wastegate porting question
#1
Rotary Freak
Thread Starter
wastegate porting question
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?
#2
Rotors still spinning
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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.
#6
Rotary Freak
Thread Starter
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.
Last edited by RotaryRevn; 01-17-03 at 12:08 PM.
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#11
Rotary Freak
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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!
#12
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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!
#15
Rotary Freak
Thread Starter
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...
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...
#16
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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
Dan
#18
Rotary Freak
Thread Starter
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?
#20
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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?
#23
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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.
Heh. Brian at BNR will either be porting my wastegate or showing me how to do such a task. Real soon. Heha.
#25
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.