Forced Induction Superchargers | Turbochargers | Intercoolers

Back pressure test results, when is it too much?

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Old Apr 26, 2012 | 11:20 AM
  #61  
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I think it would be relevant. Not every setup is going to be exact

Not sure if you posted but what are your numbers rotary?
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Old Apr 26, 2012 | 11:57 AM
  #62  
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I have what is essentially a 76GTS .96 ar on my 346 and it's donzo at around 18 psi and while I haven't measured the backpressure I'm sure it's gotta be up there. I am trying to figure out what I can do to help get that exhaust out whether it's clipping the exhaust wheel or trying another turbo but since I've got a TTi race kit my space is VERY limited and kind of excludes anything much larger than a 76GTS.

Heck I don't even know why I'm trying to make it faster or whatever, it's not like it techs for what it runs now LOL! I guess I just want to optimize what I have further.
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Old Apr 26, 2012 | 12:11 PM
  #63  
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never been on the dyno, just the track twice

at just over 3000lbs it was 149mph on the limiter and 12psi, so whatever that is

i have regeared now and will add boost to see what the turbo does

it would be interesting to get yours to the track and see what the real world power is from the trap/weight

it may be making a good bit more than you think



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Old Apr 26, 2012 | 12:54 PM
  #64  
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I trapped 134 with the tc78. I'm thinking this will do closer to 140mph. And hopfully a 9.80 or so.
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Old Apr 26, 2012 | 01:36 PM
  #65  
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Originally Posted by 98Z28CobraKiller
Ideally, you want to see 0 backpressure in the DP. Backpressure in the DP would slow spool, limit max boost pressure and create additional pressure ratio in the hot pipe. But that said, backpressure ratio is measured as close to the exh housing as possible (the way the OP did it).
I can definitely agree to that. However, including pressure measurements from downstream @ the DP will give you the actual PR across the turbine itself. Knowing just how high of a pressure drop you've got between turbine inlet and turbine outlet let's you know how effecient your trim/housing selection is at converting that high pressure to kinetic energy.

Sorry for going "Steven Hawkins" on ya..
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Old Oct 5, 2012 | 09:31 AM
  #66  
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Here is another 80/79 with issues on a small mod motor even

http://www.yellowbullet.com/forum/sh...=1#post9788923
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