The Procharger one is not adjustable. They say it’s good for up to 700hp. Since it’s always open at vacuum that’s all they needed to adjust it for.

Tim do you not get RPM increase when you lift off the throttle? Specifically around 2-3.5k?

 

Glad to see it's working out, I'm curious about it the other straight one they have if it would work.

 

No, never had that issue, even with the HKS BOV. It would've been useful to see logs of what's happening with throttle position, IGN timing or something else, during that behaviour.

 

Hmm...

Well, I think this symptom is more ECU/tune related. I'm back to pretty much the same rev hang and slight RPM bump when lifting the throttle, especially at lower RPM, where all excess boost should be being vented.

I've had the car tuned by two different people on UpRev, and I've had the same result. None of them seemed to know why or what could be causing it. This never happened under N/A set up.

Who wants to buy an HKS SC kit? haha.

 

Did you get your tune looked at after putting in the Procharger bov?

 

I haven't but when I did the Turbosmart I asked my tuner if there was anything he could do and he had no idea how to fix it with UpRev,

 

Who were your 2 tuners?

 

Concept Z Performance and then BoostedProjectz. I also hit up Admin Tuning today and he said it can happen to any car and apparently be mitigated in some beta tables in the ROM.

 

I'm tuned by Admin, and for a remote tune I'm completely satisfied how solid the tune is.
​​​​​​Maybe @seymore4 can shed some light on the topic, it would be nice if it can be adjusted in Uprev.

 

For reference you can see the behavior here. Rev hang and increase on every throttle lift.

 

Yikes, that would drive me insane.

 

Yeaaaa. It’s incredibly obnoxious.

 

Mine kind of does that but it doesn't seem to do it as much as yours. It's actually pretty minimal below 3k, but after 3k it seems to vary based on throttle input, when I clutch in etc. When I give it more throttle and try to shift fast or something it'll creep up a few hundred rpm but if I'm only giving slight throttle it barely goes up. When I had first noticed it, I sort of changed how I shift so now I typically will take a small amount of time extra after releasing the throttle before clutching in. It may be minimal for me since I'm using the big pulley though. I think on reddit you had asked me about that a while back, but you were on the big pulley initially? Has it gotten more pronounced now that you're on the small pulley?

 

It was noticeable right when I got the kit on but when I installed the 100mm pulley everything got more pronounced, compressor surge and rev hang. The new BOV got rid of the surge but the ECU still needs work to get ride of the hang and increase. Talked to my tuner and hopefully we can work on it this week. I’ll keep you posted.

 

Sort of off topic from the current convo, but on the dyno graph I posted a couple years ago on this thread, there's a slight dip in torque after 5k and then it picks back up a bit, then trails off. Is there a way to eliminate that dip, or get the torque to keep climbing? Would headers (been eye-balling the Tomei set) help with that? My tuner had mentioned that headers can do quite a bit for these cars the last time I saw him. I was also reading about the Kinetix manifold and how it helps with FI cars, but would I even see a benefit with that manifold considering I'm on the 110mm pulley?

 

If this helps, here is my graph. Kinetix V+ Plenum and DC sports headers, 100mm pulley 93octane.

 

Why is the graph scaled so high 😆 the torque curves actually seem pretty similar, yours is just *more* obviously lol. It doesn't seem to have the dip that I do around 5.3k, I tend to notice it when doing a pull and then it feels like it picks back up towards redline. It's not that bad, I just wish it didn't have the dip.

 

Moncef knows his ****. He's been pretty helpful with some other general tuning advice for me. Hopefully the tune does it for you.

Update on mine, since closing the VTA I'm finding I need to go lighter on the spring pressure to vent properly. Haven't found the right spot yet. The concern now is going too light on the spring pressure can mean you're losing some air under throttle before the plenum pressure + spring overcomes the intake pressure. Using a passive vacuum approach is inherently going to have some compromise, but the hope is it's minimal/acceptable.

The only way to truly get the best of both worlds is an electronic valve, but you've gotta dedicate time to tuning all conditions for that too. No free lunches...

 

The saga continues.

So, I am selling my SC kit and going with a kit with a Comp Turbo T4 6467. I want a set up with a bit more mid range and faster spool but still capable of between 500-600whp. I really enjoyed the HKS kit and I am very happy with the process and how much I have been able to learn from the experience. I am a tinkerer at heart and my first love has always been turbo for FI. It's always been the plan to eventually swap but with my built motor and it's higher capabilities that switch came sooner.

Anyways, back to the relevant conversation. I removed the SC kit and low and behold I have the exact same rev increase on shifts.
I am beginning to suspect this has something to do with rev up motors and UpRev. I talked to another local guy with a rev up who is NA but has a tune and he has the same issue.

Of interest. If I am in gear and let off the throttle it does not increase. If I free rev in neutral it does not increase, maybe a bit of a hang but not a bump up. When I press in the clutch to shift when driving it bumps up. I've replaced clutch, flywheel, CMC, slave, lines, clutch peddle, swapped motors from rev up to DE, reprogrammed ECU from rev up to DE. The harness is still rev up but the extra sensors are just not used. I've done all throttle relearning, I've tried two different 75mm TBs and a stock TB. I don't have any vacuum leaks. I do have a dual catch can set up that I used looking at info from this forum.

I had my tuner try to look through the beta tables in UpRev but nothing we adjusted seemed to make any difference better or worse because we were not sure exactly what the problem was. I feel like solving this issue will be like winning the lottery.