I have an Evo Stage III X50 car (chip, intake, exhaust, cats, diverter valves). If I run higher than normal octane (i.e. 100 unleaded), will I see more power? In other words, does the Evo chip adapt itself to take advantage of high octane fuels? What about leaded fuels - will leaded fuel hurt the 100 cell cats?

 

yes u will gain power. leaded fuel does kill ur oxygen sensors.

 

With that car.. if you have the exhaust too (sounds like you do) then you should get the 3X file so you can switch the the 100 Octane mode. It makes 538 RWHP... I wouldn't use leaded gas on 100 cell cats. If you want to use leaded gas.. get rid of the cats.

 

I guess I have close to what you are talking about, stage 3? X50, exhaust, bailey valves, no intake tho. I have the handheld GIAC flashloader and you can switch programs (pump, race, stock) to take advantage of the higher octane fuel. Hard to tell if the race gas and program makes a difference, no where to really do a good test. Hopefully Sharkster can tell us the difference between the two programs, maybe a dyno sheet, also benefits of removing the cats?

 

You must have the race program installed before you can use your flashloader to activate it. The flashloader will tell you what programs are available (red lights). I think you still get more performance with higher octane...just not ultimate.

 

Higher octane gas obviously produces the best results when the car is tuned accordingly (e.g., the timing is advanced). However, it is my general understanding that some power gains can be achieved with higher octane gas even if the car is not tuned for it, because the ECU will still advance the timing somewhat if it detects higher octane fuel (just as it will retard timing if it detects lower octane fuel).

Craig

 

I didn't think you could use leaded fuel in this newer cars? It won't hurt the motor?

 

aren't those mods considered a Stage II?