Compare auto reliability with reliable results at TrueDelta.com!

Compare auto reliability with reliable results at TrueDelta.com!
Results 1 to 7 of 7

Thread: On Porting + Polishing Intake Manifold...Am I Missing Something?

  1. #1
    Registered Member Riot_Polizei's Avatar

    2002 Mazda Protege5

    Join Date
    Jan 2018
    Location
    Colorado
    Posts
    73

    On Porting + Polishing Intake Manifold...Am I Missing Something?

    I've been reading up on the VTCS removal, and the accompanied porting and polishing of the runners. It seems like a cool weekend project once I pick up a spare intake manifold, and I can't wait to try it!

    There's just one thing that's bothering me about it.

    In the guide most commonly linked for the aforementioned tasks, it specifies that there's a "lip" inside the runners that "stumbles" air flow. Seems reasonable enough to shave it down for laminar flow.

    Yet, in the other pictures and diagrams, you can see that the author of the guide continued to port and polish the runners up to the open end that connects up to the engine block. Doesn't this simply create a new air-impeding lip by making the runners have a wider diameter than the ports on the block? Or, is this not the case?

    Here's a crude diagram that'll hopefully demonstrate what I'm seeing:


    Any ideas?
    2002 Mazda Protege5
    ■ Sunburst Yellow ■ Black Rear Valence ■ Goldstar Grille Intake Mod ■ Racing Beat Catback Exhaust
    ■ Moog Front Endlinks ■ Megan Racing Rear Strut Tower Bar ■ Racing Beat Rear Sway Bar


    ______________________________

  2. #2
    Registered Member

    02 protege5 ES 5dr

    Join Date
    Jul 2016
    Location
    Calgary,AB
    Posts
    188
    Quote Originally Posted by Riot_Polizei View Post
    I've been reading up on the VTCS removal, and the accompanied porting and polishing of the runners. It seems like a cool weekend project once I pick up a spare intake manifold, and I can't wait to try it!

    There's just one thing that's bothering me about it.

    In the guide most commonly linked for the aforementioned tasks, it specifies that there's a "lip" inside the runners that "stumbles" air flow. Seems reasonable enough to shave it down for laminar flow.

    Yet, in the other pictures and diagrams, you can see that the author of the guide continued to port and polish the runners up to the open end that connects up to the engine block. Doesn't this simply create a new air-impeding lip by making the runners have a wider diameter than the ports on the block? Or, is this not the case?

    Here's a crude diagram that'll hopefully demonstrate what I'm seeing:


    Any ideas?
    Haven't done it yet myself, there were a few threads here that I was going through.

    Then I got to speaking to an engineer who was of the opinion that I should be cautious 'hogging out' my intake as airflow and volume are calculated carefully and challenged that I may get results, however not the ones I would hope for ( more power ). I was calm with the idea of port matching intake, then I started reading about an acid treatment that roughs up the surface of the intake distrupting the air ( as air through centre travels at a different rate as air along the outer edge ).

    Uh, then I put it on pause because I really didn't know wtf. Heh.

    Good luck, please let me know if you get gains

    https://forums.probetalk.com/showthr...p?t=1701142946

  3. #3
    Registered Member Riot_Polizei's Avatar

    2002 Mazda Protege5

    Join Date
    Jan 2018
    Location
    Colorado
    Posts
    73
    Quote Originally Posted by horseflesh View Post
    Haven't done it yet myself, there were a few threads here that I was going through.

    Then I got to speaking to an engineer who was of the opinion that I should be cautious 'hogging out' my intake as airflow and volume are calculated carefully and challenged that I may get results, however not the ones I would hope for ( more power ). I was calm with the idea of port matching intake, then I started reading about an acid treatment that roughs up the surface of the intake distrupting the air ( as air through centre travels at a different rate as air along the outer edge ).

    Uh, then I put it on pause because I really didn't know wtf. Heh.

    Good luck, please let me know if you get gains

    https://forums.probetalk.com/showthr...p?t=1701142946
    Yeah, until I either know more about airflow or find valid before/after dyno runs of someone who ported/polished their intake, I'm not going to screw around with the IM. I'll just remove the butterflies and leave it at that, I think!
    Sigs are visible only in your first post on a page. To change your thread display preferences, click here and enable 'Always Show Signature'.

  4. #4
    ......................... i12drivemyMP5's Avatar
    Donated: $5

    323F

    Join Date
    Apr 2005
    Location
    <---------------->
    Posts
    7,438
    When I did mine, I just smoothed things out and filled the flap stick holes between all the runners....except for one. I cut off the butterfly rod even with first runner and left it and actuator in place so it looks no different than before. The difference between that and my air intake make the car throw a lean code on occassion if I drive it a bunch in the winter when the air is cold/dry/dense. It won't do it in the summer when it's warm/humid. The 1.8 coils & plugs/P&P IM/lightened pulleys/UDP/intake/header/exh does play all nice together. The car idles runs and accelerates smoother and faster and it will pull 30+ mpg if driven reasonably with AC going. Some will insist placebo and they can all they want. I know it is decent difference from brand new untouched because I have had it since then.

    One single thing may not do that much but the combo pack will wake it up some.

  5. #5
    Registered Member Riot_Polizei's Avatar

    2002 Mazda Protege5

    Join Date
    Jan 2018
    Location
    Colorado
    Posts
    73
    Quote Originally Posted by i12drivemyMP5 View Post
    When I did mine, I just smoothed things out and filled the flap stick holes between all the runners....except for one. I cut off the butterfly rod even with first runner and left it and actuator in place so it looks no different than before. The difference between that and my air intake make the car throw a lean code on occassion if I drive it a bunch in the winter when the air is cold/dry/dense. It won't do it in the summer when it's warm/humid. The 1.8 coils & plugs/P&P IM/lightened pulleys/UDP/intake/header/exh does play all nice together. The car idles runs and accelerates smoother and faster and it will pull 30+ mpg if driven reasonably with AC going. Some will insist placebo and they can all they want. I know it is decent difference from brand new untouched because I have had it since then.

    One single thing may not do that much but the combo pack will wake it up some.
    I accidentally erased my goddamn entire response, so here's one that's a little different:

    I really want to test a lot of factors I've read about in the community. If I could perhaps find a baseline for how much to port and/or whether to port at all, then I'd be glad to post dyno results. Same goes for the OBX header.

    I swear by the Goldstar grille/MAF mod, but I want to have facts behind it as well.

    Who knows. I think I'll try and make that a goal for the summer, when I'll have a bit more cash to throw around.
    Sigs are visible only in your first post on a page. To change your thread display preferences, click here and enable 'Always Show Signature'.

  6. #6
    Registered Member

    2003 P5

    Join Date
    Jan 2005
    Location
    Colorado Springs, CO
    Posts
    52
    +1 for the grille/MAF mod. Haven't been anywhere near a dyno with this car but butt dyno felt a difference.

  7. #7
    The Diagram Dude pcb's Avatar

    2002 mazda protege 5

    Join Date
    Jun 2011
    Location
    ontario, canada
    Posts
    3,752
    Quote Originally Posted by tlott01 View Post
    ... but butt dyno felt a difference.
    Keep in mind that the butt dyno has been known to be inaccurate and influenced by things such as drugs, alcohol, and too much lerninz...
    The Diagram Dude

Similar Threads

  1. XelderX's Intake Porting
    By xelderx in forum Mazda How-To
    Replies: 117
    Last Post: 06-12-2008, 09:34 PM
  2. Porting and polishing?
    By peterbuilt in forum Mazda How-To
    Replies: 3
    Last Post: 06-21-2007, 10:11 AM
  3. Porting stock intake manifold
    By reverseninja in forum Mazdaspeed Protege
    Replies: 4
    Last Post: 06-13-2006, 05:10 PM
  4. intake porting question
    By WRCprotege in forum Protege5
    Replies: 6
    Last Post: 01-18-2006, 12:06 PM
  5. Intake Manifold porting?
    By smithers_0990 in forum Mazda Protege
    Replies: 10
    Last Post: 11-03-2004, 07:26 PM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •