Hi, I have an IX, im boosting 24 psi down to 18 just below redline... What would be the best way to eliminate as most as possible boost taper? A Grimspeed or GM 3 port BCS would be the way to go?

 

That is just what the stock turbo does, the only solution to get rid of the taper would be to upgrade the turbo

 

Or you can upgrade the wastegate to hold more boost.

 

It still tapers badly. You can still adjust the wastegate but the turbo still runs out of breath

 

I used an HKS EVC 6 boost controller to get rid of some of the taper. I could hold a flat boost line of 24psi with it on the stock turbo.

There are cheaper solutions now-a-days though.

 

bump

 

would a high pressure wastegate actuator help? Stock is 11psi, so would a 17psi help, or would you have to go to something like a 22psi actuator?

 

big turbo will fix that for ya

check for boost leaks and tighten up your wastegate actuator preload and see if that helps. stock turbo should be able to hold close to 24psi to redline

 

Im running a forge wg with 18psi spring and have it 1/2 a turn from being fully tightened. Its hitting around 25psi without help from my hks ebc and it still tapers quite a bit. Only real way to keep it from doing this I think is bigger turbo. As stated before the turbo just runs out of breath. Once u get close to redline the motor is breathing so much so fast it can't hold the psi. Most stock turbo motors do this and undersized turbos.

 

wastegate has nothing to do with how much air the turbo can flow. stock turbo runs out of air pretty easy up top. its just what small snails do

 

Upgrade the turbo, the stocker isn't big enough, if not, a EBC will help a lot. I run a Blitz SBC-ID and I hold 22psi till bout 6700-6800 then it drops to about 19-20 at 7500. Before the blitz, it would hit 22 then drop to about 17, and was worse when I put in my XS intercooler

 

I can hold ~22-23 psi to redline on the stock turbo with my grimmspeed BCS if I choose to. That would be the best option IMO.

 

fp black should be help !!!

 

I'm still hitting almost 23psi @7000 on the stock turbo with the Grimmspeed 3 port BCS and ECU controlled boost. Those two things will help but you won't completely get rid of it. Like most have said, the stock turbo just runs out of breath. Even if you can get it to hold more boost you may not be making more power because you start to run the turbo out of it's efficiency range and you also won't be able to run as much timing. A little less boost and maximum timing is the way to go if you want to make more power up top but that also has limits.

 

the shortest intercooler piping should help too
mini batt and short uicp