Author Topic: Boost Leak?  (Read 1704 times)

May 27, 2009, 09:46:12 pm

Rabbit TD

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Boost Leak?
« on: May 27, 2009, 09:46:12 pm »
I've been messing with the old original T3 which I am gonna probably try on the car this weekend.  The thing that makes me wonder is the way the wastegate operates on the pressed in cannister type ones.  I took the old canister off because it was all rusted and  not working anyway.  The question is how do these things make any boost with the valve stem having a hole drilled in it lengthwise and vented to atmosphere through the opening in the cannister.  I know it's purpose is for cooling but it looks like a major leak source to me also but I'm sure Garrett knows a lot more than me about this situation.  But wouldn't it be essentialy the same thing as drilling a hole that same size in the intake manifold as far as a boost leak or am I missing something?   I'm going to run it with just the parts needed to hold the valve shut for some comparrison testing, I did lapp the valve by the way also just to eliminate that leak  possibility.



Reply #1May 27, 2009, 09:53:10 pm

vanbcguy

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Re: Boost Leak?
« Reply #1 on: May 27, 2009, 09:53:10 pm »
There's a couple hundred cubic feet per minute of air being ingested by the engine... Really not all that much air can escape out the bleed.  Yes, it's a boost leak but it's so small it's not really going to make a difference.  The KKK turbos do the same thing btw...
Bryn

1994 Jetta - AHU M-TDI - Jezebel Jetta
2004 Jetta Wagon - 1.8T - Blitzen

Reply #2May 27, 2009, 10:02:55 pm

Rabbit TD

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Re: Boost Leak?
« Reply #2 on: May 27, 2009, 10:02:55 pm »
There's a couple hundred cubic feet per minute of air being ingested by the engine... Really not all that much air can escape out the bleed.  Yes, it's a boost leak but it's so small it's not really going to make a difference.  The KKK turbos do the same thing btw...

I figured the volume must have made up for it somehow, it just made me wonder when I tore it apart and saw how it was made a while back.