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E85 timing


richardpalinkas
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14 hours ago, Puffwagon said:

Watch this clip mate. This is where a live tuning ecu will excel as even with a dyno it'd take weeks to properly dial in a flash tuned car. Although there are plenty of variables that will make this number wrong you would generally say about 6 degrees.

This is a good video for tuning spark full stop. It demonstrates why you can't really road tune effectively.

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Yeah I guess from my own testing I just felt I had absolutely no way to quantify it, once you are over 350rwkw you aren't going to be getting traction on the street not to mention how dangerous it would get. So I just used the stock MBT numbers as a guide and extrapolated them for higher loads using excel. I assumed that if I'm not getting knock then providing I'm under these values I will be ok.

Without the stock MBT numbers though I wouldn't be able to extrapolate the higher loads. Eg if you have 0s in all your spark table and wanted to determine them from first principles without a dyno, it would be extremely challenging.

Eg at 0.8 load how do you determine the max timing an engine can take? I doubt you can feel the difference in torque at those levels. Leaving it stock is fine, but then you might be missing out on a lot of midrange.

I guess you could just load the stock MBT values into the borderline knock, providing it doesn't knock you know you aren't going beyond MBT and running extreme pressures/temperatures.

A lot of guess work and assumptions though. If the stock MBT values aren't right you are screwed. Spending a day or two on a dyno and you could recalc MBT for all the cells. Would be painful to do even with 12 second flashes but it would be the only true way to tune the motor correctly. I suspect not many people do all the cells, having inconsistent IAT and ECT would make it even harder.

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11 minutes ago, Roland@pcmtec said:

So I just used the stock MBT numbers as a guide and extrapolated them for higher loads using excel. I assumed that if I'm not getting knock then providing I'm under these values I will be ok.

 

While that is guessing, it's taking an educated guess that will more than likely get you very close to where you need to be.

You can block tune and measure the changing vacuum levels with the changed timing values for lower load stuff. It'd be a bit tricky to do tho even with a friend in the passenger seat as you'd be basing your runs on the throttle position. You'd have to factor in changing vehicle and environmental conditions.

In regard to tuning from blank maps you would have to pick what you think are reasonable numbers and go from there. You can get some idea of what timing to run based on some of the engines physical characteristics. You could start tuning with a lower octane fuel to find where it knocks before the power gets turned up and then you'll have a good base to work from. There are various spark map calculators available as well that can be helpful.

Haha I don't think we'd be screwed tuning from blank maps, it'd just take forever to dial in with flash tuning, even with a dyno. Realistically you wouldn't do it on a flash based system, you would live tune the car and then swap the info over. Now that I write it down and read it back, you pretty much would be screwed for how long it'd take.

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Just quickly addressing the edits

 

54 minutes ago, Roland@pcmtec said:

once you are over 350rwkw you aren't going to be getting traction on the street not to mention how dangerous it would get.

Agreed. You can road tune on a circuit tho and 4th gear in an auto car wont get wheelspin for a long way after 350rwkw.

 

56 minutes ago, Roland@pcmtec said:

Spending a day or two on a dyno and you could recalc MBT for all the cells. Would be painful to do even with 12 second flashes but it would be the only true way to tune the motor correctly. I suspect not many people do all the cells, having inconsistent IAT and ECT would make it even harder.

I agree entirely. 

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Thanks for that video, Puff. I've just spent all morning going through his videos. 

Couple of quick related questions.  I see in the video he's chosen a couple of sell areas to tune for as an example. But when you guys are advancing timing for more power, are you doing the whole table? Or are you just looking at WOT and leaving the rest factory?

Another question, on fuel density, say we are running a particular fuel either e85 or 98 100% of the time.  There are a couple of scalars that I've noticed such as fuel weight and stoich that are fuel dependent. Should we adjust these accordingly for the fuel. eg i see that for weight its set to 73.5 but should it be 72(i think your comment says in the tune file)?  Does this effect fueling trims etc?

And the last one, the octane spark adders. If we are always without fail going to run a higher fuel octane, is there something we should change here.

Cheers Guys,

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1 hour ago, finnigan001 said:

There are a couple of scalars that I've noticed such as fuel weight and stoich that are fuel dependent. Should we adjust these accordingly for the fuel. eg i see that for weight its set to 73.5 but should it be 72(i think your comment says in the tune file)?  Does this effect fueling trims etc?

Cheers Guys,

Yes you have to change stoich, specific gravity you should change as well as whilst it doesn't make that much difference you might as well make it correct.

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Thanks for the replies guys.  All these tidbits, nuggets if you will, help tremendously.

1 hour ago, Puffwagon said:

I had a modified borderline knock map to suit my slightly larger turbo and boost pressure on 98 octane that I added some timing to from 1 to 1.6 load.

Apart from that I didn't use pcmtec to do the tune so I reckon some of what I did before will be different when I retune it with pcmtec.

Puff,  with adding spark to e85, i've seen Jet mention 6-7 degrees as well as the video above demonstrating that too.  Is there a similar amount that can be added from going from 95-98.  I'm not asking for a figure to just go +2 or +4 across the whole map and i understand every motor is different and that the standard tune can ping on 10psi with out adding any timing.  Just looking for an idea of how much more resistant 98RON is that 95 if any.  At the moment i've moved to 98 and actually pulled some timing at WOT while upping boost.  I'm not looking for the absolute edge of what the car can be pushed too.  Not until i buy some dyno time.

 

1 hour ago, Roland@pcmtec said:

Yes you have to change stoich, specific gravity you should change as well as whilst it doesn't make that much difference you might as well make it correct.

Sweet, will do.  Almost have fuel absolutely spot on with the help from darryl and yourself.  I have noticed a rich overrun at tipout, coming of the accelerator at any speed since putting in the 110lb bosch's.  Any pointers at tables or scalars i should be looking at?

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Yeah I had 6 extra degrees over stock in some spots and less or more than that in others. It was already tuned differently for higher boost and lazier turbo etc which is why it wasn't just globally adding 6 degrees to a stock map. It has been a while but iirc I did add 5 or 6 degrees to the already tuned map in the areas I mentioned.

I've found that 95 to 98 is a tiny jump compared with 98 to e85 which makes sense seeing as e85 is 107 RON or something like that.

I reckon you'd be flat out getting another 2 degrees by running 98 instead of 95 if you compared the two with the knock sensors off. It depends how much boost you run tho.

I did most of my tuning in the summer months and I was only able to run about 5 degrees when the boost hits up to 7 or something up top on 98 at around 18psi or so with gtx wheel and 0.7 comp housing. That was with a stock catback so that wouldn't have helped matters much along with the stinking hot ambient air temps.

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52 minutes ago, finnigan001 said:

Thanks for the replies guys.  All these tidbits, nuggets if you will, help tremendously.

Puff,  with adding spark to e85, i've seen Jet mention 6-7 degrees as well as the video above demonstrating that too.  Is there a similar amount that can be added from going from 95-98.  I'm not asking for a figure to just go +2 or +4 across the whole map and i understand every motor is different and that the standard tune can ping on 10psi with out adding any timing.  Just looking for an idea of how much more resistant 98RON is that 95 if any.  At the moment i've moved to 98 and actually pulled some timing at WOT while upping boost.  I'm not looking for the absolute edge of what the car can be pushed too.  Not until i buy some dyno time.

 

Sweet, will do.  Almost have fuel absolutely spot on with the help from darryl and yourself.  I have noticed a rich overrun at tipout, coming of the accelerator at any speed since putting in the 110lb bosch's.  Any pointers at tables or scalars i should be looking at?

Tip out rich indicates your minimum pulse width or deadtime is wrong. Is DFCO working? If your deadtime is wrong DFCO won't work. You can tell when it kicks in as the exhaust note changes and there are zero backfires.

What are your trims like on decel? If they are negative (rich) it also indicates the same thing.

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From what i can tell the DFCO is working.  AFRs go to 22 and instant fuel according to dash goes to 0.0.  So that's what i'd expect to see. Its the time between foot off and dfso coming on that is rich AFRs dipping in to the 11s and high 10s. Looking at fuel trims on foot off both long and short term are -5.5%.  At cruise, trims are between -2 and +3 but mostly sit at 0 and -0.8.  I did notice a lean tipin, LTs would be +8% and AFRs up to 16 for a couple seconds.

I used your ID1000 howto setup and then adjusted the slopes to the figures below.

injectors.jpg.3e09b82298030ce6d05a22dfe9135e0a.jpg

 

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If you disable closed loop O2 do you still have a rich tip out? How does steady state and cruise look, spot on 14.7 ?

Also what fuel pump are you running? If you have a walbro 460 or larger with the stock return lines and regulator you will get high pressure at idle/cruise which can cause erratic trims.

Also the placement of your O2 sensor can play a part. Eg if the sensor is now much further away your short term fuel trims can struggle to maintain the AFR and overshoot on transient conditions, eg cause a rich rip out and then immediately after a lean tip in.

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Hey Rolls,

Cheers for the help,  you're suggestions last time put me on the right track.  I spent the weekend trying to dial the injectors in again. I noticed that my breakpoint should be lower as long term trims were never coming in.  I still couldn't get them perfect, same issues etc...  Spent last night looking for actual data for my bosch 980cc and actually found a datasheet from the people that sold them on.

For anyone needing data on bosch 280158040 110lb injectors, the following may help you.

https://www.raceworks.com.au/wp-content/uploads/2017/03/Raceworks-INJ-213-1150cc-Ford-Data-Amd17.xlsx

Just to answer your other questions, for others that might find this and be wondering, I'm running a walbro 255 and did notice erratic trims on the stock injectors. O2 sensor in the stock bung just before the cat and narrowband signal wired into the ecu.

Thanks again for your help.  This forum is going to be one of the greatest resources for BA-FG falcon owners in the years to come.

Raceworks-INJ-213-1150cc-Ford-Data-Amd17.xlsx

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