detonation/ping with tuner question

[midnightdriver]

As you know, I have my car tuned with the Bama Chips, using 91 octane. Now I contacted Bama chips and they said I don't need to worry about detonation due to their tunes not being ultra aggressive/on the edge of the safe zone, that they perform testing on all types of gasoline blends and being that my car is basically stock except for K&N filter and exhaust work. Plus they told me, "If" I ever did get pinging to contact them right away and they would fix my tunes.

My car runs great and I have driven the car high temperature areas as well as lugged the car under load and never was concerned about detonation or in fact heard any on my car. (Was told it sounds like metal beads in you cylinders, kinda high pitched tinging sound.)

My concern is the changing seasons, and California's notorious high ethanol content and not so high quality gasoline. Should I worry at all? Should I carry some Octane booster they sell at the store just in case?

Thanks

 

[BurningRubber]

I wouldn't worry about it since it hasn't pinged yet. If it does start to ping, have them re-adjust the tune rather than throwing octane booster in there (that's only a band-aid fix to the problem).

If you've been lugging the car under load in hot weather and it didn't ping, cold weather and a winter blend in gas more than likely won't change that.

 

[bhuff30]

First of all, don't blame the ethanol content. Ethanol is an excellent octane booster and in amounts less than 30% it can actually improve gas mileage. I've read plenty of SAE papers studying this.

Personally, I wouldn't worry too much about a little detonation. If you get detonation, it will most likely be at WOT. In that case, you would be able to easily drive around the condition and you can send in for a better tune.

Also, I would argue that it is very possible for you to get detonation due to season change. In the code for your computer, there will certainly be some code to add timing when it sees cool/cold air. I can list 2 cases when I saw this phenomenon:

First case: I've been tuning my 97 GT using a tweecer. I added 4* of global timing and during the summer it was pretty safe, even running 87 octane. Last night, it was quite cold driving home. I nailed the gas in 3rd and it was rattling badly! Obviously, the computer added some extra timing for the cold air and I didn't have enough octane.

Second case was on my 2.3 mustang. I set up the nitrous and sprayed on my otherwise safe tune. The car rattled VERY badly and blew the head gasket. I was later looking at the code and found that it was adding timing when it saw the cold air from spraying, and it was adding timing from accelerating quickly (as if it was in 1st gear). Combined, these added 5-8* of timing across the board, which is a very bad thing when then engine is pretty happy around 17* total timing. I set these spark adders to zero and problem resolved.

So, my point is, keep listening for detonation in case the tune needs to be changed. If it does rattle, don't be too scared that the engine will suddenly implode. This engine only makes around 50-60 hp per Liter, so it will take a LOT of VERY bad detonation to do any real damage because the cylinder pressures are so low.

 

[midnightdriver]

First of all, don't blame the ethanol content. Ethanol is an excellent octane booster and in amounts less than 30% it can actually improve gas mileage. I've read plenty of SAE papers studying this.

Personally, I wouldn't worry too much about a little detonation. If you get detonation, it will most likely be at WOT. In that case, you would be able to easily drive around the condition and you can send in for a better tune.

Also, I would argue that it is very possible for you to get detonation due to season change. In the code for your computer, there will certainly be some code to add timing when it sees cool/cold air. I can list 2 cases when I saw this phenomenon:

First case: I've been tuning my 97 GT using a tweecer. I added 4* of global timing and during the summer it was pretty safe, even running 87 octane. Last night, it was quite cold driving home. I nailed the gas in 3rd and it was rattling badly! Obviously, the computer added some extra timing for the cold air and I didn't have enough octane.

Second case was on my 2.3 mustang. I set up the nitrous and sprayed on my otherwise safe tune. The car rattled VERY badly and blew the head gasket. I was later looking at the code and found that it was adding timing when it saw the cold air from spraying, and it was adding timing from accelerating quickly (as if it was in 1st gear). Combined, these added 5-8* of timing across the board, which is a very bad thing when then engine is pretty happy around 17* total timing. I set these spark adders to zero and problem resolved.

So, my point is, keep listening for detonation in case the tune needs to be changed. If it does rattle, don't be too scared that the engine will suddenly implode. This engine only makes around 50-60 hp per Liter, so it will take a LOT of VERY bad detonation to do any real damage because the cylinder pressures are so low.

Hmm interesting, I wonder why if ford put the added timing adjustment for colder air in the tune, why they did not have knock sensors on the engines equipped with this code.

What type of rattle am I looking for, car exhaust is kinda loud. Is it a metallic kinda like loose exhaust/bad cat kinda rattle or is it something deeper that can be felt while driving the car. I get kinda a rattle when I lug the engine way down like I did yesterday on accident, I was doing 25 in 4th trying to accelerate (stock gears) and the engine wanted to kinda stall out. It made a deep groaning type of noise till I got to about 35mph then it began to pull.

 

[bhuff30]

I beleive the engine actually needs more timing with cold air. I would bet your tune will be fine, especially if you are actually running 91 octane. I tend to push the octane limits and find the critical points.

To me, detonation sounds like rocks rattling in a can. It can be anything from very faint, like rattling rocks, to the sound of someone taking a ball peen hammer to your engine block in severe cases. You'll be most likely to hear it at peak engine torque (like around 3500rpm) to near redline.

Hmm interesting, I wonder why if ford put the added timing adjustment for colder air in the tune, why they did not have knock sensors on the engines equipped with this code.

What type of rattle am I looking for, car exhaust is kinda loud. Is it a metallic kinda like loose exhaust/bad cat kinda rattle or is it something deeper that can be felt while driving the car. I get kinda a rattle when I lug the engine way down like I did yesterday on accident, I was doing 25 in 4th trying to accelerate (stock gears) and the engine wanted to kinda stall out. It made a deep groaning type of noise till I got to about 35mph then it began to pull.

 

[BurningRubber]

I see what you're saying about knocking being caused by cold weather, advanced timing, and not enough octane. However, having a hot engine, hot weather, and lugging it seems just as likely, or if not more likely to cause detonation than a temperature change.

As far as Ethanol in gas, the gas you put in your car is 87, 89, 91, 93 octane regardless of the 10% Ethanol content. So while Ethanol alone is of higher octane, it doesn't mean much when it's being mixed with less fuel to reach an octane requirement.