have you backed off mechanical w/g preload from your 34psi boost spike examples within the 1st post?

if the turbo is surging = moving less air than normal = rich condition....

 

Yes, I backed it out about 2 full turns. Do you suggest backing it out more?

 

Have you logged BEC to see how much is being applied. Possibly try zeroing out your boost error correction and see if the flutter goes away; you may be overshooting/undershooting your desired PSI and the 3-port is compensating.

 

I currently have the BEC zeroed out. That was a problem when I first installed the Synapse and zeroing out the BEC did help but the problem still exists.

 

im actually having the same problem but im sure mine is cause from a boost leak. have you tested for that yet?

 

Yes twice. I'm actually thinking not having any boost leaks is part of the problem because this issue didn't exist when I had the old leaking 9 BOV.

 

Sounds like surge then. Slow your spool up some and lets see what happens.

 

Yeah I think you're right. What's the best way to do that? Reduce WGDC? Increase timing? The bummer is that, other than the flutter, the car feels great right now! It really rips and the VD numbers are outstanding for stock turbo and pump gas!

Edit: Also, I think my MAF scaling might be off some. Could that also contribute to compressor surge?

 

What about a bad map sensor? Im still new with the ecm for these cars but I'm sure the load is based mainly off the map sensor...prob maf/tps/maf also etc also? It would explain the drop in load at a certain load (has dead spot) and also the problem getting worse and worse. Got a spare map sensor to try? I'm also doing this from my phone so can't see the pics of the logs n maps good but just an idea

 

No I'm pretty sure the map sensor is good. For one, it's only a year or so old. Also, the drop in load was due to my 1byte load factor being off. I've since corrected that but the surge issue remains.

 

Yeahh and just realized it would be going lean not rich so scratch what I said

 

I suggest starting off with the turn buckle hole being below the w/g arm peg by ~1/2 the diameter.

the fp website used to have a short vid on the turn buckle / w/g set-up.

taking 2 turns out doesnt mean much, if the turn buckle is wounding completely down, basically keeping the w/g from opening any if @ all.

what w/g actuator are you running?

 

It's an FP 18psi WGA. I'm not sure why my shop tightened it up so much at first but I'll try taking a few more turns out of it and see what happens.

 

^ some people may say, back off the turn buckle to where the buckle just slides over the w/g peg/arm, then add some preload. however, just because it takes some preload to get the buckle over the peg-arm, once the buckle is fully seated, the w/g flapper itself could still spin, so people may find themselves requiring another 1/2 turn or full turn to get the desired results.

however, if your w/g arm is tweaked in the opposite way, in that as your forcing the turn-buckle over the arm & getting it to the side so you can stick the pin in, you maybe be adding some more preload...

just know that back pressure kills power....being that if your turbo only makes 2x.0 psi @ 7k revs for example....then you add more preload & more w/g duty, then your now making 2x.2psi, you'll most likely be making less power due to the added backpressure of over-driving the turbo.

i experienced this w/oem 8 turbo.....tried getting more boost up top, found the ceiling, started backing off the preload, to where i finally achieved a slighly lower boost @ that point because the w/g was opening further...that in itself allowed the engine to breath better & make more power. On top of that, my knock sensor output was smoother, thus being able to add somemore timing as well, making even more power.

 

Quick Update:

I haven't had a chance to mess with the adjusting the preload on the wastegate but it's something I still may try. However, once we started revisiting the idea of it being compressor surge I decided to see what would happen if I started the pulls around 4K instead of 2K. The result was that I didn't hear or see the DV flutter at all, which if I understand the concept correctly, pretty much confirms that the issue was/is indeed compressor surge. So at this point I guess I'm wondering what you guys think my next step should be.

A.) Leave the WGA preload where it is. My reasoning for this is because I did some hard WOT pulls going through 2nd, 3rd, and 4th and didn't get any DV flutter/compressor surge at all, thus I can avoid the problem by simply driving the car properly. Because, other than for tuning purposes, anyone who drives a stick knows not to try to go WOT in 3rd, 4th, or 5th when they're only at 2K rpms.

B.) Reduce the preload to see if that fixes the problem below 3K rpms and then retune the boost. MY only concern here is that when I first took some preload out of the WGA the car felt sluggish and was down on power even though I retuned it to a similar boost level. So I added one full turn back in and the car feels much more powerful now.

Once again, let me know what you guys think. I really appreciate all of your input!! Even if I didn't neccesarily take all of your advice, you guys at least me thinking in some different ways and helped me understand things a little better, and I think we've almost got the issue sorted out and this is definitely a run-on sentance!