[Eigdoog]

 

Off the chart by the looks of things? Still not sure what it means when it comes from 15 to 11.75? 

[Shaunee]

Targets will depend upon type of fuel. Like pump fuel, race fuel, methanol etc etc.

8 to 9's AFR at peak is very rich. I wonder if you're confusing AFRs with lambda, which uses a different scale.

Stock modern cars appear to run lean compared to older generation cars. Emissions will play a big part in that. I understand that direct injection also helps the ability for this to take place more safely.

[Shaunee]

Eigdoog,
Looks fine.

The numbers effectively show how much fuel you have vs air in the exhaust gases. This is very important in relation to fuelling. Not enough fuel and you could be running lean, causing higher Combustion temps and prone to pre ignition. Too much fuel and you'll be hampering power and possibly causing bore wash.

Sort of the more extreme ends of each end.

There's more to it than this though.

Edited by Shaunee, 28 August 2016 - 09:28 PM.

[Chungster]

Lean at top end makes power - but run the risk of det hence standard ECU runs rich at top end to cool things down. A good tuner will know the right level of compromise - good power without running the risk of blowing the engine up through running too lean at top end. Some cowboys will give you the power you want without considering the negative side of it. Generally you'd expect the AFR line to be stable and heading down wards as revs increase. You don't want any sudden peaks and drops that's for sure.


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[monopole]

Cheers for the feedback Shaunee, I have this other plot, but unsure what it is telling me;

Let me try and put what you're saying Shaunee into my plot,. The black line (stock) is running leaner longer than the red line (MTM) which means the MTM being richer in the lower range will feel stronger during acceleration but as the speed increases the ECU is cutting the timings or ignition giving a lower final result on the dyno?

[Shaunee]

Monopole,

Don't worry about the AFR's as part of my initial comment about ignition. They weren't related as I hadn't seen your AFR graph at that point.  However, we can talk about it now if you want......

 

Either there is an anomaly in that stock afr plot, or it's simply that the ECU was still learning at that point. 

 

Your previous run was with the tuning box, so the ECU thought that more fuel was needed (between 4-5k) as I suspect during this area is where boost has been increased.  More boost (air) will require more fuel to achieve the same AFR the ecu is looking for at that point.  If you look at Eigdoog, you'll see your MTM afr plot is virtually the same as his stock plot.  As expected.

 

Of course, if you then move to a setting (stock) where that boost has been removed, the afr will be rich at that point which it is on the stock run, as you'll have less air (boost) but the same amount of fuel going in.  The ECU will quickly adapt though on the next load cycle.

 

The reason, I would suggest, why your MTM figures were less than expected is due to either ignition or boost being cut by the ECU.  Logging the values I gave you before should help to deduce / confirm this.

 

Hope this helps.

[Arcam]

Monopole,
Don't worry about the AFR's as part of my initial comment about ignition. They weren't related as I hadn't seen your AFR graph at that point. However, we can talk about it now if you want......

Either there is an anomaly in that stock afr plot, or it's simply that the ECU was still learning at that point.

Your previous run was with the tuning box, so the ECU thought that more fuel was needed (between 4-5k) as I suspect during this area is where boost has been increased. More boost (air) will require more fuel to achieve the same AFR the ecu is looking for at that point. If you look at Eigdoog, you'll see your MTM afr plot is virtually the same as his stock plot. As expected.

Of course, if you then move to a setting (stock) where that boost has been removed, the afr will be rich at that point which it is on the stock run, as you'll have less air (boost) but the same amount of fuel going in. The ECU will quickly adapt though on the next load cycle.

The reason, I would suggest, why your MTM figures were less than expected is due to either ignition or boost being cut by the ECU. Logging the values I gave you before should help to deduce / confirm this.

Hope this helps.

Would logging the figures the ecu thinks it is seeing tell the story as the tuning boxes hide those figures from the ecu with a good dose of smoke and mirrors?

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[Shaunee]

Depends how you want to go about finding out the delta.

 

I'll need to confirm all of this when I do my logging, but you can log a stock run and compare that against the modded run (using an appropriate boost measuring block that see's the actual "real" boost achieved), or you could log the boost via a normal OBD boost PID on the same (modded) run. 

 

The normal boost PID (measuring block) should be what the ECU thinks it's seeing (which won't include manipulation by the tuning box), i.e. as per its stock (oem) boost targets.

 

One way the manipulation can work is that the box takes the figure seen by the boost sensor and effectively reduces it by an amount based on a table the box will hold.  Say the tuning box wants to run +2psi of boost (over stock) at 5k rpm.  When revs reach 5k the box will read the sensor, make sure it matches what is it expecting and then reduce this reading by 2psi (box target increase) and pass that back to the ECU. 

 

The ECU thinks "hold on, I need to produce an extra 2psi here.... I'll increase wastegate duty (keep the wastegate closed for longer, hence keep building boost) to get that extra 2psi".  This creates more boost and then the sensor reads that extra 2psi, which is now +2psi more than stock map.  The tuning box then sees the sensor is now matching the increased boost it was looking for, and say's "right, I don't need to make any additional manipulations" and continues to send the revised boost reading back the ECU (which will be actual boost -2psi).  The ECU still see's the manipulated figure which now matches it's own targets.  The ECU now says "OK... I'm now seeing we're making the boost I wanted to... I'll maintain this now as per normal".

 

That's a lot of words but it could look like this in steps:

 

At 5k

Sensor see's 18psi which is the correct boost for stock (for example)

Box see's 18psi

Box outputs to ECU 16psi (as it wants to ensure boost is increased by 2psi)

 

ECU expects 18psi

ECU sees 16psi

ECU increases boost by +2psi

 

Sensor now sees 20psi (more boost - more power than oem)

Box sees 20psi so now reaching its own boost target, so does no further additional manipulation

Box outputs to ECU 18psi

 

ECU expects 18psi

ECU sees 18psi (it is in fact 20psi in reality)

ECU does no further adjustment, as it thinks its achieving exactly what it targeted.

 

All the above is a very simplistic way of breaking this manipulation method down, but gives the overall idea of the concept.

[jimojameso]

Great to meet you all on Saturday! Really pleased with what my car made! Be interesting on what qst say about the mtm box

[monopole]

some pics

 

 

 

 

 

 

 

[0120raptor]

Monopole,

I've had a quick look at VCDS logging options but not actually gone out and logged any data, so I'm just using my best / logical assumptions that these data elements will provide relevant information.

 

Anyway.... Tick the following in the Advanced Measuring Values under Engine:

 

Engine speed - Log RPM

 

Charge air pressure: actual value - Not sure which sensor this is using, as this maybe the sensor that's manipulated with your tuning box (if it is, you won't see the real boost pressure the car is running with the tuning box, just what the ECU thinks it's running). I'm sure I saw a sensor reading for pressure at the turbo and manifold, so you could look at those two as well.

 

Intake air temperature - Log charge air temp post intercooler.

 

Outside air temperature - Not really needed but gives reference for delta between ambient and charge temp, post intercooler.

 

Current of oxygen sensor bank 1 sensor 1 - I'm assuming this will give you your lambda (fuelling) readings.

 

Ignition timing adjustment cylinder 1 - I'm assuming this will give you your overall ignition value attained.

 

Timing angle retardation cylinder 1 (2, 3, 4, & 5) - Should show how much ignition retard is being applied by cylinder.

 

Hopefully that will be enough to see what's going on.

 

You can do all of this on the road yourself.... no need for the dyno.

 

Just do a full gear pull, say in 3rd (or 4th if you feel like it), from low revs to the redline.  Do a couple stock and a couple with the tuning box on.  Same stretch of road and day would be good.

Shaunee

My 8V  is is on the rollers Sunday.If I log these readings would it be of any use .Or does it have to be logged on the actual road.?

[Shaunee]

Can be logged on either tbh.

 

Whether it's of any use will depend whether you need to find anything out specifically.

[Rs3443]

awesome thread guys

[monopole]

soooooo.. a little update on the status of my car/MTM and the SRR dyno results for those that have genuine interest;

 

I was at QST today, since 0930, to have Kim look into why my car produced the odd results at SRR i.e higher stock than tuned... as we know different dyno's, different days, different conditions/temps etc aside, there were some coincidental results found today between what Kim and Charlie's report from their dyno's produced. So we don't think I'm making this all up, this was also done on another RS3(stock) also at QST with me this morning:

 

(not my car) SRR stock > QST stock with a difference of ~16HP (acceptable across conditions as stated above?) (should the owner want to concur, I'll let him decide...)

 

(my car) SRR tuned = 391 > QST tuned = 375. Again ~16HP difference.

(my car) SRR stock = 404 > QST stock = xxx. HP difference which left me baffled (and no, don't try the ~16HP delta as a guide LOL)

 

what I am not prepared to divulge at this time is what my stock figure produced. Suffice to say, the car is now booked into Audi this Friday to be checked for fuelling and/or timing issues and Software update (currently at v3, to v5) as Kim identified on both his graph and the SRR graph, the car is cutting the power at around the same RPM for some reason.

 

What we did see, (same as SRR) was the MTM box providing an increase across the lower range, ergo why I can tell the difference when it is fitted (just NOT what MTM advertise!) and it deffo feels stronger with it on. Problem being, as my car seems to be messing with the fuelling/power @ approx 5500 rpm in both conditions, there could be the fuelling pressure or sensor or whatever that fault others have experienced on their cars, reigning in my output in the higher range... possibly?

 

Next step, Audi Friday to see what they find (if anything), and of course, SP on the 17th with Wayne and Shaun and from there.... ?

 

 

side note, if Audi do update my ECU software from v3 to v5 (and why shouldn't they?), the current MTM box does not support this version, but Kim will order in an updated box for when I go in after the Audi visit.

 

 

 

... to be continued ...

[Roy]

Why are you not going to divulge,,, we ARE genuinely interested 

[Eigdoog]

Nice little write up!

 

Yeah there seems to be something up here? Could you post the new graph up too?

 

Would be nice to know what the standard figures came back as, I've got a feeling though your going to tell us it came back with more power than the MTM box (maybe close to SSR figures?) This is just a guess mind you. 

 

Will you be telling Audi about the box at all? 

 

Do i remember you telling me Kim has an RS3 running the box? What did he have before and after?

 

Still going to Santa pod and looking forward to what we see here and just to have a good day out. 

[Shaunee]

Hi Monopole,

It's very dangerous to compare readings from different types of dyno..... what dyno is at QST and does it measure losses or are these applied as a fixed percentage?

 

The shape of the curve on SRR is as I would personally expect for your stock run.  The stock RS3 tends to drop off power from around 6k.  This is also seen on the other graphs posted on this thread.

 

Did QST log the car to see if it was indeed pulling (retarding) ignition?

[Uncle Fester]

soooooo.. a little update on the status of my car/MTM and the SRR dyno results for those that have genuine interest;

I was at QST today, since 0930, to have Kim look into why my car produced the odd results at SRR i.e higher stock than tuned... as we know different dyno's, different days, different conditions/temps etc aside, there were some coincidental results found today between what Kim and Charlie's report from their dyno's produced. So we don't think I'm making this all up, this was also done on another RS3(stock) also at QST with me this morning:

(not my car) SRR stock > QST stock with a difference of ~16HP (acceptable across conditions as stated above?) (should the owner want to concur, I'll let him decide...)

(my car) SRR tuned = 391 > QST tuned = 375. Again ~16HP difference.
(my car) SRR stock = 404 > QST stock = xxx. HP difference which left me baffled (and no, don't try the ~16HP delta as a guide LOL)

what I am not prepared to divulge at this time is what my stock figure produced. Suffice to say, the car is now booked into Audi this Friday to be checked for fuelling and/or timing issues and Software update (currently at v3, to v5) as Kim identified on both his graph and the SRR graph, the car is cutting the power at around the same RPM for some reason.

What we did see, (same as SRR) was the MTM box providing an increase across the lower range, ergo why I can tell the difference when it is fitted (just NOT what MTM advertise!) and it deffo feels stronger with it on. Problem being, as my car seems to be messing with the fuelling/power @ approx 5500 rpm in both conditions, there could be the fuelling pressure or sensor or whatever that fault others have experienced on their cars, reigning in my output in the higher range... possibly?

Next step, Audi Friday to see what they find (if anything), and of course, SP on the 17th with Wayne and Shaun and from there.... ?


side note, if Audi do update my ECU software from v3 to v5 (and why shouldn't they?), the current MTM box does not support this version, but Kim will order in an updated box for when I go in after the Audi visit.



... to be continued ...

You should post all the facts not just bits you want to post there is clearly something wrong .


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[monopole]

Agreed uncle, but in this case we don't have all the facts, so until I do, then all I will post is what everyone like to do best, speculate with the information I do have. What I do have is not being published here (yet) because I know how quickly people like to drag things down hill without root cause analysis being completed.

[Fivepotfan]

Why are you not going to divulge,,, we ARE genuinely interested 

 

Mine was the 'standard car' for comparison on the day - it made 381bhp on the first run and I think a tad more on a second run. 12 -15 bhp difference from the session at SRR the previous week. Still a good result and way over the standard 362bhp quoted by Audi.

 

However, Monopole's car appeared to have some possible fueling problems or maybe something else the ECU didn't like (to be confirmed through diagnostics) and generated some inconsistent results over a number of runs WITHOUT the MTM box connected. It did make additional power with the box hooked up, but not at the levels it should have done due to the car not running right from stock.

 

My thanks to Kim Collins for allowing us to bring my car along and do some power runs as comparison against Monopole's

 

Unfortunately Kim had recently sold the QS Tuning RS3 and so we didn't have it available as a comparison either.

Edited by Fivepotfan, 05 September 2016 - 07:04 PM.