Yep, no issue with this. My car does the same. Venting at cruse speed doesn't mean you should or shouldn't vent at idle. It depends on how it's all working together.

It's about dialing in the spring pressure to find the best balance for all or most conditions. Hopefully all. That's why the tune plays a huge role.

 

Even that guy has some surge at 3:03. If I can get rid of most of the surge at low rpm cruising like around 2k rpm, and extend the life of the blower, even if it's not ALL of it, I'll be happy. Hell, I was happy before I knew it was compressor surge slowly damaging my S/C, ignorance is bliss lmao thanks Green. In my case for my CEL and surge on cold start, it probably had to do with the spring pressure just being way too light in comparison to the hks bov, that thing is heavy as hell. I put the hks bov back in just so I can drive the car around and enjoy it. I'll experiment with the dual port when it comes in.

 

No I get you, discussions are always welcomed IMO. Also, yes, agreed, tuning matters! You are on a standalone using MAP, which is MUCH different then uprev amd MAF like Matt is running and I will be running. You are also at a higher boost pressure. IIRC, the Compact is rated for a minimum of 7psi but don't kill the messenger if I'm wrong lol.

The main difference according to the articles I read was flow and response time, but I do kinda agree with what you said, they ultimately do the same thing, and it VERY much depends on your setup and tuning.

Taking our opinions out of the equation, if Turbosmart and GFB are stating different requirements AND sell supercharger specific valves, I must think it is for a reason, so that's what I will run as I'm a strict person when it comes to drivability.

 

I’ve got all 6 shims they supply and it still won’t get as strong as the HKS bov 😅 I’ll try it out today and see what happens.

 

Alright so max tightness wasn't the way to go lol, was getting surging when I started the car, so I decided to start from lightest and work up. Max lightness prevented surge but when free revving it would almost stall. I think right now I'm like one turn from max tightness with no shims. Doesn't want to stall and I don't think I have surging at idle, but I'm getting surging when cruising so tomorrow, I'll go back one full turn and check again. VTA was fun but I'll probably plug it also. Does plugging the VTA change how it acts?

 

Ha, I didn't get a chance to respond to your earlier comment. I experimented with full hard and had a similar experience- pretty heavy flutter off throttle. Dialed it all the way back to just closing on idle and haven't had a problem since.

Re closing the VTA, technically no. Shouldn't make a difference. That extra air will just push out the filter. Just play around with the dial until you find the sweet spot.

 

So, this rev hang is killing me.

I called Pro Charger and chatted with their tech about their BOVs. He explained how their supercharger BOVs are designed to stay open and close when they see boost. I ordered a Bullet BOV which seems like a very similar design to the Kompact Dual Port but this one uses 38mm hose sizes, so I picked up 35mm to 38mm hoses.

Im gonna give this one a shot and see how it feels. The biggest part of the HKS kit that is killing me is when letting off the gas especially in low RPM the boost in the system is not vented fast enough and it jumps my RPM up by 200-300. I can't adjust the Kompact enough to eliminate this, I even tried VTA, no difference. The Kompact eliminated all the surge but not the rev hang. Every person I've seen or talked to that has the HKS kit has this rev hang or whatever you want to call it.

I talked to my tuner and he said with UpRev there was no settings to try to "tune it out".

The Z1 kit uses the Turbosmart Raceport BOV and I've talked to someone who had that kit and they had zero rev hang, that BOV is not a "supercharger only BOV" either. The Z1 kit uses the raceport directly connected to the intercooler, the raceport has a 50mm opening so it vents a lot of air quickly. Maybe that's how that kit prevents the rev hang.

At this point I don't know what is causing it but it's making me wish I went turbo. Hoping to get this sorted.

 

Sorry to hear man. That sounds incredibly frustrating.

 

I’ve always treated the extra rev like a built in down shift assist lol let us know how the bullet acts. I’m for sure going to need my tune adjusted a bit to get the most from the turbosmart bov, plus I’ve been having weird afr sensor problems since sealing my exhaust properly.

I (unkowingly) had an exhaust leak at the header to cat flange on bank 1 when i initially got tuned. Now that I had sealed it up, under certain conditions, it’ll get so rich that the voltage hits zero and it freaks out my ecu and shuts them both off.

Just gotta restart the car to go back to normal though, but it is annoying when it happens. It happened more often with my old (6 years old) battery that had lost its ability to properly regulate voltage, new battery the issue occurs less often so I can still have fun with car without worry for the most part.

 

That's the one I was thinking about, out of curiosity did you get the VTA version or recirc?
I was also thinking it might be beneficial to plumb the line to the EVAP port and switch the EVAP to the front port, not needed but it makes more sense to me as it's right next to the TB so it should be the most sensitive to changes.

 

I got the recirculated version. The constant jet engine whoosh of VTA on superchargers is enough to make you go nuts haha.

 

Lol, I feel ya, I watched their videos and I'm like damn that's a lot, but when they put a filter on it it was much more bearable.

 

Would shortening the length of the vac/boost tube connected from the manifold to the top of the bov increase the speed at which it opens? I remember reading in Turbosmart's instructions about that making sure the length of the tube isn't too long.

 

In theory, yes. But the way this kit is designed there aren’t many ways to shorten that vacuum line. Also I dont really think this is the big issue. Other kits mount on the intercooler which would make that cable equally long or longer.

 

Technically shorter is better, but also the optimal place for BOVS is close to TB, obviously that hardly happens due to packaging. My GTI has the BPV on the turbo and it's completely fine, but then again, electronic wastegate and BPV so IDK if that plays a role.

 

Tim, where did you find a belt for the 95mm pulley? I can find a lot of those pulleys online but the only belts I see are for the 100mm and 110mm.