Yes its a filter, if you look at the end of it... at the bottom. There is a small foam filter inside.
Interesting, I'm still having boost issues and I just had all of the vac lines completely replaced, and I even swapped in a new solenoid. My S3 setup still spikes up to 23, then drops to 18, sometimes goes back up to 22-23, it's pretty much random most of the time... no boost leaks, no vac leaks, and it holds boost just fine with an MBC. It's driving me nuts, I'm about to purchase a Hallman Pro RX MBC and just be done with it. I used to hold 25psi consistently, pull after pull, using just the AGP S3 WGA.
Consistent would be a solid number always like 23 psi... but if its fluctuating between lets say 20-23 that isn't much consistent. That is caused by running an MBC, in which causes uncontrollable spikes for the most part. I've ran those before and prefer not to use them. Now if your spiking 23psi and dropping to lets say 20 then that's usually normal if that's what the car has always ran in which this isn't the case with your car. My wife's car is a DCR S3 with almost every supporting mod. On Dab 3 the car spikes 26-27 on an AGP WGA and we are not using an MBC and don't plan on using one on her car. All vac lines are intact/PCM controlled boost.
Well, it was actually holding more boost, more consistently, on the MBC than on the solenoid, at least recently. For the longest time it was just fine with PCM boost and the WGA set to allow it to hit 25psi. After I took it to FWD Performance, they replaced all my vac lines and tightened the WGA, and it basically did the same thing, only now when it DOES want to work, it spikes 26-27psi... is that safe on a stock motor? I'm not seeing any knock on the scan gauge, but I think I need to loosen up the WGA a bit...
If you have the proper mods/supporting mods I don't see why 26-27psi would be a problem. 26psi on Dab 3 in my wife's car and she's on the stock motor. Well as far as internals go. I'm surprised your not seeing any knock. All S3 cars I know of locally are seeing knock. If your worried about the 26-27psi and think you don't have the proper supporting mods then I say lower it a bit. But here's a vid on two cars locally... the red one is now my wife's car and has more done to it since that video. The silver one has more mods then the other and both were spiking 26. [media]http://www.youtube.com/watch?v=aCcZ2Q5tQU8[/media]
Well, I'm not seeing knock on the scan gauge, however I let off when I saw it hit 27psi today, it wasn't giving me 27 psi ever before until just today (like I said, it's totally inconsistent). I suppose I could try some WOT pulls and see if it still wants to give me all that boost, I keep the scan gauge showing KR and I do have the wideband hooked up, so I can keep an eye on things. I think I'll readjust the WGA back down to where it was at 25psi... I know I have been saying it won't give me more than 20-23psi, but this thing is just so inconsistent now, and the shop tightened the WGA on it when attempting to get it back to 25psi. When they did that, it got 23-24psi, and so they gave it back to me. Since then it has been anywhere from 18-27psi at WOT...
BTW I am running a wallbro 255 with an aeromotive fpr and an upgraded fuel rail with a return line, so that's why I don't get regular S3 knock.
