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Discussion Starter · #1 ·
Well I have borlas and an STi catback. Zero afterfire no matter what I do. Given it seems to be an innofensive and cool effect, any way to induce it? Or is it an idiotic idea?
 

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'MURRICA!
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MAF + Boost + atmospheric BOV + 3" exhaust + no cats
 

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98 Red L 2.2L 5spd
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so you want to make the exhaust go pop every time you shift? my guess is remove the cat and adjust the A/F and it'll pop pop pop all night long
 

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If your NA you can get a catless exhaust and a walburrito 255 and tune your car to run 12:1 a/f ratio. This way you will maximize the most torque and hp on a NA engine. You will also get the afterfire that you want. Say goodbye to emissions!
 

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1999 Subaru Impreza 2.5rs BDP
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do you have intake already? I put the cams in my car and i can't get it to stop afterfiring! haha
 

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RWD 99 Impreza OBS
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If your NA you can get a catless exhaust and a walburrito 255 and tune your car to run 12:1 a/f ratio. This way you will maximize the most torque and hp on a NA engine. You will also get the afterfire that you want. Say goodbye to emissions!

Would this considerably decrease gas mileage or not?? More torqu and HP sounds nice.

I dont have emmisions so it doesnt matter :D
 

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I have not tried it but my friend who is a mechanic at our local Nissan dealership suggested it to me. Gas mileage would decrease since the car will be running rich. He said it would be perfect for my car since I only autocross it and haven't gone turbo yet.

You would probably need a SAFC to tune the fuel.
 

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Discussion Starter · #13 ·
How do you tamper with the AF ratio? The only method I can think about (and it's as ghetto as it can be) is tweaking the IAT sensor so as to fool the ECU that the actual temperature is a few degrees colder than it actually is. Should have a controlable effect on the AF ratio...
 

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99 Aspen White Coupe
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Trix said:
You would probably need a SAFC to tune the fuel.
That would be how to do it, but personally, I wouldn't, unless you have a good idea of what you're doing.
 

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1999 Subaru Impreza 2.5rs BDP
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APEXi's Super Air Fuel controller allows you to tune A/F ratios. they're not too expensive either.

Why do you want afterfire if i might ask?
 

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2017 WRB BRZ w/PP
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It's been my understanding that the Subie ECU's will "learn" around a SAFC. Is this correct?
 

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1999 Subaru Impreza 2.5rs BDP
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I think they learned around the first generation SAFC but APEXi released a second generation didn't they? that's why they call it the SAFC2? And I also heard the 99's are fine, but after that they have the learn around. I think
 

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2017 WRB BRZ w/PP
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I don't think it matters what gen you use, it's still the same ECU which will learn around it.
 
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