Audi RS2 timing or belt question

[twoqu]

Or it could be the altered perspective that appears to move the slot as one is at more of an angle!
We need to see a flat view from the rear so we can make a comparsion shot of the regular pulley. If someone has one for sale then perhaps you could ask for a pic. I think I have asked on here before without success.
Is it me or do the holes on the rotor seem to be in different positions. Unfortunately yours does not have a hole in the position that the other pics of the B pulley have but perhaps thats not a good indicator, unlike for example a big stamped B!
I'll check the few pulleys I have to see if they are all the same out of interest.

[minim]

Yes, my theory is that the relationship between the key position and the timing mark is the same on both pulleys but because they wanted to change the installed duration they timed it one tooth out and thats why the timing marks do not align. They may be other variables but I think one tooth is like 7 degrees so its not a precise guide.
To put the hall sensor aperature, the gap, back into the corect place they had to move it back, hence the RS2 B version. This because the Motronic uses this signal to determine the engine phase. The resident expert on here claims that its basically ignored after starting but there does seem to be some other function to it. My theory is that it is used to base some calculations on and therefore if its not in the correct position the calculations are incorrect.
I think there was an example recently on another members car where the position of the rotor effected the performance due to it not being in the position the ecu was expecting.
All this is purely academic really. As far as we know if it does not have the B stamped on the ring its not an RS2 one. All the rest of the components seem to be RS2.

This is why I think I might have a RS2 - ADU pulley since It has a different offset on the hall window than the picture sowed earlier in this thread was fitted on AAN/ABY. This without having the "B" marked in the plate tho. If I didn't compare those two pictures I would not be hesitating it but after looking at them it's clear that it's not the same position of the hall window.

Read on from this page (Post 1364)to see how the position of the hall sender rotor can have effects:

http://www.s2forum.com/forum/showthread.php?t=34052&page=91

So it need to be in a plausible position according to what the ecu expects. Oviously that is a heavily modified example but the principle is the same.

Agreed with you then on the function of the hall sensor else he would not get that problem during gear change. But that was caused by a slightly offset sensor due to a wear on the cambelt so it had slack and made the cam go off position during gear change. I have the problem during acceleration with WOT. I now regret that I didn't capture a movie while I had the car running and tested the problem as it's a bit hard to describe. Once I get the cable tomorrow I'll do a check on the hall sensor as the first thing I do with it but after comparing those pictures I have a feeling that there might not be any fault codes.

Wish someone had a picture of a ADU pulley so I could compare the gap I have on mine to that one..

[twoqu]

Read on from this page (Post 1364)to see how the position of the hall sender rotor can have effects:

http://www.s2forum.com/forum/showthread.php?t=34052&page=91

So it need to be in a plausible position according to what the ecu expects. Oviously that is a heavily modified example but the principle is the same.

[twoqu]

Yes, my theory is that the relationship between the key position and the timing mark is the same on both pulleys but because they wanted to change the installed duration they timed it one tooth out and thats why the timing marks do not align. They may be other variables but I think one tooth is like 7 degrees so its not a precise guide.
To put the hall sensor aperature, the gap, back into the corect place they had to move it back, hence the RS2 B version. This because the Motronic uses this signal to determine the engine phase. The resident expert on here claims that its basically ignored after starting but there does seem to be some other function to it. My theory is that it is used to base some calculations on and therefore if its not in the correct position the calculations are incorrect.
I think there was an example recently on another members car where the position of the rotor effected the performance due to it not being in the position the ecu was expecting.
All this is purely academic really. As far as we know if it does not have the B stamped on the ring its not an RS2 one. All the rest of the components seem to be RS2.

[twoqu]

Obviously if you want it to look stock than an original one is the only way to go. I was just suggesting a cost effective solution if it turns out what we suspect is the case. Of course if we knew the exact position that would solve your problem and answer something I have wondered about every since I found out the difference on the RS2 - Why did they do that!
At least you are getting your hands dirty which is more than most RS2 owners do!

[minim]

I still think that you are getting hung up on this 10 degree issue. If we accept the pulley key is in the same position then even with the incorrect pulley the camshafts are installed in the correct position for the RS2 when aligned one tooth out. The issue is the rotor position I think which is confusing the ecu. The inlet cam is the same as the ABY/AAN but its installed spec is different due to the one tooth out position. That what I understand. Otherwise the inlet would have been a completely different grind which could with a bit of thought been installed with a pulley which had a correct time mark. Audi or Porsche saved 0000 of Marks by using standard components and adapting then rather than tooling up for what would have been a very small production run. Again thats my theory!

We might be talking past each other due to language problems I think (my lousy english..) If I understand correctly the pulley with the key and mark in the outer ring is at the same place for ABY/AAN/ADU right? But the inner ring/disk is placed different. If you look at the video at 1:33 and pause it there I've drew some red lines where the hall window is at. Those 4 marks are for the edges on my pulleys end points and on the picture that was given here (AAN/ABY). There is a little bit of opacity in that still picture at 1:33 so you can spot the AAN/ABY pulley behind my pulley. I can't measure the offset but it's about 1/3 of the hall window's size to the left. The AAN/ABY pulley picture is the one in the front.

Since there is a offset on the hall window on the pulley that is installed in my car and the original AAN/ABY pulley I just get confused around the whole thing :X

http://www.youtube.com/watch?feature=player_detailpage&v=ntrjPm9nOO0&t=92

[minim]

Yeah I found one looking exactly like that one but as I don't know how to set the hall window I won't get it right anyways that's just why I said that I think it's better to spend the little extra in getting a OEM part rather then spending the extra money of having a professional setting the hall window. It would maybe be possible to set it if I had some good pictures of a ADU pulley but again it would be only "approx" set and not as accurate as a OEM one wouldn't it?

[twoqu]

I still think that you are getting hung up on this 10 degree issue. If we accept the pulley key is in the same position then even with the incorrect pulley the camshafts are installed in the correct position for the RS2 when aligned one tooth out. The issue is the rotor position I think which is confusing the ecu. The inlet cam is the same as the ABY/AAN but its installed spec is different due to the one tooth out position. That what I understand. Otherwise the inlet would have been a completely different grind which could with a bit of thought been installed with a pulley which had a correct time mark. Audi or Porsche saved 0000 of Marks by using standard components and adapting them rather than tooling up for what would have been a very small production run. Again thats my theory!

[twoqu]

This is not a recommendation just an illustration of a cheaper, arguably beter quality replacement than the OE. It states the hallsender rotor is adjustable.
I think you are probably spoilt for choice in your location for alternative parts.

http://npsheads.omaverkkokauppa.fi/Adjustable-cam-gear-with-hall-window-for-Audi-5cyl-20v

[minim]

It sure would be a lot easier to determine if my pulley is correct if I could get my hands on a picture from a RS2 pulley from behind to match those up and see if mine is correct. From what I saw when I compared the picture UrS4boy posted with the one I took of mine it looks like mine has a offset on the rotor. Sorry for the headache but this was the best way to show the difference I think

I did make such a thread on a Norwegian Audi forum so I hope I can manage to find a used one.

If my pulley indeed is 10 degrees off and making my engine not go as it should those $400 on a original new one is well spent in my opinion. The only thing putting me off atm is that by the looks of those photos my pulley isn't like the ones used on AAN/ABY. I do not want to go the route of an adjustable one as I think it's, for me, just saving some bucks and getting into a lot of trouble. I do not have enough knowledge to adjust one properly and I do want to keep my engine stock.

I am not so this is good information. I managed to find the reinforced version of the crank pulley from a parts dealer here in Norway so that one I will get. Is the reinforced version something my Audi dealer could sell also or is it just aftermarket dealers? Will be fun to see what the readout from vagcom says tomorrow.

[twoqu]

Indeed but the high cost also adds weight to the theory that somebody broke it, perhaps without the owners knowledge if they do not do their own maintenance, found out the cost of the correct replacement and bodged it up with a considerably cheaper and easy to source used AAN/ABY pulley. To be honest I have a used ABY pulley that looks in better condition than that one!
Apart from hurting my eyes and giving me a headache it does appear from your video that as suspected the rotor is repositioned but the pulleys are the same. We could really do with a static pic of the RS2 pulley from behind.
Its a long shot but perhaps you put a wanted advert up for an RS2 pulley. Somebody might have one. Alternatively a cost effective measure may be to use an aftermarket adjustable cam pulley with the provision to adjust the rotor position. It will be a bit of trial and error though but should be mucher cheaper than the OE RS2 replacement!
If you are not familar with the Audi I5 the key in the cam pulley is a known weakpoint as well as the crank belt pulley due to the keys breaking. Thats why at the very least its recommended to replace the crank pulley at every cambelt change. Both were a poor material choice and design really and do a lot of damage when either fail.

[minim]

Now I have removed my cam sprocket and tried to take some pictures of it. It's hard to get the exact angle to compare but I made a short video of the first attempt here. It does look like I have a offset on the housing but the key and the mark on the wheel looks like it's at the same spot. Will work on a better picture for it.

Edit: Sorry for not asking to use your picture first UrS4boy, I just came to think of it now. Please let me know if you want me to remove the movie from youtube again.

Not sure if I can get the youtube window to work but here is the link also. http://youtu.be/ntrjPm9nOO0

[minim]

I'll go out and remove my sprocket from the cam so I can try to take a picture from the same angle. It should then be possible to see if the opening is 10 degrees off or if it's at the same place as the one in picture.

[UrS4boy]

Here are a couple of photos that might or might not help.

The first is of an RS2 ADU showing the way the cams line up and also how even the "B" can be seen from the back side of the G40 Hall sender shutter wheel.



The second is a photo of a G40 Hall sender shutter wheel showing the general arrangement of the shutter opening in the wheel (I think this is from an AAN (or ABY). Looks like the shutter opening is centered directly across from the "key" for the camshaft keyway. Presumably, the ADU opening would be the same size but shifted 10 degrees) (a photo of an ADU shutter wheel would be helpful - but I don't have one).

[minim]

Ok. It does sound like a good theory. Will check for fault codes from the the sensor once I get vagcom.

I called my local Audi dealer today to check if the sprocket was available and it still is if ordered from Germany. The only bad thing is that they want $400 for one. That's a a lot for just testing if my sprocket is not the correct one. Won't order this until I've checked with vagcom atleast.