So how well do you guys think this port flows vs the stock s5?



https://www.nopistons.com/forums/gal..._42_122147.jpg

https://www.nopistons.com/forums/gal..._42_396465.jpg

did the flow bench answer the question?

i'm gonna say flow went up, but power went down

By the looks of it, it should flow a lot more. At least I hope so since I have seen a lot of ports just like that...

[quote name='j9fd3s' date='May 6 2005, 05:42 AM']i'm gonna say flow went up, but power went down


[/quote]



Agreed.



Can't see the other angles of the port; difficult to make a determination.



Flow benches aren't everything; only (potentially) one piece of the puzzle.



B

why no radius on the closing edge?

[quote name='guitarjunkie28' date='May 6 2005, 09:47 AM']why no radius on the closing edge?


[/quote]



Why so?



B

air travels better across a radius.

[quote name='guitarjunkie28' date='May 6 2005, 04:54 PM']air travels better across a radius.


[/quote]









Here is another angle of it before I was finished, give you the general idea of the closing edge. I cut down at a 45/60deg angle and removed a lot of material, instead of making a more generous radiused closing edge like I have done in the past, which removal less material. I am obviously tring to figure out what works on the bench, and then compare it to the dyno and feel of the car. I did about another 1mm of radius to the closing edge after this picture was taken.



Anyhow what do you think the gains were based on these few pictures?

[quote name='guitarjunkie28' date='May 6 2005, 01:54 PM']air travels better across a radius.


[/quote]



Even if that were so, how do you know that's going to have a positive effect on power and torque on the engine?



I can make an exhaust port the size of an orange that will flow air much more impressively than on a stock port, and will show substantially higher figures on a flowbench, but it show nothing with respect to rest of the picture. It gives no indication as to what kind of improvement (or decline in power) it will yield. It does not take into account the position, angle, shape, movement, speed, or anything else of the engine rotor, it has no knowledge of overlap, and knows nothing at all about combustion chamber shape, compression and exhaust stroke degrees, and the like.



A part of me says that there's no improvement on ramping the closing edge. After all, the charge entering the runner may have to make two turns now instead of just one as it transitions from the runner to the outlet. I've seen no actual, proven improvement on it. I believe the only real reason people harp on it now is because of the info Judge Ito brought up dealing with side seal integrity when taking iron out of the short radius all around of the port outlet. I know it's a common staple for people who "port" to hog out the closing edge in that manner, but does this really yield more power? I am not convinced at all. I think more power is yielded out of earlier opening (among other things); not later closing.



1Revvin man, I think what you've got will work. Keep the port outlets the way they are.



B