Porting 6-port
Super Moderator
Joined: Sep 2002
Posts: 2,763
From: Savannah, Ga
Originally Posted by 88IntegraLS' date='Aug 17 2003, 07:13 PM
The na guru has posted his ports! That is a large primary. 
Slap that sucker together and let's hear the performance report.
Hey are you going to use the VDI manifold on that thing?
Hey are you going to use the VDI manifold on that thing?
Im going to have a very trick intake manifold, but no details until I have pics. But trust me, it will be worth the wait.
Performance report? I can already tell you that it will make more power with the 6 ports wired closed than a stock port motor with them open. And I think Im going to have the same ecu problems with this engine as my current aux bridge motor. Sounds like time to figure out my EMS situation... But regardless, Ill dyno it after its tuned.
Hasnt Ito been on vacation for the past month and a half? Im STILL waiting on the clearance specs for the atkins seals...
Senior Member
Joined: Feb 2003
Posts: 223
From: Corvallis, Oregon
It is eerie how similar your last post was to Jimmi325i of the evil forum when I used to hound him to give up info on his ports. Total confidence in the short block but hating the peripheral components!
I am all for a custom intake manifold. When I finished my primary runners I looked at the lower manifold . . . what a disappointment. Runner width is not constant and kind of goes from very wide to a small orifice for the entrance to the port runners. Then there is the secondary and sixth port section where a runner splits into two parts with a sleeve actuator rod right in the way. All those changing cross section sizes can't be good for intake velocity.
I doubt I will do any more than just fiddle with smoothing and match porting my S4 manifold, and perhaps easing out the abrupt changes in runner sizes.
Come on, everyone, get into this! You guys have to have an opinion on the crappy stock manifold. Someone voice your opinion and be heard in the rotary porting section! Let your observations be known to the public at large.
I am all for a custom intake manifold. When I finished my primary runners I looked at the lower manifold . . . what a disappointment. Runner width is not constant and kind of goes from very wide to a small orifice for the entrance to the port runners. Then there is the secondary and sixth port section where a runner splits into two parts with a sleeve actuator rod right in the way. All those changing cross section sizes can't be good for intake velocity.
I doubt I will do any more than just fiddle with smoothing and match porting my S4 manifold, and perhaps easing out the abrupt changes in runner sizes.
Come on, everyone, get into this! You guys have to have an opinion on the crappy stock manifold. Someone voice your opinion and be heard in the rotary porting section! Let your observations be known to the public at large.
Senior Member
Joined: Jul 2002
Posts: 2,315
Originally Posted by 88IntegraLS' date='Aug 17 2003, 10:53 PM
It is eerie how similar your last post was to Jimmi325i of the evil forum when I used to hound him to give up info on his ports. Total confidence in the short block but hating the peripheral components!
I am all for a custom intake manifold. When I finished my primary runners I looked at the lower manifold . . . what a disappointment. Runner width is not constant and kind of goes from very wide to a small orifice for the entrance to the port runners. Then there is the secondary and sixth port section where a runner splits into two parts with a sleeve actuator rod right in the way. All those changing cross section sizes can't be good for intake velocity.
I doubt I will do any more than just fiddle with smoothing and match porting my S4 manifold, and perhaps easing out the abrupt changes in runner sizes.
Come on, everyone, get into this! You guys have to have an opinion on the crappy stock manifold. Someone voice your opinion and be heard in the rotary porting section! Let your observations be known to the public at large.
I am all for a custom intake manifold. When I finished my primary runners I looked at the lower manifold . . . what a disappointment. Runner width is not constant and kind of goes from very wide to a small orifice for the entrance to the port runners. Then there is the secondary and sixth port section where a runner splits into two parts with a sleeve actuator rod right in the way. All those changing cross section sizes can't be good for intake velocity.
I doubt I will do any more than just fiddle with smoothing and match porting my S4 manifold, and perhaps easing out the abrupt changes in runner sizes.
Come on, everyone, get into this! You guys have to have an opinion on the crappy stock manifold. Someone voice your opinion and be heard in the rotary porting section! Let your observations be known to the public at large.
Super Moderator
Joined: Sep 2002
Posts: 2,763
From: Savannah, Ga
There are 2 things about the stock manifold that I really dont like. First, the runner cross section is optimized for a stock motor. And we all know how well rotaries respond mods. Next is the fact that the runners for the 2 ports on the end housings are saimesed. Im not an engineer, but I can see that as being a tuning nightmare. 2 seperate pulses sharing the same runner cant be good for flow.
Senior Member
Joined: May 2002
Posts: 22,465
From: California
Originally Posted by mazdaspeed7' date='Aug 18 2003, 07:23 AM
There are 2 things about the stock manifold that I really dont like. First, the runner cross section is optimized for a stock motor. And we all know how well rotaries respond mods. Next is the fact that the runners for the 2 ports on the end housings are saimesed. Im not an engineer, but I can see that as being a tuning nightmare. 2 seperate pulses sharing the same runner cant be good for flow.
mike
