PDA

View Full Version : boost problem



chriSTi
11-03-2007, 19:02
howya lads can anyone shed some light on my boostin problem... when i put the foot down all is well til full boost (1.4)but only stays for about a second then drops to 1.0 - 1.1 and sometimes it may creep up another small bit, and as I said before it has a slight clicking on acceleration, it doesn't happen EVERY time, any advice much appreciated.... thanx :ponder:

davelegacy
11-03-2007, 21:12
boost control solinoid usually cause of clicking and could be your answer...........

Renno555
11-03-2007, 23:34
If it didnt click you would have unusual boost or overboost so you want to hear the clicking noise anyway. Did it always hit 1.4 bar and hold it, and only now it doesent ?

davelegacy
12-03-2007, 00:06
doubt it constantly hitting 1.4 bar???????? :ponder:

Renno555
12-03-2007, 00:09
... "when i put the foot down all is well til full boost (1.4)but only stays for about a second then drops to 1.0 - 1.1"

I took it that his car is set up for full boost of 1.4 bar but the problem was that it isent holding full boost ( 1.4 bar ) but droping back to 1 or 1.1 bar.

davelegacy
12-03-2007, 00:24
no there is no management system on car...... so overboost could be caused other things wouldn't you agree??

Renno555
12-03-2007, 00:42
Yeah god knows then.

chriSTi
12-03-2007, 07:09
... "when i put the foot down all is well til full boost (1.4)but only stays for about a second then drops to 1.0 - 1.1"

I took it that his car is set up for full boost of 1.4 bar but the problem was that it isent holding full boost ( 1.4 bar ) but droping back to 1 or 1.1 bar.
exactly .. its jus not holding full boost... the problem only started when the clicking started???

huzzy
20-03-2007, 23:02
I have a simillar problem when I floor it I get a slight sqeeling noise (turbo spooling up)is the noise ok??? it will hit 1.3 bar and drop down to 1.1 or 1.0 dont know what its set up for.

also sumtines it will build up unevenly its kinda a ON and OFF felling .
COULD THIS BE MY BOOST CONTROLL SOLINOID :oops:
sorry for hijacking CRIS :cheers:

chriSTi
21-03-2007, 07:18
I have a simillar problem when I floor it I get a slight sqeeling noise (turbo spooling up)is the noise ok??? it will hit 1.3 bar and drop down to 1.1 or 1.0 dont know what its set up for.

also sumtines it will build up unevenly its kinda a ON and OFF felling .
COULD THIS BE MY BOOST CONTROLL SOLINOID :oops:
sorry for hijacking CRIS :cheers:
ha ha no problem mate... not sure about the squeelin noise but it sounds similar .. i was told its the solenoid so I'm gettin an Apexi 3 port one supposed to be the bizness.. George of GT performance will look after ya.. :thumbsup:

thedoc
21-03-2007, 07:40
as far as I'm aware this is normal my last two imprezas have performed in this manner hits 1.4 bar for a second and then drops back to 1.1 sometimes even .9.

GT performance
21-03-2007, 09:18
@ thedoc

thats not normal. can happen for a number of reasons. that problem needs to be sorted asap or one of these days you'll be forking out for a rebuild


George

Niallyboy
21-03-2007, 09:52
As George say's :thumbsup:
You car should always hold boost lads, any drop in boost pressure
means there is a problem.

Huzzy any hesitation on acceleration normally indicates dirty plug's / faulty sensor

1.4bar boost is pritty high :shock: :shock: get it checked

Niall.

Norris!
21-03-2007, 09:56
before the bang :)

thedoc
21-03-2007, 11:46
Dont mean to contradict anyone but i posted this problem on the uk sites asking for an opinion form sti owners with boost gauges and theirs all performed the same peak boost of 1.3-1.4 bar settling back to between .9 and 1.1 bar

GT performance
21-03-2007, 13:15
you are right there are a lot of them doing that for different reasons, the problem ive noticed on forums especially uk ones is although you can receive good advice on them from well experienced owners and specialists you also get replies from people who really have not got a notion of what they are talking about but think they do. the other problem is you get lads who will read books and books on cars and read crap on websites and then go handing out advise on something they think they know about, when really they havnt a ****ing clue :angry:

at the end of the day forums can be fantastic and you get great advise on them on the other hand they can be a curse and it happens to lads al the time where they post a question and they get bullshit replies. my advise is if you have any problems with major components such as engine, gearbox, brakes etc. go to a specialist about it or even them a call. these cars are too expensive and too precious to be taking chances with.
when you got your replies on the uk site did any specialist reply and say it was normal??

George

GT performance
21-03-2007, 13:17
not having a go by the way mate. :thumbsup: just pisses me off when idiots go advising people on something they dont understand

thedoc
21-03-2007, 15:56
A bit o.t.t there man, I'm just saying on the boost part of the question that my sti has acted like that since i have it, and my wrx was the same i.e when you nail the throttle the gauge hits about 1.3 bar and then comes back to 1-1.1 bar I asked the question to people who owned sti's and had a gauge fitted what readings they were getting and they were all the same. I personally dont think it is a problem or will cause my engine to go bang! surely after four years of owning an impreza behaving like this it would have happened by now. I also had the car on the rollers and specifically asked about boost and they told me it was fine. I agree with you about people posting as supposed expets who dont know their ar*e from their elbow talkling about det. and engines going wallop, from my expeience and people i know who own subarus, engine trouble only comes with modification. I'm not passing my self off as an expert here only giving my experience.
By the way is the supposed problem hitting 1.3 bar or not holding 1.3 bar.

Niallyboy
21-03-2007, 19:03
Hey Doc,
your car if never modded will be factory set
to anywhere from .9 bar to 1.1 bar boost deppending
on model and year .

Id say it's more the boost gague giving a false readding
(most gagues aren't that accurate)

Im sure if you┬* connected to the ECU you would get a
boost readding of 1.1 bar period, maybe touching on 1.15 aprox
during hard acceleration┬* but it's that extra little bit of boost on
hard acceleration that can throw boost gaguges out .


Oh and Chris back to your original question as Davelegacy said
that clicking sound is more than likley the boost solenoid which if faulty
would give boost readding's like your getting.

Personaly i wouldn't run an impreza on say 1.4 / 1.5 bar boost without
upgradding the internals of the engine

Niall.

chriSTi
21-03-2007, 19:15
Hey Doc,
your car if never modded will be factory set
to anywhere from .9 bar to 1.1 bar boost deppending
on model and year .

Id say it's more the boost gague giving a false readding
(most gagues aren't that accurate)

Im sure if you connected to the ECU you would get a
boost readding of 1.1 bar period, maybe touching on 1.15 aprox
during hard acceleration but it's that extra little bit of boost on
hard acceleration that can throw boost gaguges out .


Oh and Chris back to your original question as Davelegacy said
that clicking sound is more than likley the boost solenoid which if faulty
would give boost readding's like your getting.

Personaly i wouldn't run an impreza on say 1.4 / 1.5 bar boost without
upgradding the internals of the engine

Niall.cheers niall internals have been upgraded an its jus now its actin up.... all will be well with a new solenoid... thanks again

GT performance
21-03-2007, 19:26
A bit o.t.t there man, I'm just saying on the boost part of the question that my sti has acted like that since i have it, and my wrx was the same i.e when you nail the throttle the gauge hits about 1.3 bar and then comes back to 1-1.1 bar I asked the question to people who owned sti's and had a gauge fitted what readings they were getting and they were all the same. I personally dont think it is a problem or will cause my engine to go bang! surely after four years of owning an impreza behaving like this it would have happened by now. I also had the car on the rollers and specifically asked about boost and they told me it was fine. I agree with you about people posting as supposed expets who dont know their ar*e from their elbow talkling about det. and engines going wallop, from my expeience and people i know who own subarus, engine trouble only comes with modification. I'm not passing my self off as an expert here only giving my experience.
By the way is the supposed problem hitting 1.3 bar or not holding 1.3 bar.


thats fair enough. As Niall said must be faulty gauges. if your car was spiking like that for real your engine would go wallop. there are no two ways or opinions about it.

thedoc
21-03-2007, 19:30
Where do you get your technical info Niall?

huzzy
21-03-2007, 20:30
ok not to p*ss everyone off

I have a lamco boost guage and when I floor it the guage will go to 1.3 kg/cm2 for a second and drop to 1.1 then hold that ok

so the turbo builds up this huge pressure and it will drop back down AND HOLD IT AT 1.1would this not mean that the boost solenoid is working ??? rember i am not looseing boost ... 1.1 is normal

keith dublin
21-03-2007, 20:36
Same as mine 1.3 then drop's off to 1.1 :dunno: and thats with a lamco

GT performance
21-03-2007, 21:38
the problem is caused by the 2-port solenoid on the later cars. its just not fast enough thats why the boost spikes. usually happens when decat etc. are fitted or happens when the solenoid gets older and slower. fitting a 3-port solenoid would solve the problem. if not bothering about it boost spike can cause your engine to blow. you can fit a decat on the older model impreza's(early classic) and you would have no problem with boost spike because they came with a 3-port solenoid as standard.



George

keith dublin
21-03-2007, 21:41
Mine has a 3 port valve on it are the apexi the hks ones better what woud the cost be.
Cheers George
Keith

GT performance
21-03-2007, 21:46
yours has a 2-port on it unless its been changed before Keith :ponder:

pm sent

keith dublin
21-03-2007, 22:29
It was changed to the 3 port one :thumbsup:

thedoc
22-03-2007, 07:31
Lads mine is an 02 sti which i bought with 20,000 miles and it behaves like this since i got it, which to me is the way its designed to work, I have to disagree with you George that it will damage the engine. I may have to eat my words at some stage but for know I'm leaving it as is.
I can also rule out a faulty gauge because my buddy has a 01 wrx with the same gauge fitted and his will hit 1-1.1 bar and hold steady.
Seems to be a lot of people experience this without major engine trouble!

GT performance
22-03-2007, 11:20
It was changed to the 3 port one :thumbsup:


do you have a boost controller on the car?

GT performance
22-03-2007, 11:24
Lads mine is an 02 sti which i bought with 20,000 miles and it behaves like this since i got it, which to me is the way its designed to work, I have to disagree with you George that it will damage the engine. I may have to eat my words at some stage but for know I'm leaving it as is.
I can also rule out a faulty gauge because my buddy has a 01 wrx with the same gauge fitted and his will hit 1-1.1 bar and hold steady.
Seems to be a lot of people experience this without major engine trouble!


does your mates car do the exact same? as in shoot up to 1.3 bar then settle back to 1.0-1.1bar? or does it just go to 1.0-1.1bar and stay there?

thedoc
22-03-2007, 11:50
His car is a wrx and it goes straight to 1-1.1 bar and holds. it only seems to be the sti's that are going to 1.3 bar which is 18.85 psi. I found these details on this web site which shows max boost as being 120 kpa which is 18 psi or 1.2 barhttp://autospeed.drive.com.au/cms/A_1463/article.html?popularArticle
I found some info on the my06 model which shows max boost as being 14.5 psihttp://www.cars101.com/subaru/impreza/wrxsti2006.html
I hope this info helps. :)

keith dublin
22-03-2007, 19:15
@ George no i dont just a 3 port valve.

maximusbiggus
22-03-2007, 21:47
My Type R used to(when on the road and before modification) would only hit .7 bar on the standard(subaru optional extra) lamco boost guage.

GT performance
23-03-2007, 14:07
guarantee your only getting boost fluctuation on the gauge Keith/thedoc you arent getting boost spike more so just the gauge your using isnt accurate enough.

thedoc
23-03-2007, 15:02
guarantee your only getting boost fluctuation on the gauge Keith/thedoc you arent getting boost spike more so just the gauge your using isnt accurate enough

Why does'nt it happen on the wrx?
How can all the gauges deflect by the same amount every time?
Why is it so hard for ypu to accept that it is boosting to 1.3 bar?
Did you read the article? :computer:

GT performance
23-03-2007, 15:44
:lol: :lol: :lol: its not hard for me to accept at all mate. id accept it if it was true. if your car is supposed to boost at 1.3bar it would HOLD 1.3bar, theres no pont in me arguing with you over this ive better things to be doing like fixing the 4 scoobies here today. the second link isnt working by the way. the 1st link mentions nothing on boost :ponder: :ponder:
I already explianed earlier on that reading websites and books doesnt work as you will take up the wrong meaning from them too often. Its the same as if i picked up a book on heart surgery, i wouldnt go arguing with a doctor. thats all from me on this subject.

oh and im not trying to make out that im some sort of super specialist or know the answer to everything to do with these cars but trust me mate i know what im talking about here




George

chriSTi
23-03-2007, 15:59
original post by me .... jus incase yiz forgot, my car used to hold full boost(1.4) now it doesn't, I can feel the difference in power,hear it ie: sounds like I'm ridin the clutch,and it clicks on acceleration.... lamco gauge which shows it.. so when the solenoid is fitted i'll let ya'll know the result. watch this space..... let it go lads. :wall:

GT performance
23-03-2007, 16:04
yeah back to the original problem. your car was modded and set-up in Japan to run 1.4bar, solenoid will get it back holding 1.4bar :thumbsup:

thedoc
23-03-2007, 17:27
Dont know what article you were reading there George but this is taken from it "This boost graph tells the story of the STi's on-road performance - bugger-all up to about 4000 rpm, a giant rush from 4000 to near 5500 rpm, followed by a steady drop-off towards the 7500 redline.

It's the most non-linear power delivery you could possibly imagine."
it shows on the graph peak boost 120 Kpa / 1.2 bar and then steadly dropping off just like mine.
With all due respects you have'nt seen or driven my car and that is what it does simple!

P.S I hope none of the four have boost problems :nana:

GT performance
23-03-2007, 18:36
:lol: :lol: :lol:

you see thats what i was saying about not fully understanding the topic!!

we were talking about boost shooting to 1.3bar and dropping back immediately to 1.1bar how is that the same as 1.2bar steadily dropping off?????? :wall:
THAT is exactly what i mean about you reading a website and not fully understanding what they're talking about and taking your own meaning from it. :hang: :hang: :hang:

kiaser
23-03-2007, 19:12
My advice to you lads, wud be. Buy an evo :dance:

kanye west
23-03-2007, 20:42
Who let this guy in here :angry: Wheres Norris and his bouncer :thumbsup:

huzzy
23-03-2007, 20:54
hay george :smokin:
If I was to get a boost controler bleed off valve would that not solve the spikeing???? might get one tomorrow if you think it will do the job... :pray:

thedoc
23-03-2007, 21:02
George,
┬* ┬* ┬* ┬* ┬* You originally said that the car should not boost to 1.2/1.3 bar and then drop off (which is what the topic was originally about)and if it is the problem should be sorted or i will be rebuilding the engine, my car has always done this and looking at that website and the graph this is correct, But lets just forget about all that for a minute.My car is a totally standard bugeye sti, i was messing around with it on the way home and in 5th gear at 80 mph if i nail the gas it will boost to 1.3 bar and hold steady for 5-6 seconds and then drop back Do you think this is right or wrong?

Dagnut
23-03-2007, 21:38
more importantly who would win in a fight.. a cat with a spear for a tail or a 3 legged medium sized dog??..lets say a collie

GT performance
23-03-2007, 23:59
George,
┬* ┬* ┬* ┬* ┬* ┬*You originally said that the car should not boost to 1.2/1.3 bar and then drop off (which is what the topic was originally about)and if it is the problem should be sorted or i will be rebuilding the engine, my car has always done this and looking at that website and the graph this is correct, But lets just forget about all that for a minute.My car is a totally standard bugeye sti, i was messing around with it on the way home and in 5th gear at 80 mph if i nail the gas it will boost to 1.3 bar and hold steady for 5-6 seconds and then drop back Do you think this is right or wrong?


:noway:thats not what the topic was about. the topic was about a modified classic impreza that is set to run at 1.4bar which is no longer holding 1.4bar :? :?
this is what you said your car is doing: "as far as I'm aware this is normal my last two imprezas have performed in this manner hits 1.4 bar for a second and then drops back to 1.1 sometimes even .9."

the answer to your question is yes your car standard should peak at around 1.2bar and start dropping off after 5500rpm. thats a lot different to 1.4bar for a second and then 1.1 or even .9bar?!!!!!!???!!!!!?????!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

you dont seem to know yourself what way your car is running and yet your telling lads that their car is running normal. :oops: :wazzup: :wazzup: now enough is enough just chawk it down to experience and leave it at that :thumbsup: :thumbsup:

thedoc
24-03-2007, 09:27
to be fair George In the original problem posted Chris doesnt mention anything about his car being modified just says his car hits 1.4 bar then drops off. Depending on what gear I'm in and revs the car behaves differently, say third gear 3,000 nail the gas-1.3 bar for a second and then back to 1 bar but as i said earlier if in 6th gear @ 80 mph and nail it, it will hold 1.3 bar for 5-6 seconds.I know exactly how the car is behaving maybe i wasnt clear in the prvious post.
The question I want answered Is this a problem or not? because when i originally replied with my opinion that this was ok you said this is not right it could'nt hit 1.3 bar it must be a faulty gauge. but in your last post you say it is ok for it to hit 1.2 bar and then drop off :dunno: Are you saying this is normal operation operation for a standard car and it is only a problem if you have modified to a differant boost setting?

GT performance
24-03-2007, 12:31
ok well look i wasnt clear in my previous posts either. i was talking about classic STI's i should have stated that. you car should boost to 1.2bar and drop off steadily after 5500rpm. when testing boost on these cars in a 5speed you should test in 4thgear, and 6speed in 5th gear. you see you stated earlier that you hit 1.4bar and dropped back to 1.1 or even .9bar after a second- now that would not be right and thats why i said it wasnt.

also early on in the topic it was stated that the problem was that the car was no longer holding 1.4bar :thumbsup:

to answer your question your car seems to be behaving normal, and if you had a electronic map sensor based boost gauge then your reading would be 1.2bar and not 1.3bar mechanical boost gauges are not precise.

"Are you saying this is normal operation operation for a standard car and it is only a problem if you have modified to a differant boost setting?" now you see you still dont get the difference between what i was saying is a problem, and what your car is doing.
I was saying boost spike is a problem which is not what your car is doing we have now discovered your car is dropping off gradually after the 5500rpm mark, boost spike is sudden fluctuations in boost pressure. and the problem is not the boost dropping off its the fact that the lads are saying they are boosting to 1.3bar then dropping back to 1.0-1.1bar
now there car(classic STI) is supposed to boost to 1.1bar and are spiking to 1.3bar. now please GOD understand what im talking abou now :pray: :pray:

thedoc
24-03-2007, 14:10
Why didnt you just say that earlier :P
A slight case of getting our wires crossed i think, good debate though.

GT performance
25-03-2007, 00:21
yeah should have said all that earlier alright :P :P

but as most lads will know on here i enjoy these little debates alright :D :D :subaru: :subaru: :subaru:

Niallyboy
27-03-2007, 18:17
:shock: :shock: :shock:
Sorry missed all the fun i couldn't get access
to the site and had to download Fire Fox , IE just wouldn't
log in :ponder: :ponder:


Where do you get your technical info Niall?

Doc all my experince unfortunitly is gained through having
the same probs myself .

I too had irregular boost readding's

Eventually the boost prob was sorted by AndyF and as you
can imagine i had a thousand questions for him .

Niall.

huzzy
29-03-2007, 19:13
Got new boost solenoid and fitted it to day now holding boost at 1.0 bar happy days again.. :thumbsup:

thanks lads sound out :thumbsup: :subaru:

thedoc
29-03-2007, 19:25
Did you just fit a standard solenoid?
What car is it?

GT performance
29-03-2007, 22:48
Got new boost solenoid and fitted it to day now holding boost at 1.0 bar happy days again.. :thumbsup:

thanks lads sound out :thumbsup: :subaru:


happy days, you got a 3-port after yeah??

huzzy
29-03-2007, 23:46
ya a 3 port from a 1995 sti, got it┬* from mc keevers up north.. rang them yesterday at 2.00 and got it today at 12.00. very quick :smokin:

┬* I fitted top hose from the solonide to the turbo bottom to the air box hose and the side outlet off the solonide to the waste gate actuator is this correct im not sure witch way round the 2 bottom hoses from the solenoid go..

┬* IS THIS OK?????????????????????????????????PLEASE LET ME KNOW :thumbsup:
THANKS AGAIN┬* :thumbsup:

huzzy
29-03-2007, 23:48
@THEDOC MY CAR IS A 1999 STI TYPE R :subaru:

thedoc
30-03-2007, 07:33
Thanks for the update :thumbsup: