High Compression Pistons and High Octane Fuel

[Racer 007]

I currently have JE Pistons installed in my 92ES. They have increased the compression to right around 11:1.

The highest octane rating around my parts is 91 octane and it feels as though it's not pulling as hard as it should around 5.5 to 6.5k RPM's. Do you think it is due to me requiring higher octane gasoline?

[Stealthfreak]

Well i know from my stealth (just bought it, pics up soon) I drove it home from NewYork to Vancouver BC (about 3000 Miles) :D . When i got more west, some of the gas stations only had 91 Octane gas. After filling up i noticed performence differents at high speeds (60 m/h +) and when i finally got home i put 94 octane gas and noticed a HUGE differerence when using low / high boost or just stock turbos. Dont know if that helps, though it also depends on your alltitude (the farther you are above sea level the lower your gas octane can be)


Ronan
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:car:
92 Gr Dodge Stealth RT/TT

[detpac]

You should try propane. Increase octane would help. I don't know if there is enough pressure to open the solenoid though.

[smokinstorm]

I honestly don't know if 91 is enough octane for you. You can test this lack of octane theory by putting in some race gas or making you own high octane fuel by mixing in some xylene or toluene into the 91 octane unleaded that's available to you. If you get a performance gain then, yes, you need a little more octane. I do not know if the NA cars have a knock sensor that will pull timing and cause a dramatic power loss if detonation is sensed like the turbo cars have. If they do then this may be what's happening. What kind of numbers does your car run at the track? With your mods you should be running faster but not necessarily quicker than me. Faster because you should be making more power but not necessarily quicker because you may not be applying your power as effectively as I am. I ran 9.55 @ 75.3 in the 1/8th with a 2.13 60' time just for comparison sake.