Deleting the MAF is nothing new, I've seen this on a lot of Mustangs and Subaru's too. It's pretty much for BIG power levels/BIG airflow. After a while you max out the MAF, then you have no choice but to go around it and tune it really specifically. You're talking about a pretty much straight drag vehicle with VERY limited street duty in applications like this.

I wonder why no one has produced a larger 90-95+mm MAF for these cars yet...

 

One of the reasons I got rid of my WRX was that the MAF was really hard to tune around. Intake pipes that changed the MAF pipe diameter, my upgraded turbo's, air filters that introduced more turbulence to the MAF.. All made things go awry in tuning.

 

Yes the stock MAF is a big pain in the *** on those cars. It takes a good deal of air flow like a PE1818 or a 16G turbo to max that MAF. None of the IHI's will do it and make big power. TXS makes a shorty intake that doesn't skew the reading also Perrin does.

Recently, Perrin released a Big MAF which is like 75mm I believe and adds quite a bit of headroom for big turbo guys. But with them big turbos on that small car you're going to get a fair amount of lag too.

But when you're at the limits of that MAF you're going to be waiting for something of the driveline to pop. It's a rally car, not a drag vehicle. Pretty much a sensible streetable step on those can get you into the deep 12s and still be able to tune.

My WRX is going bye-bye soon here and will be stripped back to stock...that money from reselling the mods will provide mod funds for my LLY powered HD!