Cone (open cone)still only a 14.5
When I installed a CAI box I got a 14.4.....

The numbers you show (I think) are a fluke, It's hard to believe that you could get 3 tenths better out of a cone vs. the "no filter"

I love the cone vs. panel. It certainly seems to let the sound of the SC out of the hood better than the panel did.

I don't think its that hard to believe at all. If you ever actually look at a stock intake, there is practically no airflow at all. A CAI on the other hand has almost no restriction, its an open three inch tube from the filter to the throttle body. More air is always better. I was running low 15's with the stick airbox. Now I'm running low 14's with a CAI and a 3.4 pulley. The pulley is great and all but i dont think it is responsible for over a second decrease entirely by itself......

One thing has always bothered me a little about the ET comparisons for different mods. No one seems to take into account the driver factor. While I no longer race, it was not uncommon to see major improvements as I became more familiar with the car. Quite often a major mod would make enough change in the car characteristics that a whole new learning cycle was necessary. You have probably all seen the differences that a really good driver sometimes makes, a 1 second improvement between drivers is not all that uncommon. Do you remember your first time out? For most of us it was not too great. Give your selves a little credit, maybe you are driving a little better.

My above runs were all on the same night and went over a span of about 10 different passes. I am also a veteran at the drag strip, this is not my first car that I have taken down the quartmile and it wasnt the first time that I took this car to the track either.

Debate it all you want I know that I saw what I saw.

Just getbthe cone. It's worth it.

My point exactly :rolleyes:

I'm not debating anything. I've made several runs in one night, and had results that are similar to yours without making any changes. Some runs are better than others. I'm just trying to point out that, your results are probably not typical. Like I said before, I just can't see improving your ET by 3 tenths between No filter and ,removing the air box, or, no filter and a cone.
As I said, I'm not disputing your results, I'm sure your times are legitimate and, if anyone has any similar results, please chime in, and I'll eat crow.

I'm thinking about buying a CAI and leaning towards the SLP cause its cheaper then the Thrasher, plus it says you need to buy a coolant recovery tank with the Thrasher for another $25.

Anyone know if the filter that comes with the SLP is a K&N ? Anyone know if I'd need the coolant recovery tank with the SLP?

Thanks,
Dave

The SLP filter isn't usually a K&N. Usually its an S&B. Sometimes its a K&N. It depends what they happen to have on hand at any given time.

The coolant bottle may be required w/ any CAI you buy. I believe on the '97's the bottle is in the way of an aftermarket filter system. They changed that in '99 I think, moved the bottle to the passenger side of the engine bay. Wait...now that I think about it, the SLP is very close to the stock box.

Doesn't the SLP box only house a 7" filter? vs. the 9" filter on other systems?????

Don's original question was whether or not a cone is better than a drop-in. There's been some good testing of this, but don't forget that Don said he had a '98 with the old restrictive air box. The '99+ GP's have a less restrictive air box right from the factory. If you go with a cone you'll almost definately have to move your coolant bottle, but I do think it's a worthwhile mod. When I did mine I did notice an improvement, but I never used a K&N drop in. Good luck.

The differemce between the SLP and the Thrashe/MSP CAI are that the SLP has a 7 inch cone, while the Thrasher/MSP have a 9 inch cone. The SLP is more along the lines of a less restrictive factory box, while the Thrasher/MSP relocate the PCM and definitely allow for more air to come through. IMHO the Thrasher/MSP are the best pre-fab ones out there. And I have used the K&N Drop-in and there is a huge difference between the two. Just listen to the whine when you step on it with a CAI...

There is no need to move the coolant bottle if you run an open cone. Also I am not sure that the 99 box is all that better. I did see a .3 difference with out the box...put it back in and I went .3 slower again. I did it too many times to chalk it up to not driving my car consistent. When I go to the track the first two runs are blow offs because I am getting used to the track conditions but after that I am usually within a few thousands on my times. So to see a .3 diff is huge.

Heres something I heard about CAI's. Ok this may sound stupid and this states doesnt come from me, but i heard this from some guy. ok first off all of our cars are fuel injected. They have an air temp sensor i believe for the air coming from the intake and to the engine. Now i hear that on fuel injected cars the pcm interupts with this open cai system. the cold air comes in but the sensors changes the airs temp to factory standards through the pcm. I was curious about this, sounds like some bs to me but thats why im asking you guys.
thanks

Hello,
The only thing you change w/ a CAI, is the restriction of the airflow. You lessen the restriction, the temperatures remains the same (according to the PCM). If the intake air is a bit cooler than it was yesterday, I would think the PCM would not take that into consideration. Air flow, on the other hand, will change dramatically, which is why you disconnect the battery for the given time to "reset" the PCM. So it can adjust the fuel tables according to the air flow. All in all, according to what I've read, the PCM "learns" how make the enging run optimal to most changed conditions after unplugging it for a 1/2 hour.

sounds interesting anyone else have any feedback?

Phil what are you saying? That the air temperature sensor somehow heats the incoming air back up?

All the temp sensor is, is a thermometer. It reports the temperature of the incoming air to the engine, so the correct amount of fuel can be injected. This is because the density of air changes with temperature, so different amounts of fuel are injected for hot air vs. cold air.

But all the IAT (inlet air temp) sensor does is 'sense' the temperature - it doesn't heat it back up or anything.

If that's not what you were saying, forgive me, it's still early in the AM, things are sorta hazy.

Yea I think thats where I was getting at, but like I said in my first post all that info wasnt coming from me. I was just evesdropping on a converation one day and heard that guy talking about that.

Ok - then I won't be offending you by saying that yes, it was total BS.