RS2- Just had a dyno run...power down (any thoughts?)

[weta.worker]

What does it say on the name plate on turbo??

hmmm, where does this live?

Looking at the schematic I think it says it's between the cold side and the front of the car.

But looking at physical pics it seems its on the other side?

Or am I totally reading it wrong?

And you need an endoscope to get to it...?



I thought it maybe this (pic) , right of the bolt) - cold side, facing the rear of the car, but it's blank \ no sign of plate?

[weta.worker]

also, this pic shows the plate



and this is what I see (noting the 98, 97 , then plate of above)

[RS2fan]

looks like the turbo has been changed to one of them imported outside Audi parts.

http://forums.quattroworld.com/s4s6/msgs/211339.phtml

[europeanme]

Not necessarily, the pipe from the i/c split on my UrS4 once, you could hear the leak whilst driving the car, yet over-boost protection didnt kick in.

fair point.....I've only ever had major boost leaks that re-arrange my mug!...

personally I'd fit a boost gauge as this tells you whats really going on....

and like the comment about the RS4 being the "reliable" car...oh to have such great choices!!

[europeanme]

they look like date numbers from the casting tool......normally year of manufacture... seems odd that there is 2....



I hope you get your avant sorted...

[weta.worker]

looks like the turbo has been changed to one of them imported outside Audi parts.

http://forums.quattroworld.com/s4s6/msgs/211339.phtml

I'm still not certain I'm looking in the right place.

this pic shows the tag well past the nuts and pipes. and where the hot side bolts onto the engine and cold side pipe pointing down means the tag is on the engine side of the scroll?



and this pic shows the fixings \ pipes away from tag and the main nut almost out of shot (top left) - suggesting the same thing , the tag is on the engine side.



My pic shows the blank on the opposite side (next to main nut)



the only thing that lead me to think that the tag was missing is the numbers 98, 97, then tag.

but I'm looking on the top of the turbo and slightly away from the engine. so on the opposite side (I can't get a camera down the other side)

Maybe those numbers are duplicated further around?

put my finger down where I thought it would be (according to pics) and haven't managed to find anything.

will keep trying.

[weta.worker]

they look like date numbers from the casting tool......normally year of manufacture... seems odd that there is 2....



I hope you get your avant sorted...

the pic with the plate shows 2 as well?



yeah, I hope it gets sorted as well!

it's a difficult situation deciding on what info to pass onto the mechanics and also how not to annoy \ offend them!

its my 2nd set of mechanics and these guys have a really good rep (my first , audi, had an awful one...)

it's slim pickings in NZ let alone Wellington.

I'll try and do as much as I can so hopefully can pass on good info.

[weta.worker]

f...
and like the comment about the RS4 being the "reliable" car...oh to have such great choices!!

hahahaha, yeah, I was kinda joking.

it's all relative! i've just jinx'd it of course....now the rs4 will be the one to throw it's toys and be stuck on the side of the road!

[weta.worker]

ok, using a mirror (and whole lot of swear words) I've taken a look around and can't find much more.

I'm pretty sure that blank space is where it should be, I can even see the hole where it should fix to.

not sure why it's on the other side (away from engine)

couldn't get the camera on the right angle to show the fixing point.



so i'm not sure if this turbo has been replaced or what it actually is. this car has so many weird things going on that aren't RS2 standard being the pre production etc so at this point its a mystery.

the mechanics had a few theories on power down (as they said it was boosting to 20 - 21)

- the turbo may need to be reconditioned
> not pushing the correct amount of volume
> not holding boost for long enough

not sure if their above theories will change now they have the dyno results.

from the info here

will get them to do a thorough boost leak test as the majority of people think (focusing on the known problem areas)
will get them to check vag for altitude

if they perform the above and still no good, they may still think the turbo check is a good idea and if so we'll at least know what it is (once it's out) .

hopefully they'll find a leak, fix and it'll pull fine and we won't have to play the turbo out game.

[twoqu]

I am not sure whether its definitive ID or not but all the genuine RS2 compressor backplates I have all have similar p/n in the same 7 segments up to the mounting for the ID plate. Its difficult to picture but here is a couple installed on a turbo:
(Ignore the oil cooled only centre section!)

[twoqu]

And some more of one unmounted! Its the same on an original RS2 turbo. There are no date clocks relating to the approximate year of manufacture.
The compressor housing/wheel/backplate are I believe unique to the RS2. However there was a batch of new ones made so it could be one of those. Might be better to take a pic of the front as the compressor housing on the RS2 is quite distinctive.

[twoqu]

Your turbo appears to have the same date clocks in the same place as that batch mentioned previously. It seems common practice for Turbo reconditioners to remove the ID plate for some reason hence it being missing in the pics I have posted!
So perhaps it was one of the batch and was then reconditioned for some reason.
I would follow the advice given previously before looking at the turbo as the cause. Having said that, The RS2 turbo has unique and expensive components. If it had any turbine shaft/housing damage its possible that other components might have been used which could only be verified by examination and measurement. Its possible to mate larger turbine components to RS2 compressor parts.

[weta.worker]

ah, just found results of the boost leak test that was performed.

"Smoke tested intake system, found several small leaks. Main one is from PCV valve under intake manifold area. With this blocked up system only leaks around 0.04psi, which is just on tolerance for the age of the car"

[newsh]

It would be interesting to know what they pumped it up to and how long it took to drop by 0.4PSI (if that is what they mean).

[weta.worker]

This is what I've sent to them (A bit of a cludge of various replies etc)

Hi **, hope you had a great weekend. Sorry for the barrage of emails.

Here are some replies from the RS2 forum after I posted the dyno results.

- "Looking at his dyno graphs,above 13 psi it is running way too rich,most probably an air leak. It should be slightly rich,say 12 AFR,but it goes down to 5 at one point! He could Check the crossmember to intercooler joint. They have a little rubber washer that seals that join which can sometimes fail."

- " A lot of people also add a rubber hose over the top to help seal it. It's called the Mark H mod. Have a search on the S2 Forum for Mark H mod (it was never factory). Also Roose Motorsport makes one, but something could be trimmed to suit in NZ. That is if it's the issue."

- "All you need is a simple plug for the MAF-> Turbo hose, disconnect the breather, put 1 bar in and make sure it does not drop to zero for 30 seconds."

- "As above, you need to get a correct boost leak test done, using the inlet and breather system bung and about 2 Bar of pressure. Anything less than 1 Bar isn't worth the effort to get it all air-tight"

- "After boost leak test check N75 is connected the right way around.”

- "If no leaks are found I'd check for any damage to the catalytic honeycomb. Exhaust restrictions can cause similar symptoms.”

- "VAG Com codes?

What does VAG Com say that the altitude is? This can be an issue, if the altitude sensor has gone T/U. (this is located in the passenger side foot well on RHD cars).

RS2 stock map runs to about 1.5 Bar, so your boost pressure down.”

And attached is the stock RS2 map.

<rs2-stockmap.png>

Hopefully we can take a look at all of this when the shocks arrive and it comes back in for that work.

Thanks for your time