Overboosting issue, 30+ PSI! please help. Unitronic Stage 2

[doug@frankenturbo.com]

I'd take this issue up with unitronics support. They are very helpful and will help you figure things out.

However, I'm leaning toward an intermittently bad n75 or perhaps a bad MAP sensor.

The N75 determines its duty cycles based on the specified boost and the feedback from the MAP sensor on what the boost really is.

Do you have vag com?

The OP tested with a different N75 and the problem persisted. When ECU-control is disconnected, the problem goes away. So the only remaining hardware possibility would be that MAP sensor, as groggory suggests. But this strikes me as a long-shot. I still think this is simply a compatibility issue between software and hardware. I'd bet you've got the wrong file loaded on the ECU.

[1320-20V]

My Unitronic flash report says stage 2, and this ecu

0007 | 1037367518

[1320-20V]

It was stated earlier in this thread that if I my N249 valve was indeed faulty, i should see a sharp increase in pressure when i close the throttle plate correct? I do not see this happening. What does this imply?

Also, with the N75 unpluged i will always run 5 psi, which is .3 bar. I see my local pressure at 980mbar, so i should see 1324 on the sensor, and I DO NOT. Am i looking at the wrong sensor or is it broken?

[groggory]

Also, with the N75 unpluged i will always run 5 psi, which is .3 bar. I see my local pressure at 980mbar, so i should see 1324 on the sensor, and I DO NOT. Am i looking at the wrong sensor or is it broken?

Where did 1324 come from? Did you get a hold of a vag com?

[1320-20V]

My friend has some ebay VAG-com cable, it works, but it will not look at any blocks over 27. There is a block, I forget which number but it is called "absolute pressure". With the car off it reads 980mbar, which is standard atmospheric pressure. If i run 5 psi that is and additional 300mbar, i I would expect to see around 1300mbar in this block. I drove around and the values fluctuate usually going lower but never over 1000 and certainly not 1300. This is why i suspect my MAP sensor may be bad.

However, the car does detect the presence of the sensor, because when I unplug the sensor, the car runs like crap. However im not sure that this means the sensor is really working.

Edit: 980+324= 1304mbar

[groggory]

Sounds like replacing the map may be a good next atep

[1320-20V]

New MAP will be here today. Also I emailed Unitronic over 24 hours ago, and no response. Awesome.

[groggory]

New MAP will be here today. Also I emailed Unitronic over 24 hours ago, and no response. Awesome.

https://www.unitronic-chipped.com/technical-support

You opened a ticket?

[1320-20V]

i emailed support@getunitronic.com. and got nothing.

Edit: changed to correct email address

[groggory]

i emailed support@unitronic.com. and got nothing.

Weird.

Give them a call.

[1320-20V]

https://www.unitronic-chipped.com/technical-support

You opened a ticket?

You cant actually start a support ticket. the website is an endless loop, one you select your car it tries to sell you a chip you already bought.

[groggory]

You cant actually start a support ticket. the website is an endless loop, one you select your car it tries to sell you a chip you already bought.

Step 1: Create Profile
Step 2: Log in
Step 3: Choose Technical Support
Step 4: Choose category
Step 5: Make title
Step 6: Fill out form
Step 7: Click submit form
Step 8: Check your email. It should have your ticket number.

FYI...I just make a 'test' ticket just to make sure it was working.

...but assuming you're having a problem with that, give them a call.

[1320-20V]

I just went to the dealership, where a tech was nice enough to vag-com my car for me.

Boost Requested: 2550 all the time I am at WOT.

I know the limit of the sensor is 2550. that's 22.7 psi.

So basically my question is, why does my chip want to run 22.5 psi all the time?

18psi should be about 2241mbar, so I would expect the boost demand to be around 2200, not 2500.

Furthermore, if 2550 is the max the map can output, there is no possible way for the chip to know if the boost is 22.5 or 30 psi.

Clearly I am not a chip programmer, but something seems wrong here to me.

So I have a vag com cable right now, tell me how to log and I will log everything you want to look at and post it right up.

[Mr_Long]

Also, a log of block 115 in vagcom comparing requested and actual boost would be helpful. I would think that if you are overboosting that much, you would go into limp mode unless the map sensor is bad and not correctly reading pressure.

*Edit: ^^Beat me to it.

This is what they want you to log

[1320-20V]

Ok well I dont have a log as a file but requested= 2550 and actual is 2550. My N75 duty cycle is 95% all the time (fully closed)

[dontcrossme]

When I got my gonzo stage 2 it would overboost and hit limp. If the N249 controls limp then I would suggest replacing it or testing with someones that works.

If you have diode mod REMOVE IT that will prevent the N249 from putting the car in limp mode. Limp mode is not always bad. Its a way of finding out something is wrong if your not paying attention.

Not sure how you can get 30psi on stock dv as mine wouldnt hold over 12 without the diaphram blowing open.

I replaced the DV with a forge 007 and replaced all the vacume lines going to / from n249.

In the end to fix most of my problems I had to install a MBC in line with the N75. So when it wants to overboost the MBC bleeds the wastegate and lets it open at the level I set. Mine is capped at 18-20psi and usually sits there till redline.

[1320-20V]

Installed manual boost controller today, and set it to hold 18 psi in third gear. Holds 18 for a while and then tapers down over 4000 rpm.

I am so incredibly dissapointed in this chip and Unitronic. They never even responded to my email.

[dontcrossme]

Do you hear any loud hissing on the passenger side when boosting?

If not I suggest testing with someones Piston/'Valve DV or APR R1 as i hear they can hold up too. I have the TT DV and it didnt last too long before it started collapsing. Its just rubber.

[HidRo]

Have you tested for leaks? Boost leak test?
It's way better than throwing nonsense Money at the car.

[Yosh_Cupra]

i emailed support@unitronic.com. and got nothing.

Incorrect e-mail addy...Will go to a company that does PLCs...
Support@getunitronic.com

[1320-20V]

Can i get anyone running Unitronic stage 2 to chime in and tell me what their requested boost is at WOT with vag com?

[1320-20V]

Incorrect e-mail addy...Will go to a company that does PLCs...
Support@getunitronic.com

Just to be clear, I did email my problems and request for help to the correct email address at 1:36PM Thursday of last week. It is now Monday and i have not heard a word form unitronic from my email.

[Mr_Long]

If they don't reply your emails then is time to call....you put some money on it and they need to give you the answers you need.

[groggory]

Installed manual boost controller today, and set it to hold 18 psi in third gear. Holds 18 for a while and then tapers down over 4000 rpm.

I am so incredibly dissapointed in this chip and Unitronic. They never even responded to my email.

When I said call them, what was so confusing?

[1320-20V]

I called them on friday late in the day. They told me to call my local dealer North american motorsports and have them log the car. I called NA, and they saids they typically dont do that, but said they would do it for me on monday. So I guess I will be there at 5 after work.

[Mr_Long]

now we are moving forward

[1320-20V]

i have a LOG FILE, and a working car!

How do I post the log up here?

[groggory]

i have a LOG FILE, and a working car!

How do I post the log up here?

I use drop box.

Others use google docs

Others copy and paste it inside code blocks

...any of those work...

Don't post a screen cap of the log

[Twopnt016v]

The n249 controls the diverter valve. The best thing to do is bypass the n249 but leave it plugged in. The car will not throw a code this way. Then run the DV directly off the intake manifold. The DV will be more responsive this way and part throttle issue will go away. The n249 is not your problem...however if you want to bypass it here is a nice thread with pics...

http://uk-mkvs.net/forums/t/265883.aspx

I would also say be careful driving the car like that...you can window the block easy. I had a similar issue with overboosting to 30psi on a Unitronic tune and never got the issue resolved so I had to run a mbc. It would never kick the car into limp mode either. I run a hybrid turbo which is a different animal, however the unitronic tune was requesting max boost right out of the gate which would just cause the turbo to overshoot the boost. Requesting max boost out of the gate will get the n75 working fast but the tune should build up a little to max boost, not request max boost from the jump..