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Model specific boards => Golf mk4 => Topic started by: steve_mk4t on 16 March 2012, 17:45

Title: boost help
Post by: steve_mk4t on 16 March 2012, 17:45
think i have a boost leak  :sad:

fitted a boost gauge yesterday took her for a spin and i was peaking at abwt 16-18psi and -25 on idle

bust it would hit 18psi then drop all the way back to abwt 8 to 10 psi  :sad:

still pulls like a train just a bit stumped no real sign of leaks looking over then car
Title: Re: boost help
Post by: Toby on 16 March 2012, 18:00
Cpuld be your n75?

Had it scanned?
Title: Re: boost help
Post by: steve_mk4t on 16 March 2012, 18:12
nah i aint dont know anyone with one that aint guna charge me though the roof so think im guna have to invest in one
Title: Re: boost help
Post by: Toby on 16 March 2012, 18:24
nah i aint dont know anyone with one that aint guna charge me though the roof so think im guna have to invest in one

worth while investment!
Title: Re: boost help
Post by: steve_mk4t on 16 March 2012, 18:27
yeah guna get one of those ones of ebay abwt 20 qiud
Title: Re: boost help
Post by: Toby on 16 March 2012, 18:33
yeah.

as for boost leaks, go over everything with a fine tooth comb!

the pipe under neath the inlet manofold ( also connected to the inlet mani) is prone to splits as its a oil breather hose.
Title: Re: boost help
Post by: steve_mk4t on 16 March 2012, 18:41
going to check which colour spring i have in my forge spliter valve cos this was fitted when i got the car could dis be a problem?
Title: Re: boost help
Post by: Wazzzer on 16 March 2012, 18:42
boost doesn't just hit 18psi and stay there until the redline...

It will peak then drop slightly, then tail off the higher up the revs you go
Title: Re: boost help
Post by: steve_mk4t on 16 March 2012, 18:47
so there may not be a problem then??? but to drop 10psi???? after it has peaked? i have seen videos on you tube of golfs where it will peak and then drop 2 to 4 psi then hold
Title: Re: boost help
Post by: Hulmie on 16 March 2012, 20:52
mine used to do the same mate, nothing major to worry about.

Could be a boost leak but may not be. You could have a weak actuator, max'd out MAF to get a good idea you would be best getting some data logs done.
Title: Re: boost help
Post by: steve_mk4t on 16 March 2012, 21:01
okie dokie thinking of a bigger turbo any way, good excuse to use u the missus  :cool:
Title: Re: boost help
Post by: Wayne on 16 March 2012, 23:57
Those figures are about right tbh.
Title: Re: boost help
Post by: steve_mk4t on 17 March 2012, 00:30
why drop so much?
Title: Re: boost help
Post by: Dave_IOW on 17 March 2012, 00:36
Small turbo's cant hold 18psi all the way through rev range.

As said probably a leaky actuator..

Mine used to peak at 18 and hold till something gave and knocked itself back down to 10psi in milliseconds and nearly sent you through windscreen..