Leon ARL 2256v presentation (strange noise problem)

Hello,

Eventhough I have been reading this forum for a long time, I have never created a post.

So here is my presentation, I come from northern Spain (sorry for my poor english), my car is a 2003 Seat Leon Fr, ARL. Recently I upgraded my turbo to a 2256v, alfa source.

Apart from the turbo, I also have a complete milltek exhaust system (63mm), fuel cooler, boostvalve, upper an lower strut braces, Bilstein PSS9 suspension, and other minor mods.

The car has has been remapped by "correcaminos", a friend of mine from Spain, the final remap, is as I wanted it, not smoky. And from my point of view the final result is really satisfactory.

Now for the problem. At full throttle, from 2000 to 2500 I have a kind of Shhh shhhh noise, coming from the turbo, is discontinuos, and at higher revs it disappears. I have tried to upload the video on youtube, but I haven´t been able to .
Any idea about this noise? It doesn´t sound healthy at all.

Thanks a lot for your help.

I will post some installation photos of the turbo.

Does it sound anything like this?

http://www.youtube.com/watch?v=nCj6Spwl1CU

vwmikel said:

Does it sound anything like this?

http://www.youtube.com/watch?v=nCj6Spwl1CU

Click to expand...

Well, my TDI sound is quite far from a Skyline, but yes, the shhh, shh, sound in my car is similar to what can be heard on "second 53-55, at a much lower frecuency on my car.

*** is that? too much boost requirements? the fact is that at high revs it doesn´t sound like that. Suggestions are welcomed!!

That seems to be rather light compressor surge. It sounds like the airflow is unstable, so you either need to ask for less boost, or more boost. I know someone is going to criticize me for saying to ask for more boost, but there are cases where you can sidestep the surge limit by increasing the request (and therefore shaft speed).

At last I have been able to upload the video.

http://www.youtube.com/watch?v=oi_TnvtMu3k

http://www.youtube.com/watch?v=z-Ewss_6h-M

Could it improve if I strangle internally the "red pipe" that goes from the turbo to the intercooler? I mean, to reduce the area, similar to the exit on the original 1749

MCM_FR said:

At last I have been able to upload the video.

http://www.youtube.com/watch?v=oi_TnvtMu3k

http://www.youtube.com/watch?v=z-Ewss_6h-M

Could it improve if I strangle internally the "red pipe" that goes from the turbo to the intercooler? I mean, to reduce the area, similar to the exit on the original 1749

Click to expand...

I would think that reducing that pipe diameter might actually make it worse because it would increase backpressure. That is a strange sound in those videos but I do hear a little bit of surge for sure.

Hmm..Do u hear it around 3rd gear, bout 2k - 2.8k @ rpm, when boost shows bout 22psi? Sound disappear when bout 3k on rpm..?

Then say 4th gear, also bout 2k - 2.5k @ rpm, boost show bout 18psi & up & the sound appear, then disappear when pass 3.5k @ rpm?

When driving> u hear that sound, then u let go the accerator immedietly, u hear the fluttering sound?Like some wrx after the bov *Pssssttt!!, then the dd..drrr..roo..o... x2 sound?

If 1st to 4th gear you whack till redline every gear, you are unable to get that sound right?Well, urm, maybe some time u get it in 4th..

hello Miguel!

requested boost is 1,7 bar @ 2300 rpm and 1,9 bar from 2500 to 3500.

this sound appears with requested 1,7 bar but quietly. with 1,9 bar it sounds high. could it be too much shortened the actuator's rod?

vwmikel said:

I would think that reducing that pipe diameter might actually make it worse because it would increase backpressure. That is a strange sound in those videos but I do hear a little bit of surge for sure.

Click to expand...

Hi, I totally agree with you, but as the OEM 1749 has that restriction at the turbo exit, I thought that it might help.






Thanks for you help vwmikel! I hope with your help will be able to get rid of this noise

TorqueRules said:

Hmm..Do u hear it around 3rd gear, bout 2k - 2.8k @ rpm, when boost shows bout 22psi? Sound disappear when bout 3k on rpm..?

Then say 4th gear, also bout 2k - 2.5k @ rpm, boost show bout 18psi & up & the sound appear, then disappear when pass 3.5k @ rpm?

When driving> u hear that sound, then u let go the accerator immedietly, u hear the fluttering sound?Like some wrx after the bov *Pssssttt!!, then the dd..drrr..roo..o... x2 sound?

If 1st to 4th gear you whack till redline every gear, you are unable to get that sound right?Well, urm, maybe some time u get it in 4th..

Click to expand...

You have perfectly described what happens. I would say that the noise starts at 1900-2000 until 2500rpm, when boost exceeds 20-22 psi (1.4-1.5) bar.

I have tried this morning to mantain boost at 20 psi, to check if the noise appeared or not, but it is not easy to keep the pressure at a fixed value with the gas pedal.

Do you have the same problem?

correcaminos said:

hello Miguel!

requested boost is 1,7 bar @ 2300 rpm and 1,9 bar from 2500 to 3500.

this sound appears with requested 1,7 bar but quietly. with 1,9 bar it sounds high. could it be too much shortened the actuator's rod?

Click to expand...

Hi Javi,

I will make a trial with the other remap you prepared for me at 23 psi (1.6 bar) and let you know if the noise is still there. For me the problem is not the noise, the problem is that it sounds as it will soon brake down.

Bellow you can find some pictures (I have used imageshack, I hope this is fine for this forum ) of the turbo upgrade experience. It was done by m0nch0 a wellknown forum member of Areavag, an spanish vag forum.

He lives 300 miles away, in Santiago, I´m from Burgos.

We get up very early in Spain...




I stopped in a circuit on the way to Santiago to record some logs... the last
with the 1749.






EGR radiator removal



We took out EGR and and intake pipe for cleaning with and ultrasonic machine.





Something to store..

The EGR had been "cleaned" by me 12000 miles ago.



1749 still inside

Bellow you can see the new turbo, bought in Portugal. It is sold with an adaptation to fit on tdi´s. But is not completely P&P as some things needs to be modified (exhaust, and pipes)








We decided to install the turbo from the upper side, so we had to remove some parts.

First problem, the miltek downpipe didn´t match with the turbo, so we had to "move up" the exhaust


New lubrication pipe







As we had removed the EGR radiator, we had to join the pipes.



What a wonderful tool!



Finished!



63mm milltek Down pipe, and the old and new flange.

Intake manifold and EGR after the ultrasonic clean










Downpipe already welded to the new flange.



This was necesary to reach the turbo exhaust level

Minor modifications were required to fix the inlet pipe





We removed the return pipes from the EGR radiator





We modified the bracket that supports the turbo, is not very refined but it was fairly late...





Engine bay was washed the next morning.




Summary of the return trip!








Hope you like the pictures!

And finally some pictures of the car, as someone might not know the Seat Leon FR

Maranello


Kotarr Circuit (Burgos)



Adenau (Nurburgring)

That is a very nice looking car!
Very similar to a VW Golf but with an aero design rear roof slope.

I wish I could figure out a way to import a Leon Cupra 4

MCM_FR said:

Do you have the same problem?
.

Click to expand...

Ya, sort of...

Surge for sure, to high requested boost for the setup. Mine does the same! And have exactly the same sound.

Theo

nice upgrade..
The exhaust manifold with the adaptorflance, where did you buy it ?

PapaBare said:

That is a very nice looking car!
Very similar to a VW Golf but with an aero design rear roof slope.

Click to expand...

Thanks, I´ve just included a picture from the front.

For those with the same problem as me, what have you tried to reduce surge? And for how long have you been suffering it?. In other words, how long until the next turbo replacement??

Grede said:

nice upgrade..
The exhaust manifold with the adaptorflance, where did you buy it ?

Click to expand...

I bought it to some kind of Portuguese turbo dealer. Not very happy with him now, as I was not expecting this surge problem.

Before buying the turbo, the turbo was pretended to do 1.85bar (26.8psi) @ 4000rpm. When I informed him about the noise, he told me that the max boost was 1.65 bar (23.9psi) @4000 rpm...

After having a look at the exhaust manifold, it doesn´t look very difficult to make one. You need and old exhaust manifold, you cut it, and then you weld the flange that matches your turbo.

I have included some pictures of mine.

correcaminos said:

hello Miguel!
requested boost is 1,7 bar @ 2300 rpm and 1,9 bar from 2500 to 3500.
this sound appears with requested 1,7 bar but quietly. with 1,9 bar it sounds high. could it be too much shortened the actuator's rod?

Click to expand...

1.7/1.9 bar boost equals a PR of a little over 2.7/2.9. On all maps that I've seen of a 56mm wheel (one example below), the surge line occurs at mass flows of no less than between 15-20 lb/min (depending mostly on trim) at the abovementioned PRs.

At 2300 RPM, I estimate that the engine is flowing 12 lb/min in the most optimistic case (have you done a dyno test? - what's the torque at 2300 RPM?), so on that, I would say you're definitely running in the surge region.

If you do a dyno run in the current condition, I'm sure you'll see the plot go crazy in the RPM band where you're hearing this noise. You need to reduce the requested boost.

TDIMeister said:

1.7/1.9 bar boost equals a PR of a little over 2.7/2.9. On all maps that I've seen of a 56mm wheel (one example below), the surge line occurs at mass flows of no less than between 15-20 lb/min (depending mostly on trim) at the abovementioned PRs.

At 2300 RPM, I estimate that the engine is flowing 12 lb/min in the most optimistic case (have you done a dyno test? - what's the torque at 2300 RPM?), so on that, I would say you're definitely running in the surge region.

If you do a dyno run in the current condition, I'm sure you'll see the plot go crazy in the RPM band where you're hearing this noise. You need to reduce the requested boost.

Click to expand...

Thaks, TDIMeister.

We (MCM and me) did a lot of attempts, always with sourge... even with vnt17 remap!

Today, MCM is going to try new version with 1,5 @ 2000, 1,55 @ 2250, 1,65 @ 2500 and 1,85 @ 3000 to 4000 rpm.

Thanks a lot

While this is not directly relevant to your GT2256, the following I replied to someone concerned about surge in his GT2260 might help...

I'm exhausted from re-translating this back; try http://translate.google.com . You might understand the Spanish translation from Google Translate better anyway, or I will post it in English tomorrow...

Also, bei irgendwelchem GT22 sollte spitzen Ladedruck an einem 4-Zyl. TDI auf keinen Fall unter 2000 1/min vom Steuergerät gefragt werden, sonst betreibt den Verdichter innerhalb der Pumpengrenze, je nachdem Verdichterkennfeld. Man kann den Sollladedruck rechnen, um nicht in der Pumpengrenze bei bestimmten Motordrehzahlen zu betreiben, aber es gibt keine gute Daumenregel. Die Pumpengrenzlinie steht hauptsächlich je nach Verdichterraddurchmesser und Trim. Natürlich bei einem größeren Verdichterraddurchmesser des GT2260V-Laders im vergleich zum 52mm im T4-Lader, sollte diese Pumpengrenzlinie im Kennfeld nach rechts bewegen... Ich würde empfehlen, dass bei einem 60mm Rad, sollte der Ladedruck maximum auf ca. 2,0 bar (absolut, also 1,0 bar Überdruck) bei 2250 1/min, 1,8 bar bei 2000 1/min, <1,4 bar bei 1750 1/min, usw. bleiben...

Click to expand...

TDIMeister said:

1.7/1.9 bar boost equals a PR of a little over 2.7/2.9. On all maps that I've seen of a 56mm wheel (one example below), the surge line occurs at mass flows of no less than between 15-20 lb/min (depending mostly on trim) at the abovementioned PRs.

At 2300 RPM, I estimate that the engine is flowing 12 lb/min in the most optimistic case (have you done a dyno test? - what's the torque at 2300 RPM?), so on that, I would say you're definitely running in the surge region.

If you do a dyno run in the current condition, I'm sure you'll see the plot go crazy in the RPM band where you're hearing this noise. You need to reduce the requested boost.

Click to expand...

Thanks a lot for your numerically supported answer. I haven´t done a dyno run, so no idea about torque.

I have just come back after trying a new remap with reduced boost in the lower range. The result is much much better, correcaminos has been able to reduce the surge to a small band between 2200 and 2400. The response at that revs is similar as before, better I would say, as I can accelerate without surge (=fear)

We will try with a new remap version, with a bit less of boost in that area.

TDIMeister said:

While this is not directly relevant to your GT2256, the following I replied to someone concerned about surge in his GT2260 might help...

I'm exhausted from re-translating this back; try http://translate.google.com . You might understand the Spanish translation from Google Translate better anyway, or I will post it in English tomorrow...

Click to expand...

I would appreciate if you could please translate it into english, whenever you can. It is impossible to understand the translation from google.

Thanks in advance!

It might be my bad German and not the translation

With any GT22, the maximum boost pressure in a 4-cylinder TDI should under no circumstances be requested under 2000 RPM by the ECU, otherwise the compressor will operate within the surge region, depending upon the compressor map. One can calculate the requested boost pressure in order not to operate in surge at specific engine RPMs; however, there are no good rules of thumb. The surge line lies principally depending upon the compressor wheel diameter and trim. Naturally, with the larger compressor wheel diameter of the GT2260V turbo in comparison to the 52mm of the T4 (Transporter) unit, the surge line will be moved toward the right on the map. I would recommend, that with a 60mm wheel, the maximum boost pressure should remain at a maximum of about 2.0 bar (absolute, that is, 1.0 bar gauge) at 2250 RPM; 1.8 bar at 2000 RPM and <1.4 bar at 1750 1/min, etc. ...

Thanks a lot, very well explained.