help me solve my boost controller probs (1jz)

[Ribfeast]

Here is how you fit a boost controller to your twin turbo setup.



Replace the black hiperboost box in the picture with your boost controller.

Your current setup will grenade your turbos in no time if you keep driving it like that.

[JP]

what's the boost actually spiking to?

My manual 1J with FMIC and 3" exhaust with no boost controller installed would hit boost cut pretty easily.

[Ribfeast]

In the pics he has his wastegate actuators totally disconnected. So he would hit runaway boost until it hits boost cut or blows his turbos etc, whichever comes first

[rob]

Here is how you fit a boost controller to your twin turbo setup.



Replace the black hiperboost box in the picture with your boost controller.

Your current setup will grenade your turbos in no time if you keep driving it like that.

in natens 2nd pic he has it set up the same as the pic u posted but reduced the amount of hose by only taking pressure signal from 1 turbo. his wastegate actuators are NOT disconnected

[Ribfeast]

Ah I see, good spotting I saw the blocked off compressor output on one turbo and went OMG

The valve you have fitted is a pressure relief valve, not a pressure regulator. You need to fit the other (grey) one to have boost regulation. They work as a pair, and you will probably get odd results with just the one there.
Alternatively you could just buy one of the Turbotech ones off eBay if you don't want 2 valves.

[rob]

he said he only wants stock boost he has no need for the extra valve to control boost pressure all he wants is to keep the wastegates closed until 10psi

but its not happening

[JP]

if you try and keep the gates closed until 10psi with stock boost it will spike for sure

[Ribfeast]

Correct, a spike is inevitable, especially the more aggressive you set it to build boost.

[naten]

hey guys

ribfest: I do have it hooked up like in that pic im not that silly! As rob said ive tired to keep the piping as.

JP: Normal boost run sees it hit 11-12 and drop ever so slightly as it hits higher revs
How can you reduce your boost below stock? with stock wastegates? That is impossible or so im lead to belive. My understanding is that you can make more pressure hit the wastegates to open so therefore you cant boost less then the stock wastegates. As changing the flow of air to the wastegates only makes more boost.

What makes you say it would boost spike if its on a stock boost of 10psi? from what ive read people have had good success with this setup on stock 1jz's before.

Id happily shell out for the second valve if i thought it would actually help me. My thinking is that the pressure regulator wont stop it from spiking becuase it cant help the wastegates open any quicker or better. All it does it stop the wastegates opening and hence bringing on more boost.

Im not trying to be smart or anything but thats my understanding of how it all works, if someone can enlighten me then please do.

[naten]

just to clarify i dont want to have the wastegates shut to 10psi even 5 psi id be happy with

[JP]

what setup do you have exhaust and cooler wise?

Do you have an accurate peak recall boost gauge?

Mine would spike to 14-15psi and taper to 11psi with just the exhaust and cooler.

If you get it dyno'd on a dyno dynamics unit with the map sensor from the dyno connected you can get an accurate representation of the boost curve you're working with.

[naten]

i have a generic fmic 3" inlets either side straight through bout 400 ish wide

zorst is a 3" dump of the stock y pipe to a 3" system with a 2.5" muff on the rear

sorry but you didnt answer my question about lowering the boost below stock, afaik its not possible with the same wastegates etc and just a boost controller

[Ribfeast]

You can't lower it below stock.
Putting a restriction in the line (ie the pressure relief valve) and then suddenly removing that restriction (ie when the pressure relief valve opens) is likely to cause a spike.
A spike isn't too bad as long as it less than your boost cut level (unless you fit a FCD)

[naten]

yea exactly!


arg why does it work for everyone else but not my setup

[JP]

I was using an emanage as a FCD so the initial spike didn't cause boost cut.