Hey everyone,

As the title says, I have an odd boost problem. My mods are in my sig below.

If I start my car, drive it around to full operating temperature and then go WOT in first gear my boost looks like so.

First gear, 8 psi, not sure what it creeps up to as im watching the road.

Second gear,and third gear my boost creeps up to 12. So its holding at a desired level, but its too bad its creeping up there.

So heres the problem.

If I start in third gear, and haven't gone WOT in any lower gears my boost goes like so.

3krpms-6900 rpms it will creep up to 12 like normal. but the SECOND, and I mean faster then I can blink, I hit 7k rpms my boost spikes up to 16.8 psi, and I hit fuel cut. Its not creeping up there, its instantanious.

What I dont understand is that it doesnt happen in first and second gear. (not sure about 4th) only if I start in third.

Steve Kan suggested I changed my plugs ( had an incident where they got INCREDIBLY fouled out) And I did, but that didnt change anything.

so I hope this is enough info and someone might have an idea, because Im incredibly confused.

Thanks again!

Steve

 

just a thought: could it have something to do with limitaions on the boost controller??
FYI i have no experiance at all with boost controllers, but it feels like something is popping over some limit

 

I would think you need to port the wastegate.

 

I don't think you need the Blitz boost controller if you have a Power FC.

My car is similar in setup and with my Power FC the boost is set at .9 and I do not get any creep or spike.

 

ok reply time

First. Porting the wastegate is not going to fix my boost problem, it will fix my creeping from 8-12psi. But at the speed that the boost goes from 12 -16.8 is faster then you can blink, and thats not creep.

Second, The power FC to some isnt as good at controlling boost as others. And I got the Boost controller before I got the power FC.

So yeah.

Still havent figured out the problem =\

 

"3krpms-6900 rpms it will creep up to 12 like normal. "

In 3rd what is your boost pattern? What does it drop to in the transition? If its not dropping your secondary isnt kicking in at all. The problem may be that at 7k your secondary is kicking in and spiking the boost up that high.

 

Your discription of the problem isn't very clear. From the original post it appears that you are describing the primary boost climbs slowly to 12 psi and the secondary boost doesn't come on until 7K. You need to explain your boost pattern in better detail for us to help.
Also, do you have the boost controller running in automatic or manual mode?

 

Either Port the wastegate or get an aftermarket one.

 

I assume or correct me but when it moves up to sixteen you can feel the extra power the engine is producing even for the small time your there? If not and theres enough time at sixteen to feel something, you are looking at a electrical device and it could be skewed as well. If I see a temp gage reading 280 and don't have a boil over it would make one think about the indicator. Just a thought and since we only have a little info thought I would mention this.

 

Sorry let me be more clear.

My Boost in third gear will start at 7psi when the primary comes online with full boost. And its hitting 7 PSI because the boost controller is at 0 with the manual setting, so basically turning the boost controller off,

It will creep up to around 10 or so, then the secondary kicks in like normal and then it creeps up to 12 by about 6.5k rpms. All is fine during all of this. The system works perfectly.

the instant I hit 7k rpms and NEVER anytime before, I spike to 16.8 psi quicker then you could blink; FAR quicker then the secondary takes to come online. Its seriously faster then you could imagine. So once it hits 7k rpms, up goes the boost, in comes fuel cut, out goes one giant backfire and the party is over.

I like to think of myself as pretty mechanically inclined for my age, all mods have been done by myself, but this one just goes right over my head.

Nope. The millisecond it takes to hit that boost, my pfc throws in the fuel cut and everything just stops. I know its not a mechanical or electronic device failing because the PFC is throwing in fuel cut.

I just cant figure it out. I have no problem unless I start my run in third.

I have to try to figure this out before I go to gingerman the 31st'

Thank you all for your help.

 

bmp

 

this statement makes me think two things...

1) Your pressure chamber or vaccum chamber lines could have poped off.

more questions...
2) have you done a silicon hose job? and Do you have the wg and pc pills in the lines?

 

Yes I did the vacuum line job about a year ago, and everything worked perfectly afterwords.

And no, I dont have the pills in the line because im running an aftermarket boost controller.

I dont understand, if the lines popped off, wouldnt I have the opposite problem in that I couldnt build any boost?

 

I had a boost problem where I couldn't transistion into the secondary, UNLESS I boosted in a gear previously...i.e. pressurizing the pressure chamber thru the check valve, then once filled... I could boost properly.

check your vacuum chamber hose.

did all this happen after the boost controller install?

primary should 10psi instantly unless 8psi is what you have it set too.

 

When you remove the pills and or turn your boost controller off, the system only boosts to 7psi.

My secondary transition works perfectly every time, right on the dot. Dip from whatever it crept to, so say it crept from 7psi to 10psi from 3k to 4500 rpms. Once it hits 4500 it will dip down to 8 when the secondary comes online, then go back up to 10 after the transition. THEN It starts to creep again and will get up to 12 by 6900 rpms.

the second I hit 7k, it spikes faster then you can blink to 16,8 psi, and I hit fuel cut.

This problem is if I START in third gear and HAVE NOT boosted in previous gears. If I boosted in PREVIOUS gears, then the problem doesnt exist.

this is very hard to explain so I hope your all understanding

please help!

Steve

 

Oh and this all happened when I didnt go WOT for 4 months. The car WAS driven periodically, but I did not go WOT ever as I was temporarily running the stock ECU with a midpipe.

 

so you are saying you can hit 16.8psi with no cat (danger zone) and the boost controller turned off?

recheck the wiring/lines on that thing.

Does this spike pull like all hell? or is there no difference in power? Rpms shoot up as well?

electric boost gauge or manual...defi...electric I'm guessing.

(btw...All mods done bymyself when I was 17 (im 18 now) <---this part of your signature is lame )

 

Yes, Boost controller off. Its like having no pills in the lines on a stock setup. I keep having to re explain all this lol.

As ive said a few times so far, the second I hit 16.8 psi, the rpms go nowhere, and I dont feel any more power because the power FC initiates fuel cut. Yes, with no cat, I am running a midpipe, and yes I know its a danger zone. Turning a boost controller off, reverts it back to the stock system basically without the pills.

I'm not mesuring boost from my guage, im measuring the speed it spikes at because I couldnt even catch the change.

The digital SBC-ID boost controller is what im reading it from.

Thanks for the comment on my signature. That was a few years ago as you can see ive been here for a while. Back then when I got my car, I was proud of being able to do my own work when I was 17, and prove that not all the young owners are truely idiots.

But thanks for showing how you feel.

 

Maybe your boost controller is going.

 

I was thinking about that, and im gonna run the two lines together to see if its sticking or somthing. I'll post results later.

 

well wait... if my boost controller is off, then I dunno how it could be failing exactly.

 

I'm tired of seeing your cocky *** asking questions and then making fun of everyone that replies

so I'll set a few thing straight for you.

If you understand how electronic boost controllers work you'de know that when you have the boost controller OFF but there is power to it then you will get your lowest boost which is 8 for you and creeping to 12 totally normal for a ported motor or midpipe. If you have the solenoid and everything in there but dissconnect the boost controller of power then you have no boost control at all. Any way what I'm saying is that your boost control solenoid is still working even when you have it off because there is power to it.

Next, why would you get that boost contoller when a profec b has been proven to work amazing in conjuntion with a pfc.

I dont know the history of your car but if I were you Id take out the boost controller totally and run with no pills in the lines like now and see if this happens still. then if it does you know its something else. Then youll have to start checking pressure chambers and solenoids especially the wastegate solenoid.

do whats obvious first and take out the boost controller.

 

Thanks for the reply,

First off my intention was not to come off as being cocky. I was giving answers to questions, and the questions were being re asked. How was I making fun of people? The same questions were repeatedly asked, and I had answered them before. I mean people were suggesting I get an aftermarket Wastegate, when we're talking about the stock twins... It just seemed to me that they were going no where is all. I do appreciate the replies, but it was bothering me that the same questions were being asked. Sorry I came off ******* ish.

I had the boost controller way before I got my power FC. At the time, I wasnt expecting on getting a power FC for a long long long time. However things changed, and I ended up in the position I am now. The situation does suck, I could sell it and use the Power FC, but I'm commander-less at the moment so I couldnt make any adjustments.

I understood that the creeping was normal, but it was misunderstood that I thought that was a problem because I didnt understand it was normal to see that with a midpipe. It seems that it was misunderstood that when my boost went from 12-16.8 psi that it was creep, but it happened too fast for creep. Perhaps I didnt explain it very well.

Is running the two lines to the solenoid together as just hooking everything back up normally but pill-less? If I do that and cut the power would it be the same? or should I just remove it entirely.

Again im sorry if I came off as being cocky, I was just tired of reanswering things. And then someone directly insulted my signature from years ago. when I was trying to show that some younger owners can be respected a bit more then being accused of idiocy due to young age. I'm sorry if I came off as cocky when I Was offended by that. I'm not sure how Im supposed to reply if someone replies to me in an insulting manner. I do admit to being a little too assholeish and I appologize for that. Sorry dubulup, I probably replied to you a bit on the ******* side when you're trying to help, but please dont insult somthing in my signature when you dont know why its there.

Thanks for your time.

 

ok cool

sure just unconnect the power from the controller and take off the lines and then put back the lines just like it was stock without pills and try it. Once you do this then you can see if its the boost controller or not and move on. Im glad you were watching the boost gauge because if you dont let off with 16.8 psi youll blow the engine. Even if the pfc does try to cut boost it may not be enough and plus you are right on the edge of what the stock map sensor can recognize. It reads 1.15bar which is 16.something. So if you boost to 25psi it says oh **** lets put in fuel for the highest # I can measure 16.__ and you blow the engine. You can have your pfc tuned all day to dump fuel once you overboost but it can only provide the fuel for the max # the map sensor reads.

 

Ok. Here's a SWAG. Have there been any instances that a WG would close up at high RPM? Obviously you're creeping to 12 since the WG can't bleed off enough air. That spike, to me, could easily be contributed to the WG closing up for whatever reason.

That being the case, solenoids, vac. lines and whatnot should be checked. The fact that it's only happening in 3rd boggles the mind. I dunno what to tell you there. Do you need a commander or datalogit? If it's quick, you can use mine since I'm still outta commission. That might help to see what the PFC is looking at and may give you some answers.

[hijack]BTW, I'd love to get out to Gingerman. I started a thread on that, but time isn't on my side and I'll still be immobile by then...[/hijack]