I have an issue with a car where the secondary turbo creeps as soon as it comes on. Before you say port the wastegate, this has been done already. I have an Apexi AVC-R installed however it is set to off so it is not doing anyway and should provide close to wastegate pressure on both turbo's. The car had the same problem before the boost controller was installed with stock restrictors so the boost controller is definitely not the problem. Also, since the restrictors are now removed (version 2), those are not the problem either.

I have included graphs to show exactly what the boost is doing to help identify possible causes. I tried hooking up the boost controller 2 ways, I included the diagram at the bottom of the post to show exactly how its hooked up. It has the same creep with both setups but the second one has a higher start boost on the primary/secondary.

My only guess is that one of the actuators aren't working. I was going to have the them changed to check but I figured it would be a good idea to see if anyone had any other ideas.

Another question I wondered. Do we need to cap the hard lines that go to the solonoids? I capped them but I wasn't sure this was necessary. And now that I have typed this I wonder if it can affect anything?

Version 1


Version 2




thewird

 

the only input i can give is to try searching for info on boost spikes.

 

It's not spiking. Its creeping. You can see it in the graphs. I did try searching but theres so many boost problems and the ones I looked at did not pertain to me.

thewird

 

Assuming you have a full exhaust system, boost controllers do not help with boost creep much at all, spiking mainly. Couple years back my car would creep even with my ported wastegate. I asked a few members and they led me to install a restrictor plate in my exhaust, though it is not ideal, it worked! I forgot what size i put in.

 

That's not the solution I'm looking for lol. >_>

This car pulls damn hard for what it is. I'd like to keep it that way if possible.

thewird

 

I'm curious to know more about this as well.. my fd is all stock (has downpipe and rb catback, but stock main cat in place - oh and BNR's with ported wastegate) and more often than not I see this "exact" level and amount of boost creep, exactly to 12. If it's a cold nite, I have to ease off the throttle big time.

I have not tried a Version 1 or Version 2 set with an ebc or like Damians setup (my dream track fd) yet, but like the other guy just said, something to restrict the exhaust would prolly be the safest.. and quickest way to test.

I would love to know another way too tho. maybe trying a different ebc if you can get your hands on one. like the hks 6 or something comparable.

 

My issue is unrelated to a boost controller as it was doing this before installing.

Also, it doesn't go exactly to 12. I let off at 12 because that's about where it starts running out of fuel (100% duty cycle). If I would hold the throttle, it would keep climbing.

thewird

 

I think you have a problem with the hose hook-up to the actuators.If you are running on the waste gate spring then your primary turbo pressure should be the same whether you use version 1 or 2---so why is it 2psi higher for version 2?

 

I'm 100% sure they are hooked up correctly. I checked and double checked it multiple times.

thewird

 

Oh yes I forgot to mention,I have a Greddy E-01 controller hooked up per version 2 and I run 12psi before and after transition (with my BNRs).
I have the hard pipes capped to prevent vacuum leak and pressure bleed from the tanks.
I have adjusted the transition to high rpm for smoothness,so basically I get 12-10-12 at 6000rpm.(courtesy of Apex-i)

 

Maybe you need to lengthen the waste gate actuator rod??

 

thewird,

It sounds like the wastegate, even ported, cannot handle the amount of flow you have with your setup. This is not unheard of as several people have needed alternative solutions. If this is the case, you have a few options:

1. Use a restrictor plate. I doubt you would need much restriction at all to bring it under control. I also doubt you would notice it there.

2. Get a pre-control door and replace it for the wastegate door to allow for more porting. The pre-control door is larger.

 

I'll try option 2. Thanks.

thewird

 

^ please keep us updated. I'm very curious on this situation.

 

I have a set of BNR 3's with about 8k mileage on them now, seem to have a slight oil leak on secondary turbo which I hear is pretty normal?

But, I was thinking that one of these actuator rods "could" help control boost creep? The turbo precontrol? ( top rod ) has an adjusting nut, but I haven't adjusted it one way or the other.. yet. Anyone else try this?

I'm surprised to see the DP still has the high temp paint on the outside of the wrapping.

 

I never noticed that on my old BNR's. Might be interesting if its adjustable.

Forgot to update. Nothing was able to fix the problem. We pulled off the turbo's to see if it could be ported more and try Mahjik's suggestion and then found there was a major crack in the housing near the wastegate. So we tried replacing the turbo's with a good set and all problems were solved. So it was assumed the damaged housing was somehow causing the issue.

thewird

 

I was going to suggest bigger injectors so you don't run out of fuel. Then you could enjoy the extra boost.

This of course is a sad attempt @ a joke

 

Until you find a solution, if you have the PFC or another programmable ECU, you could pull the timing to zero deg at whatever pressure you don't feel comfortable with. That is both a safety net and a way to stop boost creep with no restrictions needed at the exhaust. This is the way I deal with mine.

- Sandro

 

That's hardly the correct way of dealing with it lol.

thewird

 

It works for me just a bit of misfire at the end of the occasional straight...
and superfast spool up before it...

RP Supra pump, direct wiring to the battery, stock injectors, no cut, boost target 13 psi, ignition soft cut at 14 psi, 10.20 AFR when safety row is hit and injectors are max out. Single digit knock.

In all cases though, it's a good safety net to have, as per Chuck's notes.

- Sandro