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factory boost cut
Posted: Tue Jul 19, 2011 2:43 pm
by jedi
hi guys ive recently had to swap my big 20g turbo back to my big 16g due to me damaging the compressor wheel when taking it apart :x i was running 10.5 psi with the 20g which was fine but but running the same on the big 16g just seems to slow more responsive but not much legs anyway i wanna put boost up but my boost cuts at 12 psi ive herd of starion running up to 15 psi how do i get rid of my boost cut im not going to run dumn amounts of boost to lein engine out just wanna run bit more than 12psi just pain in ass because think its a fuel cut one and just about throw ya though windshield when ya hit its an 84 gsr3 factory intercooled any help would be great thanks
Posted: Tue Jul 19, 2011 6:19 pm
by fugazi
You may need a fuel cut defender...
Use the search and write in "fcd".
OLD FART maby still has one for sale?
ok
Posted: Tue Jul 19, 2011 9:38 pm
by jedi
yeah that didnt cross my mind until u said i remember talking to some one about it while back and that's the conclusion we came to i mite not bother yet its only a temp power increase until i get dohc in it.
thanks i found this
http://www.wbperformance.com/store-prod ... 70850.html
Posted: Wed Jul 20, 2011 4:07 pm
by redzone
Nz/imported cars seem to cut at 12psi from what i've heard, aussie ones do it at 14psi..
Posted: Wed Jul 20, 2011 10:32 pm
by kushman
the uk/nz ex cuts at 15psi , the jap imports 12psi
yeah
Posted: Thu Jul 21, 2011 5:43 pm
by jedi
kushman wrote:the uk/nz ex cuts at 15psi , the jap imports 12psi
yeah mines a jap import so its cuts at 12psi is it in the ecu its self? because an mate did some research a while back and told me you cut a yellow wire and it stop the fuel cut it a little back box that sits on the fire wall on right hand side inside engine bay its got about i think three vacuum hoses going into it and plug with lots of wires that's where i chop the yellow one a while back didn't make much of difference a part from not making the boost cut so hard. been driving it around for years with the wire cut car still work fine.
Posted: Fri Jul 22, 2011 12:32 am
by enthuzed
Jedi, you got a photo of what you're talking about?
pic's
Posted: Sat Jul 23, 2011 10:47 am
by jedi
sorry there only one vacuum hose going into it
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Posted: Sat Jul 23, 2011 1:53 pm
by bigmoz
if i remember correctly cut the yellow wire and that will solve all your problems, although this may cause problems if you run your boost up past 15psi so take care
moz
Posted: Sat Jul 23, 2011 2:17 pm
by redzone
it can make em run really rich at light load too, hence why fcd's were invented..
Posted: Sat Jul 23, 2011 6:42 pm
by jedi
bigmoz wrote:if i remember correctly cut the yellow wire and that will solve all your problems, although this may cause problems if you run your boost up past 15psi so take care
moz
yeah i cut that years ago i cant run anymore than 12psi with the turbo's im running because with my 20g i could only run 10psi because it started running out of fuel at 11psi now running big 16g im not wanting to run more than 12 after that im sure it runs out fuel i just wanted it so wouldn't hit the fuel cut. :beer at 12psi
cheers
Posted: Tue Jul 26, 2011 6:51 am
by Xentro
Anybody ever try a zener diode? and maybe some basic other electronics parts.
the fcd is basically a maximum voltage regulator.
It limits the maximum voltage the ecu will see and therefore defeat the fuel-cut
Posted: Tue Jul 26, 2011 12:45 pm
by Komeuppance
I'm running a zener diode, works quite well. 4.3v seems to have right cut off. I've installed on two other cars as well, and they were able to run higher boost without problems. One guy ran up to 18psi on an 16g before his stock fuel pump was letting him lean out.
-Robert
Posted: Tue Jul 26, 2011 11:12 pm
by kushman
the saving grace with running higher than stock boost on a starion is the very low compression ratio (7.6:1)
13 maybe 14 psi would be the most id boost ina stock staz
also remember differtn models run differtn injectors and ecu , so 15 psi on a later model may be ok, but on a early model it will lean out and could go bag!
Posted: Wed Jul 27, 2011 1:07 am
by Komeuppance
We have 7.0:1 compression in our G54B motors. Also twin 850cc injectors. 13, 14, 15psi is going to be different depending on the turbo, a wideband will help to protect your engine.
-Robert