Disappearing Boost?

[T.D]

Hey, just got a small problem that hopefully someone can clarify for me. Car in question is a S2 R33 GTS-t.

Previously, my car would hit max boost between 9.8 and 10psi (E-boost peak recall tells me so).

However, after doing this mod: http://www.skylinesa...d__pid__5386208

I have noticed I'm only hitting 8psi max, and I'm not sure what could be wrong. I've tightened all hose clamps, intercooler pipes and checked every line that I have touched/removed from doing that mod but still can't figure why I'm only hitting 8psi. At first I thought there might be a leak somewhere, but the car idles perfectly and still drives more or less the same as before so I'm guessing a leak is out of the question. Unless there are other tell tale sgns of a boost leak I should be checking for?

Settings for the boost controller are still the same and have been untouched.

The only thing which I think may affect it is the change of my pod filter, as at the same time I did the above mod, I changed the 6"-inlet Blitz Sus stainless poddy to a brand new 3"-inlet DRIFT cotton poddy (hole in the blitz one ).

Any ideas? Am I being too paranoid and its just a natural thing (eg. due to ambient air temp, humidity etc.) or is something amiss and I need to check?

Cheers.

Edited January 2, 2011 by turbodragon

[Moodles2]

It's possible you hit 10psi during a cold night, were the day(s) hot when you were hitting only 8psi?

[Shazza24]

I guess change the settings on the boost controller up bit by bit until you are back at 10psi. If you have warning/boost cut on your EBC set to 12psi.

With my EBC lately i have been switching between my two settings alot because of hot then cold days. Its ultimately easier to run a adjustable wastegate actuator because once set the spring will only open the wastegate @ the pressure thats set and not really be affected by temperature differences day to day.

Not sure if this is you problem, but hey what do you expect for nothin.

[lachlanw]

im not too familiar with eboost but does it have a return line from the solenoid into the hose from afm to turbo?

the intake pipe could have had significant vacuum in it before and now will have less . less air flowing through solenoid at the same duty setting =less bleed off = more pressure to waste actuator = less boost ?

does boost not have closed loop and adjust it back to 10 psi like you set it to ?

[T.D]

It's possible you hit 10psi during a cold night, were the day(s) hot when you were hitting only 8psi?

That's what I thought at first, but I have noticed on hot days I hit in the ballpark of low 9s but on colder nights (like last night), I would consistently hit 10psi (close thereof, sometimes 9.8-9.9)

I guess change the settings on the boost controller up bit by bit until you are back at 10psi. If you have warning/boost cut on your EBC set to 12psi.

With my EBC lately i have been switching between my two settings alot because of hot then cold days. Its ultimately easier to run a adjustable wastegate actuator because once set the spring will only open the wastegate @ the pressure thats set and not really be affected by temperature differences day to day.

Not sure if this is you problem, but hey what do you expect for nothin.

I was thinking about changing the settings on the boost controller but I want to check all avenues before I move on the settings as a last resort. Reason being I don't want to feed more boost into it just to compensate for a leak or whatever, so would rather find out whats the go before upping the settings on the controller.

Im not too familiar with eboost but does it have a return line from the solenoid into the hose from afm to turbo?

the intake pipe could have had significant vacuum in it before and now will have less . less air flowing through solenoid at the same duty setting =less bleed off = more pressure to waste actuator = less boost ?

does boost not have closed loop and adjust it back to 10 psi like you set it to ?

The Eboost solenoid runs 3 lines from the solenoid:

- from the cold side of the intercooler piping (the one connecting to the crossover pipe just before throttle body)

- from the wastegate

- vents to atmosphere

I'm not sure if it's closed loop, but I'll re-set it back to 10psi if all else fails

[Rolls]

I used to see up to 2psi variance on a cold night vs a warm day on my rb20det with stock turbo.

Can always tweak the ebc settings to get two settings like mentioned.

Boost leak almost always results in clouds of black smoke and a whistle.

[T.D]

I used to see up to 2psi variance on a cold night vs a warm day on my rb20det with stock turbo.

Can always tweak the ebc settings to get two settings like mentioned.

Boost leak almost always results in clouds of black smoke and a whistle.

Ohh ok then, that does give me some comfort knowing I'm not the only one with variance lol just that my variance hasnt been this big before though.

Is there any other signs of telling of a boost leak? Reason being, I can't see behind me when I'm driving and my exhaust is too loud to hear anything AT ALL hahaha can just hear the turbo spooling over my exhaust if I'm lucky.

[Rolls]

put it on a dyno and stick your head in the engine bay, you'll be able to see it is running way too rich as well.

[T.D]

put it on a dyno and stick your head in the engine bay, you'll be able to see it is running way too rich as well.

Alright then, no worries. Won't have access to a dyno for a couple of months though, so I guess I'll needa get someone to stand behind the car haha

[T.D]

Any other ideas? I've double checked all hoses and clamps but still no good. I've even chucked the old Blitz pod back on but still not getting the 10psi I used to get

By any chance, could doing the metal pipe intake mod (thread in my first post) affect my boost at all?

[Rolls]

The metal pipe intake mod should actually increase the boost if anything, not decrease it, at that low boost level though it would probably not do much.

I've heard of people spraying something in the intake to see where leaks are but I am not really sure how they do it. Apart from putting all new clamps on and checking all joiners there isn't much you can do without a dyno, imo you don't have a boost leak, it is just fairly normal variance.

[T.D]

PROBLEM SOLVED!! :D:D

The problem wasn't a boost leak or anything to do with the metal pipe.

It was one of the hoses running from the solenoid (the vent to atmosphere one) which I tucked and folded out of the way when I was working on fitting the metal pipe. The way I folded and tucked it was enough to block air off so the e-boost wasn't getting the right readings and was reverting back to stock boost. So in a way, lachlanw was correct

Thanks for everyone's help :thanks: