General Attention High Compression E85 Users-Ignition timing questions

[bastarddsm]

Looks like there is a lot of sharp edges.

Is your boost way down? 68% idc seems kinda low. Is that normal for your car?

 

[bastarddsm]

Another idea, have you had your injectors checked recently? You could have one way down making it lean in that cyl.

 

[Kapok6]

Looks like there is a lot of sharp edges.

Is your boost way down? 68% idc seems kinda low. Is that normal for your car?

Curt did the head and block so I assume he knows what he is doing with these motors so I haven't really questioned anything. As for IDC, those IDC's are at about low to mid 30's psi. Yeah, those IDC's are pretty normal on all the motors I have had.

Another idea, have you had your injectors checked recently? You could have one way down making it lean in that cyl.

The injectors were literally just at FIC a few weeks ago and flow within 1.5% of each other and they said they found no issues with them.

 

[bastarddsm]

Yeah I knew Curt did the work. Sounds like it shouldn't be having issues.

See if you can get ahold of some E98 and just try it. If it cures the knock it's real and something is probably wrong. If it stays, then it's probably not real, and just ignore it.

 

[Kapok6]

If I can't get 98, how about 116oct, like C16 or Q16? Like adding 1/4 tank to my e85? I have FIC 1550's so I am not sure about fuel compatibility as I have never messed with race fuels.

 

[bastarddsm]

I wouldn't recommend that. I've read a paper once, as well as saw a bunch of forum posts about leaded fuel and ethanol are a no-no. Causes detonation.

If I was going to try Q or C16 I would get it back on gas and run it straight.

I'm not trying to treat you like a toddler with the easy questions, but have you verified what your ethanol percentage is? I know I've seen a big difference in knock activity between E50 and E70, and I'm only 8.5:1

 

[bastarddsm]

I've been fighting some issues with mine right now and I'm not sure whats going on either. I'm getting trace knock counts at 15-16* up top at 40psi. It's moving ~70lbs/min and trapping 141. I'd think it should be doing better and wants more timing.

 

[Kapok6]

last tested was mid 70's.

Again, here with the he said she said; when I was talking to another reputable DSM tuner a few months ago he stated that his understanding is that anything above 60% and you are pretty much receiving the full benefits of e85.

I'm not trying to start a pissing match with anyone. Just trying to utilize all the info that people I know in the dsm game with good reps have given me.

 

[Kapok6]

I'm striking out on e98 here. man this is infuriating.

 

[biglady112]

If it makes you feel any better, I have been using e85 since 2005 and have never once tested my e85. From the pump or the barrel. I tune for what the car wants that day.

 

[bastarddsm]

last tested was mid 70's.

Again, here with the he said she said; when I was talking to another reputable DSM tuner a few months ago he stated that his understanding is that anything above 60% and you are pretty much receiving the full benefits of e85.

I'm not trying to start a pissing match with anyone. Just trying to utilize all the info that people I know in the dsm game with good reps have given me.

It's cool. I know the exact paper that came from. Keep in mind that was tested on low rpm engine at nowhere near the bmep we achieve. I think it's a very valid point, and 50% does perform much closer to 85% than 0%, but maybe with 10:1 your requirements are high enough that you really need 85%
I think mid 70's should be good enough though, but it's tough to say.

Anyway your getting knock well shy of mbt. The question is how to fix it.

Can you find a 5er of methanol and pour that it? hell even a couple gallon cans of denatured alcohol I think it's mostly Meth and Eth.

 

[Kapok6]

It's cool. I know the exact paper that came from. Keep in mind that was tested on low rpm engine at nowhere near the bmep we achieve. I think it's a very valid point, and 50% does perform much closer to 85% than 0%, but maybe with 10:1 your requirements are high enough that you really need 85%
I think mid 70's should be good enough though, but it's tough to say.

Anyway your getting knock well shy of mbt. The question is how to fix it.

Can you find a 5er of methanol and pour that it? hell even a couple gallon cans of denatured alcohol I think it's mostly Meth and Eth.

https://en.m.wikipedia.org/wiki/Denatured_alcohol

I can get that at home depot...

 

[bastarddsm]

Proof it up!!

 

[Kapok6]

I'll pick some up tomorrow, dump it in, let it rip and get some logs this weekend hopefully.

 

[boostdawd]

@bastarddsm are u still doing remote tunes??

 

[boostdawd]

Thanks @biglady112 for the knock sensor tip. Its made a big difference on my setup and get way less sporadic knock issues than before. I'm sure the OP will benefit from this as well

 

[jakk220]

@bastarddsm are u still doing remote tunes??

^^ this. I messaged him about a week ago and haven't heard anything back. Wondering the same thing myself.

 

[Kapok6]

Alright, so, I put about a gallon of denatured alcohol in yesterday afternoon into abut a full tank of e85, richened my afr's up to high 10's/low 11's and went and tried to do some pulls but could get any clean ones in due to traffic, the few partials I got showed knock sporadically so I ran some errands and called it a day.

So this morning I went out to do some pulls before traffic picked up down here in mexico. Attached are the logs of 4 of those pulls. This is what's odd; on pull 1 I couldn't get any knock to show. So I added 2deg I think from 4500 up. Did another pull, aside from like a little blip of 1-2cts, no knock. So I add another degree, swapped in a fresh plug do a pull, and get knock as you can see in the pull 3 log. So I then toss in another gallon of denatured alcohol for pull #4 (as you can see AFR's lean out a bit now to low 11's) and still shows knock. So I pulled it back a degree and knock came back down to the 1st and 2nd pull area.


Attached are pics of the spark plug after pull 3.

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[bastarddsm]

Well the plug looks like real knock, and your well short on timing. Looks like it's gonna want 3*+ if you can get the knock fixed.

Can you turn the knock based timing retard off in link?

 

[Kapok6]

Can you elaborate on "its gonna want 3*+ if I can get knock fixed?" Are you saying that it wants 3* more that what I'm running based on the color markings of the ground strap?

I don't run Link. I run werewolf and I can tell the ecu to ignore knock at whatever psi I dictate. I.E. ignore knock at or below 10psi, etc.

Side note. Did you see where it had a blip of knock here and there at like 1.2psi?

 

[biglady112]

There are some speckles on the porcelain. That shows the real knock. The coating flaking off kind of distorts where the burn is but, the ideal burn mark is on the 90* bend of the strap to slightly towards the bottom right after the bend. Yours is too high and closer towards the end of the tip. That is how you can tell the timing is not enough.

If it is too much timing it will be at the bottom of the strap and often burn it right off.

 

[donniekak]

Either something is wrong with the setup, or its octane limited.

I don't know why everyone wants to reinvent the wheel here. A simple 8.3:1 bottom end with any decent 272 cam, tuned on link, and e85 makes 550 all day with that turbo.

 

[Kapok6]

Ok, so basically I am running too much timing and not enough timing at the same time? How is something like this remedied? On one hand, timing is high enough to have knock, on the other hand it's not high enough to be where it "should be?"

 

[Kapok6]

Either something is wrong with the setup, or its octane limited.

I don't know why everyone wants to reinvent the wheel here. A simple 8.3:1 bottom end with any decent 272 cam, tuned on link, and e85 makes 550 all day with that turbo.

I'm well aware of what the setup you referenced above can do as I trapped 130.75 in a full weight street car on a similar setup. I went 10.5 per the builders recommendation.

 

[bastarddsm]

Basically Steven elaborated for me.

Don't know what to tell you. What's your alc percentage now?

I don't know how ww does it, but if it were me I'd set it keep it from retsrding the timing with knock and see how.it does on a pull.

Do you have your catch can recirc back into the intake? Is your fmic full of oil?