I have been planning to port my miniscule wastegate for some time now. I am taking it to a local machine shop tomorrow and getting it ported to about 33-34mm. I would do it myself but I don't have air tools. I will post a before and after pic to show the results.

 

you can also shave down the backside of the flapper door, so that it opens further

 

opening the door father does nothing. once its open, its open.

 

Well thank you S & H Automachine in Fortuna, CA for doing an amazing job. Great guys. Here are my after ported pix. It is ported to 33mm.

 

^Holy **** thats nice!!!! How much did that cost if you don't mind me asking?

+1, hook up a hand bicycle/vacuum pump to your wastegate line after doing that mod and note how far the wastegate actually moves the flapper. I felt pretty dumb after I spent like 20 minutes sitting there porting the backplate with my dremel.

 

cost dude

 

They charged $80/hour and it took a little over 2hrs but he only charged me for 2 and they welded the flapper for me. I gave it to them at 9am today and had it back at 2pm.

I finished putting it all back together and wow! Way faster boost response. I am going to go out tomorrow and re set my boost controller. I am very happy with the results though, top notch quality.

 

Yes it does, I proved this on the Dyno. With my S5 turbo's ported WG I could still creep to 10psi, with the ported WG, and the backing plate shaved down I couldn't boost anymore than 7.2ish... Hooked up the boost controller, and I can boost 10psi again. BDC was there, and saw this.

 

So it worked for you too?

 

No, the opposite. Your result was due to the boost controller.

 

Nah it didn't work for me. I'm using an S4 actuator on an S5 turbo with a bent rod though so maybe thats only true of the S4 actuators. I applied pressure to mine (already confirmed the backplate was ported right and the additional movement of the flapper with no wastegate) and it didn't go further than before I did the porting.

 

Well there seems to be zero boost creep now. Before I would creep up to 9lbs or so. Feels so good!

 

No, the Boost Controller was never hooked up. Once we used the boost controller it allowed about 2.5-3psi of creep. Before the boost was rock solid at 7.2psi, prior to that with the stock plate I could boost 10-13psi without issue, and that was with a massive WG.

I know this works on the S5 with a ported Wastegate, the S4, I can't say, but from the sounds of it it doesn't work.

 

I had an extra S4 hotside laying around, and last night i checked it with 10psi. the wg arm moves about 1/2 inch, which makes the door just touch the back of the housing. grinding down the back of the door may or may not help, but it definately cant hurt