chickenbrest

iTrader: (3)

One more thing.... I was told by several people that it would do me no good to run 100 ocatne in my car ( I can currently get 93). They said that I would not get any performance increase at all. Unless I had a boost controler or had my ECU flahsed to run at 100 octane.

However if what you say is correct then my stock ECU should be able to advance the timing and increase performance.

thoughts?

MP5

iTrader: (4)

See what an undisclosed I think so statement does?

chickenbrest

iTrader: (3)

MP5,
ya - I only agreed with him on the detination issue - so putting in some higher octane will help that -- but I have never heard of getting better performance from better gas by defualt. I have always been told you have to tun for that gas as well.

Az3ar

iTrader: (18)

Will I am sure I lost HP since I moved here to LA. How much? dunno maybe 5 to 10 at the most. My post is simple all I am asking if my EVO ECU will fail if I keep switching between 91 and a mix gas. Yes you will gain power if you are running 93 or 94 instead of 91 for sure but you wont gain power on a stock ECU if you are running 100 octane

mikesevo8

When I read my owners manual I was surprised to find the statement on octane.
It says to use 98 RON, or 94 MON, or better.
In our US measure ( R+M/2 ), that would be 96, which is better than most of us can find.
Even on 93 or 94, I imagine the ECU is responding to knock of some sort.
So tossing in some 100 would probably make mother very happy...

MP5

iTrader: (4)

Right equation Mike wrong applicaton bro it actually eorks out to about90 equiv

ScoobyBoost

iTrader: (1)

That's a bit of a blanket statement. It really depends on the car's ECU. For my 87 Supra, anything below 92 [EDIT: should be 93 for the Supra] will cause the ecu to pull the timing back. However it depends on how far it can and will advance the timing. The Supra goes out to 100+ and you will see benefits in power as it advances the timing with batter gas.

On the Evo I don't know as much about the ECU and fuel management (other than it's pretty pig rich). However I know it will pull the timing for anything below 92. I would be suprised if the ecu was not programmed to handle at least up to 100. However that's just a guess on my part so take it with a grain of salt.

The bottom line is that if you are using 91 octane in your Evo it will definitely pull the timing back. How much is another guess. I would say from the anecdotal info I've seen here and other plaecs, that it's probably pretty minimal. If you were using a higher octane (say 94) and switched to 91, you should be able to notice some difference.

Sorry for the long post. Anyhow as others have said adding 100 octane will not hurt anything. YMMV

ScoobyBoost

Az3ar

iTrader: (18)

mon which is Motor Octane Numbers and ron which is Research Octane Numbers. Mon is higher than our gas octane and ron is lower. our ( R+M/2 ) was made to be in between.

Az3ar

iTrader: (18)

Thanks Scooby

Az3ar

iTrader: (18)

i am going to fell it up with 100 and see if their is a big difference.

ScoobyBoost

iTrader: (1)

NP Az3ar,

Just remember that the ECU doesn't "know" what octane you put in the car. It will learn as you drive the car how far it can advance the timing. This usually takes from 45 minutes to several hours depending on how much/what type of driving you do. You can also reset what the ecu has learned by pulling the power. It will then start over again. This is why a modded car sometimes runs "rough" when you first start it up after completing a project that involved diconnecting the battery (ask me how I know).

Az3ar

iTrader: (18)

so you are saying i should fell it up couple times befor i get some real results?? or should i let it run for 45 min in the grage but then their is no load and the ECU wont realy learn am i right??

Thanks

Az3ar

iTrader: (18)

You know what you are talking about, i can tell

ScoobyBoost

iTrader: (1)

The ECU learns as you drive it under load in the real world. When I reset the ecu on the Supra, I let it idle for a bit to warm up again (like normal) then go for a fun spirited ride. Usually it starts a little rough (hesitation, rough idle at stops, etc), but it starts smoothing out pretty quick. After a good 45 min ride it's usually purring again.

Az3ar

iTrader: (18)

thanks