Cobb Ap FMIC map with Cobb FMIC not driveable

[Unoriginalusername]

I am getting boost cut galore after the temps cooled down and the humidity left today... i cleared the data and did a few hours of driving and i can't get in the gas at all without a huge cut. AP reads 22 or 23 psi before and then the cut happens.

are there better fmic maps on the way? the car is not useable for performance now and i can't say that is what i was after

[numbnuts22715]

What other mods on the car?

[Unoriginalusername]

Originally Posted by numbnuts22715 What other mods on the car?

cobb sri, cpe tbe with a cat. Cobb fmic and ap... hks recirc bpv today and it was the same

[gsrtype1]

wouldn't you hit cut anyway if your getting 22-23psi?

[numbnuts22715]

Originally Posted by gsrtype1 wouldn't you hit cut anyway if your getting 22-23psi?

There has to be a reason why hes seeing so much boost though.. that's not right.
Did you drive around and give it time ot adjust?
are you sure all of the clamps and couplers are tight and on correctly?

[JeepJockey]

I thought aaron was getting the same cut with the FMIC maps and had to back down to the Stage2+ maps. His car cut without the AP after the addition of the intercooler.

[Lex]

I think the cut at 22-23 psi is fine. The question is - why are you getting so much boost so early? Check wastegate connection.

[Unoriginalusername]

Originally Posted by Lex I think the cut at 22-23 psi is fine. The question is - why are you getting so much boost so early? Check wastegate connection.

i know three of the four people locally who have the ap, cobb fmic and similar mods. the third one was getting installed today so we'll see how that goes but my other friend can't drive his car either.

all conections are tight, i don't think the maps are where they need to be yet.

[ZooZoom]

he didn't say it was over 22-23 in a particular gear.....namely 1st or 2nd gear.

with a sri, fmic, and open exhaust it seems reasonable to boost that high later in 3rd or 4th gears without proper boost control.

the real question is: Cobb fmic map supposed to regulate boost lower than that?

then the inevitable questions/arguments if its "running out of fuel pump" or simply cutting back due to over-boost reading?

[Unoriginalusername]

Originally Posted by ZooZoom he didn't say it was over 22-23 in a particular gear.....namely 1st or 2nd gear. with a sri, fmic, and open exhaust it seems reasonable to boost that high later in 3rd or 4th gears without proper boost control. the real question is: Cobb fmic map supposed to regulate boost lower than that? then the inevitable questions/arguments if its "running out of fuel pump" or simply cutting back due to over-boost reading?

everthing on my car from suspension to power with the exception of the tbe (which is catted and ok according to cobb) is cobb so it should all work together better then it is imo

[Lex]

Have you asked them what the boost cut is set at for that map? Perhaps the wastegate becomes inefficient when you open it all up. It's very common to get boost creep on internal gates. Does it spike to 23 or creep there?

However, you are right in that they should have accounted for that in the tune.

[ZooZoom]

Uno - I completely agree with you.

I was just suggesting it might be excess boosting (boost creep is correct term) and not necessarily fuel-cut due to fp pressure drop.

Boost creep is attributed to the limited flow volume of the wastegate port and how the shutter valve/actuator/controller interact.

My Subaru legacy suffered from boost creep when I put a full open (non-catted) TBE on. Solved it with a metallic hi-flow cat welded in.

but since you've got a catted TBE, it seems less likely.

I agree that the Speed3 is much more finicky when you go beyond the simplest mods like intake & better TMIC. (that's why I've been staying there for some time).

[Unoriginalusername]

Originally Posted by Lex Have you asked them what the boost cut is set at for that map? Perhaps the wastegate becomes inefficient when you open it all up. It's very common to get boost creep on internal gates. Does it spike to 23 or creep there? However, you are right in that they should have accounted for that in the tune.

it spikes vs. creeps which is why i don't think it is a waste gate issue per say vs. the tune itself as the wastegate is electronic and is controlled by the ecu.

it happened easier and slightly more often with the HKS BPV but it happened without it to... in either case as cobb is coming out with a bpv the tune should account for any increased ability to hold the requested psi

[Lex]

Wastegate is still vacuum actuated and the boost control is done using a solenoid only used to increase boost (bleed boost from wastegate seeing it), not lower it. If you open up the intake and exhaust too much the wastegate opening won't be able to bypass enough exhaust and you will get higher than desired boost no matter what the ecu is trying to do. Lower ambient temps make this worse still.

How much boost were you seeing before the FMIC?

[Unoriginalusername]

Originally Posted by Lex Wastegate is still vacuum actuated and the boost control is done using a solenoid only used to increase boost (bleed boost from wastegate seeing it), not lower it. If you open up the intake and exhaust too much the wastegate opening won't be able to bypass enough exhaust and you will get higher than desired boost no matter what the ecu is trying to do. Lower ambient temps make this worse still. How much boost were you seeing before the FMIC?

after a flash 18 at peak but later was 16-17 on avg. depending on the weather most often

[dadasracecar]

BETA anyone? How can you guys tolerate this from COBB? Letting a customer flash his car so that now he's seeing 23 psi on the stock turbo is stupid, if not negligent.

[dadasracecar]

THere is no way this is boost creep with the stock turbo. I was running a CAI/FMIC setup with the complete stock exhaust on the speed6 and could dial whatever boost I wanted. Never creeped, ever. The stock wastegate is more than capable of bleeding enough exhaust for the stock turbo.

[aaronc7]

yep sounds just like what I got with the FMIC maps. Should be new beta maps soon..cmon christian! lol

BTW unoriginal... stage 2 + sf v101F map works great for me. let me know if you want/need it!

[Lex]

Have you tried going to an AP map that opens the wastegate earlier? Like one with lower target boost?

[Lex]

Originally Posted by dadasracecar THere is no way this is boost creep with the stock turbo. I was running a CAI/FMIC setup with the complete stock exhaust on the speed6 and could dial whatever boost I wanted. Never creeped, ever. The stock wastegate is more than capable of bleeding enough exhaust for the stock turbo.

You had the stock exhaust though. Exhaust has the biggest effect on creep.

[ZooZoom]

Intake/Exhaust flow capacity has EVERYTHING to do with boost creep. It has little to do with the by-pass valve and wastegate actuator (i.e. ecu function control) as long as they are functioning properly. Its purely a hardware thing.

and from my experiences, I can tell you that "boost creep" is a misnomer in terms of suggesting it's a slower transient event.

when my Subaru had boost creep, it would SPIKE RAPIDLY FAST at pressures 3-5 psi higher than the ecu was set to limit.

boost creep does not behave like an "inverse" of graceful boost fall-off as rpms rise. its very immediate and harsh.

[Erich]

Originally Posted by dadasracecar BETA anyone? How can you guys tolerate this from COBB? Letting a customer flash his car so that now he's seeing 23 psi on the stock turbo is stupid, if not negligent.

We get it you don't like COBB and CP-e is god. It would be nice not to have to read your BS in every thread about a COBB problem.

[Lex]

He might be able to limit boost a little better by allowing the gate to open earlier (ie set the targets lower)

[ZooZoom]

Sorry, nope. Again, is a physical orafice problem......if it's really boost creep.

No matter how soon or how quickly the wastegate valve is opened, if the engine's air pumping capacity/density (intake & exhaust in conjunction with denser FMIC cooled air) exceeds the wastegate's physically limited flow capacity then a turbo is capable (with sufficient compressor flow) to overwhelm it.

this is the principle reason for External wastegates on really big turbos. but it's most definitely a problem on internally-gated turbos as you purposely reduce air flow constrictions. I've been there - done that.

[dadasracecar]

Originally Posted by Erich We get it you don't like COBB and CP-e is god. It would be nice not to have to read your BS in every thread about a COBB problem.

I never mentioned cp-e but the OP flashed his car with the map specified for his setup - all COBB products - and he reports "undriveable" and boost spikes up to 23 psi. That's fucking dangerous to both driver and motor. I'd flash that thing back to stock and see if he's getting "creep."

Fellas, it's not about me or my relationship with cobb. I'm not bashing. If I was in the OP's place I'd be scared about what the next map would bring. I'd fear things like 23 psi of hot air from a completely maxed turbo on my stock block.

[Lex]

You are not taking into account the fact that the gate is closed to begin with and there is a transient time period related to opening it and the onset of it starting to open. If the gate was opened all the time you would be correct but this is not the case. The principle is correct however.

[ZooZoom]

remove the vac line from the wastegate actuator entirely. that ensures that the WG flapper valve is fully open after you exceed the WG actuator spring setting, usually around 7-10 psi (not sure what the stock WG spring rating is).

if you get boost spiking (boost creep) then that's what you're dealing with. may need to move up to a stock turbo kitted with a bigger wheel and maximum ported WG opening.

[Lex]

Originally Posted by ZooZoom remove the vac line from the wastegate actuator entirely. that ensures that the WG flapper valve is fully open after you exceed the WG actuator spring setting, usually around 7-10 psi (not sure what the stock WG spring rating is). if you get boost spiking (boost creep) then that's what you're dealing with. may need to move up to a stock turbo kitted with a bigger wheel and maximum ported WG opening.

No no, don't do that. The vacuum line is what applies the boost pressure to the actuator opening it. If you are going to do anything, bypass the solenoid with a piece of hose, but don't disconnect the actuator or the WG will never open.

[ZooZoom]

you may be right. don't mean to sound like I really know what I'm taking about here.

but I do know there's a way to make the WG actuator operation limited (max. psi) by only the WG spring.

that's why I paid a tuner (Harmanmotive in L.A.) to do all my Subie work.!

FWIW - the WG spring is not the spring in the by-pass/BOV. Its inside the actuator attached to the turbo.

[Christian.]

Well, hopefully I can use this post to demonstrate proper etiquette. Instead of bashing, I will try to contribute to this conversation. I too am dissatisfied with the way our FMIC calibrations are performing. We are currently revising these calibrations now and we should have new revisions ready for release by the end of next week. Aaronc7 informed us of this inconsistency in performance a few weeks ago and we started working on a solution then.

Boost creep is a mechanical issue and cannot be tuned out, just so you are aware. Much of how a turbo responds to having too small of a wastegate passage depends highly on the exhaust system before and after the turbo. Comparing how a turbo performs with with a stock exhaust system, a catted high flow exhaust system, or a catless exhaust system is vastly different, and will depend on several factors. I put this document together to help some of our Subaru AccessTUNER Race users determine if they have a mechanical boost creep issue. The data was collected from a Subaru, although the same principles apply to any turbocharger.

Please read through and let me know what you think of this document = How To Determine If You Have Mechanical Boost Creep v1.01

Boost creep is an entirely different phenomenon than boost spikes, and I want to make sure we can discern between the two. I will be happy to discuss the differences between these two different events if you all would like?

Take care,
Christian.

[kingpin748]

Do you guys have a big list of all these helpful little documents sitting somewhere that I could get to them?

[Lex]

Originally Posted by ZooZoom you may be right. don't mean to sound like I really know what I'm taking about here. but I do know there's a way to make the WG actuator operation limited (max. psi) by only the WG spring. that's why I paid a tuner (Harmanmotive in L.A.) to do all my Subie work.! FWIW - the WG spring is not the spring in the by-pass/BOV. Its inside the actuator attached to the turbo.

It's a vacuum actuated diaphragm inside internally gated turbos. It is not at all related to the bypass valve which lets out excessive air in the intake tract when the throttle plate is closed.

So the boost you are applying to the actuator pushes it and in turn pushes the wastegate flapper open. An internal gate meant to open at 8psi will require that 8 psi applies to the actuator port to open the flapper. The only other way to force i always open is to jam the gate open or use an external pump not attached to the engine to open it as you wish.

In external gates you can set this opening force required by changing the spring (4 psi, 8 psi etc). However in internally gated turbos the wastegate is not serviceable and the diaphragm should not be opened up.

Christian, is it boost creep or spikes (due to too much delay in the solenoid actuation) what he is experiencing here?

[Laloosh]

lol still beta testing? Funy my fully bolted car doesnt creep or spike...gee i wonder why, thats right im not a fucken 700 beta tester thats on the verge of blowing up

[aaronc7]

not a "super duper mod" anymore huh, laloosh?

[kingpin748]

Originally Posted by Laloosh lol still beta testing? Funy my fully bolted car doesnt creep or spike...gee i wonder why, thats right im not a fucken 700 beta tester thats on the verge of blowing up

YEAH! Here we go again! I'll be back in a few hours to catch up on the drama. Go ahead without me.

[Laloosh]

Still slow huh? being that i didnt do shit modding wise it doesnt effect me either. My attitude wont change. And being that this is a problamtic cobb thread, its all fair game

Do you realize what fuel cut is at 23 psi........that ure engine running lean as fuck at 23 psi.....keep testing, maybe cobb will eventually get it right, in the mean time your decreasing your engine life...one stutter/cut at a time.

[mk_slayr]

Originally Posted by Laloosh Still slow huh? being that i didnt do shit modding wise it doesnt effect me either. My attitude wont change. And being that this is a problamtic cobb thread, its all fair game Do you realize what fuel cut is at 23 psi........that ure engine running lean as fuck at 23 psi.....keep testing, maybe cobb will eventually get it right, in the mean time your decreasing your engine life...one stutter/cut at a time.

-
Wasn't there a guy from Canada, Tiniz or something like that, that's had problems with his CPE flash? Something about being undrivable? I believe he had a turbo back with a front mount. Btw funny enough, it was suggested that he check his spark plug gap, something that Cobb was ridiculed for suggesting.

Iirc, he has to now drive 10 hours back to cpe to get it sorted out.

At least with the cobb if you have a problem you can change maps on the fly...

At least try to call it straight. If you don't like a company that's fine, it's getting ridiculous though.

I'm almost embarrassed to point new people to the AP thread for the maps. High school was a while ago but people still seem to be acting like kids.

Mods should have a bit more class and unbiased statements.

Bash me if you want, I could care less, I probably won't check back for a few days, I have a life outside the internet.
-

^ to the OP,

How did you put your mods on. Did you space them out at all or install them all within a relatively short time frame?

[dadasracecar]

Actually he came down and it was sorted out personally by Jordan today. Had nothing to do with the flash. Believe it or not it was weird reaction to a one of the PID parameters of the boost control. I don't know what he set it at but when they went back to the default setting his hesitation went away completely.

THanks for bringing that cp-e topic up in this COBB AP/FMIC thread. It's extremely relevant to this situation...

[Laloosh]

yea start your own thread if u want to compare cpe parts lol

[dadasracecar]

One more thing, if you're reading boost on the AP, i.e. over the OBDII port, realize that the stock MAP sensor is only good to 22-23 psi. It won't ever read higher than that. So unless you have a gauge that goes to 30 or above and that's what you're reading boost from, there is really no way of knowing what your actual spike was.