It's 12 PM your time no wonder you are awake John

That was my finding with K&N as far as heat soak goes. Wow, looks like you really tested everything and all possible combinations. What kind of gain did you see with GruppeM? I love to mod my RS but Porsche did their home work with this OEM airbox. I was even more impressed when I was able to keep pace with mooty's dual air-inlet 2010 RS

 

Never been a fan of alphaN. It does not adapt well to altitude or weather change. It's a great program for race car but be ready to tweak the software with every single race .... $$$$$$

 

These work:

1. stock airbox with quality panel filter cheapest and best

2. cup airbox requires new deck lid and maf removal and dme tuning if you get it right it works but still oem is better down low and car runs smoother.

3. http://www.sportec.ch/page3590.html Nice idea retains back of oem box and double air flow tricky to cut the lid hall in the right place. Same kit sold by Manthey for their 4l kits

4. GruppeM based on oem box concept but with way more volume https://rennlist.com/forums/996-gt2-...-mk2-sold.html

Fabspeed, cone filter with elbow, no filter. Dont work.

 

Yeap its 12 and I am "working"

WHOT he couldnt outrun u? before u removed the carpets or after?

 

Is the bmc filter the best for stock air box? Where can I get it?

 

while it looks like K&N did a much better job sealing the filter off from the engine bay than they did on their "regular" 996 and 997 intakes, it still looks as though the box for the filter is made out of metal. If that's the case that's where your heat soak issues come into play. Though that could be solved with some gold tape on the whole assembly.

 

You are absolutely correct. Manthey keeps the stock air box, and installs a "sport" panel filter. They cut a second hole on the driver's side of the air box. It is a tricky procedure since it also involves creating an air intake on the other side of the wing, and keeping the cooling fan.

 

Stock box wrapped in a gold foil tape for heat soak is the best.

 

I have no explanation for the improvements that we saw on the dyno with the kn above 6500 rpm

I witnessed it on 2 different cars - both .1 RS

 

tuner friendly dyno?
kn kit vs. oem paper filter?
car hot vs car cold?

 

dyno jet
as we were checking kn claims - we started with a new factory filter
car hot

look... I am not saying it is all that and a bag of chips, but it is an improvement over stock with Porsche filter.

kn claims 20+ hp which I thought was ridiculous so that is how this experiment started....

if you compare like to like with stock vs kn - like to like meaning the parameters are as close to identical as possible (same car, same temp, same tires, same set up (sport on) and the only difference being airbox/filter change) you will see a double digit gain on a hot car above 6500 rpm using the kn kit

now that being said - first pulls were with stock box and then the kn set up... so aforementioned heat soak could very well play in.. however, at speed I think the metal housing that is coated stays as cool as porsche's plastic housing

it makes power but not as much as they claim under identical conditions
it is a nice kit
especially nice for the price

it flows more cfm on a flow bench

I am not a kn desciple... say it gives you 5 hp over 6500 rpms... it is $300... equivalent to one front tire...

on my 996-3 it was less effective on the dyno and prior to kn install we modded my stock box by removing material and "smoothing out" the airflow using a flow bench to measure progress... the kn flows as much as the modded stock box which is to say more cfm than just stock

is all of this better than a drop in bmc - I do not know

is it better than the no airbox fabspeed set up - I would say so as that makes no sense to me.

 

so far the winner is OEM ( free and works better in hot air)
I trust Mikymu ( the test muel owner)
One good reason than someone should not jump on a suggestion quickley

 

...or you can go with the OEM Motorsport airbox
wurlie

 

^ That + this : ///thread

 

I am less trustworthy for sure

hmmm... it seems that I did not jump on the suggestion as I tested it etc.. but whatever... I have less fans than mikymu and know it...

do it, don't do it... as long as everyone is having fun

I am not out to sell anything