So since I added methanol and updated my tune, I've gotten compressor surge instead of blow off valve noise (vented to atmosphere). If I switch back to my tune before methanol, my blow off valves work every time. With my methanol tune I get compressor surge and don't get the blow off noise. Every once in a while I'll get the surge and then right at the end the smallest little bit of blow off valve noise.

I'm tuned with Torrie at Unleashed. I emailed him and he said he did nothing but add boost. Don't get why it would work with one tune and not another if he didn't change anything else.

Any ideas as to what's up? Just don't want to wreck my turbos as apparently surge is bad.

How much boost are you seeing now with the methanol tune?  You could always have the boost backed down to see if that is contributing to the compressor surge.  Any smoke from the tailpipe?

It could be the factory BOV's not working and nothing to do with the tune.

See what bugs me is that if I just Rev it lightly in park, the bovs don't work with my meth tune. I'd only be making like 4 psi under a Rev. If I switch to the tune before, light revs will work with the bov. So the bovs do work. I don't see why the increased boost would cause them to not work when making the lower boost. Like I could see at 23 psi they could possibly not open up, but they should open under a Rev or when making low boost.

Make sure you don't have a boost leak, I'd check all piping to the turbos visually first. If you don't see anything you can build a boost leak tester and that to rule out a leak in the system. Might be leaking at the higher PSI.

I've been doing research all night and I guess I'm just still confused. Why would I be able to switch a tune and the blow off valve works flawlessly every time, then switch to a another tune and it never works. A boost leak doesn't seem to explain that. If I make 8 psi in either tune, one will open bov and one won't. I'll check all the piping/hoses and wires, but still doesn't make sense to me. It's like one tune doesn't create negative vacuum somehow to open the bov. I can do some testing on that today too.

The bov's on these cars are electronically opened and are located in the tube coming from the turbos to the intercooler. The waste gate's are inside the turbo's allowing exhaust to bypass the turbo.

Your issue from what I understand Is you do not hear boost blowing off when you let off the gas correct?

Or are you saying your boost pressure is surging in large increments under a load?  If you upload a data log of the issue it would help.

Under boost and throttle let off, I don't hear the psshh, the bovs aren't opening. I hear a whine/whistle, the sound of air going back through the turbos. If I switch to my previous tune the blown off valves work all the time. I realize they're electronic because there's no line going directly to the bovs. As I'm typing this I just checked all my lines and they looked good. I just switched back to my old tune again and the bovs work fine. Gonna go for a cruise and see if they keep working under high boost.

Quote from: Wojomojo on May 05, 2015, 11:18:34 AM
Under boost and throttle let off, I don't hear the psshh, the bovs aren't opening. I hear a whine/whistle, the sound of air going back through the turbos. If I switch to my previous tune the blown off valves work all the time. I realize they're electronic because there's no line going directly to the bovs. As I'm typing this I just checked all my lines and they looked good. I just switched back to my old tune again and the bovs work fine. Gonna go for a cruise and see if they keep working under high boost.

All you can do then is try to log the pressure surge and show Torrie the issue.   

I probably should make a note that this behavior can change with tunes.  For example, with some of LME's tunes, it is common to hear a honking sound (like a duck call?), while with others it's a normal BOV sound.  May not be anything amiss with the tune at all.

Quote from: SHOdded on May 05, 2015, 11:40:20 AM
I probably should make a note that this behavior can change with tunes.  For example, with some of LME's tunes, it is common to hear a honking sound (like a duck call?), while with others it's a normal BOV sound.  May not be anything amiss with the tune at all.

Quack Quack lol SHOdded.

Here is what is happening. The last Rev you can really hear the screeching of the turbos. If I switch it back to my previous non-meth tune I get the normal psshh blow off valve noise.

Holy christ. Look at your charge pipes flexing. You may be experiencing a problem as there is in influx of pressure heading into your inner cooler tubes.... but due to the expansion of the rubber, it is not making it into the manifold. This absolutely would cause surginess and with the map sensor not reading the proper pressures, it doesn't know when to open the waste gate and a multitude of things. I vote that is your problem right there.

Here is a video of my previous non-meth tune. Charge pipe still flexing and blow offs working fine. I just swapped to this tune now after previous video.

Are you seeing the boost vary at all (spike up and down) during this event?

Compressor surge 1:
https://www.youtube.com/watch?v=nCj6Spwl1CU
Compressor surge 2:
https://www.youtube.com/watch?v=jEUWEsqoWz8

Any difference if you undo the VTA mod?