there is a thread on here for match porting the s4 n/a intake but the pictures are long gone (they dont load anyway) does anyone have any pics that they could upload for how a good porting job should look on this intake?

any help is appreciated

/anthony

 

you can search on the internet port matching intake manifolds for any application and find great pictures and work, also not so good of work. I'm sure most of them use the gasket as an outline. Only sometimes the power gains will be worth the time

 

thanks for replying GrossPolluter! i had already done that and saved a bunch of pictures i just wanted to be extra sure i wouldnt eff it up
ill be popping off my intake tomorrow so wish me luck!

 

kinda hard to screw it up. lay a gasket on both surfaces and use a sharpie to outline onto each surface while the gasket it centered. trim the painted areas down into the runners about 2-4" or more if possible.

 

That's exactly how to screw it up. Match porting hurts airflow. It makes a "bulb" in the intake tract where the air slows down then speeds up, which takes away much-needed flow energy.

 

i'm talking about 1-2mm and porting it back into the runner as far as possible, that does not disrupt airflow as there is no "bulb" in this regard. now if you were trying to port match a FD to S5... different story.

the proper way is to extrude hone the complete manifold bolted together, however not many people are going to spend $400 for almost no noticable gains.

 

1-2mm is even worse.

If you're going to match port, only match port the engine, not the intake manifold. Or only match port the lower, not the upper.

 

Can more people post this on the fd uim post someone just made? "Hog it out so it bolts up , and matches"

 

Given that meercat is a decidedly Nordic mammal, it's unlikely that extrudehone is a viable option, what with shipping and pirate insurance.
Perhaps forcing lingonberries through would be close?

 

thanks for the replies guys! (the preferred media we use is fermented herring. the perfect blend of fishscales and horrid putrification make for a really fine finish we save the lingonberries for the meatballs )

i whipped off the UIM yesterday when i got a little leave from daddy-duties and took a couple pics. i havent got the LIM off yet because im scared of my girlfriend. if your not scared of your girlfriend wait till she becomes a mother. yeah i said it
anyhoo took a couple pics, its just the join between the UIM and LIM..







i thought the gasket matched up quite well. i have been told that port matching can give gains but i dont know how "exact" its supposed to be. in the upper picture you can see where the factory has tapered the opening somewhat but running my fingers (perfectly manicured as you can see) over the part where it continues into the runner revealed quite a pronounced bump. im thinking that making the transition less abrupt would improve flow? i personally wouldnt judge any opening up of the port necessary but i have no frame of reference considering this is my first time.







placing the gasket on the UIM showed a little bit of a step. it wouldnt hurt to clean this up a little? i havent removed the dynamc chamber yet but im assuming the same thing would apply?

apropos the LIM.. peejay mentioned that i should only port that. i have all new gaskets so isnt it worth doing the lot? i appreciate the help guys this has been bothering me for a while really dont want to eff it up. as clokker mentioned earlier, i would more than likely be forced to import if i fail, and everyone knows pirates arent to be trusted..

 

you won't really notice anything by doing it, so if you're worried about screwing it up then i suggest just not doing it.

 

the main reason i started fiddling with the intake was to change my secondary injectors back from purple 550cc's to browns (reddish-brown?) 460cc's. i had put them in because i had nothing else at the time but it runs like complete and utter ***** as soon as i get past 3800rpm. im hoping that changing back to the originals will be the solution to that problem.

so i thought while i was giving the intake a good ol' grope i would take the opportunity to port it as well. the reason i have been considering it for a while is because of this thread here. there are quite grandiose claims of 15-20hp which i am unsure about but if i could get a little bit of power out of it i reckon its worth a go. it also caused me to start this thread because all the pictures are gone from the thread which makes a little harder to follow. i was also very intrigued by this egg-shaped porting theat was mentioned can anyone confirm if deviating from the original shape in this way is a good idea or not?

i forgot to mention that my engine is fully rebuilt and street ported with a full rb true dual system, lightened flywheel amongst other bits and bobs that i cannot remember offhand.

while the missus is away the shade-tree mechanic will play so i whipped of the LIM today and took a couple more pics. even if i decide not to go through with this i think it would be good to have some pics up of how it looks in case anyone else is interested in this. a picture speaks a thousand words as they say!

i thought i would mention that the gasket between the LIM and block is a mazda original part and the other two gaskets are from atkins rotary.





pics of the block.













then the LIM















LIM to UIM pics are posted earlier so heres the runner to dynamic chamber.









there are these kind of abrupt transitions on the runner to the dynamic chamber as well i noticed. would it be recommended to smooth these out too?

removing the intake reminded me there were a few small fixes i should have written down before so even if i dont port it (i really want to now that i have pulled it all of though hehe) it wouldnt all be for naught.
as always, all help is appreciated!

 

Since everything is apart it wouldn't hurt since it's on your mind. I'm not sure on gains if any, but if your thinking about doing it, now is the time. Most porting is done just to smooth things out, not so much to make it bigger. Extrude honing would be nice but pricey. I doubt it would be worth the money. I think clokker mentioned dingleberries. I believe he meant one of those honing tools with abrasive ***** at the end. You could try that If it fits

 

i was considering the dingleberries (kånkelbär here) but then i found this. on second thoughts maybe not eh?

im doing my work experience at a boat yard where there are some very nifty welders and all the equipment to cut the intake open and weld it back together is there. once the various parts of the intake are open i could get in there and do it by hand. would make the process alot cheaper no? considering she's an NA, i dont want the insides of the intake to be completely smooth right? as far as i know they are supposed to be at the least 80 grit to help with moleculiseation of the fuel or some such..
the only problem is that this is a bit of a race against time because it is getting proper bitch-cold here now. theyre´forecasting an unusually cold winter this year too so im wondering if such complicated plans, if at all worth it should wait until we get to the other side of "ze vinter" and just do a quicky this week and pop it all back on by the weekend..

 

does your engine still have the n/a winged exhaust sleeves? if so then almost nothing you do to the intake will offer much benefit.

 

It's long been an engine builders truism that you get 90% of the power/performance with the first 50% of the work and the last 10% costs proportionately more and takes longer because it's a collection of small tweaks and processes.

Seems like you've put the horse before the cart (reindeer before the sleigh?)...is your car even running reliably/consistently yet? If not, how would you even know if all the port matching does anything?

 

the exhaust port diffusers are long gone sir!

as you have followed my build thread from the beginning i know you know the linear development of my situation. basicly little to no knowledge with a garage to a ok bit of knowledge and no garage. so flippin typical

im 99.9% sure that this is the only reason she's running like poo. theres not much left for me to check/replace and all the symptoms point to the injectors. im hoping i can give you an answer this weekend. you are correct in that i will have no frame of reference when it comes to any power gains and to do this properly i would need to replace everything now, test, then port but as gross polluter said, i might as well while ive got it off eh?



what are you guys opinions on the value of this mod considering your previous experience and considering that N/A owners seem to do the most desperate things for 2-3hp?

 

those port matches actually look pretty good. i think i would just clean everything really well, then look/feel for any big casting boogers/seams etc and grind those down and then clean it again, and put it back.

the reason the stock intake limits power isn't the quality of the casting, its the design. its long, which gives a power peak that is at a lower rpm, and then it has a lot of bends in it. if you look the S5 and Rx8 both use shorter intakes, and the Rx8 has larger radius bends

for diameter, you basically want the smallest that will still deliver the peak power that you want. the speed the air is at matters quite a bit, and if the air speed is too slow, you loose power. since the engine has to work from idle to redline, you need to compromise, and have the smallest diameter runner possible, without limiting top end power too much, as this gives the best overall performance. this is the reasoning behind the staged throttle body, and the 6 ports, and VDI, and stuff.

if you want to have some ideas about how to improve things, look at the Rx8 intake, it uses the same ideas as the S5 intake, except its much more developed. each pair of runners (primary, secondary, and the 6 ports), are a unique diameter and length, also its more staged, uses better bends etc etc.

 

One thing I did to make assembly easier is pin my flanges so they line up perfectly.

Another option I have used is to put a sleeve on the studs so the flanges fit tightly together with no axial play.
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Maybe match porting is good on that intake, maybe not. Its hard to say.

Mazda did try to use both positive and negative pressure wave reflections in the 2nd gen Dynamic Effect Intake, so perhaps strengthening the reflections helps.

Was it the Paul Yaw site back in the day that compared match ported 1st gen FI manifold to stock and they lost power? I believe it was just from removing the anti-reversion step in the upper manifold piece (it was slightly smaller diameter than the lower piece).

Best change you can make is to get aftermarket manifolds (intake & exhaust) on the NA rotary even though it completely does away with the Mazda DEI tuning and uses only short runners and Helmholtz intake tuning on the intake side and exhaust velocity and pulse collection scavenging only on the exhaust side instead.

The Mazda intake tuning works very well as a whole system with the stock production constraints (intake noise, exhaust noise, emissions, off idle tractability, etc), but really holds back power production once you start optimizing for performance only.

 

thanks for the tips guys! it seems that the general consensus is to not eff with them at all. ill try to get over to my buddy tomorrow he has a nice tool for this. reckon ill try to do a little clean-up job and get it all back together by the weekend. it is getting colder every day. #becausescandinavia

 

I have almost the same setup (albeit a s5). Street ports, RB duals light fd flywheel. I Port matched all of my manifolds, used glass beads to texture the interior surfaces, and ceramic coated the whole thing. (you can read about it here https://www.rx7club.com/naturally-as...build-1065289/) I have no dyno charts to say one way or another, but it's not a huge gain in power (if any) but every little bit helps. It will take about three times longer than you expect so maybe closing them up might not be a bad idea since winter is apparently coming. I don't know how fast you can get parts from the US, but throwing some of these 84-92 Rx7 Atkins Designed Six Port Actuator... on might be well worth your time, even if you don't port match.

 

Sorry wrong post

 

sorry wrong website

 

i have many n/a complete intakes, if you should need any! faster and cheaper shipping than from the US.

 

Maybe I need to get my eyes checked...

...but am I seeing butterflies in the intake for the 5th and 6th ports?