No pressure port

[thiazole]

My new turbo (E3 16G) doesn't have a pressure port and every configuration for my boost controller and for the external wastegate seems to want a pressure port out of the turbo. Is this common with 16Gs? Does anyone have experience with this? Should I tap the compressor housing, the LICP, get pressure from a different source....?

[dsmguy3]

I just used the TB, Even though the turbo is the best spot.
I think if you can get a little bung welded on the j pipe that would be best.

[thiazole]

My EVC is supposed to be hooked up the same way as e-Boost - one hose to turbo pressure, one to throttle body pressure and one to the wastegate (the external wastegate wants both sources as well). Does anyone know why it needs two sources of boost? It seems irrelevant what boost is coming out of the turbo since all I care about is what is getting into my engine. What would happen if I just T-ed off my throttle body pressure source and hooked it to both sides? Does it need a pressure differential to work right?

[t_jolt]

On the evo 16g the place to tap is on the j pipe. Ive done 10+ evo 16g turbo installs and all of them had to tap the boost from the j pipe. This is on the evo 16g only

Tyrel

[thiazole]

Alright, that is easy enough. I'll just do that.

[dsmguy3]

I haven't heard of one needing two boost sources.

[dsmguy3]

Tyrel is correct though the best place is on the j-pipe

[thiazole]

Here is what the instruction manual says for my EVC:

1. Manifold Pressure Sensor Port 1
This port when connected to an uninterrupted intake manifold source will allow the EVC micropocessor to sample plenum conditions every 2.5ns. Using this data, the EVC can constantly feed the wastegate corrections. Makes sense.
2. Control Valve Pressure Inlet Port 2
Pressurized air, drawn directly from the compressor housing (discharge side) or compressor outlet pipe (before intercooler), is routed to the control valve pressure inlet port #2. This pressurized air is then modified (by the solenoid valve housed within this chamber) according to the selected control module setting. Pressure is pressure - why does it need to be tapped on the turbo?

3. Control Valve Pressure Outlet Port 3
From the control valve pressure outlet port, constantly modified pressurized air received by the control valve pressure inlet port is routed to the wastegat actuator. This precisely regulated pressure maintains accurate wastegate action resulting in stable maximum boost leve in any gear and almost any atmospheric condition.

4. Bleed off port #4
Through this port, excess signal pressure is discharged.

[thiazole]

Perhaps having a port directly off the turbo minimizes boost spike since it is an instantaneous source of boost as it is coming out of the turbo.

[dsmguy3]

Perhaps having a port directly off the turbo minimizes boost spike since it is an instantaneous source of boost as it is coming out of the turbo.

^That is the way I understand it^
From what the manual says it looks like you need all three hooked up.

[t_jolt]

Here is what the instruction manual says for my EVC:

1. Manifold Pressure Sensor Port 1
This port when connected to an uninterrupted intake manifold source will allow the EVC microprocessor to sample plenum conditions every 2.5ns. Using this data, the EVC can constantly feed the wastegate corrections. Makes sense.
2. Control Valve Pressure Inlet Port 2
Pressurized air, drawn directly from the compressor housing (discharge side) or compressor outlet pipe (before intercooler), is routed to the control valve pressure inlet port #2. This pressurized air is then modified (by the solenoid valve housed within this chamber) according to the selected control module setting. Pressure is pressure - why does it need to be tapped on the turbo?


You want to tap it like that cause:

1. pressure is different on different sides of the throttle body. Cause we dont run at WOT all the time.

2. It does help reduce spikes.

3. It will help compensate for the pressure drop from your IC

[thiazole]

It just seems like from their explanation, that this pressure is used for nothing but as a source of power to open the wastegate (the EVC doesn't actually monitor pressure at this source). If I have my boost controller set at 7psi, then I can understand how I might have 11 psi at the turbo which would be enough to open the wastegate, but the 7psi at the manifold might be insufficient, so I wouldn't have boost control at that pressure. But if I have it set at 20psi, whether the boost controller uses 20psi from the manifold to open the wastegate or 24psi from the turbo, the wastegate will easily open.

Either way, it is easy enough to install the port, so I'll do it anyway. An added question for someone using an external wastegate - mine has a 7 psi spring, but came with other combinations including 14 and 17psi. In your exerience, if I want to be able to run more than 20psi, is the 7 psi spring sufficient, or should I put a stiffer combination of springs in.

[t_jolt]

the 7 psi spring should be enough cause your just running a 16g. I dont believe that you would run enough cfm's to blow it open

Tyrel

[Wazzelby]

You should be fine with the 7psi spring. IIRC the spring rate really doesn't have anything to do with how much boost you can run, it's more for how little you can run. But I could be wrong here.

[D Walker]

When regulating boost with an external gate using the top and bottom ports is the BEST and MOST ACCURATE way to control boost.

The reason the EVC wants to get signal from behind to TB is to be able to show vacumn, but the boost solenoiud should never see anything but pressure, therefore pretty much all boost controller instructions will read this way. This has nothing to do with reducing spikes, however they typically want to keep the hoses between pressure source, control valve, and WG as short as possible for better control. The EVC's use a "fuzzy logic" setup to learn the turbos boost curve so that it can predict how best to hold the boost level you want.