Huge Boost Creep

[R34NRG]

current setup is

3.0L

3.5inch dump to cat then 3" all the way

44mm tial gate with .9bar spring

6boost manifold

GT35/40 .82 housing

the car just cannot hold boost. its making 300rwkw at 4000rpm and just keeps going because it cant hold the boost.

wanted to ask the gurus out there wat are the main causes?

44mm gate cant possibly be to small?

Dump to big?

faulty manifold?

trying to dc the gate, so it shouldnt make any boost. which will rule out the gate theory.....

was wondering if anyone had any other ideas?

*******************UPDATE**********************

blue = with gate

red = without gate

its defiently the manifold. it just cant flow enough air.

next step is possibly redesigning the manifold to have 2 outlets merging into one or getting a new one.

or a bigger housing like mentioned above which i doubt will help due to the manifold.

on a positive note.....quite responsive as u can see lol

Edited April 21, 2008 by R34NRG

[Craved]

current setup is

3.0L

3.5inch dump to cat then 3" all the way

44mm tial gate with .9bar spring

6boost manifold

GT35/40 .82 housing

the car just cannot hold boost. its making 300rwkw at 4000rpm and just keeps going because it cant hold the boost.

wanted to ask the gurus out there wat are the main causes?

44mm gate cant possibly be to small?

Dump to big?

faulty manifold?

trying to dc the gate, so it shouldnt make any boost. which will rule out the gate theory.....

was wondering if anyone had any other ideas?

so boost is dropping off below the .9bar ?

or do you mean the other way around and boost is increasing?

[R34NRG]

so boost is dropping off below the .9bar ?

or do you mean the other way around and boost is increasing?

boost in increasing...just keeps gettn higher and higher.

we set it at .9bar (gate spring) and it will go as far as 22psi

Edited April 18, 2008 by R34NRG

[VB-]

it also seems to have a bit of a step in it (on dyno graph), a very big step so kinda ruled out a bigger spring in it

[R31Nismoid]

Drop the exhaust from the dump (before cat) and see what it does.

Failing that, DOUBLE check the gate is connected correctly (hoses are the right way around) sounds like it might not be as this can be a cause for it to skyrocket with boost for no reason.

After you find those two things out post back.

I would also up the gate spring to 16-17psi if your going to run over 20psi

[paulr33]

do a careful dyno plot with the wastegate disconnected, the vac line

this will mean unlimited boost (almost like how it is now) so dont trash it on the street, dyno only

a great way to kill your engine is by stuffing around with the boost on a fresh new engine

if you get the same result, either the vac signal to the gate is incorrect or the gate isnt working correctly

how much boost do you want to run ?

[R34NRG]

Drop the exhaust from the dump (before cat) and see what it does.

Failing that, DOUBLE check the gate is connected correctly (hoses are the right way around) sounds like it might not be as this can be a cause for it to skyrocket with boost for no reason.

After you find those two things out post back.

I would also up the gate spring to 16-17psi if your going to run over 20psi

gate is 100% connected correnty. one of the 1st things we done.

not so sure about taking off the exhaust.

wouldnt that cause spike and not creep?

the cars currently on a dyno as we speak......

do a careful dyno plot with the wastegate disconnected, the vac line

this will mean unlimited boost (almost like how it is now) so dont trash it on the street, dyno only

a great way to kill your engine is by stuffing around with the boost on a fresh new engine

if you get the same result, either the vac signal to the gate is incorrect or the gate isnt working correctly

how much boost do you want to run ?

we are dc-ing the gate atm to test that theory......if we dc the gate it should make no boost right?

we plannin to run 20psi for a start.....not sure how high we willl go

Edited April 18, 2008 by R34NRG

[R34NRG]

.

[Craved]

if the gas isnt being bypassed through the gate due to a flow blockage after teh gate - then this can cause the boost to creep - hence the suggestion to remove the exhaust

what boost controller you using? how many vacuum lines to the gate?

[R34NRG]

using the apexi avcr. not sure about how many vac lines im using but ill get back to u.

ill run the exhaust thing by the tuner....

[VB-]

2 lines to the gate, they are the right way around as we checked them with a diagram (Me and the mechanic both went over it at the same time)

atmo gate, exhasut wont matter

boost controller is AVCR set everything to minimum (basically turned off) so should be running of the spring only.

current test is holding gate completely open to see if its flowing adequately

[R31Nismoid]

What do you mean your not so sure?

You dont even know whats causing it, drop the exhaust and see what it does... and double check the gate.

There isnt much to infinite boost climbs, its only a few things that will cause it.

blockage/restriction after the turbo or something not connected correctly before it

Exhaust WILL matter. Come here asking for help and then tell me it wont matter when you obviously dont even know?

Why ask for help if you know it?

[Adriano]

I would bypass the boost controller, run one boost signal to the bottom of the wastegate, leave the other one disconnected

[R34NRG]

found the issue.

droped the gate off and its still causing creep.

the manifold isnt flowing enough air to the gate so thats why its creeping.

very hard to believe being a 6boost manifold.....

only solution atm is possibly redesigning the manifold.

Edited April 18, 2008 by R34NRG

[VB-]

nothing to see here..

Edited April 18, 2008 by VB-

[Craved]

i thought 6 boosts manifold ran dual outlets off the 2 sides of the collector - that is strange

[R31Nismoid]

If you havent dropped the exhaust then you dont know for sure.

[R34NRG]

yeh i dunno, things just never go right -___-"

gonna give kyle a call tm to see wat he thinks

[Al]

I dare say that the 6boost item is a tried and proven design, you are not the first to use it and many people before you have had no issues.

It seems you unfortunately don't want to listen to any advise given to try and help your cause.

Before questioning the work of someone else, do the VERY SIMPLE test:

- Unbolt the cat from the dump pipe and do a power run. A restriction in the exhaust causes back pressure, thus causing boost to creep/increase.

If you are not prepared to listen to any advice, best not to ask

What is the I.D. (Inner Diameter) of the wastegate pipe/flange, before the wastegate?

[R31Nismoid]

So many great minds around!!!

Dropping the gate wont really prove much other than you have a problem, which you already know.

Drop exhaust, its the key to working out what is or is not wrong