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Old 04-11-2002, 02:23 PM   #1
8Complex

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Default Wastegate to Atmosphere questions...

I've only been able to find one discussion of this on the board and it didn't get much into detail...

Assuming 2.5L with an external wastegate setup :

1. When venting the wastegate to atm. is it (by itself) as loud as a straight pipe out of the turbo?

2. Would it shoot flames on a regular basis, or just when tuned more rich? I'm assuming it'll just do it during shifts or when the throttle is let up and pressed again.

3. Would the backpressure of it's own routing (tubing, muffler, etc) cause backpressure to build up and more of the wastegate to be less accurate/effective?

4. Does anyone have a sound bite, or could someone take one? I think everyone would like to hear this anyway, so it might be a good time.

Lastly - if there is such a thing as a resonator, why can't I find any on Jegs, Summit Racing, etc's sites? I know there is such a thing, but someone it eludes me.
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Old 04-11-2002, 04:22 PM   #2
RS2000
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Don't do it. I have my wastegate vented to the atm. and it sounds aweful. When the wastegate dumps it to the atm. it is so loud it actually drowns out my exhaust noise. I'm not sure if it varies depending on the wastegate or not but I have a Deltagate right now and am going to switch to a Tial and if i still don't like it i'm going to route it into the downpipe as far down it as i can go. As far as shooting flames, that i don't know. I am running a little rich right now and I know I can shoot a flame out my exhaust but I never got anyone to see if anything comes out of my wastegate.
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Old 04-11-2002, 05:18 PM   #3
subachad
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Mine is currently to the atm and well, it's kinda embarrasing. The car is relatively quiet until I "get on it" then it sounds like my exhaust manifold just blew out and all of a sudden, I can't hear anything but "BWAHAAAHHHHHHH"

I feel like a "ricer" when that happens.

I plan on fixing it soon...

Chad
93 1.8T
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Old 04-11-2002, 05:52 PM   #4
8Complex

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Do either of you guys have small mufflers on your wastegate dump? I'm wondering if that wouldn't be a good solution too. A small tube with a muffler welded to the bottom would work well and bolt right to the wastegate easily.
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Old 04-11-2002, 05:56 PM   #5
zaidallas
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I love the atm. vented tial . However my wife thinks its loud so i'll have to reroute it now. It actually sounds very nice and scary from the outside and not ricey. It doesn't shoot flames since like you mentioned , most flames come out not under boost but shifting so its closed then . Its not loud like an open header but its loud in a more high pitch or something kinda hard to explain. I'll try to post some sound bites later.
zaidoun
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Old 04-11-2002, 05:57 PM   #6
Happy
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They are pretty loud, but not as loud as my turbo when it's on song

I had a small custom exhaust silencer made for mine. Very cute but it makes it much quieter. I use the Racegate, but I'm sure it can be done to other makes, certainly the Deltagate.

Happy.
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Old 04-11-2002, 07:04 PM   #7
RS2000
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I don't have anything on the dump pipe. This is how i look at it. Its dumped to the atm. instead because its supposed to help spool the turbo quicker because there is no restrictions. Wouldn't putting a little muffler on there cause a restriction and effect spool up anyway. Might as well just keep it routed in the exhaust.
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Old 04-12-2002, 03:24 AM   #8
Happy
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The wastegate should be "shut" while the turbo is spooling up. That way ALL of the exhaust gas is forced through the turbo exhaust turbine, and giving quick spool up.

Part of the problem you guys have, is that because you only apply pressure to "OPEN" the WG, and or, use a very soft spring to limit boost, you're probably suffering from WG creep.

Re a silencer on the WG, so long as it doesn't cause overboost, it will be fine.

Mine was originally made with perforated exhaust baffle across it. On the dyno we found that this was fine at low boost, but once we tried to run over a certain level, it was so restrictive, that boost wouldn't drop below about 20psi, even with the WG fully open............. I run a 10psi spring.

Happy.
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Old 04-12-2002, 10:57 AM   #9
Wreckleford
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I tested out a small silencer in my wastegate dump tube. It was sort of like those silencers that Apexi put in their muffler tips. It had fiberglass insulation in it to kill the sound, but the insulation didn't last too long due to the heat. I was thinking of using steel wool but that might rust out in no time. I was considering using some aluminum swarf from a machine shop or stainless steel if possible. I took it back out, but I still plan on making a better one in the future as it was effective in lowering the noise. It was still loud but the BLAAT sound was diminished, making it sound more like a whoosh sound.
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