I brought my car into the mechanic this morning, makeing a strange noise from the rear end.
Anyway were out driving, discussing my next mods.
And he asks how much boost im running.
I said just normal 6 in first, 10 in seccond and 14.7 from third up.

He kind of just gave me a look.
Said that with my mods and such, 15psi is fine. But he said thats too much boost on the stock wastegate. And really if I go to the track, my engine might go boom.
So I geuss im going to port the wastegate.
Just want to make sure this is necessary and if porting it is the right way to go.

 

sorry power mods are in sig.

 

I'd port it. Would hate to get some boost creep there.... Get up to 16psi and maybe blow off the vacuum tubes or something... I'd do it simply for caution To be careful and all...

 

1 bar on the TMIC?
You can probably tell your power is flatlined above 12PSI.
The extra boost creep is just extra stress without much benefit.

 

Saying it doesnt make more power past 12psi?
I have noticed that it doesnt seem to pull more.

So I geuss im going to port it.

An FMIC is on my list here very soon.

 

if you are running 15psi and want to run 15psi. then you don't need to do anything to the wastegate... it won't make any diff.


running 15 psi on the stock turbo and IC is dumb and pointless....


what fuel mods do you have to be enough?...

 

720cc injectors (mods in sig)

I didnt set the boost to 15, i got the car and this is how it was running.

Now im trying to get everything set up correctly (for my modest 300whp goal). Im not just some idiot who cranks up the boost.

 

You got it.
Some day I plan to have better fuel management like yours.
Port the WG for now to take the extra stress off the turbo.
You can always dial up the MBC when you go FIMC.

 

Well The way to remove stress from the engine is to reduce the boost to 12-13ish.

Anything over that and your pretty much just over spinning the turbo and hurting it.

You have a MBC. Turn it down.

The S4 WG is known to be crappy though.

You can always upgrade to a S5 turbo

 

No offense. but the "throw in bigger injectors and she'll be right" attitude never ceases to amaze me. Apart from the fact the running 15psi on the stock turbo and intercooler is not too smart, those injectors are not going to do squat if the pump is unable to provide the required flow and pressure.

It's not just fuel flow that must increase as boost increases, but the fuel rail pressure must also be higher to overcome the higher pressure in the manifold. On an FC (and many other cars) the pump is always the first thing that needs to be upgraded. With the correct pressure and control, the stock injectors can flow enough fuel for ~300hp, but the stock pump certainly cannot do that.

Also, running those injectors without a fuel controller means that most of the time your mixtures are far too rich. Stock mixtures are already conservatively rich under load, so this will make it worse (as long as the pump can keep up anyway). The correct order for fuel mods is pump, controller, injectors. Most people seem to do that backwards...

The reason you have such massive boost creep is because the stock wastegate port is tiny. The first thing you should do is get the turbo off and have the wastegate replaced with a bigger one and the wastegate ported to match the new flap. This will give you proper control over boost. On the stock turbo and intercooler 10psi is good, 12psi is pushing it if you want it to last long.