Say you put in 89 instead of 93 octaine. What would the symptoms be.

Severe detonation?
AFR going from 11.1 to 10.5 @ WOT?
Spark variations?

Thanks

 

the higher the octane...definitely safer in regards to knock...
commanded AFR vs actual AFR will change between different octanes and the motor will usually make more power at a higher AFR with a higher octane...
you can definitely run higher spark levels w/ a higher octane as well...
whether any of this is noticeable between 89 & 93...???...I dunno...I doubt it...
I'm referring more to the difference between 93 and say, 110...

where are you N. of ATL? I assume near the Anheuser-Busch brewery...?

 

People holdin their nose?!

 

I was gonna say, "when YOUR window won't roll down in MY truck!"

 

OK, simpler put. I have a Radix & cat back running 7psi. I normally run 93 octane.

If I screw up and put in 89 octane what could I expect to experience?

 

I can't imagine much more than pinging and rattling...
you have an AFR gauge in the cab?
If not...get one!
you near Cartersville?
nice looking engine bay by the way!

 

Yes I'm in C'ville, Thanks
Yes on the AFR (PLX) on the pillar.

Well I had my tune flashed for Transmission tweaks only. On the way home I get horrible rattling. I call and the tuner is gone but I'm told it's normal after a flash for a relearn to happen. I was also asked if perhaps I had made a mistake at the pump.
Well 5 days later the ping is all but gone now and my AFR's are still @ 10.5 when they used to be 11.1 or 11.2 under WOT. I let the current tank get to 1/4 and filled up with 93. Who knows I may have not pressed the button enough, BUT I Doubt It!. I have had the blower on for near 5 years now.

What gets me on the relearn thing, the trans is on a different CM isn't it. And how come after the Dyno tune flash I had no relearn woes?

What do you think?

 

there shouldn't be any wot relearn. your fuel trims should be off while at wot. also there shouldn't be any KR to do any KR learn at wot. your trans and eng are both ran by the pcm.

 

Just checking in case you made a type-o. Should be or shouldn't be.

Thanks!

 

they should be off while wot. it goes open loop. so unless your open loop stft are on it will NOT set fuel trims at wot.