I would run a tank of the worst fuel you have around there and do the data logs on that. Have the tune adjusted to those logs. It will cost you a little HP but it is the safest way to go.

 

If you have an A/F gauge make sure it reads 11.5 to 11 on 93-91 octane when WOT.

 

That’s what we ended up doing for a tow tune. When I head out to my home town in west Texas, there is no 93 available. Also, any time I head up to Colorado, no 93 available (save for a gas station or two along the way). Both of those trips are the majority of my highway travel outside of the Dallas/Austin areas.

I haven’t taken the time to work on the 93 tune much to get it dialed as I don’t use it much. I’m going to run these plugs for an oil change interval and inspect them, then start that 93 process again with some octane booster and go from there.

 

I’ll check the logs here in a bit for timing and a/f, it’s been a while since I’ve run 91/93. Do you mean a stand-alone wide-band? I have lambda displayed on my ngauge.

Looking back the logs, a/f was in that range when we were working the 93 tune. The knock retard was 4ish degrees with the target timing at 18.5.

On the 91 tow tune there is very little knock, a degree or two here and there but nothing sustained. The mix on that tow tune is a bit fatter at my request.

 

Just look for the white specks.

 

18.5 degrees is a lot of timing on pump gas for a gen 3 Coyote. My gen 2 is running lower compression, and I can't even run a full 18.5 degrees on nothing but the best 93 pump gas (Synergy Supreme+ at Exxon) on what I assume is lower boost then you (2.3l Roush blower compared to your Whipple). I'm going to double my recommendation for octane booster every tank...especially since you've already started to abrade away your pistons from deto.

 

I want to say mine is about 17 degrees.

 

Same.. I see 16-16.5* on pump 93
20-21* on E30-85

On a side note, curious what plugs are you guys using? I see Sharkhunt is using Denso ITV22.
I'm still using NGK LTR7IX-11's. Gapped @ 0.028 - 0.032
Looks like they cross reference though so probably doesn't make a difference..

 

18 sounds like a lot on a gen3. But Direct Injection allows more timing, period. It's very very likely a perfectly fine amount of timing. don't underestimate DI.

 

I went with the Densos since that is what Whipple supplies, so I went back with those. I can't say I know which is objectively better. I read somewhere what the iridium in the Densos produces a better spark in the short-term but NGK stands up longer, no idea if either is true.

It is on the high-side. Not crazy high (at least in my mind), but pushing a bit for performance. "Hot street" 93oct tune kind of thing.

I do want to try the gasoline you mentioned above and see how it goes. I can surely find an Exxon with it closeish in my area. It boggles my mind that my 3 closest gas stations' 93 consistently allow for a net of only 16-17 deg.

I will get that sorted before going back to a gasoline-only tune. If I have to pull a couple of degrees out, so be it.