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

Reply Subscribe

Thread Tools

Search this Thread

10-08-2018, 10:59 AM

#21

concealer404

Elite Member

iTrader: (3)

Join Date: Aug 2011

Posts: 10,917

Total Cats: 2,201

80s tech is even a stretch....

10-08-2018, 11:01 AM

#22

18psi

VladiTuned

iTrader: (76)

Join Date: Apr 2008

Posts: 35,821

Total Cats: 3,481

why isn't a t25 as good as an EFR6258?

10-08-2018, 11:02 AM

#23

concealer404

Elite Member

iTrader: (3)

Join Date: Aug 2011

Posts: 10,917

Total Cats: 2,201

Why isn't one horse as strong as hundreds of them?

10-08-2018, 11:15 AM

#24

stratosteve

Senior Member

iTrader: (1)

Join Date: Nov 2010

Location: Marylandistan

Posts: 1,052

Total Cats: 196

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.

10-08-2018, 11:19 AM

#25

andyfloyd

Senior Member

Join Date: May 2017

Location: Louisville,KY

Posts: 1,129

Total Cats: 97

Quote:

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.

10-08-2018, 11:21 AM

#26

18psi

VladiTuned

iTrader: (76)

Join Date: Apr 2008

Posts: 35,821

Total Cats: 3,481

Quote:

Originally Posted by concealer404

Why isn't one horse as strong as hundreds of them?

Why isn't donkey as stronk as ox?

10-08-2018, 11:52 AM

#27

Joe Perez

Boost Pope

iTrader: (8)

Join Date: Sep 2005

Location: Chicago. (The less-murder part.)

Posts: 33,027

Total Cats: 6,593

Quote:

Originally Posted by 18psi

Why isn't donkey as strong as ox?

Bad port design and low static compression.

10-08-2018, 12:00 PM

#28

Savington

Former Vendor

iTrader: (31)

Join Date: Nov 2006

Location: Sunnyvale, CA

Posts: 15,442

Total Cats: 2,099

Quote:

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...

Quote:

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.

10-08-2018, 01:41 PM

#29

sixshooter

Moderator

iTrader: (12)

Join Date: Nov 2008

Location: Tampa, Florida

Posts: 20,652

Total Cats: 3,011

Quote:

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!

10-08-2018, 02:19 PM

#30

stratosteve

Senior Member

iTrader: (1)

Join Date: Nov 2010

Location: Marylandistan

Posts: 1,052

Total Cats: 196

What part of vortex dont you understand? Jeez

10-08-2018, 02:39 PM

#31

18psi

VladiTuned

iTrader: (76)

Join Date: Apr 2008

Posts: 35,821

Total Cats: 3,481

who wants their air STRAIGHT anyway?

10-08-2018, 02:41 PM

#32

stratosteve

Senior Member

iTrader: (1)

Join Date: Nov 2010

Location: Marylandistan

Posts: 1,052

Total Cats: 196

Right

10-08-2018, 02:43 PM

#33

Marioshi

Junior Member

Join Date: Feb 2018

Location: Sacramento CA

Posts: 210

Total Cats: 38

Quote:

Originally Posted by 18psi

who wants their air STRAIGHT anyway?

GAY air has more fun!

10-08-2018, 02:54 PM

#34

burdickjp

Junior Member

Join Date: May 2018

Posts: 58

Total Cats: -5

Quote:

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?

10-08-2018, 03:13 PM

#35

emilio700

Supporting Vendor

iTrader: (3)

Join Date: May 2005

Posts: 7,330

Total Cats: 2,382

Quote:

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.

__________________

www.facebook.com/SuperMiata

949RACING.COM Home of the 6UL wheel
.31 SNR

10-08-2018, 03:16 PM

#36

sometorque

Junior Member

iTrader: (1)

Join Date: Jul 2018

Location: Coral Springs, FL

Posts: 187

Total Cats: 57

Quote:

Originally Posted by 18psi

who wants their air STRAIGHT anyway?

it's 2018. We need to let the air choose it's orientation.

10-08-2018, 03:16 PM

#37

Savington

Former Vendor

iTrader: (31)

Join Date: Nov 2006

Location: Sunnyvale, CA

Posts: 15,442

Total Cats: 2,099

Quote:

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

10-08-2018, 03:21 PM

#38

18psi

VladiTuned

iTrader: (76)

Join Date: Apr 2008

Posts: 35,821

Total Cats: 3,481

Quote:

Originally Posted by sometorque

it's 2018. We need to let the air choose it's orientation.

unnatural aspirations

10-08-2018, 03:31 PM

#39

burdickjp

Junior Member

Join Date: May 2018

Posts: 58

Total Cats: -5

Quote:

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; 10-08-2018 at 04:00 PM.

10-08-2018, 03:59 PM

#40

Twibs415

Senior Member

iTrader: (8)

Join Date: Feb 2011

Posts: 615

Total Cats: 112

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

Reply Share

First
Prev
2 / 3
Next
Last