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Author Topic: EA888 cam timing figures  (Read 2814 times)
quattro85
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« on: August 15, 2022, 04:55:16 AM »

Hi everyone,
I was searching a lot to find some information about cam timing of different variation of those engine - unfortunately without success.
Can you share some figures if you find it somewhere?

Until now I know, there is slight difference in exahust cam profile for 2nd generation 1.8tfsi and 2.0tfsi (without AVS) engines. Intake camshaft looks to be the same (still there is different part number also for intake cam).

The only confirmed information I found was regarding exhaust cam in 2.0TFSI with AVS (SSP 922903 page 12).
Small lobe have lift of 6.35mm, duration of 180°, exhaust valve open 2° ABDC, and closes 2° ATDC;
Big lobe have lift of 10mm, duration of 215°, exhaust valve open 43° BBDC, and closes 8° BTDC.

For gen3.b (AVS also for intake) engines I found quite insufficient info (SSP 645 page 24-25).
Small intake lobe have duration of 140°, while big one have 170°.
MAYBE large lobe (or maybe gen3) close intake valve 20 degrees BBDC, so intake should open 10 degrees BTDC (if it is really for big lobe of gen3.b engine).
Small lobe closes intake valves 70 degrees BBDC, so intake should be opened 30 degrees BTDC

I think all Audi stated numbers are at 1mm valve lift.

According dbilas site for road application they offer cams with valve lift 11.4/10mm and duration 256°/248° (I think this is total duration at 0.1mm valve lift) - those offering is for gen2 engine, so It should be slightly more lift/duration compared to stock cams. I think dbilas exhaust profile is very close to big lobe profile of 2.0TFSI with AVS but with different centerline.

Unfortunately I didn't find any info for gen2 without AVS cam profiles, neither for intake cam of every EA888 before gen3.b

Can you help to gather some info here, so everyone can see it on one place.


Update:
I found some information about EA113 2.0T:
Intake camshaft have duration of 190° and lift 10.7mm. Intake valves open (1mm lift) @28° ATDC in fully retarded position of the camshaft, so they close at 38° ABDC. EA113 VVT have 42° range;
Exhaust cam have duration of 200° and lift 10mm. Exhaust valves open (1mm lift) @28° BBDC and close 8° BTDC

As a matter of fact this is exactly as 1.8T cam durations. I was wondering if EA888 figures could be pretty close to those too.

Another thing that bothers me much - why in 1.8TFSI files max retard position is 38°, and in 2.0TFSI files it is 28°. It seems that 1.8 and 2.0 cams should have 10° difference in centerlines, but to me they both looks exactly the same - no difference in lobes, neither in a position of VVT.
« Last Edit: August 17, 2022, 02:18:38 AM by quattro85 » Logged
quattro85
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« Reply #1 on: October 27, 2022, 08:10:19 AM »

So I found some interesting info on page 1439 and 1440 of EA888 ULEV MED17.5 FR that is wildly available on the internet.
Looking at it I was trying to pull those numbers from few fully defined MED17.5 files I found for 2.0TFSI and finding the same constants in my 8P A3 convertible 1.8TFSI file.

This puts some light, still some figures confuse me a little bit - how it is possible to have 0° offset between 0.5mm & 1mm valve lift timing (DWGVOE for 2.0TFSI & DWGVSA for both).

Now I'm trying to figure it out how AVS is controlled but of course I can't find any info in MED17.5 FR.

Any help in this? Something you can share for reading before bed time?  Grin
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quattro85
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« Reply #2 on: November 12, 2022, 01:44:32 AM »

It turns out it is not easy to find med17.1 FR for 2.0tfsi engine.

It will be great if someone could point me in the right direction - Am I right to think AVS control of exhaust cam is related to swirl flaps? Is it hidden in LBKSOL?
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quattro85
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« Reply #3 on: November 14, 2022, 01:14:58 AM »

Ok it seems AVS control is in BGBKVS.
However what I see there, doesn't match what I see looking at measuring values in VCDS.

If I get it correctly (without FR) - there is MILSVSMX and MILSVSMN, which looks like hysteresis for switching between small and large cam lobes.

looking at VCDS it seems that it is idling on large lobes (I don't know why), slightly over idle it switches to small ones and above 3000rpm it goes again to large lobes.

Looking at values in those two lines, I can't explain what I'm seeing in Measuring Values.
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prj
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« Reply #4 on: November 14, 2022, 10:25:25 AM »

If you want to get anywhere start logging with a real tool and not VCDS.
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quattro85
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« Reply #5 on: November 15, 2022, 01:03:55 AM »

Completely agree on this point with logging - not the great with VCDS, however on UDS at least sampling rate is not so bad.
On the other hand - I miss a lot of useful variables - so it is not great.
On TP2.0 it helps a lot to make own measuring blocks, in order to get the best you could from VCDS logs.

However I'm not doing this things for living, neither I do it for any money - just spending money on such toys (wife not happy so far Smiley).

I'm just a petrol head, I like cars, changing cars frequently, and tune mainly my cars most of the time on the road, not on some exact location with dyno. So OTR I can get only mobile data.

It is quite hard for me to justify 600€/year +adding new protocols, when changing the car.
Right now I own 4 Audis - EDC16, MED17.5, MED17.1, SIMOS18. VCDS is the only one solution I was able to find that could be used on all of my cars during years so far.

I already get somewhere with the cars I'm modifying for my self, however I'd like to get deeper in such things like cam timing now, so I can examine if something could be gained there both powerwise and like efficiency.

Don't get me wrong - I know the right way is to utilize some good data acquisition solution - that's why I refuse to friends of mine with BMWs/MBs to mess with their cars also.
Right now I'm thinking maybe I should find some FR first, so I can get the actual flow of BGBKVS, because what I see in bin, doesn't match what I see in logs that I can get.
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prj
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« Reply #6 on: November 15, 2022, 04:06:03 AM »

What I see in the map matches exactly what you are explaining. But you did not post any logs.

Use my tool: https://www.vehical.net/
Subscription only has to be active when you are licensing the VIN.
So for one car a "forever" license costs 100 EUR. If you buy for multiple cars at once in 30 day period, then each additional license will only cost you 50.
You could solve logging for 3 of your cars forever for 200 EUR.

If you have 4 cars you sure as hell can afford to spend 200 EUR.
« Last Edit: November 15, 2022, 04:07:36 AM by prj » Logged

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quattro85
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« Reply #7 on: November 16, 2022, 01:25:00 PM »

Quote
What I see in the map matches exactly what you are explaining. But you did not post any logs.
Well noted just made some log with two WOT runs and some casual driving inside.
I colored AVS switchover rows and put some comments in Column A&K.

Really I can't get why this thing is running on large lobes on idle, and why it switches at these points.
If I'm right that MILSVSMX and MILSVSMN are some hysteresis lines I'm expecting when milsol goes above MILSVSMX then ECU to switch to large lobes, and when milsol drops bellow MILSVSMN to switchback to small lobs. However I can't see this in this log.
Even made a chart, to get those two lines more visual - still can't get what happened.
Reading trough SSP doesn't help either.

Quote from: SSP 922903
When the engine is started, the larger contour lobes are
in position. Immediately after engine start, the system
changes over to the smaller contour lobes.

When the engine stops, the AVS switches back to the
large contour cam.

Quote
Use my tool: https://www.vehical.net/
Subscription only has to be active when you are licensing the VIN.
So for one car a "forever" license costs 100 EUR. If you buy for multiple cars at once in 30 day period, then each additional license will only cost you 50.
You could solve logging for 3 of your cars forever for 200 EUR.
This was game changing explanation - it makes the whole thing easier to digest - one time 100 sounds way better than 600/year Smiley
I'm thinking to borrow dyno of a good friend for a day at the end of the year, so maybe it will be nice to have better tool then.

Quote
If you have 4 cars you sure as hell can afford to spend 200 EUR.
4 are Audis  Roll Eyes
Still no Porsche in the stable - so still fasting for it  Grin

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biela
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« Reply #8 on: November 17, 2022, 01:51:29 AM »

May be larger lift lobes at idle generates lower pumping losses and then less fuel consumption?
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quattro85
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« Reply #9 on: November 18, 2022, 04:41:45 AM »

Possible, but my understanding is just for the opposite.
I mean that on idle and low load you have relatively small amount of residuals that needs to be expelled. Biggest cause for pumping losses at idle is due to small opening of throttle body, not for restrictive opening on piston upward travel.
In my opinion if Audi will to improve pumping losses on idle and low load they should use small lobes and very advanced intake cam. Possibly in this configuration you will get very rough idle.

Even if we count large lobes on idle just for improving smoothness, and not efficiency (because of relatively small amount of time engine runs at idle).
WTF makes switching to small lobes @1068rpm and 18% normed load (first switchover in log file), while MILSVSMN looks to be prohibitive in this range, because milsol is not possible to be lower than zero.
Why it goes on large lobes again @3240rpm and 62.4% normed load (second switchover in log), when much earlier @1800rpm there is already load above MILSVSMX.
It seems MILSVSMN & MILSVSMX are not exactly hysteresis lines, or I read them wrong.
 
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cherry
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« Reply #10 on: November 18, 2022, 04:51:51 AM »

I think you are on big lobe at idle to avoid never beeing switched for "low rev" driver. Same with intake manifolds. They just avoid to get it jammed if not really in usage. I played with rpm switching point in CESA engine and thought earlier switching does make sense, but i only got boost lag...  Grin
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quattro85
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« Reply #11 on: November 18, 2022, 05:20:53 AM »

Yeah sound reasonable for idle switchover strategy. However SSP claims that every start is on large lobes and immediately after start it is switched over to smaller ones.

You mean that you played with switchover point of AVS or manifold flaps (LBK)?
If it is AVS - could you explain little bit how it works or share some information about BGBKVS module.

Opening of LBK sooner really doesn't make positive results at least with stock turbo.
On my older convertible (A3 8P) I used this strategy of opening manifold flaps sooner only for eliminating surge of badly matched CESA hybrid turbo - doesn't gained anything in terms of power.
It seems CESA turbo is perfectly matched unit in terms of compressor/turbine/engine.
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cherry
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« Reply #12 on: November 18, 2022, 08:51:07 PM »

In my CESA file it´s only done by rpm, not by load. Anyway i set it earlier once for test by just changing axis. I also think it´s maybe not all in any Bosch FR, because it´s "vag own code" and not from bosch. There are additional docs, i think the biturbo stuff from EDC17 is the same. I dont know because i dont have it.

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quattro85
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« Reply #13 on: November 21, 2022, 02:48:17 AM »

I think I get it.
Still not sure about it, but maybe two lines are little bit misleadingly named in the map pack.

After many hours looking at values and chart here, and comparison with values in logs, I think small lobes are active only inside hysteresis formed between two lines (MILSVSMN & MILSVSMX).
Outside this area (above MILSVSMX and below MILSVSMN) it is working on large lobes.

It is not! Unfortunately it seems LARGE lobe position is "natural" one.

So it is really hysteresis curve, but only for activating small lobes. Once milsol is above MILSVSMX ECU switches to small lobes. If milsol drops below MILSVSMN it switches exhaust cam to LARGE lobes.
Not very handy if you like to take some benefit tuning those lines.
Fortunately S-tronic will bring engine speed above 3000rpm every time you floor it, so not a big disadvantage in cars with automatic transmission in real world.

This is the best fit explanation I could find for figures in log file.

Still CESA stock values confuses me quite much Smiley
« Last Edit: December 05, 2022, 01:59:34 PM by quattro85 » Logged
quattro85
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« Reply #14 on: March 03, 2024, 03:24:19 AM »

And here some numbers on CAT CAMS tuning upgrade.
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