A good trip almost went bad

**CT-MSRT** · 05-26-2009, 09:16 AM

Memorial day weekend, we always go up to our place just outside of Augusta, ME. We had not been up in a while with the state of things and i had forgotten about what they had done with their GAS last year. I have been running really well on a slightly tweaked 93oct diablo tune and life was good. Door to door i use a little over 3/4 of a tank and this time a little more since there were 5 people in the car and some immense weight in the trunk due to some stuff we were going to leave at the house this trip(20.3mpg!). I packed everything including my laptop and some other crap to get work done this weekend. Well, Friday night went fine and I did some errands and a little bit of driving on saturday after a nice round of golf. Sunday morning came with an empty tank and time to fill... $hit! Maine only sells 91 octane now. I know the cars are smart and could probably retard things enough to not cause any serious problems but that was the last option in my mind. Then it clicked. I condensed some crap a few weekends ago at the track and my tuner was back at the house in my laptop bag. made a call and had someone drive it out to me since i didn't have enough gas to make a round trip pickup. Loaded the 91 tune at the pump and was good to go. Can't wait to fill back up with 93 once this stuff is purged from my tanks and load my tune back in.

**gn300** · 05-26-2009, 09:35 AM

And 2 octain points makes enough difference that you were worried about causing damage?

Can't think there are not safeguards built in .

you think some owners that are trying to save a buck on fuel won't be using low grade fuel?

Am i mising something or is your diablo tune include no variables?

**slideway** · 05-26-2009, 10:19 AM

Hi Mike! Glad you guy's had a great weekend! Sound's like what your saying is with the car loaded with people and good's(6,000+lbs.?)And crappy low oct. gas, you wanted to ward off part throttle pinging. I know you wouldn't drive with your family like you do when your alone. LOL! (Mike's a guy who knows what the top end of his car is)

**CT-MSRT** · 05-26-2009, 10:58 AM

bill hit my concerns right on. I was probably right at or slightly over max load for the car. I am not confident enough in knowing how well these cars handle KR(i have heard the sensors are very sensitive). Even though it might have been fine after enough pinging it would have done some LT timing reduction. i had the spark advance out and it was tuned as far as i could get it for Sunoco 93/94 and the car ran fantastic. I don't want the combustion chamber to get more than a couple degrees of knock since this car has to last me a long time. And no i don't need an excuse to get a stroker until i can afford one. Also from the gas station i was at i highly doubt it was proper 91 and would be closer to proper 89

**Super T** · 05-26-2009, 11:01 AM

Assuming your tune was resulting in 0 degrees w/ the 93 octane, you'd be fine. It could pull up to 20 degrees on its own.

**CT-MSRT** · 05-26-2009, 11:21 AM

Originally Posted by Super T

Assuming your tune was resulting in 0 degrees w/ the 93 octane, you'd be fine. It could pull up to 20 degrees on its own.

That's great to know for piece of mind. I still would never want to have my engine retard that far.

**gooeytek** · 05-26-2009, 11:37 AM

you had someone drive out to the gas station with your predator so you could load the 91 tune because it didnt have 93 octane ? wow.

**Chewbacca** · 05-26-2009, 12:04 PM

This is one reason my predator never leaves the trunk of my car!

**CT-MSRT** · 05-26-2009, 12:49 PM

Originally Posted by gooeytek

you had someone drive out to the gas station with your predator so you could load the 91 tune because it didnt have 93 octane ? wow.

yea, in retrospect i probably could have filled up and drove back from the house. I think it came down to i didn't know if i had it with me. I called to check and while i had them on the phone i said how bout you just drive it out to me.