after RS2+ upgrade, Fault Code 00519 and Boost fluctuating / going limp mode.

[UrS4boy]

Here you can see how the boost shifts around all over the place...

http://www.youtube.com/watch?v=L86ETOHoS_M

http://www.youtube.com/watch?v=2oVrJvFfEDE

That looks a bit like when I first ran a 1.9 Bar Wastegate spring on my RS2'd AAN. I left the spring perch at the same position that I had been running it at with the stock spring. With the 1.9 Bar spring, that was way too much pressure. I would get a nasty boost cut/boost return/boost return/boost cut....cycling/fluctuating as the ECU tried to figure out WTF was going on.

Solution was to turn the spring perch up significantly until the cut/return/cut cycle disappeared.

For comparison, the 1.9 bar spring is shorter and stiffer and it on the left. The stock spring is taller and more slender and is on the right.

[prj]

I know for a fact that the chipset he has is for stock spring and 0.4 bar pressure.

And I also know that one should not screw with the screw Unless of course mapping specifically for it.

[RustyNut]

Slight hi-jack here but may I ask a question which is relevant. I've just had a full RS2 conversion done on my car, changed everything to rs2 spec but have not touched the wastegate spring. I'll only be running a stock RS2 chip set until I'm happy everything is running ok (thanks Andy!) and will then either get an upgraded chipset or will get it re-mapped (if PRJ makes it over here soon!). Am I ok leaving the stock spring in or do I need to change it? As it goes we can't get the car to start at the moment and suspect its the CPS which has had to be changed.

[prj]

You do not need to touch the stock spring at all, just make sure it's set for 0.4 bar (which it is standard) and everything will be fine

[RustyNut]

Thanks PRJ, i'll leave well alone. Hope we can find the cause of the non start, it's taken too long to get to this point and I'll be gutted if I miss Coombe.

[UrS4boy]

You do not need to touch the stock spring at all, just make sure it's set for 0.4 bar (which it is standard) and everything will be fine

Lots of UrS folks on this side of the pond have turned their stock wastegate spring perch down by up to 6 turns without *ANY* negative effects, just sharper initial tip-in boost rise rate. Does not affect max WOT boost whatsoever. This is on stock ECUs, Stage 1 (250 kPa MAP) and Stage 1+ (300 kPa) software.

Your experience may be different.

[prj]

Yes, my experience is very different, because I got 20hz datalogging from the boost chip vs butt dyno

[Foeglass]

Prj:

Thanks for your reply,

Ok lack of information from my side and i can see what you find contradicting, i hope the picture is more clear now?
Yes the car ran good and perfect before i installed the final stage the Injectors and the ECU.

Well i had bend rods on a car before, and you could clearly notice a difference in both sound and how the engine turned over / run.
Thats why i suspect the Rods are probably ok because the car still starts up and runs nice and smooth as it allways did.

But i will take your advice and test the compression of the engine first and check the depth of all pistons before going on any further.
You got more experience with these engines than i do.

The wastegate on my car was allready tampered with before i got it. and if you say that with 0,6 bar the screw has to be way down than i suspect i got a stiffer spring as mine is only 4 / 5 mm's down, the inside of the cap looks original no spacer rings or anything that suggests that there has been tampered with, (but again i havent had other wastegates apart from an 5pot Audi.)

But i get your point. ill get the top of the wastegate of this weekend and mesure up the spring and take a picture mabey someone can spot a difference?


Ross, thanks that makes sence actually. ill check if the N75 get a signal, i got an LED box i can hook up to different actuators.
And perhaps the N75 valve is the issue here..

And yes the Boostgauge was isntalled right next to the ecu line.

Thanks again for the suggestions and help.

Ill have time to look at the S2 this weekend again, ill let you know my findings.

Cheers,

[prj]

Definitely take the spring out and take a look at it.
As for the N75 getting a signal - if it wasn't getting a signal, you would have 0.6 bar boost.

As a test - disconnect the electrical plug from the N75 and please note how much the car boosts.

[Foeglass]

Sorry for late reply i've been busy with work.

I've had the cap off and took the spring out, also made a picture the spring is about 9 / 9,5 centimetres long.
All looked perfectly normal to me.

PRJ's warning did make nervous, so i did
I've modified an old spark plug and made it hollow, than took a piece of barsteel wich fitted in tight. marked the bar at the first cilinder TDC and checked against the other 4cilinders who all came up to the same mark .. that was a relief

I think the pressuregauge im using is also not that accurate as im not getting any overboost faults when the car must only boost 1.9Bar max?

Perhaps PRJ can see from the pic if my spring is original..

I've also ordered a new N75 valve again. should arrive tomorrow.
Anyway im going to put it back together again this weekend
Also attached a picture that shows how my N75 valve has been mounted.


One other weird thing i find is that this faultcode also occured while very slowly accelerating up to the third gear without even boosting..

If the MAP sensor were to be wrongly installed in anyway would that give these sympthons?

[UrS4boy]

Your spring DOESN'T look stock.

1.9 Bar on the left, Stock on right. Then yours.

[prj]

I think the pressuregauge im using is also not that accurate as im not getting any overboost faults when the car must only boost 1.9Bar max?

There is no cut active in the software you are running.
The N75 might be the wrong way around, hard to tell from the picture.
Which is the longer end in the picture, the left or the right one?

You also definitely need a stock spring with that SW.

[newsh]

Here's another stock spring, looks very similar to me.

[twoqu]

I have measured a stock wastegate sping and like Newsh its @85mm long top to bottom with a wire thickness 2.8mm.
It looks like that spring is over 100mm long from the ruler. Other than that it looks like it has the same form.
What the increased length affects I have no idea!

[Foeglass]

The longer section of the ""T" is inserted in the hose between the LMM and turbo, so the Right side will be the longer side..

The wire thickness is 2,7mm at mine and the length i just remeasured it it's 88mm long to be exact. The picture might give it a strange view..