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Why aren't miata engines so good for all-motor power?

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Old Oct 8, 2018 | 10:59 AM
  #21  
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80s tech is even a stretch....
Old Oct 8, 2018 | 11:01 AM
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why isn't a t25 as good as an EFR6258?
Old Oct 8, 2018 | 11:02 AM
  #23  
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Why isn't one horse as strong as hundreds of them?
Old Oct 8, 2018 | 11:15 AM
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Obviously you guys havent tried the tornado on your n/a builds. This was engineered in a wind tunnel! Reap the rewards of whirling air no matter how small your ports.
Old Oct 8, 2018 | 11:19 AM
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Originally Posted by stratosteve



Obviously you guys havent tried the tornado on your n/a builds. This was engineered in a wind tunnel! Reap the rewards of whirling air no matter how small your ports.
When I worked at Autozone many moons ago we sold those LMAO.
Old Oct 8, 2018 | 11:21 AM
  #26  
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Originally Posted by concealer404
Why isn't one horse as strong as hundreds of them?
Why isn't donkey as stronk as ox?
Old Oct 8, 2018 | 11:52 AM
  #27  
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Originally Posted by 18psi
Why isn't donkey as strong as ox?
Bad port design and low static compression.
Old Oct 8, 2018 | 12:00 PM
  #28  
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Originally Posted by Joe Perez
I'm not disagreeing that the port design in the Mazda BP-series heads is sub-optimal, but those photos seem disingenuous to me.
Ehh...

Originally Posted by Full_Tilt_Boogie
I noticed the same thing. It definitely makes the BP ports look smaller than they are. The shape is very obviously worse though.
...exactly. The size of the port is not actually of all that much consequence. Bigger ports mean less velocity, which means less low-end torque, even if the flow numbers are the same. The port design is what those photos are showing. The BP's short side radius is laughable. When a pro ports a BP head, they can't even touch the ceiling of the port, because literally all they can do is make it worse. The B16 port looks like a factory race head, just like all of Honda's heads do.
Old Oct 8, 2018 | 01:41 PM
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Originally Posted by stratosteve



Obviously you guys havent tried the tornado on your n/a builds. This was engineered in a wind tunnel! Reap the rewards of whirling air no matter how small your ports.
Because every car performs better with an inlet restriction!
Old Oct 8, 2018 | 02:19 PM
  #30  
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What part of vortex dont you understand? Jeez
Old Oct 8, 2018 | 02:39 PM
  #31  
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who wants their air STRAIGHT anyway?
Old Oct 8, 2018 | 02:41 PM
  #32  
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Right
Old Oct 8, 2018 | 02:43 PM
  #33  
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Originally Posted by 18psi
who wants their air STRAIGHT anyway?
GAY air has more fun!
Old Oct 8, 2018 | 02:54 PM
  #34  
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Originally Posted by Savington
When a pro ports a BP head, they can't even touch the ceiling of the port, because literally all they can do is make it worse. The B16 port looks like a factory race head, just like all of Honda's heads do.
My initial impression after pulling a silicone casting of the intake port was the opposite: leave the floor and work the ceiling.
Have somewhere you can point me to talking more about this?
Old Oct 8, 2018 | 03:13 PM
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Originally Posted by burdickjp
My initial impression after pulling a silicone casting of the intake port was the opposite: leave the floor and work the ceiling.
Have somewhere you can point me to talking more about this?
Port a head and stick it on a Dyno. That's what Andrew, myself and a few others have done for the last decade or so. Bowl blending doesn't mean port shaping in my view. That's just correcting for low cost manufacturing processes. Filling in the short side radius time-tested approach to low port angle heads. In another life, we did that to 2.0L Pinto heads.
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Old Oct 8, 2018 | 03:16 PM
  #36  
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Originally Posted by 18psi
who wants their air STRAIGHT anyway?
it's 2018. We need to let the air choose it's orientation.
Old Oct 8, 2018 | 03:16 PM
  #37  
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Originally Posted by burdickjp
My initial impression after pulling a silicone casting of the intake port was the opposite: leave the floor and work the ceiling.
Have somewhere you can point me to talking more about this?
Google "short side radius"

Or

mondello.com - Home

Old Oct 8, 2018 | 03:21 PM
  #38  
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Originally Posted by sometorque
it's 2018. We need to let the air choose it's orientation.
unnatural aspirations
Old Oct 8, 2018 | 03:31 PM
  #39  
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Originally Posted by emilio700
Filling in the short side radius time-tested approach to low port angle heads.
I took a casting of a VVT head and then laser scanned the casting. Here it is: https://a360.co/2JKtHkp
Rounding out the flat roof from the injector pocket through to the bowl looks to me like one way to achieve the appropriate change in cross section through the length of the port.

Even with filling the floor as an option I didn't see the shape up top as being good. It doesn't look like it has an appropriate change in cross section through the length of the port.

Last edited by burdickjp; Oct 8, 2018 at 04:00 PM.
Old Oct 8, 2018 | 03:59 PM
  #40  
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Just to make some things crystal clear here.. The port roof is where the guide protrudes out of, and the floor is where the short turn radius is.

Id never touch the floor with a carbide cutter because the short turn is so bad



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