Fooling the ECU

[Zuffen]

I've often thought about fooling the ECU into thinking the engine was flowing less air than it is by allowing some air to by-pass the AFM then using larger injectors and allowing the ECU to use it's "learning" capability to sort the mess out.

Whilst surfing the net looking for information on Karman Vortex AFM's I came across this site http://suprasonic.org/lexusriemer/lexusnotes.html which is worth a (longish) read.

Some of it is well over my head so comments from more knowledgable members than I would be appreciated.

I figure if the Supra can do it, it stands to reason the 1UZ can as well.

 

[Lambo]

Afm and fooling the Cpu

Hi Zuffen, After having a look at the article above i remembered seeing an article some months ago, anyway did some internet explorer history digging, i have set my internet history for 365 days comes in handy for pages i have visted, there is some good info here it relates to a supra using the lexus afm, the mods they did, long but well worth a read http://rob.carlile.home.mchsi.com/lexus/lexus1.htm

Regards
Lambo

 

[Zuffen]

Lambo,

Interesting read.

Now the question still remains is this an avenue for us to explore?

I would love to retain the stock ECU (for the driveabilty) with some simple mods.

 

[Lextreme II]

I like the Adjustable FPR and the Injector plug adapter. I wonder if we can get those parts.

 

[sideshow]

by far a cheap and crude way would be to add an extra injector

then use an auxilary injector controller

u could use one of these if u run a blower or turbo on lowish boost

control it by rpm and load

that way all the way up to boost u run std settings

maybe even have a 2ndary butterfly like the walkinshaws

the 2nd butterfly opens when main butterfly is at 80%

this way below 80% it is all std

 

[SCV8]

I have ported out my MAF, and upped the fuel pressure to match without affecting the balance/emmisions/open loop function.
It's a delicate operation, takes time and patience to tune, but worth it IMO.
I'll have to look at that write up, thanks for the info.

 

[Zuffen]

SCV8,

When you say you ported the AFm, how much did you gain as a percentage of cross-section.

Following the theory in the links it should be possible to use a samll diameter pipe to by-pass the AFM so the engine can flow (say) another 25% of air.

I'm looking to retain factory style drivability but need to flow 25% more air thru the AFM so it is the same flow as my twin blade throttle body.

There are a number of options out there but I want to keep it drivable.

No point in having 500 horsepower you can't use because the car is a pig!

I'm torn between Kalmaker and any system that would allow me to retain the standard ECU with a piggyback.

 

[SCV8]

I figured it out once, haven't been messing with it since I got it dialed in last time around, it was right around .125 of material, totall, removed from both the top, and bottom surfaces inside the main opening.I also machined down the sensor mounting pads on the top of the MAF housing to get the sensor more central to the actual airflow.

You don't want to mess with the bypass area. I started out by just filing the blunt edge between the bypass and main openings to get rid of turbulence, increase flow, making the radius on the main opening side so you don't screw up the bypass settings. The screen retainer got pitched, screen stayed, the airbox gasket got trimmed to fit the opening also.
I have used the bypass trim screw for fine tuning(mark the original location) after that operation, but it's actually now right back where it started, which is a sign to me that things are balanced.
I upped the FP after porting the maf, installing a larger air filter, and cleaning up the heads a bit.

I could see maybe getting serious power (390-400)and still possibly passing smog, but definately having great driveability,great torque range assuming you used improved cams, larger intake runners, don't know about the stock based fuel control at that point however, the maf would probably hurt it.

The driveability is actually what improved the most from my airflow mods.
It would be nice to know what improvements were made to the actual flow, but there are so many other variables within the motor, I'm just glad it can keep up with an SVT Stang on the highway.

I just looked at an airflow calculator on the web; it would take a 10mm enlargement in each direction of the MAF housing to achieve the 25%, my small increase alone is likely not the source of the improvement I recieved, but more likely that it was the sum of all the others.