NefMoto

K04 hybrid, rods, DW265 pump, 630 injectors with 4 bar fpr so 715cc or so. Seeing max of 90% DC and fuel is following request so I have fueling sorted. When I was running 93 I was only getting occasional single digit CFs at 13* advance at peak load...so after verifying fuel was good after the switch to E85 I incrementally added timing up top and am now at 23*. Obviously no CF because E85. KFZWOP is 33* up top on a lot of stock timing files. Anyone have any experience getting closer to KFZWOP than I currently am without hurting parts??

If you're no longer knock limited, you need a dyno to figure out MBT.

Fair enough....going to wait for dyno until after 5120 then....no sense in doing it twice. Thanks!

Good start is to set KFZW = KFZWOP.
30 degrees on high rpm is just fine.

But obviously it's best on a dyno to see where it stops making power.

Thank you PRJ. I will eventually spend some time on the dyno to find MBT, but until then that is exactly what I was hoping for. “This is as far as you should push it without being on a dyno”. Thanks again.

Also, with Nyets approval I think I’m going to post the BIN for 93 as well as E85 with a list of everything done to the car in the community tunes section. i have searched E85 and timing in every way I could think of on here and there are several threads with good information, but it took a long time to find and weed through what was true and who just got lucky. One thread with what I have learned to get this thing running good (by my standards anyway) will hopefully be helpful to others.

Your bin, do as you please :)

Awesome  :) a few months ago I made my first post after losing commercial software. I owe the site for where I am now.

It's pretty much impossible to tell though, it could stop making power at 25-28 degrees, could still make power up to 30 degrees @ 7000 rpm.
Depends what's done to the engine.

But generally KFZW/OP is MBT on research fuel as per calibration documents.
Without a dyno, take KFZWOP, knock off around 3-5 degrees and you should be pretty safe.

I would just take this approach, there isn't that much you will be leaving on the table; there are plenty of other places to look for more power first.

What about fueling? What is your desired lambda?

In my logs I’m seeing .78-.82 lambda

That said...I have also confirmed with my version of ME7.5 anyways that fueling flat lines at .75 lambda.

I'm currently running my otherwise stock 1.8T on E85 with the timings slightly modified. Would be really interested in your findings. Especially in the low throttle & low load areas where the engine is not knock limited I'm experimenting with a slight retard due to the quicker flame speed of E85, for a slight improvement in economy. This is how SAAB tuned their 1.8T BioPower for running E85, reducing the timing at cruise loads in lower RPM areas. They actually pulled towards 10°  :o in some fields compared to the gasoline map. Obviously different engines but I'm thinking the fuel properties are still the same, hence the minor timing retard in my map. My map below:

(https://i.imgur.com/fM8XsYJl.png)

Offset compared to stock:
(https://i.imgur.com/DisnCZol.png)

When I get home I will post screen shots of KFZW and KFZWOP. I do not have VVT on mine anymore so I didnt touch the tables for when camshaft adjustment is enabled.

Really appreciated  :)

VVT-activated KFZW2 and KFZWOP2 tables are stock on mine, too. No need to touch them as the cam adjustment is only active during cold starts.

Btw, I made a simple graph of the timing offset for Saab's 1.8t BioPower factory tune:

(https://i.imgur.com/DWZdaMvl.png)

Hope this is helpful.

Thanks! Did you dyno it to get those numbers?

No I did not. The car likely has more in it, but based on what PRJ and Nyet had to say as well as searching I have done here and elsewhere this is as far as I feel comfortable pushing it without being on a dyno to know for sure when it stops making more power.

Thankfully with E85 it isn't so much that you're pushing anything (other than making more tq than your rods can handle :P), its just that you start losing power if you get too close to ZWOPT in some operating regions. Also lambda can have a huge effect (more so than timing) once you get to that point, and you can easily have one start to affect the other.

I do have aftermarket forged rods with 20mm pin and AEB pistons. I was under the impression that if you advance beyond maximum torque you run the risk of causing catastrophic lower end failure due to the ignition happening so early that it tries to force the piston down before he's made it all the way up.

The timing would need to be extremely over-advanced for that to occur. Detonation would also likely occur.

The whole point of proper ignition calibration is to use the Minimum ignition timing that produces the maximum power at all RPM points in the operating range. Any additional timing advance will reduce power by building too much pressure before the piston reaches TDC which is negative work.

As GWS pointed out, you're conflating two different things

1) ignition advance WAY to soon (past ZWOPT, generally) - not making more power, just going to break shit
2) ignition advance too close to ZWOPT - for some operating regions, depending on lambda, you may be leaving hp on the table

I was being flippant about my rod comment, didn't mean to confuse things with 1), which rods won't help with :)

My voltage regulator crapped out on me out of nowhere today, hah. Replaced and back to tuning now  ;D

Roughly which operating regions are we talking about, if known, for the 1.8T?

In another thread you said the manufacturer has tuned ignition for maximum efficiency in the lower load regions. What's your opinion on retarding sligtly in those regions on E85, considering the faster burn rate of ethanol? Looking at the table, the stock tune is almost 15° below KFZWOP at some spots in the 10-20 % load region where it's unlikely knock limited in any way.

no clue and have not had enough dyno time to give you an accurate answer.
as prj said above, pull a few degrees from OPT and call it a day


Same as above :) ymmv, hell, even with a dyno you'd have a tough time judging fuel economy. The average person just doesn't have those tools. If you are motivated enough you could compare IDC with HP (and attach an emissions sniffer) at a given rpm and dyno load but geez not sure there is a point. You're not trying to impress the EPA.

Gotcha Nyet. All of that said I don’t feel the need to advance any further. The car runs really really well. It is significantly smoother than on 93. When I made the switch I changed KRKTE (duh) and KFZW, nothing else. So kind of a mystery, but I’m ok with that.