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Max Exhaust Port Width

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Old 04-28-2004 | 04:51 PM
  #11  
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Ive got an Idea



couldnt u welt two peices of metal to support the seal and make them flush with the housing wall, it would hurt flow but you could go alot wider and therefor increase the flow overall?
Old 04-28-2004 | 05:43 PM
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Originally Posted by RETed' date='Apr 28 2004, 11:38 AM
An idea on a mild exhaust port...





-Ted
That's a gorgeous port!
Old 04-28-2004 | 06:13 PM
  #13  
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Originally Posted by RETed' date='Apr 28 2004, 11:38 AM




An idea on a mild exhaust port...





-Ted
i likey! be neat to see a pic of that next to a stocker
Old 04-28-2004 | 06:42 PM
  #14  
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Ive come to the conclusion that North American tuners dont do adequate work with the exhaust ports compared to the intakes on average. Its nothing like the work done in Oz or Japan. It also seems the solution to everything here is a bigger turbo or more boost, not making the most of what you already have.


Very well said........I totally agree.







Going really big on exhast can really change your low-mid range. I think thats why many people here in the US dont port big and then just add more boost for the big hp numbers. Its all a compromise no matter what you do.


I don't think it hurts the midrange at all. My ports looked similar to the one Ted is showing here and that is using a TDO6H-20G #17 exhaust side. You can see the Dyno in this post.



Exhaust Ports



My midrange was excellent. The Shops here in Japan definatley use larger exhaust ports than people in America.......you would be suprised how big they go. They do however warn about going to wide.
Old 04-28-2004 | 06:52 PM
  #15  
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Exhaust porting is very very sensative. I did the exact same exhaust port on 2 engines, except it was located slightly lower in one of the engines. The midrange and low end on the one with the lower exhaust port was much stronger, with no apparent loss in the top end. I was amazed at just how much of a difference it made in drivability.
Old 04-28-2004 | 07:31 PM
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Originally Posted by mazdaspeed7' date='Apr 28 2004, 03:52 PM
Exhaust porting is very very sensative. I did the exact same exhaust port on 2 engines, except it was located slightly lower in one of the engines. The midrange and low end on the one with the lower exhaust port was much stronger, with no apparent loss in the top end. I was amazed at just how much of a difference it made in drivability.
thats just from less overlap, some is good but you can have too much (iHmo)
Old 04-28-2004 | 08:17 PM
  #17  
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Thats an awesome looking port,.. I just measured with a caliper and a 2.25 inch wide exhaust port leaves almost exactly 1/2 inch on each side, so it looks like the i heard bout right...Anyone with a degree wheel know how many degrees per milimeter up or down it is?
Old 04-28-2004 | 09:32 PM
  #18  
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Originally Posted by j9fd3s' date='Apr 28 2004, 08:31 PM
thats just from less overlap, some is good but you can have too much (iHmo)
Well, Ill have to disagree on the blanket statement that some is always good. For instance, F1 engines run zero overlap, and the redlines are creeping past 19K rpm. Many new production cars, most notably the newer hondas, including the S2000, run zero overlap, as well as the Renesis engine. Yes, I know those two examples are polar opposites, but its to make a point. In both cases, the advantages of overlap did not outweigh the disadvantages.



Now, take old school pushrod V8's. They need a lot of overlap to make power at higher rpms. But they lose a lot of low end from the overlap, and drivability as well.



I pretty much only port down. I take the top edge up to the top of the stock bevel, and then bevel that. I get enough extra overlap from the early open SP. Then I just port down and out.
Old 04-29-2004 | 02:00 PM
  #19  
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Originally Posted by mazdaspeed7' date='Apr 28 2004, 12:23 PM
I like your definition of mild
Yeah, that's my Stage I exhaust port.

It widens significantly, but I don't drop the port too much - maybe 1/4" or so.



These are the Stage II exhaust ports - dropped almost 3/4".











Comparison to stock port





-Ted
Old 04-30-2004 | 04:29 AM
  #20  
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Thats huge,.. I feel insipered....


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