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Not Hitting Boost Like It Should Be..


AdrianGTT
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To be honest if it is happening around 3000-4000rpm and sounds like a rev limited.

If you find that it wont rev past that point then its 95% of the time your AFM

Try using a friends to test this.

But my friend just had this exact problem with it only reving to 3000-4000rpm and then would limiter bash.

It turns out his AFM was not plugged in

I might also add that it could be hitting boost cut.

You can adjust your boost by that black thing you are holding in the picture above.

It should have a screw or maybe the whole thing itself can turn.

Turn it anti clockwise which should turn the boost down

Repeat and test

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I looked at that Controller and it has no screw in it, but i can see the thread :/

im a bit lost to where my problem would be, can i rule anything out like AFM, pod filter?

http://i1272.photobucket.com/albums/y396/Adrian701/IMG_0140_zps511f9081.jpg - what about these nipples, clearly their are hoses missing off them, and that bolt i found in the pipe nipple kinda puts me off..

Where would i go from here, thank you!

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I looked at that Controller and it has no screw in it, but i can see the thread :/

im a bit lost to where my problem would be, can i rule anything out like AFM, pod filter?

http://i1272.photobu...zps511f9081.jpg - what about these nipples, clearly their are hoses missing off them, and that bolt i found in the pipe nipple kinda puts me off..

Where would i go from here, thank you!

Only way you can rule out the AFM or Pod is by replacing them with another working item.

As I said I can pretty much be 95% sure its going to be the rev limited of a faulty AFM.

Does unplugging you AFM change anything?

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unplugging the AFM will make the idle horrible, so i need to get my hands on another pink label AFM? it needs to go regardless since the top mounting flange on it is snapped.. Should i worry about the hoses? if they are in the right place or not, how can i find out

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unplugging the AFM will make the idle horrible, so i need to get my hands on another pink label AFM? it needs to go regardless since the top mounting flange on it is snapped.. Should i worry about the hoses? if they are in the right place or not, how can i find out

Hoses are fine.

When you rev the car to 3000rpm does it jolt and splutter or does it sound like the rev limiter?

You should get an AFM anyways as you said and that will possibly fix the problem.

It it doesnt then we can move onto other things such as changing spark plugs and testing coils.

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i went for a drive again, and you can hear the car boost but its gutless, and sounds rough the whole car vibrates more then it should almost making a WRX sound when accelerating, the idle sound is still rough thats the best description i can give right now!

ill start looking around for an AFM, i really hope its only the AFM and nothing serious...

thanks for your input mate

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that black bit is a GFB boost controller, should have a allen key screw in top.

screw it all way in till it just bottoms out, then wind out 3 turns, go for drive, adjust for desired boost.

i got one running 10psi, goes fine. cheap, but so was the car and its a weekend hack.

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To be honest if it is happening around 3000-4000rpm and sounds like a rev limited.

If you find that it wont rev past that point then its 95% of the time your AFM

Try using a friends to test this.

But my friend just had this exact problem with it only reving to 3000-4000rpm and then would limiter bash.

It turns out his AFM was not plugged in

I might also add that it could be hitting boost cut.

You can adjust your boost by that black thing you are holding in the picture above.

It should have a screw or maybe the whole thing itself can turn.

Turn it anti clockwise which should turn the boost down

Repeat and test

well whats happened to the stock boost feed from the compressor cover then?? im confused why the boost is fed from that t section...

how could it be a rev limiter cut? hes got a stock ecu doesnt he??? he'd need atleast a power fc to implement a rev cut?

what boost cut are you talking about, i have a s2 and when i had stock computer with high flow there was no such thing, it just boosted up and up and up so im confused here... i think he should just connect the stock setup like it would be stock, and replace afm and connect filter again ...

If your after an afm i have one sitting on my desk here that no one would buy, if you pay for postage its yours...its mint

Edited by SliverS2
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Silver go turn your boost up and see what the stock ECU does without nistune. It revs hard and then cuts like a massive jolt.

Or go unplug your AFM and notice how the car won't rev past 4K it's a safety feature built into the stock ECU to make sure it won't do much damage when it doesn't know the air to fuel ratios.

The aftermarket boost controller connects to a boost source most probably on the intercooler pipe and then into the actuator.

On the stock setup it also has a line going to the intake from what I remember and this is blocked using a screw or in the case of an aftermarket intake it's non existent.

No offense bro but maybe you shouldn't be giving advice if you can't spot an aftermarket boost controller setup

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SilverS2, pm'd

thanks for everything guys, ive ordered a few parts, a new K&N apollo pod filter, ARK Design Boost Controller, and a Turbosmart Boost gauge, which should be here next week, i take it that ill have to return the standard setup when i take out that GFB boost controller?

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No. If you're taking out the little GFB controller to put the new one in, then just install the new one according to either its instructions or common sense (depending on which makes the most sense!). There's only 2 main connections to teh car. 1) The boost sense source (off the compressor housing or the intercooler pipe) and 2) the actuator. It's difficult to make a proper mistake.

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Silver go turn your boost up and see what the stock ECU does without nistune. It revs hard and then cuts like a massive jolt.

Or go unplug your AFM and notice how the car won't rev past 4K it's a safety feature built into the stock ECU to make sure it won't do much damage when it doesn't know the air to fuel ratios.

The aftermarket boost controller connects to a boost source most probably on the intercooler pipe and then into the actuator.

On the stock setup it also has a line going to the intake from what I remember and this is blocked using a screw or in the case of an aftermarket intake it's non existent.

No offense bro but maybe you shouldn't be giving advice if you can't spot an aftermarket boost controller setup

Kasko- i used to have a stock computer and it allowed alot of boost with none the the jolting cuts, it just lost alot of power , you have a series 1 and he has a series 2, thats why i thought id comment, no offense taken. :) Im sure theres good reason to take the boost reading from the comp cover or close by, taking it from the manifold cant be right, what about the pressure drop thru the intercooler,

Edited by SliverS2
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While we are talking about boost controllers, I have a turbosmart boost tee connected to the plenum. It is normal for them to bleed air at idle from the little port on the side yeah? Or is this why you say connect it to a pressure source?

Also since I fitted my ATR43G3 last week I have noticed that manifold vacuum has dropped from ~24inhg to 20inhg. I made up a 4" intake and after I reinstalled noticed I had an extra vacuum line that I totally forgot where it goes. Stuck a bolt in it for now, it comes from the t piece that supplies the wastegate actuator. Anyone got any idea where that is meant to go?

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