The reason is very simple .. the lean out is from more air flowing in .. but still the same amount of fuel being injected ..

the load tables for AFR goes from 9.4 at 240 (approx) to 9.0 at 280 load .. at 0.2AFR ratio jump per 20 loadcell .. a filter changes the load by approx 5-15 loadcell difference ..

refer DB's #3 for the rest .. I believe in the airpump theory too

MAF scaling is available on the X .. just not released (yet)

 

So, a drop in filter changes the load cells? I thought only a larger maf housing would do that by tricking the ecu. With a larger maf housing, there would be more air coming in, but because of the diameter being larger, velocity would over the maf would be reduced so it would run a lower load cell. With a drop in filter, the stock maf housing is retained, so I would tend to think that velocity would actually increase, seeing as how mass increases while diameter remains contant.

In theory, this would cool the hotwire maf more, telling the ecu to dump in more fuel, and I'm sure it does during cruising conditions to maintain stoich, but it sure as hell doesn't do it during WOT (which you agree with) because every dyno graph of a drop in filter that I have seen has shown leaner A/F ratios. Mojito, this would mean that the ecu does NOT add fuel in open loop mode, because it relies on predetermined maps that don't change based on feedback from the maf. This would make the most sense, as in cold weather, for example, a boost spike at WOT can lean out the A/F ratios and cause a detonation.

Obviously, this is during open loop and the ecu isn't adding any fuel in this situation, so I don't see how it would be any different in any other open loop circumstance. Granted, if you are using ecu controlled boost then you don't really have to worry because you have boost correction, but with an MBC...boom! Although, this brings me to something else that I find kinda strange: the ecu can use boost correction to raise or lower WGDC values on the fly to prevent under or over boosting and it can do it at WOT in open loop, but yet the ecu isn't capable of compensating for fueling in open loop?

Although technically, I guess the short term fuel trims during cruising conditions over time become long term fuel trims that can make static changes that will carry over to full throttle, but the short term fuel trims don't apply directly in open loop. In any case, I will try to find some dyno graphs showing the leaner A/F ratios from a drop in, because I find it very strange that you guys didn't see this in your test.

 

ECU is not sensitive to MAF readings in fuel management at WOT? This does not make sense to me at all. Unless ecu asumes that only that much air can pass through at a given load (subject to external parameters like temperature etc.), which doesn't make sense also, because this would be "filer specific", and dirty clogged filter would result in super-rich condition under wot.

 

It seems there are lots of theories, but very little testing. The way to do this is to test a stock intake setup witha drop in on a tuned car & test a car with a full intake kit & larger MAF housing that is tured for the intake & scalled for the MAF. I am not saying there will be any a big diffrence or not, but untill a test like this is done there will only be speculation. It would also be nice to do a test like this on a full bolt on & cammed car or turbo upgraded car to see if other mods will affect the HP numbers between the intakes.

 

Its not tricking the ECU .. maybe you should stop thinking the MAF behaves like the karman sensors ?? (sure seems like you are )

If you have seen the fuelmap .. I'll say again .. the jump in fuelling is minute compared to the freer flowing air .. that's why you see a lean out .. hope the pict helps out slightly

 

Hopefully this will aid in your quest:

Stock filter Vs. Drop in. Boost and AFR overlay:



Stock filter Vs. Cone Filter. Boost and AFR overlay:

 

Read below...

Mojito, the fact that the ecu isn't capable of making on the fly changes to fueling under WOT seems kind of ridiculous to me as well, but it's just the way it is. You would tend to think that with how advanced modern day cars are today that the ecu and maf would be a bit more advanced, but oh well...

 

Oh no, I know what you are saying... I just used the phrase "tricks the ecu" because to me it's a good way of explaing what's going on. The ecu normally runs a certain load cell, and when an intake with a larger diameter maf, or a drop in filter causes that to change, the ecu is running a load cell normally reserved for a different throttle level and rpm thus the word "trick" was appropriate, I thought. Either way, I do appreciate the explanation and the chart.

 

Yes it does, thanks!

 

Here is a before and after dyno chart of an ETS intake install. Our Dynapack reads pretty close to local Dynojets. The lower red and green runs are with the car all stock. The higher red and green runs are with the ETS intake only installed. (nice gain)



Here is boost before and after the intake installed. It went up a little.




Now the ETS has a cone filter on a machined bell mouth adapter that bolts to the stock MAF housing. After the stock MAF housing they use a nice mandrel bent 3” diameter pipe to the turbo inlet.

On this car I happened to log the car all stock and then with the intake installed on the dyno runs. ECUTeK’s logger does not let you see boost, load or charge temp without a license in the ECU so the log does not have those. Now I only went to analyze 6k rpm because that was where some of the biggest gains were but as far as timing and injector duty cycle, it is pretty darn close before and after :-/

Here is a look at 6K.



About the only real difference is the #1 wastegate worked a little harder with the intake installed and there was actually one degree less ignition timing right there on the after run. Does anyone have any logs they want to post to show what they are seeing? Here is a link to the four full logs: http://roadraceengineering.com/etslog/ They are saved in .csv files if anyone wants to get all nerdy with them.

Now, with all this information. Can we say this intake makes decent power for its ~$250 price? Or is it also bad in some way? Am I missing some trickery?

Mike W
(Disclaimer: I am in cahoots with ETS ‘cause I sold a couple of these intakes, CHA-CHING!)

 

So this is with the stock ECU map Mike?

 

Yes. Stock map.

Some of the power would be from the 1.7 psi boost increase. All of it? No. I am thinking that a good 1/2 of the power gain is from more air flow. Up to 4250 rpm boost is essentially the same other that a little difference in the throttle tip in on the run start and the car made much better torque with the intake installed. At 6500 and up at redline boost is the same and that is roughly a 20 hp increase at those points too.

Mike W

 

What does this have to do with the thread title?

WHAT IS AN INTAKE REALLY WORTH WHEN YOU ARE TUNED?

You stated that there is no license on the ECU which means to me that the car was not tuned.

We are not talking about adding an intake to a stock ECU car.

The discussion is about a tuned car with stock intake compared to a tuned car with an aftermarket intake.

If this is not the case in your test, then your post is off-topic.

 

Actually .. there are still gains .. but not the usual claims of 20-30 .. its effectively halved ..

When you're tuned .. granted difference between stock and aftermarket is no longer such a large disparity .. but it's still gains ..

I will agree with you IF YOU INTEND TO KEEP THE CAR TOTALLY STOCK, tuning the car without any parts is the best (but still an oxymoron )..

Once you change anything else that affects the suck-squish-bang-blow cycle .. you're better off doing everything as a package ..

 

If I put up an example of adding an intake with a tune, unless I posted the map along with the log along with a gaggle of third party witnesses I'd just be accused of shenanigans.

This thread is based on the premise that intakes only making power because they cause the ECU to read from different load cells than normal. There is a lot of speculation that that is how intakes make power. Actually the ECU relies a lot on the MAP sensor too for calculating load. Anyone that has tuned an EVO by modifying the MAP signal knows this.

I have posted some evidence of some very similar air flow readings, ignition timing and injector duty cycle runs with very different HP results. This is evidence to my little brain that an intake can make power legitimately.

Mike W