I for one would like to know your E85 concentration and see your IGN tables. IIRC you were running 22-23PSI boost on a TQ making GT28.

going bast MBT could certainly be what caused your rod failure.

Edit: and I don't want to have a blown engine thread up here in a few days/months...lol

4 gallons eth

From 4000: 9.5 11 13 14.5 16 18 20

I totally agree with that, but 4 gallons of eth isn't going to allow you to go there without knock.

maybe but when I was tuning with E35 =4/8 mix, using VD as feedback with very controlled conditions, I did see a drop in power past a certain point and didn't get knock. I then pulled a degree across the board and the power came back.

I believe the results are in Dustins battle VD thread.

jussayin...

entire range please, 2-7k

edit: FWIW here is my curve from 2K so I run more timing that you were.

-2 1 2 6.5 9 11.5 13 15 17 19 21 22

Thats alot of timing @Dano...i like your style

I'd just like to see what the actual dyno curves look like.

Interesting

-7.9 -3 -1 7 9.5 11 13 14.5 16 18 20

Although that is putting quite a bit of faith in VD, I understand what you are saying.

I still don't think 4 gallons of ethanol allowed Keith to tune his car past MBT without knock, and therefore popped his motor.

Doesn't add up. "jussayin".

Quite interesting....me thinks @Dano will be dialing timing down.

current timing on e23
-12.00 -9.00 -6.00 -3.00 0.00 3.00 6.00 8.00 10.50 12.50 14.50 16.50 17.00 18.00

bah!


humbug....my timing is staying....

I have walked it up and down numerous times using VD, same day, same stretch of road and always made more power up to just beyond the curve I posted. Then pulled 1* across the board and left it at that.

now that I see CK's timing curve I don't think he was beyond MBT to I aint scurred.

Thanks, Dano and Keith, for posting those timing curves. You guys have the most comparable cars with the GT28's and timing curves. On the K04 eth mix cars, I have seen almost as much timing as Keith's on the low end, and just as much on the top end. I'm too much of a bitch to go farther than that without seeing it on a real dyno.

Here in the next month or so, I'll have a 50/50 car on the dyno, and we'll see where things end up. We can add it to our "ethanol timing curve database".

I do think it is doubtful that Keith's was really beyond optimal, though. Every car is different, so it is very difficult to say. Hopefully a failure analysis is done, and we can really find the culprit.

Man, I'm not sure if that is true. The low eth mixes are so tolerant of knock it's scary. Hence why I haven't taken the timing curves farther without seeing it on a real dyno.

When I started to get beyond 20° on mine, I was just thinking "wtf am I doing, this is INSANITY!!", and that was on a real dyno.

wait a minute...IIRC @6.5K you were running 22* and 24 at 7k??? If that's not the case perhaps I will pull a little bit more...lol

Ok, so I just heard back from DJ who is on vaca so probably why he hasn't popped up during this discussion (didn't want to bring him up until I knew he didn't care). It was his opinion after looking at my tune that i was past mbt POSSIBLY. He definitely did not say he was for sure, but that the signs pointed to that being a likely culprit.

Nothing else he noticed seemed out of whack in the tune. I'll search for logs and see how often I had my post spool up lean spot, even thought that was not always present and hit 13.5ish for like 1/10 of a second. I actually thought it might have been blow out... I'll have to go check why, but I had my reasoning. Just can't remember now.

I almost wish it was that I was past mbt, because it would take care of much of my worry about my next motor.

I did lose 2 rods (we think... don't have the car home yet) though, and Idk how i would lose two at the same time from prolonged stress??? But maybe it is normal... I haven't been around cars long enough to know

NO! I was just speaking about some of the E-Tunes I have done. On E85, fuck yeah I run 24° @ 6,500. The only other E85 car I have had on a dyno had an almost identical timing curve. So we have proof that my car is not just a freak, lol.

I don't see the same thing on the cars that I have worked on (i.e. low mixes of e85) . I don't know a few things that are relevant...

I'd like to know

1) Keith, have you changed your knock sensitivity?
2) If raising the octane level of the fuel we are using is allowing past mbt operation without knock, what mix does everyone feel comfortable tuning off the knock sensor with?

I'm also more inclined to believe that the timing earlier in the rev band is what is causing the rod stress rather than the 20* @ redline.

I was DEFINITELY KR limited at 5500+ with 4 gallons both in 100* weather and 60ish* weather. When I went above the values I listed I would see increasing KR, and at those values I only get a sporadic * here or there (got a sporadic * I should say haha!)

I never really saw kr below 5500 IIRC regardless of timing

never touched KR sensitivity. I would get KR on my AP datalogs at times but never showed on my aeroforce gauge which I think had KR set up incorrectly as mine NEVER went above .3-.5. I haven't logged in a bit and I wonder if I was getting significant KR and just wasn't aware of it??? idk

And yeah Rob, Dustin thought the issue with my timing was in the 4500-6000 range.

There are lots of variables here, since Keith's car is a GT28 car. More air, thus more cylinder pressure (possibly needing less timing). So it could be that 4/9 was not enough to stave off knock, completely.

@rfinkle2 - I don't tune off of the knock sensor unless it is a pure gas car.

This could all be good news and bad news.

I still use the knock sensor on my own car, as well as other cars I'm working on, but try to stay as close to Evan's 50/50 curve as possible.

This is eye opening to say the least.

Keith, I'm sorry that you had to take a hit for the team, but you likely are going to save quite a few guys from the same fate (note fate / not PHATE lol).

I think it is important to note that I have almost strictly worked with K04 cars. BT cars are a different story, as I'm finding out.

Thanks, but I'm not sorry at all. If we can get solid information out of my situation, thats awesome! I'm still worried that we may not though. And I would rather it be me than someone who is not interested or could not afford to build their motor (or even replace it).

And I definitely feel better that my timing wasn't retarted crazy anyway... makes me feel like not as big of an idiot... I just need to learn patience and have a more systematic and conservative approach to tuning.

Same here.

I try to make a habit of experimenting on my own car 1st, then adding things proven to be useful to maps.

The one shortfall to that idea is the lack of long term data / findings.

I am thankful to be a bit conservative, now more than ever.

FWIW, this is my current timing on a 2.5gal/E85 10gal/91octane mix and I'm completely knock free running 19-19.5psi targeting 12.0 AFR's. IAT's have only been as high as about 80 with this map, I'm curious how this will work when summer arrives.

-12 -7 -2 0 2 4 6 8 10 12 14 16 17 18

Here is something I think is silly important to this thread.

I think many of us have seen instances on high concentrations of e85 where on 1 log, afr's are very close to commanded, and in the next, they are in the 13's.

We really need to pick @ David to find out where this difference is coming from.

I think there is a distinct possibility that some guys could be running 13 afr's without knowing it (when a previous log has shown otherwise).

Not everyone monitors afr's every time wot, or has the ability to do so.

Also a quick question. I am running the above timing on the 2.0, 2.06, 2.13, and 2.19 load lines. Are you guys running your max timing on the 2.19 load line and vertically interpolating or going from 2.0 down as I am? I realize those of you with heavily scaled MAF curves this wont matter as your probably above 2.19 the entire run anyway.

You guys keep talking about not seeing knock.....You won't see it until its too late practically..Right?

I know on our a BT your MEGA limited with e85. The injectors don't seem to take much past 22 psi on a gtx 3071....Im just assuming it would be the same on bigger turbos. So much air and not enough fuel.

Ahhh! another excellent point.

Lex recently found a glitch in the gen2 tables where timing and load don't exactly match up per the tables.

I would definitely scale timing down by a .5 degree of so as load increases (each line of load), in the extra 3 lines of resolution seen in the latest atr.

Dustin's comment is interesting considering I run a full 2* more timing that you do and he thinks its possible you were beyond MBT... not sure MBT is the smoking gun you are looking for....not yet at least

CK from 2.5K:

-3 -1 7 9.5 11 13 14.5 16 18 20

Dano

2 6.5 9 11.5 13 15 17 19 21 22

note to self: run compression check soon

lol....note to self back offset of knock sensor down LMAO!

No, I saw kr a bunch when i was tuning with 4 gallons when I went to far with timing in the higher rpms... saw up to 3 somefin a couple of times... it was absolutely real kr.

But that gives you less timing than commanded plus a BT car will remain above 2.19 for the majority of the time if not the entire time then add E85 scaling to the mix and the ign table isn't a factor.

yeah, when you posted your timing earlier, i noticed that and you may be right. I just REALLY HOPE that we can find the smoking gun, whatever it is.

How often do you WOT and how many miles do you put on your car a month? I only ask cuz I do around 50-100 miles a day and get at least 3 and up to 10 pulls in there... not always full pulls.

That is my #1 cringe when I see it posted (the knock offset tables)...

I think that some guys can get away with it, but am always afraid of the newest guy to a thread popping in and using screenshots of tables of in his own map.

Thats no beuno keith....

What i did....

After getting fully mounted I went back to my 93 map and did a bunch of logs to see where i was getting "engine noise" KR at. Once I got that tuned out I then copied those settings for the offset over to my 50/50 map. That way I wasn't tuning out what may have been actual knock...weird thing is I can't remember seeing knock ever on 50/50. Only time you would maybe see some is between shifts.....


LOL you make a valid point here....

"oh that knock isn't real its just engine noise"

"Just adjust the offset table LOL"

I always watch AFRs and since getting my weird issue corrected a couple of months ago, I only run a tenth of a degree rich from time to time... maybe a bit more. I never see 13s except for a cell or two on a log after spool up.

Quick question. I am on 6 gallons of E to a full tank. I want to step up to 50/50 mix...roughly 8 gallons per tank. What percentage should I scale the entire maf range in the map going from 6 gallons to 8 gallons in order to get close to AFR targets? Any thoughts?

Thanks.

Going from 6-8, scale up your 6 MAF curves by ~4%.

Your better off to run 50/50 on a 6 Gallon basis.... As you can't squeeze much more than 13 gallons in the car and putting 6.5 in would be tough

So true.

I have had a few occasions when the last light of my fuel gauge has gone off, drove a bit, put in 7 gallons of e85, and only fit about 6.5 gallons of 93.

Going backwards a little bit to the timing on BT setups. I was knock limited at 17* Peak in 90*F ambients with a 3/9 mix @ 12.0AFR @ 22psi/2.4 load. With lower temperatures I could probably push timing a little further but am not interested in making a cold weather only tune. Just another datapoint.


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