Excellent write up. If you're going to be playing with the timing, you need to learn to read the ground strap of the plug real quick. BTW, I like your choice of plug. Can you post a pic of one of the plugs, focusing on the ground strap? Starting with 20 degrees of timing was very smart. 20 degrees is very low for alcohol. You're going to see some impressive gains as the timing is moved up. To give you an idea, I run 30 degrees at 30 psi boost with 100% methanol. I like to keep the timing on the conservative side. As you step up on the timing, you'll notice a point where the performance increase begins to nose over. Don't push the timing to get that little extra performance. It's not worth it. Pick a conservative timing setting and leave it. All the while reading your plugs very carefully. You want to look for heat discoloration of the ground strap. This is an indicator of a good timing setting. The discoloration should extend half way back the ground strap. The further the heat discoloration extends back towards the thread end, the more heat that's being developed. On an NGK, you only want to see that heat discoloration extend halfway back. No further. The 11.1 a/f ratio reading is about perfect. Don't start leaning it until you've found a good timing setting first. I wouldn't lean it any further than 11.3:1 for a final tune with a conservative timing setting. A conservative timing setting for me would be 2 degrees retarded from the point where further timing increases is netting little performance increase. Again, very good write up. I enjoyed reading it. Thanks.
If you're seeing that fouling is not a problem, you might consider stepping to a colder plug, if one is available. It's best to use the coldest you can get away with. As you are studying the ground strap for timing, carefully inspect the end of the ground strap for any form of heat deformation. A magnifying glass is good for this. If you see any at all, figure out if there was a problem with the tuneup (safe fueling, no leaning anywhere, steady timing, coolant temp normal, intake air temp normal, boost level steady), and if everything looks OK, back off the timing 2 degrees, and continue testing and inspecting the plug very carefully. NGK plugs are very easy to read once you've learned how to, but don't get that ground strap too hot. Alcohol is additive when tuned to the edge, but it is definitely not forgiving when pushed. Good move stopping the boost level and injector DC where you did. You have some good tuning sense.
Thanks Don! On gas I can always see the bluing of the strap to gauge timing. Ths time out I couldn't see it at all. I will try to get a pic up here soon. It was amazing going from 20 to 23 degrees....can only imaging when I start leaning on it more. 22 psi is low for me. I usually Max out my 3 bar sensor on race gas I will do some more testing next weekend. There is a decent track 15 minutes away but they are strict on roll bars. I pissed them off a few weeks ago when I coasted through at 10.3 @ 100 MPH....needless to say my car is marked. My friends and I have made it pretty hard for any turbo regal to go through tech down there haha. Hope to be able to get a bar in there this month.
I would start making one degree changes on the timing after 25. A 3 degree step is a little scary. It's understandable from 20 to 23, but as you move up further you need to be very careful. I'm not real sure how ethanol acts as far as detonation and preignition, but I would not depend on my knock sensor to tune with. For instance, with methanol, if you get knock, it's probably too late. Detonation with methanol is very, very rare. Methanol likes to go straight to preignition and push rods out of blocks. Remember, there is still a little pump gas in your fuel.
That's what I figured on the stepping up the tune. A degree at a time after 23 or so. I don't have a knock sensor hooked up. This engine is out of my old car and still has a solid roller cam. I wanted to go hydro but didn't have the funds. The knock sensor and the solid Roller didn't get along lol. That's why I check plugs after every run. I start low and work my way up. If the plugs show an issue gong from one little step to the next I think I avoid damage. Probably the reason why I still have this engine after 5 years of abuse and never blew a head gasket but it sure didn't set any records in tsm either.
Here are some phone pics of the plugs. Let me know if you need higher quality ones. I will have to barrow the wife's camera.
Wow. That's pretty clear. Start inspecting all the plugs so that you can begin to identify which cylinders always seem to show signs of being hotter than the rest. Then you'll know which plugs to go straight to for a read. Always use the plug that shows the most heat to judge your tuneup. That strap looks pretty good. I don't know that I'd change the timing with that. If you feel you want to try a few more degrees, I would move to a colder plug first, do more runs with fresh plugs with your present timing, and read the plugs. If the plugs look the same, I would be real careful trying more timing. Maybe make a 1/2 or 1 degree move with fresh plugs to get a good read.
The main thing you need to learn on the ground strap is that burning the plating off is one thing, and finding the heat marking is another. It appears that the plating is burned back, but the picture quality is not allowing a good read of the heat mark, if one did start to develop.
The plating burned off the top of the threads and into the threaded area is an indicator of the fuel mixture. If those were my plugs, I'd be real happy. Looks like you've burned the plating into the first thread. Very good. I wouldn't lean it any further until you find a timing setting you're going to stick with.
Try adding fuel. Target 10.8:1 on the meter. I know mine makes good power from 10.5 - 11.3:1. If you can make the same power at 10.8:1, I'd go with that. It's safer. Especially as you start to increase the boost, AFTER you get larger injectors.
I will try to add some fuel and leave timing alone. Injectors are number one on the list right now. Would also like to start upping the boost. I would love to get a 9 second pass out of e85. I think I will be able to do it.
Remember, try a colder plug. If you are not experiencing fouling, there is no good reason to have a plug in there that is hotter than you need. It looks like the ethanol mixes burn really clean. YOU WANT THE COLDEST PLUG YOU CAN GET AWAY WITH!
As you slowly increase the boost level, keep a check on the plugs. Just because you reach a level where the plugs look real good at say 25 psi, the read could change on you as you increase the boost. When you finally reach the max boost you intend to use and you get the plugs looking good, then you can relax on reading plugs. Just keep on top of reading the plugs (fresh plugs) as you step up the tuneup.
It's still hard to tell. It looks like the plating is burned away, but it's too hard to tell if there is a good heat mark. The light colored deposits make it harder still. I wish I had that plug in my hand.
What heads are you running since the r5671a-9 has a different reach than the stock head plugs? Do you plan on upping the gap, would help your cruise and possibly start up with E85. I don't see how you couldn't fire off a .032 considering us E3 plug runners are .040 and mid 20's psi. So this is a double pumper Walbro through a -8 with 96lbers correct? With the 6768 turbo at 24psi, 11:1 AF/R and that crazy rpm I could see 90% IDC creeping up on you. Time for dual DW's or Jay Racing pumps (these are the highest flowing pumps so far). No one else is scratching there heads at 6900rpm on a 109 stockish block? Appears as if that build was a good one.
No matter what gap you pick, the target is 40 kV at WOT and the planned max boost level. Running larger gaps and higher kV just unnecessarily taxes the secondary circuit. The smaller gap brings down the kV.
