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.


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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

[quote name='BDC' date='May 6 2005, 06:30 PM']

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


[/quote]





for the first part, all other things set aside, air flows better across a radius.



i'm not talking about the type of ramping to soften the edge for an unsupported side seal, i'm talking about giving the closing edge a radius. the purpose isn't to extend the port timing, but to get rid of the sharp edge.

if you look at the renisis port timing, it closes about the same but opens eariler, the side exhaust lets em do it without having "too much" overlap

^ zero overlap.



but the renesis has its own demons. side exhaust is really restrictive and beats up on the side seals. i'm looking into dinding a company that will coat the side seals with something for more durability.

[quote name='guitarjunkie28' date='May 7 2005, 11:03 AM']

but the renesis has its own demons. side exhaust is really restrictive and beats up on the side seals. i'm looking into dinding a company that will coat the side seals with something for more durability.


[/quote]



how many failures have you seen due to this? do you have any proof that this happens? any pics of the side seals?

[quote name='j9fd3s' date='May 7 2005, 10:58 AM']if you look at the renisis port timing, it closes about the same but opens eariler, the side exhaust lets em do it without having "too much" overlap


[/quote]



in this case opening the side ports earlier only adds to the amoutn of air entering the engine. since it still has zero overlap it cant really be compared to the regular side port with pport exhaust.

[quote name='guitarjunkie28' date='May 6 2005, 06:40 PM']for the first part, all other things set aside, air flows better across a radius.



i'm not talking about the type of ramping to soften the edge for an unsupported side seal, i'm talking about giving the closing edge a radius. the purpose isn't to extend the port timing, but to get rid of the sharp edge.


[/quote]



That's true, but that still doesn't answer my question -- how is the sharp edge on the stock port's closing edge detrimental to how the charge flows into the chamber?



B

brian,

when the rotor gets to the point where it's closing the port, the radius makes the air turn and shoot almost straight up--adding swirl and mixture.



kahren,

these are from a stock renesis i got to take apart with 26k miles on it. i fear for the future of these engines.



what caused it? all the intake ports looked fine around the edges--no signs of impact whatsoever. the exhaust ports on the front and rear side housings, however, did show some signs of either impact or scraping. maybe it's from the extra expansion of the side seals because they're in contact with the exhaust gas??? i'm not sure, but that'd be my best guess for the time being.



i think if mazda reduced the exhaust port size about .3-.4mm from the wall, it might eliminate this.[attachment=30678:attachment][attachment=30679:attachment]

i talked to jhb about coating the side seals and they said they weren't sure if they had anything that would be totally appropriate, but they could try experimenting with coatings.



that may be a good idea for the rx8 guys.

i dont think coating them would help much, the coatings may wear out after a while most likely sooner then later. if anything you should try treating the seals.

do you have any better pictures of the side seals?

i'm not a photographer.



my idea of coating isn't so much for the wear surface, but heat rejection, to lower expansion. i dunno if it'd work all that well, but it'd be worth a shot.

[quote name='guitarjunkie28' date='May 7 2005, 09:10 PM']i'm not a photographer.



my idea of coating isn't so much for the wear surface, but heat rejection, to lower expansion. i dunno if it'd work all that well, but it'd be worth a shot.


[/quote]



maybe thats why they only experimanted with side ports in the 70's

reguardless of the problems they're seeing, they brought the rotary back, so that's something to be happy about. i'm sure they're working on it-even as we speak, so maybe the '06-'07 renesis motors won't have this problem.



i guess you gotta take the good with the bad.

I cant for the life of me figure out why they release the car with 225 NA HP only to find it makes less and the 1st ones out had sticking intake. They started getting badpress right off the bat.

Why would they not have beatin the **** out of these motors for a year or so.Now they are going to have more liability problems and bad reps like the old R100..

R&D needs to fix all this BEFOREit hits the market. FD: vacume lines,IC tank ends,over flow tank, fuel problems, turbo problems on on on on

zoom zoom boom!

BTW nice port...flow must work with all the ports in and out. Please post results.

wouldn't it be great if EVERYTHING were dialed in before a car was released?



EVERY manufacturer goes through this with a new model car...how can you get absolutely everything perfect the first time???



have you ever blown a motor or made some other kind of mistake with the work you've done on your own car? not exactly the same scenario, i'll admit, but i'm glad the rotary is back state-side and i'm sure they'll get everything worked out.



p.s. i'm not really defending the problems because they are there.... i'm just trying be a little more mature about some of the issues and the way they're resolved.

well they dont have to fix everything, but people are wary of the rotary, they should have made the cars at least not flood.... ecu startup tuning is terrible you can smell raw fuel behind the car when you start em. i dont get it either, the fd's really dont flood much, its not like they dont know how to do it https://www.nopistons.com/forums/pub...1047683561.gif

its definetely a fragile car from the factory.......

[quote name='BDC' date='May 7 2005, 09:36 AM']That's true, but that still doesn't answer my question -- how is the sharp edge on the stock port's closing edge detrimental to how the charge flows into the chamber?



B


[/quote]





Here is how it was explained to me. The laminar air that goes arround the radius of a port sling shots the non laminar air. It makes the air on the inside of the port move faster.



Ever been behind a Ski boat when it makes a turn? For a short time you end up going faster than the boat.



If you need it explained in pistion terms its kinda the same reasoning behind a 3 angle valve job.



https://www.nopistons.com/forums/pub...1047683473.gif

Of course, as you have already pointed out, this can be good or bad depending on what your looking for as a result. Fluid dynamics really suck https://www.nopistons.com/forums/pub...IR#>/smile.png and sometimes they blow

[quote name='1Revvin7' date='May 6 2005, 05:30 PM']Anyhow what do you think the gains were based on these few pictures?


[/quote]





There were some gains in high end and overall power and some losses in the lower rpms.



Now since your using a tense that indicates you have some numbers for us why dont you post them.

[quote name='j9fd3s' date='May 9 2005, 03:42 PM']well they dont have to fix everything, but people are wary of the rotary, they should have made the cars at least not flood.... ecu startup tuning is terrible you can smell raw fuel behind the car when you start em. i dont get it either, the fd's really dont flood much, its not like they dont know how to do it https://www.nopistons.com/forums/pub...1047683561.gif


[/quote]





Indeed, RX-8's are flooding way to much.. If you move the car 3 times in your garage (we don't do that, but there are much people who don't have the knowledge of the rotary engine) you need to A) pull it with another car so it starts and the plugs dry (only for mt's) B) change spark plugs, wich really sucks when you can't move the car up...





An example I had a TII FC wich had stand still for more then a year, car wouldn't start, apexes sticked or something, low compression for sure, I put another car in front, it started after pulling 20m. My sister drives an RX-8 (190hp version), it flooded, It started when pulling, after 700m or so..



I don't know if it's something with the side exhaust ports, but an FD or FC idles way nicer then an RX-8 in my opnion..

[quote name='Rub20B' date='May 9 2005, 01:33 PM']Indeed, RX-8's are flooding way to much.. If you move the car 3 times in your garage (we don't do that, but there are much people who don't have the knowledge of the rotary engine) you need to A) pull it with another car so it starts and the plugs dry (only for mt's) B) change spark plugs, wich really sucks when you can't move the car up...




[/quote]





or c) hold it WOT for 2 seconds while cranking....but if you like tow starting, cool.

[quote name='GMON' date='May 9 2005, 01:38 PM']There were some gains in high end and overall power and some losses in the lower rpms.



Now since your using a tense that indicates you have some numbers for us why dont you post them.


[/quote]



After a few people post what they think the percentage gain in air flow is I will tell...

[quote name='GMON' date='May 9 2005, 09:39 AM']Here is how it was explained to me. The laminar air that goes arround the radius of a port sling shots the non laminar air. It makes the air on the inside of the port move faster.



Ever been behind a Ski boat when it makes a turn? For a short time you end up going faster than the boat.



If you need it explained in pistion terms its kinda the same reasoning behind a 3 angle valve job.



https://www.nopistons.com/forums/pub...1047683473.gif


[/quote]



lol, i didnt really get it until we went canoeing last summer. the river flow is almost stagnant on the inside of the turn, it will actually spin the canoe if you let it

[quote name='guitarjunkie28' date='May 10 2005, 01:41 AM']or c) hold it WOT for 2 seconds while cranking....but if you like tow starting, cool.


[/quote]



Yeah, WOT starting didn't help, I'm not going to put a car in front if I didn't tried to start is with WOT, if the plugs are wet the chance is big you'll need to do it that way..

I bet it flows like ****!!!!! https://www.nopistons.com/forums/pub...1047683785.gif nice work

probably flows 10% more

I'll go out on a limb here and say 20%, assuming flow was measured at various stages whilst porting.

[quote name='guitarjunkie28' date='May 9 2005, 03:41 PM']or c) hold it WOT for 2 seconds while cranking....but if you like tow starting, cool.


[/quote]



that doesnt work if the cars been really flooded. we did one the other day, the plugs were literally dripping wet

[quote name='1Revvin7' date='May 9 2005, 03:47 PM']After a few people post what they think the percentage gain in air flow is I will tell...


[/quote]





For fucks sake el spit it the **** out. https://www.nopistons.com/forums/pub...>/rolleyes.gif



I am very curious to see how flow bench numbers correlate to HP/TQ numbers. My guess is that the ports of a rotary engine are so dynamic that flowing the open port is really no indicator at all of wether or not it will make more power.



Think im crazy? Put a rotor in the housing with the apex seal directly in the center of the exhast port and tell me what flow does.

[quote name='GMON' date='May 10 2005, 10:33 AM']For fucks sake el spit it the **** out. https://www.nopistons.com/forums/pub...>/rolleyes.gif



I am very curious to see how flow bench numbers correlate to HP/TQ numbers. My guess is that the ports of a rotary engine are so dynamic that flowing the open port is really no indicator at all of wether or not it will make more power.



Think im crazy? Put a rotor in the housing with the apex seal directly in the center of the exhast port and tell me what flow does.


[/quote]



Exactly. A flowbench is great for heads, but i dont think it will carry as much weight with rotary ports. You could make the port HUGE and have good flow numbers, but make **** for power becase the shape is not detrimental to optimal amounts of overlap and air/fuel charge mixture, etc.