banzaitoyota

I can port your housing for a reasonable fee.

jon88se

wastegate porting should also improve spool

dr0x

Hows that exactly?

NZConvertible

Wastegate size has no effect on how fast a turbo spools. In fact the best way to spool a turbo faster is to keep the wastegate completely closed until the desired max boost is reached, which is exactly was an EBC does. Normally the wastegate starts to open before max boost is reached, which is called wastegate creep (different to boost creep).

iluvrx7z

Pic of my wastegate

RotaryRevn

Wow, that is a big port! I would be interested in seeing a pic of it with the flapper closed. I want to see how the flap is attached to the arm, if there is any room for it to slide a little like the stock one, or if it is solid on there. Is that a valve used for the flap?

RotaryRevn

Actually it doesn't look like a valve, probably just a big flap from something else.

scathcart

Yes

scathcart

2

scathcart

last one

scathcart

Flapper door shut


Flapper door open.
The top wastegate hole feeds from the back runner, just like in the S4 design. This hole is 19mm in diameter (0.750"), as opposed to the stock 12mm of the S4 design.
The bottom wastegate hole feeds off of the front runner. It is 24.5mm (0.950") in diamater. The stock S4's do not even HAVE this hole.


This just shows how the bottom wastegate hole curves around to feed off of the front runner.

I measured the wastegate holes with a digital vernier caliper, so they are accurate.

Sorry for the low-res pics.


This is just a spare housing I have laying around. Anyone want to purchase it? I'll even port it for you.

600HP CLUB

ok i'm about to do this porting, but i don't know how to dissemble the turbo and reseemable it, so i'm asking do ineed to take it apart when i grind the **** out of it?

-mike

jetfire76

same here. should i disasseble the turbo or can i just port the wastegate and blow some compressed air in there to clean up the shavings?

600HP CLUB

i thnk you should disaasemble it and then port it, just use white out to mark the center cartridge and the housing to kinda accuratly install it back with the wastegate in the correct position.

$150FC

iluvrx7z: Is that a.. BNR Wastegate Port I see?

NZConvertible

That would blow metal shavings into the turbo and possibly the engine. Absolute no-no!

Take the turbo off and remove the exhaust housing. It's quite easy, you just disconnect the wastegate actuator arm, undo the bolts holding the housing on and it should pop off. As mentioned, mark the relationship between the housing and the center so you can reassemble it correctly. Be careful not to damage the turbine wheel while it's apart.

joelu

i ported mine to 22mm. i cant remember the size of the stock door but i ported it bigger. the thing is that when the door is shut it, closes on an angle so the gap is minimal maybe 1mm around. and no catching.

Fingers

Does the s5 wastegate also need porting? What if i just upgrade my fuel, and add an safc to support the increase of boost?

gsracer

the s5 wastegate is leaps and bounds ahead of the tiny s4 wastegate, but it might need porting as well. It all depends on your application and what mods you are planning on going with. Yes you could increase the fuel to support the extra boost, but imo that's crude because you have no control of your boost.

Fingers

sure i do. I have tons of control. But i want to control it at a higher level

Fingers

oh yeah, mods? I think i'll be sticking with the stock airbox/snorkel... exhaust will be 2.5" racingbeat downpipe, presilencer, and catback will either be a dynomax superturbo or the corksport single

gsracer

you'll probably be fine without porting the wastegate on the s5, especially with stock intake.

NZConvertible

While this won't do any harm, it will lose you a bit of performance. If the flap can't seal the port, then exhaust gases will leak through it even when it's supposed to be closed. This means the turbo will spool slower than it should, reducing mid-range and transitional performance, although max boost and peak power won't be affected.
If you're going to port the wastegate bigger than the stock flap you should investigate putting on a bigger flap. A few people have posted how they did this, or you could get a turbo shop to do it. A quicker spooling turbo makes a car much nicer to drive.