Pages: 1 [2]
Author Topic: E85 and timing  (Read 9693 times)
Jorgeminator
Jr. Member
**

Karma: +8/-0
Offline Offline

Posts: 27

Golf MkIV 1.8T AUM


« Reply #15 on: May 27, 2020, 10:39:26 AM »

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

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:

« Last Edit: May 27, 2020, 10:42:05 AM by Jorgeminator » Logged
justinvw2646
Full Member
***

Karma: +17/-3
Offline Offline

Posts: 191


« Reply #16 on: May 27, 2020, 03:50:53 PM »

Hope this is helpful.
Logged
Jorgeminator
Jr. Member
**

Karma: +8/-0
Offline Offline

Posts: 27

Golf MkIV 1.8T AUM


« Reply #17 on: May 28, 2020, 03:16:08 AM »

Thanks! Did you dyno it to get those numbers?
Logged
justinvw2646
Full Member
***

Karma: +17/-3
Offline Offline

Posts: 191


« Reply #18 on: May 28, 2020, 04:36:36 PM »

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.
Logged
nyet
Administrator
Hero Member
*****

Karma: +604/-166
Offline Offline

Posts: 12232


WWW
« Reply #19 on: May 28, 2020, 06:01:21 PM »

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 Tongue), 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.
Logged

ME7.1 tuning guide (READ FIRST)
ECUx Plot
ME7Sum checksum checker/corrrector for ME7.x

Please do not ask me for tunes. I'm here to help people make their own.

Do not PM me technical questions! Please, ask all questions on the forums! Doing so will ensure the next person with the same issue gets the opportunity to learn from your experience.
justinvw2646
Full Member
***

Karma: +17/-3
Offline Offline

Posts: 191


« Reply #20 on: May 29, 2020, 09:26:25 AM »

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.
Logged
GolfSportWagen
Full Member
***

Karma: +10/-10
Offline Offline

Posts: 100


« Reply #21 on: May 29, 2020, 12:14:54 PM »

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.
Logged
nyet
Administrator
Hero Member
*****

Karma: +604/-166
Offline Offline

Posts: 12232


WWW
« Reply #22 on: May 29, 2020, 12:22:22 PM »

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 Smiley
Logged

ME7.1 tuning guide (READ FIRST)
ECUx Plot
ME7Sum checksum checker/corrrector for ME7.x

Please do not ask me for tunes. I'm here to help people make their own.

Do not PM me technical questions! Please, ask all questions on the forums! Doing so will ensure the next person with the same issue gets the opportunity to learn from your experience.
Jorgeminator
Jr. Member
**

Karma: +8/-0
Offline Offline

Posts: 27

Golf MkIV 1.8T AUM


« Reply #23 on: May 29, 2020, 01:09:19 PM »

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 Smiley

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

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.
« Last Edit: May 29, 2020, 01:35:37 PM by Jorgeminator » Logged
nyet
Administrator
Hero Member
*****

Karma: +604/-166
Offline Offline

Posts: 12232


WWW
« Reply #24 on: May 29, 2020, 01:56:43 PM »

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

Quote
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.

Same as above Smiley 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.
« Last Edit: May 29, 2020, 06:50:59 PM by nyet » Logged

ME7.1 tuning guide (READ FIRST)
ECUx Plot
ME7Sum checksum checker/corrrector for ME7.x

Please do not ask me for tunes. I'm here to help people make their own.

Do not PM me technical questions! Please, ask all questions on the forums! Doing so will ensure the next person with the same issue gets the opportunity to learn from your experience.
justinvw2646
Full Member
***

Karma: +17/-3
Offline Offline

Posts: 191


« Reply #25 on: May 29, 2020, 03:43:37 PM »

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.
Logged
Pages: 1 [2]
  Print  
 
Jump to:  

Powered by SMF 1.1.21 | SMF © 2015, Simple Machines Page created in 0.046 seconds with 16 queries. (Pretty URLs adds 0.001s, 0q)