mikey D

hey i see in the faq that if you run 87 it can help pass smog.

Why is that? what does it do? conservitive timing and less boost?

casio

i read this and starting thinking. then i went and read that portion of the FAQ. it didn't specify T2, but i dont see a difference. when you're going through emissions, your turbo won't be hitting full boost (i guess there would be a way around this if crazy gear ratios or something are involved). so you wont need to worry about detonation/knocking (i need to study those terms more, i admit). all i can come up with, since no one else has answered, is that higher octane is needed for boost and as an anti-knock formula. since the higher the octane, the harder it is to ignite, i believe the lesser chance all the fuel is burned. without all the fuel burning, you have leftover HCs (fuel). that in turn raises not only your HC level, but also CO and CO2 (but also lowers NOx which is good and bad, depending on where you stand in the other fields [HC, CO, CO2]).
i'm not 100% sure on this, so if anything its a free bump for curious minds.

mikey D

thanks for replying. i have been waiting unimpatiantly..

I wondered what the detonation problems may be from running 87!! or does the ecu go hell no and put the car in a limp mode like nissan cars do...

casio

i dont know if the T2 computers are as smart as newer computers (no, i know they arent, but in the case of octane, i dont know how different they are). my friend has a new turbo jetta which only calls for 87. makes sense, newer cars are better about taking care of themselves. supposedly some cars, i believe the wrx, react well to higher octane fuel because their diagnostics recognise it and i believe advance the timing. its mostly (okay all) hear-say as not only do i not have a turbo car, i cant afford a nice new one. also, when i do get a turbo setup, i'm sure i'll have a haltech and never mess with piggybacks and stock ecus (thats assuming i never run a simple stock turbo).