finksgt

I just recently bought a diablo tuner for my 2000 mustang gt. I was wondering how much is too much timing at wot?

I did some data logging and saw 23 degrees in 2k-4k and 26 degrees from 4k- redline that was with the 93 octane performance tune I didnt hear any detonation but I dont want to use that as a whole reference either. I didnt know if I could run more timing or if 26 degrees is too much at wot? Mods so far are slp cat back and jlt rai also using 93 octane.

cliffyk

+26° is safe with 93 octane, you may be able to add 2-3° more depending on air temperature. altitude, etc.--but keep a close ear out for detonation. Also, be aware that setting the timing just below the point of detonation does not generally add much power. It does however greatly increase to potential for disaster.

Here is a great Spark Timing Myths Debunked article from Innovate Motorsports...

WannaBeGearHead

Wish we had 93 octane here. I'm running 21* with 91 octane.

finksgt

Thanks for the input guys and the article provided it helped! So it should be fine running close to 28-30 degrees of total timing for n/a motor with the 93 octane? I know I should check my afr, cause that has some to do with detonation and keeping the mixture from igniting to soon.

I will be putting on an off road x pipe sometime with in the next week and trying to hear pinging will be hard to detect from what I have heard. Thats why I was trying to see with the datalogging where I was at degrees wise and see if that was too much or if I could go alittle more.

cliffyk

It may or may not be "fine", it all depends on your engine and the actual octane of the fuel--which can vary by +/- 1 point and still meet the specs, and be down by 2 points at shadier stations.

"Fine" (as in safe) is the 26° that the canned tune was set for.

The other issue is ambient temperature. Here in Northeast Florida I have three tunes, one for each of the three seasons we have; nice, hot and friggin' hot. We are are now in "nice". The fundamental difference in these tunes is ignition timing.

The "nice" tune runs 28° maximum advance, the "hot" tune 26°, and the "friggin' hot" tune 24.5. All accomplished by altering the Global Spark Adder scalar value.

The "f'n hot" tune also has the target WOT AFR set to 11.8:1--just to be sure. I run a 180° thermostat year-round also.

These are arguably 0.5° to 1.0° less than I could push, however as inaudible detonation can be a destructive as that you can hear--and I do not care to be rebuilding my engine over a possible, MAYBE, 2-3 rwHP increase.

Do not mess with the fueling unless you have a wideband O2 system. The canned tune will have almost certainly have already leaned out the Stabilised Open Loop Fuel table to account for the pig-rich OEM tune.