Boost gauge install

[sartain87]

As i was busy today I had a garage install my boost gauge for me so I can check boost pressure.

I red a guide which said to use the vacuum tree, but they seem to have taken a feed from the dump valve is this right?

[stribo]

No, it'll only read boost when the dump valve opens. Should be the vac tree.

[sartain87]

This is what it reads, surely that's vacuum pressure it's reading as when you boost the needle goes to zero where as it should start at zero and go clock wise?

[T5frankie]

This is what it reads, surely that's vacuum pressure it's reading as when you boost the needle goes to zero where as it should start at zero and go clock wise?

that reading is correct at idle, it will only go to zero when you turn it off, take it for a drive and see what it reads

[stribo]

They may have run the pipe from the dump valve to the vac tree, and then tee'd into it for the boost gauge in which case it may work as it should.

[M-R-P]

The dv runs from the manifold (vac tree), as does the gauge. It's gonna work there but the reading may be affected by the dv moving. There's nothing wrong with this setup but its best go get the reading directly from the manifold.

[sartain87]

New developments, this is now how he's moved the pipe:



And at idle reads:



Sorry for the rubbish pictures its dark, on boost it doesn't even get to 5psi

[Kingsford G]

What bunch of numpties lol U should b getting 15-16psi boost after 3k revs if u still have mapped ecu in it.

[stribo]

It should read vacuum at idle.

[T5frankie]

it should be -20 at idle like already said, whats the problem? dump valve to vac tree simple

[sartain87]

I assume the actuator could give different readings if it needs adjusting?

If it was connected as it was before, with the dump valve would it be a massive false reading?

[T5frankie]

how fast is the car?

[sartain87]

Quick enough, Adam mentioned the actuator may need adjusting.

Was quicker and boost seemed stronger when I first got it but that might be me just getting used to it

[T5frankie]

when adam had it at first it wasnt boosting at all, didnt he have the turbo rebuilt? it should read

at idle -20 ish
turned off 0
full boost 15-16psi

[LeeT5]

UPDATE:

when adam had it at first it wasnt boosting at all, didnt he have the turbo rebuilt? it should read

at idle = -20psi
turned off = 0.
When decelerating in gear, foot fully off the throttle = -24psi
full boost 15-16psi

That's covers it.

[sartain87]

Well I've now done it straight from boost gauge to vacuum tree,

Idle -20psi
Boost from 3.5k onwards +2psi

Yeah he said he had the turbo rebuilt mate

[T5frankie]

it should be a minimum of 6psi as thats wastegate opening pressure, something is wrong, does it feel 250bhp?

[sartain87]

Yeah it feels quick and boost punches it at 3.5k revs fine, could it be aleak from the vacuum pipe to the gauge? Or a similar leak?

Will have to check in the morning as its obviously dark now.

Thanks for your help so far though guys.

[T5frankie]

i remeber julian thought his 850r was quick and dyno'd it at 130bhp lol i took him out in mine and he was amazed at the difference

[sartain87]

Haha I hope this isn't the same case