Unseen24-7

Hi,

When porting a s4 WG I see a bit of a problem. You can port that sucker as big as you can but it is still only venting the one exhuast runner, the other is still heading uninhibitied into the turbine.

So I'm thinking you could drill a hole through the wall between the runners so that at least some exhaust from the front runner could be vented out, allowing better boost control.

Has anyone tried this? Would the hole disrupt exhaust flow badly when not venting? Any thoughts?

Unseen24-7

Anybody have some ideas on this?

eage8

iTrader: (9)

I don't think anyone's had issues after porting the crap out of a S4 wastegate. The S5 waste gate has a hole for each runner, it seems like it would be easier just to upgrade to an S5 turbo.

Unseen24-7

But if you HAVE an s4 turbo wouldn't it be easier to just drill a hole and do some minor porting, not to mention cheaper as you don't have to buy a turbo.

SpeedOfLife

iTrader: (16)

I have, and I know there are others as well. My S4 WG is ported to 30mm and I still creep well above stock levels in 3rd and up. Now, it's manageable most of the time and hits about where I want it to, but it gets a bit hairy when it's cold out.

For one, drilling a hole through the runners would in all likelihood to terrible things to the flow, ESPECIALLY if you still use the twin scroll flapper. My God, I don't even want to think about that. For two, it would make the old cast fall apart even faster. There may be other reasons not to do this as well, HOWEVER, it's an interesting thought and no one's stopping you from experimenting. If you or anyone else is going to try this, I want to throw this out there: Instead of porting a hole between the runners, just cut away all of the divider 'til about the middle or back end of the wastegate opening (back as opposed to the front, front being the part the exhaust gases reach first) and taper the remaining bit of the runner divider.

freemanrx7

If you can find a blown s5 turbo all you need is the manifold and hotside of the turbo. You can use the s4 coldside. I did this since my s4 turbo was in mint condition and I have no boost creep problems running 2.5" RB exhaust and a TID.

Unseen24-7

Thats an interesting idea, just simply removing the divider up until the WG opening. Would probably work much better than a hole anyway.

Really? A s5 hotside housing just slips over a s4 turbine wheel? That would be a good option too.

freemanrx7

Might as well go this route if u plan on using the stock turbo. The s5manifold has seprate runners as well.