OFT - Example alternate maps for AT, 98RON, E85, MAF Scales

[steve99]

Originally Posted by Trettiosjuan

Also noticing the high ltft when idle or releasing throttle, I only copied the economy related tables and this started as far as I can tell when I zeroed the CL Fueling Target compensation tables (A+B) which I skipped the first time. Don't fully understand the purpose behind changing these...

LTFT can vary a bit at idle due large temperature differences of Intake air temp which effects density of air and the maf scaling is also adjusted by ecu due to intake air temps.

Its also an area of very low flow so any differences between cars MAF sensors get noticed.

don't completely zero the CL load AFR compensation tables or you will disable LTFT in closed loop, leave a small negitive value in their like wayno has like -0.01

This is the compensation due engine load in closed loop , basicly you just running 14.7 afr in closed loop at low engine loads and rpm , to save fuel.

Once your at higher loads and rpm's its back to normal

[steve99]

Originally Posted by Kodename47

I've had a quick scour of this, might be worth a read. They mention advancing the intake AVCS might help quite a bit. However having not seen the maps I can't confirm if this is already the case.

http://www.romraider.com/forum/viewt...p?f=15&t=10725

That guy is running a speed density tune.

We only going for economy at low load and rpm ie cruising round in traffic or on highway

As out cars are fairly aerodynamic we are only seeing loads of 0.6 or so at 100kmh on highway (about 2600-2800rpm) , and also only up to about 0.7 around town if your reasonably light on throttle and stay under 3000 rpm .

so we are only adjusting below 3000 rpm loads under 0.7. This is giving us better economy with almost no loss in power and actually smoother drivability. Once over those rpm/loads we still going for full power.

We have found we can run 14.7 (CL/OL) (adjusted to petrol scale) in that whole area (could probably run leaner if ecu would allow it) on E85 , its magic stuff, if we tried it on petrol it would knock like crazy.

[Trettiosjuan]

I'll let it be if no harm...
(almost zeroed, typed zero but it does say -0,01)

[Kodename47]

SD or not, I figured that every little helps. It's another avenue to test that may get you some better mileage. Actually the main difference I would be aware of from that example is the CR and the relationship to the exhaust AVCS settings. However I have no idea if that area is knock prone on E85 on the twins already.

[steve99]

Originally Posted by Kodename47

SD or not, I figured that every little helps. It's another avenue to test that may get you some better mileage. Actually the main difference I would be aware of from that example is the CR and the relationship to the exhaust AVCS settings. However I have no idea if that area is knock prone on E85 on the twins already.

Reading that thread seemed mixed results did not work well for others when they tried it.

the other issue is those guys probably have Flex fuel sensors , and in their tunes they had disabled LTFT, we need that active to account for ethanol percent.

Interesting concept probably worth a look, they also targeting 14.2 afr which seems counter productive, but probably need the dyno to sort that out.

[504]

so based off all of this, would it be safe to say that due to the much more strict closed loop compensation table to maintain the required afr that ltft is much high reading? I'm hitting as high as 9% on idle and 5% under light load and I'm making a big guess in saying that the number isn't as dangerous as it seems due to the much more strict closed loop compensation table... correct me if I am wrong here


EDIT: After reverting back to v23 Maf scalings, fuel trims are spot on!

EDIT: After reading evo forums, apparently 14.7(more strictly lambda = 1) on e85 is "really rich" and numbers like 16.5 under idle and cruise is considered acceptable. ethanol puts out 30% more fuel and the combustion process runs cooler overall so the heat associated with running lean from the formation of nitrogen oxide MAY not be too bad for this fuel. An interesting approach to this ethanol economy situation (even though currently I am sitting at 10c cheaper per Litre overall compared to 98 ron)

[Wayno]

You need to flash and run shiv's tune for a while as a baseline before you waste your time going around in circles about fuel trims. You'll do your head in.

Then go read about cl/ol and you'll realise ltft is only relevant in ol.

[s2d4]

Originally Posted by 504

I'm hitting as high as 9% on idle and 5% under light load

Temp bro.

[Wayno]

Roms attached to first post have been updated.

See inside zip for all changes.

- Stg2 BPB 98RON map re-made.
- E85 now using petrol MAF scale as a base which is good for about +0.25 AFR in open loop.
- E85 has slightly modified MAF scale to lean up 3.2V and 4.06V by a further +0.25 AFR.

I.e.
3.2V = 69.5 (-1%)
3.44V = 87.74 (0%)
3.71V = 112.57 (0%)
3.91V = 134.75 (0%)
4.06V = 152.05 (-1%)
Before (OTS E85 scale - flat, but hitting 11.5 AFR at 7200rpm):
http://datazap.me/u/lipton54321/v44-...22-168-189-204


I'm currently running these values for my MAF. I haven't seen another car resemble mine though, even with the exact same hardware.

3.2V = 67.4 (-4%)
3.44V = 87.74 (0%)
3.71V = 110.3 (-2%)
3.91V = 131.8 (-2.2%)
4.06V = 150.2 (-2.2%)
Before (OTS E85 scale - 11.7 at 6000rpm, 12.06 at 6800):
http://datazap.me/u/wayne/206-stg2-u...zoom=1249-1419
After (OTS PETROL scale - 12.5 down to 12.06 at 7200rpm):
http://datazap.me/u/wayne/v48-5-dry-...1934-1941-1955

[cawith]

I'm copying over to my G rom some of the changes you make, but with some of the tables I'm not sure, if I should change them or not. I mean if they are different because your car has AT or if it's due to your optimizations.

I'm mostly thinking about the following tables, as they are also different in Shiv's I rom:
- Timing Compensation (IAT)
- Timing Compensation A (ECT)
- Timing Compensation B (ECT)

I've also found that my fuel trims seem best with the MAF scaling from your v33 rom with a few % changes in some areas. However I see that in your v49 rom the Front Oxygen Sensor Scaling and Front Oxygen Sensor Rich Limit are different. I can't seem to find any guidance on how to scale this myself. Should I just let it be, if I keep my own MAF values?

Also, is Misfire Count MAP Threshold B, Overrun Fueling Cut Counter RPM Threshold, Catalyst Warm Up Idle and Non-Idle only different because of the transmission type?

[steve99]

Originally Posted by cawith

I'm copying over to my G rom some of the changes you make, but with some of the tables I'm not sure, if I should change them or not. I mean if they are different because your car has AT or if it's due to your optimizations.

I'm mostly thinking about the following tables, as they are also different in Shiv's I rom:
- Timing Compensation (IAT)
- Timing Compensation A (ECT)
- Timing Compensation B (ECT)

I've also found that my fuel trims seem best with the MAF scaling from your v33 rom with a few % changes in some areas. However I see that in your v49 rom the Front Oxygen Sensor Scaling and Front Oxygen Sensor Rich Limit are different. I can't seem to find any guidance on how to scale this myself. Should I just let it be, if I keep my own MAF values?

The IAT table was changed to address knock at high intake air temps mainly on petrol, your 98 may be superior to ours or your climate temperatures much lower.

The engine coolant temp tables were changed to give some extra safety if your coolant temps got very high.

To scale the 02 sensor yourself you would need to install an aftermarket O2 sensor and calibrate off thar, that is what ztan did to do the rescale

[cawith]

Originally Posted by steve99

The IAT table was changed to address knock at high intake air temps mainly on petrol, your 98 may be superior to ours or your climate temperatures much lower.

The engine coolant temp tables were changed to give some extra safety if your coolant temps got very high.

To scale the 02 sensor yourself you would need to install an aftermarket O2 sensor and calibrate off thar, that is what ztan did to do the rescale

Okay, we very rarely get more than 25-30C here, so guess that won't be a problem for me.
We don't actually have any 98 fuel anymore, only 95 or 99 (V-Power only). Tried to run the base timing of the US 93 map once while on V-Power but had knock, so guess our 99 RON is only as good as US 91.

But the O2 sensor table (readings in mA) have been changed since v23 of Wayno's map. Stock readings go from -0.76 to 0.58, where as the new reading go from -0.98 to 0.43. Seems as if some values above 0 have been skipped to add some extra negatives. I guess that is to smoothen the curve.
Are those changes a specific tune of his car/intake or would it be fine/safe to apply those changes to my car with the stock O2 sensor and without using the same MAF scaling?

Also, I edited my previous post right about the time, when you were posting, so I guess you didn't see my edit

Are Misfire Count MAP Threshold B, Overrun Fueling Cut Counter RPM Threshold, Catalyst Warm Up Idle and Non-Idle only different because of the transmission type?

[steve99]

Originally Posted by cawith

Okay, we very rarely get more than 25-30C here, so guess that won't be a problem for me.
We don't actually have any 98 fuel anymore, only 95 or 99 (V-Power only). Tried to run the base timing of the US 93 map once while on V-Power but had knock, so guess our 99 RON is only as good as US 91.

But the O2 sensor table (readings in mA) have been changed since v23 of Wayno's map. Stock readings go from -0.76 to 0.58, where as the new reading go from -0.98 to 0.43. Seems as if some values above 0 have been skipped to add some extra negatives. I guess that is to smoothen the curve.
Are those changes a specific tune of his car/intake or would it be fine/safe to apply those changes to my car with the stock O2 sensor and without using the same MAF scaling?

Also, I edited my previous post right about the time, when you were posting, so I guess you didn't see my edit

I would not worry about rescaling the 02 sensor only rearly needed if your boosted and want to read richer afr.

Your IAT temps will likely climb when stuck in traffic to above 40c so might be worth doing that change.

The other tables you mentioned
"Are Misfire Count MAP Threshold B, Overrun Fueling Cut Counter RPM Threshold, Catalyst Warm Up Idle and Non-Idle only different because of the transmission type? "

were not changed so likely they are due to different ROM type. so would not change those.

[Wayno]

Economy:
- Primary Open Loop Fueling
- Primary Open Loop Fueling Additive
- CL Fueling Target Compensation A (Load)
- CL Fueling Target Compensation B (Load)
- MAF Sensor Scaling
- Base Timing B
- Requested Torque B (Accelerator Pedal) (AT ONLY)

Cranking:
- Cranking Fuel Injector Pulse Width A (ECT)
- Cranking Fuel Injector Pulse Width B (ECT)
- Cranking Fuel Injector Pulse Width C (ECT)
- Cranking Fuel Injector Pulse Width D (ECT)
- Cranking Fuel Injector Pulse Width E (ECT)
- Cranking Fuel Injector Pulse Width F (ECT)

Safety:
- Timing Compensation (IAT)
- Timing Compensation A (ECT)
- Timing Compensation B (ECT)
- Radiator Fan Modes A (ECT)
- Radiator Fan Modes B (ECT)

Idle:
- Idle Speed Target A (AT ONLY)
- Idle Speed Target B (AT ONLY)
- Idle Speed Target C (AT ONLY)
- Idle Speed Target D (AT ONLY)
- Idle Speed Target E (AT ONLY)
- Idle Speed Target F (AT ONLY)
- Total Injection Ratio Port Cold
- Total Injection Ratio Port Hot
- Total Injection Ratio Port Warm

Driveability:
- Requested Torque B (Accelerator Pedal) (AT ONLY)
- Total Injection Ratio Port Cold
- Total Injection Ratio Port Hot
- Total Injection Ratio Port Warm

Other:
- P0420 Cat Effeciency Below Threshold
- P0700 (AT ONLY)