Ok, I ported my wastegate today. I was wondering if there were any benefits or negatives to drilling a hole through the center iron in the manifold so that the wastegate would bleed air from both sides simutaneouly. You know, drill a hold straight across from the wastegate hole in the center. Also you would think that this would help equal the pressure in both chambers. Anyone done this?

 

I assume this is on an S4 turbo? No there is no advantage. The factory exhaust manifold pretty much mixes up both pulses from each side of the engine since it is in itself just one common chamber. You'd be better off porting the openings of the turbo (exhaust side) so that they more closely match the opening in the manifold. Stare at the manifold and the turbo next to each other and you'll see what I mean.

 

Here is my runner porting, I wouldn't go as thin on the divider as I did

 

I ported one last week that was pretty similar to that one. I actual went a little more extreme than that. I too thinned the divider but he also removed the flapper door so it doesn't get in the way anymore. How much better was the response in your opinion?

 

I haven't finished installation yet. I'll let you know. My wastegate opening is about 1.5 X flapper door diameter

 

Thanks for the input guys, I was planning on porting the exhaust side of the turbo within the next few days if I get time, and I buy some bits to do it. I was borrowing my friends carbide bit to do the wastegate. I wasn't planning on going too thin on the center, I just want to round off the beginning of the divider. That should lower the friction of air entering there and hopefully not crack like most of them do in that spot. I will refer to the exhaust manifold to see how big I can go Here are a few pics of the wastegate before and after. I may clean up the hole just a tad bit more. Thought I'd through in a pic of me peeking inside the exhaust port, looks pretty good in there! I will post pics as I port the rest of the parts.

 

OOps, lets see if I can get these pics uploaded right this time.

 

anyone got a pic of a s5

 

Here's the pic before I ported it. Of course the pics aren't exactly the same size or distance from the hole but you can tell the difference in size.

 

And my peek-a-boo shot looking into the engine after removal of the turbo.

 

Banzi, Looking at the inside of the manifold you ported, looks like your wastegate hole is pretty big. Were you able to backcut it.......what I mean is make it kinda taper in at at angle to the wastegate. I wasn't able to do that with the big bit I was using with the drill. Your porting looks sweet!

 

Yes, I backcut the living F#!@#^ of of it! I also took out the Nub at the 2:00 o'clock position of the housing. I use a die grinder with a 6" long carbide bit for that part. I'll ost more pics when I get back from the Bahama's next week! Thanks for the complement!

 

Cool, Have fun on your vacation!

 

I have a picture of my wastegate port done by Brian @ BNR. I don't know how to post it though...It came out to 34.8mm

Dan

 

Iluvrx7z,

Did Brian leave the stock flapper on the wastegate, or did he weld on a bigger flapper? I have heard of people using valves and what not but I am not clear on how to do it. Looking at the stock flapper, it is a little loose to help with sealing. I am not sure how to get a new flapper on there and have it properly seal...

 

It appears to be a new flapper all together. If you look at the pic the wastegate hole is huge in comparison to stock as is the flapper. He wrote on the flapper door "34.8mm" Hope that helps!

Dan

 

Brian does huge wastegates. 35mm vs the 12mm stock.

 

35mm, wow, that is big compared to 12mm. Thanks for the specs, I didn't measure mine before so I wasn't quite sure what the stock measurement was. Anyone have experience putting a different flapper on there?

 

Id figure you would have to figure out how the valve (or whatever) seats onto the flapper while sitting flush against the wastegate wall and weld it on like that.

 

Not to sound like a total n00b, but what does porting the wastegate help? I understand matching the ports between the manifold and the turbo, but what is the big deal about the size of the wastegate?

 

people port wastegates (especially the small s4 ones) to prevent boost creep. Boost creep happens when the turbo can outflow both the engine and the wastegate combined, which makes boost pressures rise, which can cause the engine to run lean.

 

Ahh. Thank you for turning on the lightbulb.

 

Gee. Nobody Stole the idea of my username, did they?

Heh. Brian at BNR will either be porting my wastegate or showing me how to do such a task. Real soon. Heha.

 

how much does brian charge for that?

 

Comes standard w/ all of his turbo upgrades/rebuilds. I dont think it would be worth shipping your turbo to him just to port it? Find a local turbo shop... they could probably do something similar.