I pumped a tank of 91 Octane by accident, didn't see much difference with butt dyno. But my G-timer registered a 0.04 loss of Max G on 3rd gear, which translated into 0.5 second loss on 1/4 mile performance.

Just got a new tank of 93 in, now the G force is back.

Anyone see similar things?

 

91 is all we have out here in cali.
45k on motor with 91 only you are fine.

 

I feel lucky now, was looking for Sonoco 94 but they don't have it anymore, they used to have it around here, now the 93 is the highest.

I bet if you put some race gas to raise the octane to 93, you'll get just a bit faster in 1/4 mile. I don't think it matter with NA car though.

 

assuming you're tuned for your gas octane, raising octane won't boost your power unless you were pinging with lower octane gas and the engine management pulled timing from detecting knock

 

lol I have never seen anything higher then 91 in Utah

 

^^^yeah same here in cali 91 is the highest..

 

i used to see 100 octane @ some 76 stations in cali and vegas.. but since 76 got bought out.. no more 100...

 

If your tune is for 92-93, I wouldn't be putting your fi setup though it's paces on 91. Even the stock knock sensor isn't going to catch everything.

 

It's never turned. It's for stock car & with HKS locked box.
Plus, there's no AWD dyno around here.

I have cat, ME spacer, I am pretty sure on the 91 Octane,
the factory ECU has dialed the timing back.

Next steps, remove ME spacer

 

+1

If you're getting pinging, then you'll just need to adjust your tune for whatever octane you run. If that involves a different EMU, then...

 

Do not push your car on a lower octane that what it's tuned for! Or else kaboom sooner or later.

If you have not touched the HKS box, one would hope that HKS tuned for the lowest premium octane in the States, 91. If that is the case, you should be ok.

 

Good point, I don't know what Octane they turned it for, I assume the box was turned in Japan, I wonder if they have different practice there?

But if my G-time is of any indication, then 93 Octane is needed for HKS S/C, not a good news for CA guys.

Or, is it possible that the Box was tuned for stock with 91 & the addition of Stillen Cat back changed the requirement to 93+,

Migh try some 95 mix see if I get more gain on the G-timer.

 

This is why I like EMS that is not locked, looking at your A/F will not give you any indication if you are getting knock. Lately I have been seeing knock on ECU control (No Boost), my Utec don't take control until there is at least 0PSI and for some reason I'm knocking crazy on -3psi from low to High RPM. It turn out that I got a bad gas even though I always put 93 on my car. Needless to say I'm a strong believer of Logging, or at least have the capability of doing it every now and then.

Even though it is looked did you check if any Authorized HKS tuner can re-tune it or maybe plug an HKS Navigator or something so you can see what is going on?

 

HKS prodealer can unlock the box, but there isn't a shop around here in Maine
can do this. I talked to the so called (only one) pro dealer in Maine, he does not know how to unlock the box & he does not have an AWD dyno either (Nobody has AWD dyno in Maine) So I am left with my alternative indirect methods. AFR+G-Timer combination.