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Author Topic: S3 AMK - with a few mods LAMFA queries regarding MAF wall at 188g/s  (Read 5033 times)
stuartdean
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Hi,  I finally got my car MOT'd so I can play around with some maps - but I think there is too much blow-by gas as its puffing out of the dipstick - it was a hard job to get it through the emissions too - don't believe the breathers are blocked as it puffs out of there too.
anyway..

just a quick overview S3 AMK - I have 2 ECUs the standard one and a spare as a backup recovery in case of issues.
I bought the car a couple of years ago with a Stage 1 243BHP map and paperwork and a new air filter.  I have fitted a B5 TIP + Cosworth S2000 filter, 3inch Downpipe with 200 cel sports cat and 64mm Inlet/Outlet Welly Cooler, new fuel pump, dog-bone upgrade, catch can and some rubbish plastic arches covering over the rusty wings Cheesy  plus the obvious normal brakes, suspension, drop links and various sensors fixed, replaced repaired.

but.. anyway with the original MAP and the updates I could get MAF 194g/s - but I think it was too lean and sort of ran out of steam at 5500) so I bought an ebay "285BHP" ECU with encrypted map (I reckon this caused my engine issues) and the MAF only went to 201g/s. which is about 250BHP (although the Android Torque did state 240BHP at the wheels - which is more like 265 if you believe those calculations) although it now revved freely to the red line and the cat threshold fault didn't appear etc -  anyway I am digressing.

I started with a map based on my Stage 1 map to be more generous with fuel, add a little more engine load, map out the sports cat P0430 error, fix the issue with the cold morning starts where it doesn't use the N75 or whatever that error is and add 2 step launch control.

But, I have now run about 3 or 4 slightly different MAP variations but seem to hit a MAF wall at about 188g/s (I have managed 191g/s one a cold early morning) the only unchanged item I have kept in the MAP variations is the LAMFA. 

To be clear I have updated a stock BAM map with additional fuel and load or my original AMK stage 1 map with the same fuel and load and also one with slightly more engine load - all of my tests have reached and held 20psi on the boost gauge (Android Torque values vary)

What I am wondering is whether my LAMFA profile to too rich for a standard K04 and the few mods I have mentioned.

This is my LAMFA  the engine load figures are vertical and rpm is horizontal
<--  1000  - 6000  -->
1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00
1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00
1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   0.95   0.95   0.92
1.00   1.00   1.00   1.00   1.00   1.00   1.00   0.95   0.95   0.95   0.92   0.92   0.90   0.90   0.95
1.00   1.00   0.95   0.95   0.92   0.92   0.92   0.90   0.90   0.90   0.90   0.90   0.90   0.90   0.90
0.95   0.95   0.92   0.92   0.90   0.90   0.88   0.88   0.85   0.85   0.85   0.85   0.85   0.85   0.83


This is a suggested LAMFA for stage 2 which was provided to me
<--  1000  - 6000  -->
1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00
1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00
1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00
1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00
1.00   0.90   0.90   0.90   0.90   0.90   0.90   0.90   0.90   0.90   0.90   0.90   0.90   0.90   0.90
0.95   0.85   0.85   0.85   0.85   0.85   0.85   0.85   0.85   0.85   0.85   0.85   0.85   0.85   0.85



This is the LAMFA I had on my stage 1 map originally delivered (which did get to 194g/s)
<-- 1000 - 6000 -->
1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00
1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00
1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00
1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00
1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00   1.00
0.95   0.95   0.95   0.95   0.95   0.95   0.95   0.95   0.95   0.95   0.95   0.95   0.95   0.95   0.95


I think my next test will be to use the LAMFA with only the last two engine load lines changed instead of the curve.

This may simply be that the engine is now too tired to be made to work like this.


I do need to do some proper logging but have struggled with the VisualMELogger logging program, even through I got it working in August using a power supply on an ECU in my house - the blue KKL lead keeps looping saying trying to connect then could not connect to ECU - that's a different story


Thanks for your time and my apologies for the long post Smiley


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KasperH
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« Reply #1 on: November 14, 2017, 04:02:59 PM »

Lamfa axis is RPM & %Pedal.
so from what you are saying, it sounds like you were actually leaning out your engine.

you need to know what you are changing in the maps before you do so.

as for your "MAF wall" my guess is that you are hitting a pressure limiter.
« Last Edit: November 14, 2017, 04:07:54 PM by KasperH » Logged
stuartdean
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« Reply #2 on: November 14, 2017, 04:39:00 PM »

Thanks for the reply,
sorry yes vertical is % pedal travel (getting my grids mixed up)

my knowledge is limited but 1 is 14.7:1 isn't it which is 14.7 parts air 1 part fuel and therefore 0.95 is 13.5:1 or similar providing more fuel to air?  so richer than 14.7:1 ? so under an aggressive drive more fuel is added to AFR to assist with cooling and engine protection rather than so much heat and pre-ignition risk etc?

---
from an AFR article  - http://tunertools.com/articles/AFR-Tuning.asp

A reaction in which all components are completely consumed is considered to be stoichiometric (stoich). For gasoline/petrol this mixture is approximately 14.7 parts air, to 1 part fuel (14.7:1) for E85 this ratio is approximately 9.7:1 (note these ratios are approximate based on theoretical data assuming perfect laboratory samples, these ratios may vary slightly due to variations in regional and seasonal blends of fuel.)  A ratio which has more fuel left over (ratios lower than stoich) are referred to as rich, while those higher, and thus having excess air, are lean. In all but very specific and extreme cases rich ratios should be the goal, this is due to combustion and flame behavior as well as safety reasons and avoiding accidental ignition of the mixture as leaner mixtures are easier to ignite.



AFR
 
Lambda (λ)
 
14.7:1    =  1   = Stochiometric
12.8:1    =  0.87 =  Lean Best Torque (LBT)
12.2:1    =  0.83  = Mean Best Torque (MBT)
11.76:1  = 0.8  = Rich Best Torque (RBT)
11.01:1  = 0.75 = Flame speed fastest in cylinder
 

Table 1: AFR influence on Engine Behavior (Gasoline/Petrol)

The table gives a basic overview of AFRs influence over engine behavior and dynamics and should serve as a general guide when determining air fuel ratios at full power/Wide-open-throttle. Assuming knock is not a limiting factor, Mean Best Torque should serve as a general starting point (if knock is a factor, more fuel, less spark advance, or less boot/compression will generally be required.) Note that best torque does not occur and the fastest flame speed.  Any ratios richer than 11.01:1 should be avoided, as there is a very sharp and rapid decrease in torque at ratios richer than this point. Worth mentioning is also the fact that we may often see ratios leaner than 12.8:1, which is where lean best torque occurs. While this may sacrifice a small amount of torque the fuel economy and emissions at peak power can be improve which may be desirable (and necessary) on many street/pollution controlled vehicles.


------

I am not trying to create mega power but trying to improve on the previous 1 AFR across the board - as with the original stage 1 map it was actually safer to drive at WOT than 90% pedal travel as the LAMFA target was 1 not 0.95 AFR ?


so the MAF issue may just be the air filter is poor? do you reckon if the engine is breathing a little heavily with blow-by it would affect the MAF readings - I don't think it is the actual MAF sensor as I unplugged it and the other Android Torque estimations and boost etc were very similar.

Thanks Smiley
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KasperH
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« Reply #3 on: November 14, 2017, 05:07:11 PM »

Thanks for the reply,
sorry yes vertical is % pedal travel (getting my grids mixed up)

my knowledge is limited but 1 is 14.7:1 isn't it which is 14.7 parts air 1 part fuel and therefore 0.95 is 13.5:1 or similar providing more fuel to air?  so richer than 14.7:1 ?

yes and yes.

so under an aggressive drive more fuel is added to AFR to assist with cooling and engine protection rather than so much heat and pre-ignition risk etc?

all of the above.

I am not trying to create mega power but trying to improve on the previous 1 AFR across the board - as with the original stage 1 map it was actually safer to drive at WOT than 90% pedal travel as the LAMFA target was 1 not 0.95 AFR ?

Yes, but all fueling isn't controlled by only LAMFA.
There are MANY more maps influencing the final target lambda.

so the MAF issue may just be the air filter is poor? do you reckon if the engine is breathing a little heavily with blow-by it would affect the MAF readings - I don't think it is the actual MAF sensor as I unplugged it and the other Android Torque estimations and boost etc were very similar.

i was thinking of pressure limiting in the ECU.
and heavy blow-by will decrease engine performance significantly.
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aef
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« Reply #4 on: November 15, 2017, 05:33:42 AM »

logs?

AMK comes with egt sensor and will enrich on its own.

too much text  Roll Eyes
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IamwhoIam
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« Reply #5 on: November 15, 2017, 06:50:07 AM »





too much text  Roll Eyes

way too much
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I have no logs because I have a boost gauge (makes things easier)
TijnCU
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« Reply #6 on: November 15, 2017, 07:21:32 AM »

Lamfa has no axis with pedal. It is requested torque %.
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KasperH
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« Reply #7 on: November 15, 2017, 08:06:19 AM »

Lamfa has no axis with pedal. It is requested torque %.

Yeah sorry, it's requested torque Smiley
I made my pedal request 1:1 a long time ago,
so I forgot the extremely non linear request from pedal travel.
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stuartdean
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« Reply #8 on: November 15, 2017, 03:20:18 PM »

thanks - is it possible the fuel is maxed out, as the standard S3 injectors are only supposed to be good for 270BHP - therefore if I am adding extra fuel compared to other recommended lamfa profiles?

The car feels good.

I will sort out the logging issues.
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nyet
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« Reply #9 on: November 15, 2017, 05:05:22 PM »

There is zero point in guessing. Huge waste of time. Just log.
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