Timing increase with increase in fuel octane number

[jg04lightning]

U7158, Lightning
Revision 9R01
2004 F150 Lightning

I am running fuel with a 98 to 100 octane number ((R+M)/2) in my Lightning. My boost is 15-16 PSI with the attached tune. The tune is for 93 octane fuel.

How much more timing would you recommend that I add with my predator to take advantage of the higher fuel octane number?

I believe the predator gives the changes in timing in percentages; what is the relation beteen percentage and degrees?

Or is this something you guys should change for me by modifing the attached tune

Reference attached tune.

[sohfast94]

I'll modify it however I need you to confirm that I am not liable. How are you attaining this fuel? Is it actually race fuel?

[jg04lightning]

I am mixing 93 octane pump gas with the appropriate quantity of Toluene (~1.5 gallons 114 octane - Toluene per 25 gallons of 93 octane)

Brian, niether you nor Diablo sport will be liable for changing my tune to take advantage of the 98 to 100 octane fuel. I do want to know how much timing you are adding for my reference.

If you have any concerns, lets discuss them now.

[sohfast94]

We're going to do this in steps. I'm familiar with toulene. How good are you at reading plugs? What plugs do you have? I'm going to give you this and don't go out jumping on it right away do some rolls first make sure there is no detonation. Do you have a wideband handy cause it's prolly going to lean out some even though your target AFR is like 11.5 which is very safe. 12.2 would be more the rae AFR. I need ot make sure everything is good first and then we'll try some other stuff.

[sohfast94]

[quote="jg04lightning" I do want to know how much timing you are adding for my reference.
[/quote]

A couple here and there....

[jg04lightning]

Brian,

Just ot clarify, I am mixing the fuel such that the octane numberof the fuel is 100. The tune file name is throwing me off just a bit, 5400_shift_tune_114.frg. An octane number of 114 is the octane number for Toluene. Is this rough tune designed for 100 octane number for fuel or 114?

I have a wideband ready to install, but it will be 2 weeks before I have time to install it. I have an accurate boost gauge and a fuel pressure gauge will be installed at the same time I install the wideband. A new fuel filter will also be installed.

I have a full racing exhaust. I will roll the driver window down and try to hear for detonation. The question is will I hear it?

Knowing this, do you still want me to do some rolling short burst runs to listen for detonation?

[sohfast94]

The timing is not that drastic. You will want to roll the window up with out the radio or AC on to hear it the best.

[jg04lightning]

U7158, Lightning
Revision 9R01
2004 F150 Lightning

Brian,

I will run the tune on Friday as you discribed - do some rolls and listen for detonation. Feed back willl follow.

Some additional infomation some of which you may already know through the comments in the notes of the tune.

Mafia installed on setting 2
big oval throttle body
ported throttle to blower adaptor
as mentioned before 15 to 16 PSI boost at redline
Johnny lightning bullet proof short block (I hope John is watching this forum)
Stock heads
Dynatech long tube headers no cats no mufflers 2.5 inch pipes side exit as with all Lightnings

Is your Dyno available?

[sohfast94]

Is mine available? Why you live around here?

[jg04lightning]

Not close enough - I thought you guys were just south of Melbourne. I am 205 miles away from Boca.

I forgot to mention I am running the stock air box with K&N. I have a AEM CAI but ran some tests and found it is a HAI - takes in to much hot underhood air for me (IAT reached ~131 F° on test day - idle at stop lights). I will build a box around it in the future to make it truly a CAI. I will modify tune at that time.

I will make the rolling runs Friday as mentioned before.

[jg04lightning]

Brian,

The plugs are NGKTR6 gapped at .035

[sohfast94]

.29-.32 is my personal favorite but it's up to you.

[jg04lightning]

It just became mine. I need to change my plugs anyway. But for our test, the gap will be .035

[sohfast94]

Make sure you run that stuff through the fuel system.....

[jg04lightning]

I am going to make up a batch that will give a bit more the 100 octane to be on the safe side.