996-LO

i do not hav any tools to data log, we are a young team in regards to Porsche experience and fuel injection all together. But make no mistake we are problem solvers. This is the second time in a year this car has hit the track and less than a month ago this car was in pieces after being dissassembled a year ago from an engine failure. We run in a local club at a modest budget so spending thousands right now is not an option.

I cannot disagree with anyone because like i said my experience with Porsches is only days old. Also i am well aware there could b a deeper issue we are not seeing because there are so many frikin codes on its like Christmas on that dash. As i understand it the K&N air intake system has an inside diameter of ~3 inches and a perfect cylindrical shape where the MAF sits. Also the MAF is located right after the air filter and the overall intake length is much much shorter than the stock box. As opposed to the stock airbox that is a larger unit, the MAF housing is ~3.5 inches and an oval shape. What the K&N intake is doing is speeding up the velocity of the air in such a way that the MAF is getting a voltage reading that is off the charts and therefore telling the Ecu to dump fuel as opposed to the design of the stock airbox that moderates the velocity of the air passing through the MAF giving a more balanced fuel trim. So what we are testing at this point is using a .05 cent resistor to manipulate the signal since we do not hav an airbox nor any larger MAF housings. We also decided we could make the test more effective with a potentiometer instead of changing out resistors on the dyno.

996-LO

Also wanted to share some images of how we installed the resistor. The potentiometer is the little blue box thing with a gold screw that varies the resistance from 0-1000 OHMS of resistance by turning the screw.

Imo000

You got something else going on. +1 for this being a band aid. The resistor trick is an old one, the tuner crowd loves it because its cheap but its a false sense of security. The engine now thinks it is getting less air than it really does. If you dyno it now and looks good and then the air gets thicker (colder) then what?

Flat6 Innovations

It doesn't cost thousands to get fuel trim data. It's the proper diagnostic method to gain an understanding of why the engine is doing certain things.
Most any intuitive scan tool will offer this and even a durametric does.

mcipseric

Why not put a stock intake on the engine and see what happens...?

utkinpol

It is a bad idea to use k&n intake on a track car. You will be sucking in hot air from engine bay on a track. It is quite bad. I bet you have problems with maf sensor, probably oil is on it from this intake so it mixes up everything and you adding up resistor to alter maf sensor signal proves that. Put back stock intake box and try to wash or replace maf sensor. If you want better intake than stock one - get a dual port intake box from x51 kit.

996-LO

K&N filter was washed thoroughly and any oily residue was eliminated. Also a new MAF was installed and is only days old.

I could not agree with you more. The K&N intake is great in terms of the lack of heat soak due to the plastic tubing. However, we need to design a more efficient cold air design.

996-LO

Dyno vids are coming but here are a few dyno graph screenshots with the "band aid" .
These are direct comparisons from Weds night dynos.
In case there is question, yes at ~3200 RPM that is an approximate 75 lb/ft torque gain...

996-LO

thank you for the suggestion, i just learned we do hav a stock airbox so we would like to a direct dyno comparison with it as well.

Imo000

You said you are new to EFI, what about the others in your team?

996-LO

I personally have more experience in EFI than the others. I hav never however until last weekend driven or ever turned a bolt on a Porsche until i did my first club race ever last Sunday lol.

Imo000

Porsche or not, it doesn't matter. Basic EFI experience should tell you why the resistor to the MAF is not a good idea. I get the feeling that somehow you don't get this.

Flat6 Innovations

It's not just EFI, it's engine management.

What you probably also don't realize is that you may have ignition issues too... Safety retardation can be impacting the engine and your resistor may not make up for that.

You'll learn.

996-LO

I understand your opinions are well founded thank you. But my question is if i had an engine problem would it not show up on a dyno reading?

alpine003

Is your dyno guy monitoring knock in any way?

Also in regards to basic obd diagnosis, you could even do one step better and get a Piwis cable from overseas for under $30. This isn't popular with everyone but certainly another option.