Quote:
Originally Posted by 2forme
First, some back ground info
I have a 6MT BRZ Limited with just over 2000 miles.
My mods thus far are Perrin crank pulley, SRT HB Exhaust, and Visconti STG1 e85 tune. With these mods, I've never experienced any issues.
After installing the AIRAID intake, I immediately noticed a loss of low end throttle response. I originally thought it was just the ECU going through it's learning process. However, the car started occasionally cutting power and jerking while pulling away from a stop or accelerating heavily from low RPM. I managed to capture this on a log seen here:
Under heavy throttle, the MAF reading started spiking up and down. As a result, the ECU cut all the ignition timing. I sent the log to @ Visconti and am waiting to hear what he says.
Now, Cobb uses "air straighteners" in all of their subaru intakes right before the MAF. The stock intake also uses these. An example is here:
I'm willing to bet, the stock MAF is tuned to use these and having the MAF so close to the velocity stack is messing with out readings. I'm surprised aftermarket companies overlook these. Especially with these molded plastic parts, it would be entirely easy, and cheap to implement.
That's my theory anyway. |
This sounds like the problem. The air straighteners in the stock intake are there for a reason. When switching to the CAI/SRI the MAF is not able to read the air flow correctly because its just a sucked in, and it might not be getting picked up correctly as it "swirls"(dunno how to describe it) past the MAF.
With the straightener it allows the air to do just that..straighten out for the MAF sensor. This was a big issue for the 6th gen Civic Si's. When Injen, and AEM released their CAI for the cars, people were bogging down, and throwing CEL because the MAF wasn't detecting the air right. It could be resolved by flashing with a tune, and switching to MAP. But most people didn't want to have to do that. I know that AEM released a 2nd version with "veins" around the MAF sensor which resolved the CEL issue and any bogging down without needing a tune.
With that said, I'm not sure how our ECUs work, and I don't know if we can switch to MAP or not. But it sounds like the intake companies need to install veins into the intakes for our cars.