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

[220bhp]

I agree with Newsh and Twoq, the stock spring should be 85mm. However some time ago I took my wastegate apart on my S2 because of running issues, and I found the spring was also 100mm long. As far as I know the spring was original, and had never been touched. The anti tamper plug on top of the wastegate was also untouched.
You have said that you have a 3bar map sensor in your ecu, is it a bosch, or none bosch, item,such as a motrola.

[Foeglass]

That i wouldnt know what Map sensor Paul uses. i know that its a very small one, so i think its a none boschi wouldnt know.

Gonna try the new N75 valve this weekend and see if that clears any issues..

[Henkjan]

did you remove it during the build? if so, please double check, because what you discribe sounds a lot like what I had when I made an with the N75

http://www.s2forum.com/forum/showpos...3&postcount=79

[prj]

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..

There is no hose between the MAF and the turbo.

There is a hose between the turbo and the N75, between the N75 and the wastegate and between the N75 and the MAF->Turbo hose.
So in which of these hoses does the longer end go? If it's the right side on the pic it should be OK.

Swapping N75 is pointless, you will not get rid of this behaviour until you change the wastegate spring to stock.

[Foeglass]

But my old N75 valve and the new one have the exact same partnumbers 034 906 283K. and the valve worked good with the standard S2 software. i didnt had these symptoms at that time..

And i beleve the longer tube blocks the air from memory.. gonna go over to the dealer in a few mins.. so ill check it on the new one also..

[prj]

Yes, longer T end blocks air, and it should be inserted directly into the maf->turbo hose.
You have some sort of non-standard setup there as you have a hose.

I've told you what's wrong with the car

[Foeglass]

There is no hose between the MAF and the turbo.

There is a hose between the turbo and the N75, between the N75 and the wastegate and between the N75 and the MAF->Turbo hose.
So in which of these hoses does the longer end go? If it's the right side on the pic it should be OK.

Swapping N75 is pointless, you will not get rid of this behaviour until you change the wastegate spring to stock.

There is no hose between the MAF and turbo now your contradicting yourself?
Like i sayd the longer section of the tubes on the N75 is connected to the MAF->Turbo hose. the hose between the MAF and the turbo..
now your making me confused??

Its the big hose that runs from the LMM/MAF down to the Turbo, the N75 valve connect to this and the crankcaseventilation from the valve cover, and the Divertervalve connect to that hose.

The bottom section of the T is connected to the hose to the Turbo and the left side of the T is connected to the WG..

From the information i see from 220HP and twoqu my spring is near original measurements it's 2,7MM thick and measures 88MM long wich is 3 mm longer than original But as 220HP says he also had a original spring that was near 100MM long.

So from that information i cant really find much wrong from my spring?
Does anyone know where i can find / order an original spring?
im willing to try it offcourse.

[prj]

There is no hose between the MAF and turbo now your contradicting yourself?

Correct, there is no hose between the MAF and the Turbo in relation to the N75 and boost control
There is a hose between the MAF and the N75. And between the N75 and the Turbo. But there is no direct hose between the MAF and the Turbo.

This is looking from the standpoint of the N75 boost control.

Of course there is a big MAF->Turbo hose as well, but this is not used for boost control.
Probably we are misunderstanding each other - I am only referring to the 2/3 little lines connected to the N75.

So from that information i cant really find much wrong from my spring?
Does anyone know where i can find / order an original spring?
im willing to try it offcourse.

Your spring is clearly not stock from the picture. It's not only the thickness and measurements that define the spring.
You can easily see how much spring boost you have by taking off the electrical connector of the N75 and doing a WOT run.
The boost should be 0.4 bar. If it is not 0.4 bar your spring is not original.

[Foeglass]

I think i indeed misunderstood you.

I will try a WOT with the N75 valve disconnected..
and i will use a different pressuregauge a more accurate one.

Because the one i used now is not really accurate i suspect since it was only 10 euros and its 5 years old... i was using it to show the boost fluctuations for the film.

But on this gauge the pressure was set at 0,6 Bar.
So if its still the case i get 0,6 bar i need another spring.

Does anyone have any idea on where to get an original spring?

And you say my software doesnt have a boostcut? that doesnt feel right to me..

Thanks again for the help and suggestions will update as i tryed it out.

[Jonas_R]

Have you checked that the hoses on the N75 is actually ok? They look old and possible they may be leaking.

[twoqu]

Measure the spring vertically on a flat surface. It still looks longer than you are stating. We are talking about the total length from the flat at the top to the flat at the bottom. Not the easiest thing to measure with calipers.
As the wastegate is adjustable you need to make sure that you have the baseline 0.4 bar without the N75 connected electrically. Whether its the spring or the wastegate screw, you need to see that first. Obviously accurate measurement of the pressure helps.

[prj]

And you say my software doesnt have a boostcut? that doesnt feel right to me..

I don't feel - I know, as I have that software sitting on my hard drive.

Besides, you can't run 1.9 bar boost on a 300kpa sensor and expect to have a functioning boost cut.

[Foeglass]

I would rather have a boostcut / overboost protection. if the turbo can blow 2,3 bar now without getting cut that doesnt feel right.
The risk of engine damage is something i like to minimize.

Can i ask what would you recommend? as i see and read you are quite a guru when it comes to tuning the 5pots..

[prj]

You have two options really.
If you want to use a 300kpa sensor, then the boost should be set lower, max. 1.8 bar and then the cutoff at 2.0 bar.
Alternatively, it is possible to use a 400kpa sensor, and then the cutoff can be set at 2.1-2.2 bar with 1.9 bar setpoint.

I personally only use 400kpa sensors. There is no price difference and no disadvantage to using one - well one must know how to re-calibrate the ECU, but that's not an issue for me.

Keep in mind, most of the software out there has no boost cut...

[prj]

I would say that's a stock spring.

You are right John, it could well be. I was mistakenly looking at UrS4boy's pictures.

Then all that remains is pull the electrical connector and try to make 0.4 boost.
If this is not doable even with the wastegate cap screwed out all the way, then this could be a 10v spring, they came with 0.6 bar stock springs.