rideau

I have the EVO intake on my 2001 3.4 Cab. In my opinion, one should not use the K&N oiled intake.... it contaminated the MAF with oil and a new one was required as cleaning didn't work.
As far as performance gains (GIAC flash as well), I finally noticed that there may be modest gains to both modifications on the Andretti straight at Mosport. A fellow driver (2001 3.4 Cab) who was behind me and slightly faster than me in T 2 through 5b noticed that I would pull ahead noticably on this uphill straight......he came over after our session wondering what was done to the car.
Conclusions?
1. If the purpose of the mod is to go faster on the track, I would be better off having spent the dough on instructed track days
2. I don't regret it...sounds good, a source of conversation at track days and finally there was some kind of test (even though it wasn't scientific) to rationalize the purchase.
3. A modification per year keeps me away from the Porsche dealership looking at 997S cabs!
Cheers

GeoT3

dumb question. does cup car for that matter any off road cars have MAF in them. The racers all use some form of K & N filters but I don't think they care about longevity of engines just getting as much air flow as possible without ingesting pebbles...

8haggis

If an engine is electronic fuel injected, then the ECU will need to determine the amount of air entering the engine to determine the proper injection pulse to achieve ideal combustion mixture. (Lambda = 1)
There are 2 ways of doing this:
1. Measure the airflow amount directly - Mass Airflow Sensor (MAFS)
2. Infer the amount of airflow by measuring the manifold pressure and engine speed and compare these values (plus some modifiers) to a look-up table.

Most car manufacturers at this time use MAFS due to continously tighter emissions regulations, however some Honda vehicles and all non-diesel Chrysler vehicles use the indirect method of airflow measurement.

I would guess (I really don't know for sure) that since the base cars are MAFS based, the Cup cars are also a MAFS based system. (The engine calibration workload increases quite a bit to develop both systems.)
As far as using K&N filters on Cup cars...have you noticed the K&N decal on the car? The owners don't put that sticker on there just to get free $50 filters. The K&N is very good for racing for a couple of reasons:
1. K&N gives them money. (Good marketing strategy)
2. Engines in race cars are rebuilt and refurbished continously.

Therefore, since the engines are rebuilt and they have budgets for this, replacement of a MAFS every-so-often is not a big deal, I would imagine. Also, any damage to the liners, rings and valves are addressed by the rebuilds.

For me on a humble non-racing, family man, going to put 2 through college, kind of budget - I will stay OEM grade on engine filtration.

unclejosh

After reading perhaps >> 100 posts on a variety of forums, it sure seems that money would be better spent on fresh rubber and track day time than exhaust/intake/chip upgrades.


How can Porsches stock designs for exhaust, etc be so far off the mark ? Not likely !

There is no free lunch: witness the cost of the OEM Powerkit at $ 17 K:
to get 26 hp PROPERLY, so the car runs well, new heads, intake, etc.

Finally, I salute 8haggis for taking the time to post the truth about these aftermarket products.

kauai_diver

+1 8haggis Thanks, excellent info.

PM me if you want the jaggies out of your avatar.

SilverBlue

This thread is by far the most reasoned and informative that I've read on the various intakes. Thank you, 8haggis. Or maybe I'm just too rational, being an engineer too.

John

dndodd

I talked to some people who race 911's at the recent race at Barbers. They generally replace engines after 3 races that is less than 1000 miles. They all seem to use an EVO like set up.

8haggis

Thanks for all the kind comments.

JasonAndreas

The cup cars are Bosch Motorsports ECU based (MS3.1/MS4) running a MAP sensor and delivered with a BMC air filter.

PORSCHE CLUB

Shaggis, thank you for your impressive insight on air intakes.

given time, would you also care to add if all the aformentioned points, remain unchanged when a turbo is involved ?

(would the exposure to more dust, create a bigger, smaller or no different in 'damage' from a NA engine to a turbo engine ?) (like with the 997 Turbo)

thanks very much.

MJS NYC

+1, excellent thread, thank you.

8haggis

PORSCHE CLUB, I don't believe that the turbo requires higher filtration efficiency, but I will look into it. The turbo-diesel applications (non-Porsche) do require higher filtration efficiencies, but I believe that it is due to the diesel engine and not the turbo. (Basically, I don't think that the turbo itself has such a tight clearance that micron size dust would cause issue.)

I will post again if I find a good answer to your question.

PORSCHE CLUB

Thank you shaggis.

we will hear from you on this subject if and when you have more info. thanks for that.


i ask as i would like to install the fabspeed's twim air intakes into my new turbo. their sports exhausts are certainly going in.


all the best to all and thanks again.

8haggis

PORSCHE CLUB,
I reviewed the Carrera S system again and found that the filtration efficiency of that system is over 99% for SAE fine dust. This is a very good performance number, but not unusual for a paper media filter. I am not sure if the Turbo filter media is different, but sometimes filter manufacturers print the dust holding capacity and filtration efficiency along with the manufacturing date code and part number on the end of the element. If you want to open your airbox and take a look, you might be able to find out if it has the same filtration requirement or not.
The Fabspeed unit appears to be a non-woven fabric media and is likely oiled, but I can't be sure from the picture. These types of filters have trouble achieving the 99% efficiency without significant oiling. Fabspeed also state that their filter doesn't impact the warranty, but I would check with your Porsche rep at the dealer level to be sure. You could also ask Fabspeed directly on whether they have performed any filtration efficiency testing of their filters and ask for a data comparison between the stock unit and their unit. You can also confirm if it is oiled, and if so, be sure to also ask your Porsche rep on how he would handle a failed MAFS if this unit was installed.
My final observation is that there is no protection from hot air recirculation with this design. This may not have as big an impact on the turbo due to the intercoolers as compared to the normally aspirated Carrera, however you could get more bang from the system if you could seperate the filters from the rest of the engine bay. Maybe this could be done fairly simply by a thin plate installed vertically behind the filters which would seal to the front edge of the rear decklid.
Let us know if you find out anything.

Dan_997

Any thoughts on the advantages or claims for the RSS Plenum ?

http://www.roadsportsupply.com/IPD_P..._Porsche.html#