Testing: 3A92 engine intake performance

[Timinator]

I looked at my fuel chart. Ive been super lazy keeping up with my MPG...there is a hard red bar thats all factory, then the next bar i removed the resonator. I only ever use circle K or costco fuel. I got a membership to SAMS so I fill up there now, no loss in MPG. Still average 42mpg across a tank. I also highly recommend everyone reset the car every 6 months. Just pop the negative off for a few minuets and the car sometimes is much peppier

[Tyrelirwin]

I looked at my fuel chart. Ive been super lazy keeping up with my MPG...there is a hard red bar thats all factory, then the next bar i removed the resonator. I only ever use circle K or costco fuel. I got a membership to SAMS so I fill up there now, no loss in MPG. Still average 42mpg across a tank. I also highly recommend everyone reset the car every 6 months. Just pop the negative off for a few minuets and the car sometimes is much peppier

Do you have a picture of your engine with no snorkel and no resonator?

[Eggman]

I removed my resonator last winter and noticed no difference in power output or fuel economy. It was louder though.

[phaux]

I removed my resonator last winter and noticed no difference in power output or fuel economy. It was louder though.

Same. Though I eventually just bought a cone filter and some tubing (and Doax's MAF housing) and built a straight intake (puts the filter in the hole on the passenger side of the radiator). I don't feel an increase of power but it seems a little more responsive. Maybe I have more air velocity with this setup? I'm also running 91 as 87 pings for me in the summer in Arizona (IATs well over 160!).

[Timinator]

I can get a picture tomorrow. I run 93 octane fuel. The car bucks and is ****ty on 87. Maybe my car is a factory fluke that is better tuned for 93 E10??

[Eggman]

I can get a picture tomorrow. I run 93 octane fuel. The car bucks and is ****ty on 87. Maybe my car is a factory fluke that is better tuned for 93 E10??

The Mirage is not tuned to run on 93 E10 gas. I wonder if you might have some fuel system contamination causing rough running. Costco fuel is Top Tier but I would avoid buying gasoline from Circle K and Sam's Club.

Top Tier - Licensed Brands

Have you tried using fuel system treatment?

Back to 3A92 intake modification - I'm not sure this would impact how your Mirage runs, but it might be worth putting the resonator and intake snorkel back on just for kicks.

[Timinator]

It doesn't matter where I gett he 87 from, the ecu is constantly pulling timing causing the car to jump around, where with high test its very smooth and constant with the power. The engine is a decent compression so higher octane fuel lets the ECU throw more timing at it, for more power

[Eggman]

It doesn't matter where I gett he 87 from, the ecu is constantly pulling timing causing the car to jump around, where with high test its very smooth and constant with the power. The engine is a decent compression so higher octane fuel lets the ECU throw more timing at it, for more power

Interesting. I didn't know the Mitsubishi Mirage ECU can detect the octane rating of the fuel in it's tank.

How do you suppose that works? I'm not aware of any octane rating sensor in these cars.

Do you think there might be something else causing your rough running engine?

[Timinator]

Not octane sensors, knock sensors. No knock=more timing most new cars have them and adjust timing to what the ecu "hears" from the motor

[Eggman]

Not octane sensors, knock sensors. No knock=more timing most new cars have them and adjust timing to what the ecu "hears" from the motor

I see what you mean. I thought it took Many Tanks of gas for an ECU to adjust to changes in octane.