Forced Induction Custom FI Setup Questions

big turbo on a 35mm wastegate

Old Dec 15, 2008 | 11:23 PM
  #21  
Scott-EP's Avatar
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Default Re: big turbo on a 35mm wastegate

Back on topic

you should be just fine. I ran that same turbo on a CDM manifold at 7psi with a turbonetics wastegate for a while. Not one bit of creep.
Old Dec 15, 2008 | 11:56 PM
  #22  
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Default Re: big turbo on a 35mm wastegate

awesome, didnt think id here so much reassurance
Old Dec 16, 2008 | 04:03 AM
  #23  
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Default Re: big turbo on a 35mm wastegate

Why was this even asked? at HMT we run what we have.
Old Dec 19, 2008 | 11:56 PM
  #24  
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Default Re: big turbo on a 35mm wastegate

Originally Posted by AaronZ34
No, less boost is harder to control, since then more exhaust must flow through the WG and bypass the turbocharger.
But with more boost, you also get much more pressure in the exhaust manifold. That extra pressure helps open the valve by itself, and at some point overcomes the spring. Much more so on a weak spring than a high-boost spring.
Old Feb 18, 2009 | 03:03 AM
  #25  
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Default Re: big turbo on a 35mm wastegate

Originally Posted by HiProfile
But with more boost, you also get much more pressure in the exhaust manifold. That extra pressure helps open the valve by itself, and at some point overcomes the spring. Much more so on a weak spring than a high-boost spring.
With high boost, less exhaust gases must flow through the wastegate and more gases flow through the manifold and into the turbo, lessening the possibility of boost spike (which was Delspool's main concern). In a low boost situation, the wastegate must bypass a large volume of exhaust gases so that they do not force the turbo to build more boost; but, the manifold itself has less pressure, since it is being bled off by the wastegate . For larger turbo setups, the wategate may not flow (get rid of) enough exhaust gases and boost spike occurs. What you describe is the opposite of boost spike (when a turbo is too small for an engine and boost tapers off when an engine hits is peak volumetric effciency, or when a spring is shitty and too weak to maintain its pressure rating). Boost tapering off is not Delspool's current problem. Also, the exhaust gases don't actually push open the wastegate valve, only pressure from vacuum lines from the boost piping/intake manifold is involved in overcoming the strength of the spring and opening the valve.
Old Feb 18, 2009 | 03:11 AM
  #26  
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Default Re: big turbo on a 35mm wastegate

Originally Posted by HiProfile
But with more boost, you also get much more pressure in the exhaust manifold. That extra pressure helps open the valve by itself, and at some point overcomes the spring. Much more so on a weak spring than a high-boost spring.
exhaust gasses cannot overcome the spring, it is opened with boost pressure. First try to open the wastegate by hand, then try to hold the pressure in the manifold with that same hand, then come back here and tell me which was harder to do.

I second Jee ewnits notion.
Old Feb 18, 2009 | 03:54 AM
  #27  
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Default Re: big turbo on a 35mm wastegate

i'm suprised jd hasn't come in this thread
Old Feb 18, 2009 | 12:28 PM
  #28  
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Default Re: big turbo on a 35mm wastegate

Originally Posted by Adam Hopkins
There is no such thing as too much boost. You could have too little rod, piston, or sleeve. But never too much boost.
Also too little turbo, for example an HX-35 beyond 50psi starts to snap shafts.
Old Feb 18, 2009 | 12:39 PM
  #29  
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Default Re: big turbo on a 35mm wastegate

Originally Posted by turbob16hatch
i'm suprised jd hasn't come in this thread
Try this on for size: you're a dumbass.
Old Feb 18, 2009 | 01:59 PM
  #30  
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Default Re: big turbo on a 35mm wastegate

Originally Posted by Joseph Davis
Try this on for size: you're a dumbass.
LOL

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