Little to no boost increase

[DaBo$$]

Hey all, having a little issue with my 8th gen auto vr4 and could use some advice.
Car has front mount, hard intercooler piping, chipped ecu, ebc, safc 2, upgraded wategates and stock exhaust.
My issue is my boost pressure is around stock levels of 9 psi even though I have the internal wastegates installed with 15 psi springs. There should be noway for my boost to be less that what the spring rates are. The ebc is an aem tru boost which is installed correctly and I have maxed out the duty cycle with basically the same results.The stock boost solenoid is still installed.
Any help is appreciated and welcomed.

 

[BCX]

If you have another ebc, then youll probably want to bypass the ecu controlled solenoid.

Are you able to describe how the ebc is connected?

Also if the ecu is tuned, then I'd be questioning the need for the safc2. Reflashed ecu negates the need for the safc2 as all parameters can be changed within the ecu's tables

Do you have a wideband to verify the afr are correct, especially if you are interested in increasing the boost?

 

[6A13TT TYPE S]

The stock vaccum lines and solenoids have restrictor pills in them. If your using an aftermarket controller use and aftermarket solenoid and bypass the OEM system entirely with new vaccum hoses. To the aftermarket controller can work as intended

 

[DaBo$$]

If you have another ebc, then youll probably want to bypass the ecu controlled solenoid.

Are you able to describe how the ebc is connected?

Also if the ecu is tuned, then I'd be questioning the need for the safc2. Reflashed ecu negates the need for the safc2 as all parameters can be changed within the ecu's tables

Do you have a wideband to verify the afr are correct, especially if you are interested in increasing the boost?

Sorry for the quick explanation without giving all information. Just was typing and didn't get to put all.
Flashed ecu was bought and not done locally, no one where I live can re-flash and tune. So safc installed to adjust fueling as needed.
EBC is still using stock lines for pressure and vacuum sources. Did not disconnect factory boost solenoid.
Boost pressure goes to port 3 of solenoid, port 2 is attached to to both wastegates and port 1 vent to atmo.
Yes wideband installed.

The stock vaccum lines and solenoids have restrictor pills in them. If your using an aftermarket controller use and aftermarket solenoid and bypass the OEM system entirely with new vaccum hoses. To the aftermarket controller can work as intended

Ok. Will try this weekend as I only teed off what lines where available to install ebc.

 

[BCX]

No probs, makes sense.

As @6A13TT TYPE S mentioned, the hose with the red painted end has a brass restrictor in it.

Get some new vac line, replace it all with new and you should be good. Just leave the stocko solenoid with no lines going to it.

 

[DaBo$$]

No probs, makes sense.

As @6A13TT TYPE S mentioned, the hose with the red painted end has a brass restrictor in it.

Get some new vac line, replace it all with new and you should be good. Just leave the stocko solenoid with no lines going to it.

Hopefully this helps!!! Have mamba turbos installed with their aftermarket wastegates and changed to 15psi base springs. As is still only 8 to 9psi wot.

 

[DaBo$$]

Update!!!!!
Removed the stock boost solenoid out of the system, it wasn't plumbed to the wastegates, just inline from the turbo intake to a tee that was going to the fuel pressure regulator and then to the intake manifold.
Anyway I completely removed it out the system, made sure the ebc and wastegates were plumbed correctly and still only getting 9psi of boost with the boost controller off and about 12psi with the controller on and at 50%duty cycle.
I don't know how this is even possible with 15psi springs installed.
Only if the springs are rated wrong or their is a leak under boost.
Doubt the springs are rated wrong, but not sure as the information about these wastegates is not in abundance.
Guess trying to get a boost leak test is next.

 

[Baba Galant]

It really sounds like a boost leak somehow. I've done this to myself at least 3 times, generally a loose clamp somewhere, we run about a dozen I guess?
Hitting 8 PSI consistently kinda leads me to believe this, work backwards from the throttle body through the engine bay and then check the intercooler joins.

 

[DaBo$$]

Update....
Did a boost leak test found some points of interest cleared them up but have not had time to really test as I tried to change my cv joints to deal with shaking under acceleration and the new ones didn't fit so had to put back in the old broken ones to remain mobile and now car doesn't shift in drive, just stays in gear one.
Boostlife!!!

 

[mezje]

Boost life? Or incompetence life?

 

[6A13TT TYPE S]

A 10psi spring =/= 10psi boost at zero duty
Its a combination of drive pressure in the turbine housing and the size of the wastegate flapper valve.

A 10psi spring will only exert a given ammount of force on the pullrod of the internal wastegate actuator regardless of the size of the turbo, turbine drive pressure and flapper size.

For example the internally wastegates borg warner EFR turbos have large wastegate flappers to help avoid boost creep for high flowing engines.
However the larger the flapper means the pullrod of the actuator needs to exert more force to hold the flapper closed at a given drive pressure than a smaller flapper

i.e: a 1 square inch flapper will require 10 pounds of force to hold back 10 pounds per square inch of turbine pressure.. assuming your drive pressure is 1:1 to your boost pressure you will make 10 psi of boost.
Simple right
But if your wastegate flapper is 2 square inches. It only takes 5psi of drive pressure to create 10pounds of pullrod force on the actuator.. meaning for the same spring you get half as much boos with a flapper thats twice as big.

As Our turbos are horribly inefficient im willing to bet they have a drive pressure to boost ratio more in the range of 2:1
So say you have 10psi of pressure in the turbine. Assuming a 1 sq inch flapper and 10pounds of pressure on the pullrod you will only get 5psi of boost pressure.

These are all just numbers ive pulled out of my ass to help illustrate a point but ive used borg warner efr internal wastegate turbos before and had to put 24ish psi worth of spring into the actuator to get it to make 12ish psi of boost because of the combination of high drive pressure to boost pressure ratios and the large flapper

 

[bjk]

^ that was actually very helpful and explains why I only got a 1psi increase (from ~8 to 9) when Vectose put the stronger actuators with the 11psi springs in. Had assumed they were just underrated.

 

[6A13TT TYPE S]

Then when your trying to add boost ontop of your spring pressure the ratio of area of your actuator diaphragm vs your flapper area (or valve for an external gate) comes into play.


This is exactly why with external wastegates the diaphragm gets proportionaly larger with the valve size. As if you had a huge 60mm wastegate with only a small 38mm diaphragm, you wouldnt have a shit show using the boost pressure to hold back the turbine pressure. But with internal wastegates the likes of those turbosmart actuators are a set size diaphragm and they have to work on a broad range of internal gate flapper sizes, hence why their "PSI Rating" is often wildly wrong.

Thats Why having EMAP is such a handy bit of data to have when choosing turbine housings. Lets you know your drive pressure vs boost pressure.

I would like to know the drive pressure on a stock TD03 at 1 bar boost because I bet its horrific. But 9n the flipside the turbines are so small the wastegate flapper area is probably equally small.

 

[6A13TT TYPE S]

Conveniently Jay uploaded this on his channel today.
Hes really good at making somewhat complex things reasonably easy to understand for the layman.