Nice 91 octane Ride

[QuadManiac]

Air/fuel ratio also significantly affects pre-detonation, so if you're 'juiced' a little lean, you are likely to have pre-det with the appropriate knock sensor reduction in timing advance and concomitant performance. Higher octane in this case should help overcome the pre-det and return the lost performance.

 

[Capt John]

I waited today until the temp was about 90 degrees so I could eliminate the cool morning temperatures being the reason for the Spyders better performance, and not the 91 octane fuel I'm running. Now I have absolutely no doubt in my simple mind that the 91 octane performs much better in my Spyder than 87 octane. The owners manual states 87 octane or higher--The or higher is what I'm going to run. I think, if the ECU has detonation sensors and can adjust the engine timing to eliminate knocking, then it must retard the timing a significant amount to allow a engine with 10.8:1 compression ratio to run on 87 octane fuel; and there goes your performance.IMHOnojoke:lecturef_smilie:

Michael:doorag:

Do you still have your JB at the same settings or have you adjusted it while using the higher octane?

 

[BLACK WIDOW]

JB settings

Do you still have your JB at the same settings or have you adjusted it while using the higher octane?

I think I have made some minor adjustments since we last talked (not sure). Here are the ones I am currently running.

Mode#1--Not used
Mode#2--4.5
Mode#3--6
Mode#4--6
Mode#5--2
Mode#6--2

I keep playing with the thing but I seem to always get back to, or at least close to, these settings.:thumbup:

Michael:doorag:

 

[BLACK WIDOW]

Sputtering

I think the individual mods are a good thing to look at pertaining to octane use. I filled up with 93 today--- and will run a few weeks on it to see if I notice any difference. Since my sputtering was intermittent - it's hard to tell what the fix will be. Not sure if I've had as much sputtering since I pulled the evap can. Going to keep an eye on it.

Just gonna keep an eye on it....

Don't you think that a "Sputtering" engine usually indicates a overly rich condition (to much fuel or not enough air). It has been my experience that if running lean the engine will hesitate, cough, and surge; but not necessarily sputter. (or at least based on my defination of a sputter) What is your opinion? If you are running rich it will regardless of the octane. nojoke


Michael:doorag:

 

[Firefly]

Don't you think that a "Sputtering" engine usually indicates a overly rich condition (to much fuel or not enough air). It has been my experience that if running lean the engine will hesitate, cough, and surge; but not necessarily sputter. (or at least based on my defination of a sputter) What is your opinion? If you are running rich it will regardless of the octane. nojoke


Michael:doorag:

Guess I'm just going to have to check the plugs after a ride and see what they look like.......