Boost fluctuations

Mark Griffiths · 24-12-2005, 05:39 PM

I have had problems with the boost on my car for a little while, Nothing major. I've tested a few things for leaks, ie the intercooler, intake hoses...
I have just fitted a hks ssqv and still have the same problems.

basically what happens is it boosts too high, sometimes nearly 1bar for a car that should be running o.5bar this worries me a little, especially seeing as how my turbo could blow up. the other slight problem is that it doesn't feel like it boosts very much atall.

I was thinking that maybe it could be the boost control valve so was possibly gonna change this (I want to put an electronic controler on it at some point anyway, so why not do it sooner rather than later). What does anyone recomend for about £200.

Also do you have any ideas what it might be if not the control valve.

Any help is appreciated.

davegtst · 24-12-2005, 10:05 PM

I had the exact same problem. Disconect the vacuum line to the standard bov and put a blanking plate between the inlet pipe and the standard bov ( i used a coke can for the plate). This sorted mine out right away and it felt like a totally different car.

cornhoolio · 24-12-2005, 11:54 PM

I was thinking that maybe it could be the boost control valve so was possibly gonna change this (I want to put an electronic controler on it at some point anyway, so why not do it sooner rather than later). What does anyone recomend for about £200.

Hello there, try www.nengun.com for a Greddy Profec B II delivered for about £177, may take a few weeks to get here though. If you also have a de-cat be careful as I have just destroyed one of my turbo's by overboosting, only went over 1 bar twice I saw on the gauge, then KABLAAMMMO!

Ian

GT-R R32 · 25-12-2005, 12:27 AM

Negun ,you wont see you stuff for at least a month,well my cam belt & cover was ,good prices though http://cgi.ebay.com/ebaymotors/HKS-E...temZ8024225639 i,ve brought stuff of the guy before ,he always very fast shipping ,& good gear

Gambit · 25-12-2005, 12:31 AM

Nengun were damn good for me. Ordered a power fc and c's short shifter on the 6th, was emailed 2hours later to say it would be shipped on the 18th, arrived on the morning of 22nd. No customs charges either.

GT-R R32 · 25-12-2005, 12:41 AM

Quote:

Originally Posted by Gambit

Nengun were damn good for me. Ordered a power fc and c's short shifter on the 6th, was emailed 2hours later to say it would be shipped on the 18th, arrived on the morning of 22nd. No customs charges either.

Dont get me wrong i will use Negun again

,Brilliant prices & if you dont mind waiting ,and like you said no customs charge eather

thats what i want a C,s shifter for my GTR gonna get one from there aswell

Gambit · 25-12-2005, 12:50 AM

Your telling me, pfc+commander for £388 delivered and the C'shifter...well worth it mate

Back on topic,what are you measuring your boost with, standardor aftermarket gauge ?

Mark Griffiths · 25-12-2005, 12:20 PM

Both, I've just fitted an Auto gauge boost gauge in the A pillar and also the standard boost gauge is still plugged in. It was overboosting before, It just feels like the turbo is spinning to easy and you don't really feel the kick of the turbo. Doesn't sound like its leaking anywhere though.

I've been around all of the pipes in the engine bay with leak detector spray and nothing has shown. Did find a small leak once, fixed that but didn't make much difference.

Gambit · 25-12-2005, 12:31 PM

if your not using a boost controller then I reckon it's possibly a problem with the wastegate? or actuator arm? the wastegate's not being alllowed to open.

Mark Griffiths · 25-12-2005, 12:38 PM

Quote:

Originally Posted by Gambit

if your not using a boost controller then I reckon it's possibly a problem with the wastegate? or actuator arm? the wastegate's not being alllowed to open.

Thats exactly what I've been thinking over the last few days. Would fitting a boost controler solve this?

Mark Griffiths · 25-12-2005, 12:45 PM

Few pics showing where I've T'd the hose for my boost gauge, Is this a good place to fit it?

On a different note, I was thinking of turning the BOV around 180* so when it dumps it blows the air around the turbo area poss keeping it cooler. A good idea?

Gambit · 25-12-2005, 12:48 PM

Maybe/maybe not, but it is still a worthwhile investment.

Id buy a controller, something like the profecB II, get it plumbed in and drive the car with it switched off. That way the turbo is relying purely on the actuator to open the wastegate not a solenoid. With mine off she still registers .68 to .70

If its still overboosting, you'd need to speak to an expert on how to check the actuator. There are ways of doing it but I'm not sure what they are.

Gambit · 25-12-2005, 12:51 PM

Just seen the pics, was told thats not a good place for the pickup, it caused my boost gauge to go nuts. Best place is the original gauge's pipe on the other side of the plenum, leads to a black box.

http://www.skylineowners.com/forum/s...8&page=3&pp=15

Post 34 is a pic of how mines done.

SPEARMINT · 25-12-2005, 01:07 PM

Mark thats where I've had my boost gauge plumbed in for 6 months now. No problems to report.

Gambit · 25-12-2005, 01:11 PM

On the dump valve?

Might have just been me then, I tried my gauge on there and it just bounced up and down. Tho it was on the standard re-circ one if that makes any difference.