Difference in S4 and S5 N/A Intakes?
02-05-03, 04:56 PM
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Difference in S4 and S5 N/A Intakes?
quick question, is there any difference between the Lower Intake Manifold off of a S4 n/a and a S5 n/a? specificly are the control rods for the 5/6thport sleeves any different between those series?
i broke the top of of my control rod and none of the local yards have any S5's to pull parts off of, so i need to know if a S4 rod would work in its place
i broke the top of of my control rod and none of the local yards have any S5's to pull parts off of, so i need to know if a S4 rod would work in its place
02-05-03, 08:02 PM
#3
Hooray For Boobies!!!
I hear you have to bend the S4 rods to make them work with an S5 manifold. I could be wrong though. Do a search for manifold ports, manifold mods ect. to see more info. I am looking into porting and S5 manifold for an S4 engine and the searches help. I am now a few questions of my own that I could not fine or overlooked in the searches, so you may see a few threads I started on this topic.
02-05-03, 09:10 PM
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Originally posted by x605p747
I hear you have to bend the S4 rods to make them work with an S5 manifold. I could be wrong though. Do a search for manifold ports, manifold mods ect. to see more info. I am looking into porting and S5 manifold for an S4 engine and the searches help. I am now a few questions of my own that I could not fine or overlooked in the searches, so you may see a few threads I started on this topic.
I hear you have to bend the S4 rods to make them work with an S5 manifold. I could be wrong though. Do a search for manifold ports, manifold mods ect. to see more info. I am looking into porting and S5 manifold for an S4 engine and the searches help. I am now a few questions of my own that I could not fine or overlooked in the searches, so you may see a few threads I started on this topic.
i'll try searching agin, but generally i ask too specific of questions and get no resultsi am tempted to jb weld the hole in manifold where it goes and just leave that sleave out all togther, but fixing it correctly would be the best thing to do... now only if i can afford to do that.
02-05-03, 10:38 PM
#5
boost on the way(GTU II)
stock port s4 w/ported s4 intake .better?? than if i had a s4 engine w/stock ports and a stock port s5 intake??
one more thing.... which one would be better ... those 2 i mentioned or a s4 engine with stock ports w/a s5 ported intake??
thanks guys im interested in the swap myself
jack
one more thing.... which one would be better ... those 2 i mentioned or a s4 engine with stock ports w/a s5 ported intake??
thanks guys im interested in the swap myself
jack
02-05-03, 11:22 PM
#6
The control rods themselves appear the same. The actuators aare different. The rear bolt hole between the upper and lower manifolds is also spaced farther back. The egr passages are different.
The S4 engines responds very well to putting the S5 intake manifold on. You will gain power on a stock port engine. You can't do much work to the S4 manifold short of actually cutting the plenum in half and hogging it out to one large one and using a single plate throttlebody. I did this to my S5 manifold and love it. The S5 manifold responds well on the top end to the manifold porting described here in an old thread. However midrange does suffer a little. I hogged my runners out but then went back and filled them in. I have done some very serious work to that manifold beyond what anyone on here has done. My results have been fantastic!
The S4 engines responds very well to putting the S5 intake manifold on. You will gain power on a stock port engine. You can't do much work to the S4 manifold short of actually cutting the plenum in half and hogging it out to one large one and using a single plate throttlebody. I did this to my S5 manifold and love it. The S5 manifold responds well on the top end to the manifold porting described here in an old thread. However midrange does suffer a little. I hogged my runners out but then went back and filled them in. I have done some very serious work to that manifold beyond what anyone on here has done. My results have been fantastic!
02-05-03, 11:59 PM
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thnaks rotary god... i just saw your thread about the custom intakes and plenum moddifcations on the S5's. thats how i got into this mess, as i pulled everything to do the basic porting and discovered both the aux ports and the vdi were too gummed up to be working. and then the rod breakes on port 5 when i try turning it wth pliers. damn thing required a press to get out.
but if the s4 rods are the same ( no reason they should change i would think, but everythng seems to be lightly different between the s4 and s5's) then i should be able to pull one form a junkyard car ( there are no s5 in any of the yards here)
anyways back to your s5 plenum modification, i noticed how increably stupid mazdas looked, and was intested in how yours turned out... but your saying you went back and undid it or just the runner portings?
but if the s4 rods are the same ( no reason they should change i would think, but everythng seems to be lightly different between the s4 and s5's) then i should be able to pull one form a junkyard car ( there are no s5 in any of the yards here)
anyways back to your s5 plenum modification, i noticed how increably stupid mazdas looked, and was intested in how yours turned out... but your saying you went back and undid it or just the runner portings?
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02-06-03, 12:23 AM
#8
This is going to get long so grab a snack!
If you are looking at the pictures of my S5 manifold with the single throttle plate then you can also see that I completely filled in the secondary injector locations, moved them, and then ground the inside of the intake runners smooth leaving no sign the injectors had ever been there. In those pictures you can also see the egg shape that I cut the runner shape into at the opening between the upper and lower manifold. This is what was done on the other thread. The problem with this is that the factory made the intake runner expand (get wider) in area as it neared the injector bump to help air get around them. While hogging them out does work I had no real need to do this since I no longer have that restriction. In fact with the port job the port now gets wider for a while in the middle manifold before getting smaller in the lower. This kills velocity and is an adverse effect in the low to mid range power region. Only the extreme upper end benefits. Since my restriction is no longer there I wanted to keep the intake velocity as high and constant as possible. I filled back in everything that I had ground out. I even added epoxy in farther up the intake runners to make the port shape as constant for as long as possible. The result was less runner area with more airflow and therefore greater intake velocity. If you look at the middle intake manifold long enough you'll eventually figure out what I mean. The result of this work was not only restored low to mid power that was lost after I (and everyone else porting these manifolds) hogged it out but also the gain on the top end that the original manifold porting job gave.
As far as the damn plenum (dynamic chamber) goes, I felt that if air could flow through it better then more power could be had (duh?). As it turns out in flowbench testing the plenum is the least restrictive part of the intake manifold. This doesn't mean that changing airflow through it won't give us more horsepower. Since I now sped up the air through the entire manifold, it is only appropriate that I improve the flow through here as well. By hogging it out I did change the way Mazda tuned the car. Then again I also removed my actuators permantly and did the same thing there too. So what! If you look into the plenum you can see that while the upper flows good the lower has some wierd internal shapes and air has to turn sharp. By hogging this out to one open area, the air doesn't turn near as sharp entering the primary intake runners. Since the secondary runners are still in line with the throttle body their airflow isn't really even affected. I added the single throttleplate because it can flow more air and without a dual plenum why be so complex with 3 plates? The result is a car that revs much faster, and responds better to throttle inputs. I don't have a problem with bog anywhere. I don't know how gas mileage was affected since I'm always on it pretty good (not my daily driver!) but I know it really isn't affected all that much. FWIW someone once commented that going with a single throttle plate on a rotary is bad for gas mileage and drivability and there was a reason that Mazda designed that system that way and by changing it I undid all of their hard work, time, and money spent on the project. If it were so good stock then they wouldn't have changed it with the Renesis. Incidentally the Renesis has 1 throttle plate and still has VDI. Sound familiar?
For any other specific questions please PM me so I don't waste pages upon pages of thread with my responses!
If you are looking at the pictures of my S5 manifold with the single throttle plate then you can also see that I completely filled in the secondary injector locations, moved them, and then ground the inside of the intake runners smooth leaving no sign the injectors had ever been there. In those pictures you can also see the egg shape that I cut the runner shape into at the opening between the upper and lower manifold. This is what was done on the other thread. The problem with this is that the factory made the intake runner expand (get wider) in area as it neared the injector bump to help air get around them. While hogging them out does work I had no real need to do this since I no longer have that restriction. In fact with the port job the port now gets wider for a while in the middle manifold before getting smaller in the lower. This kills velocity and is an adverse effect in the low to mid range power region. Only the extreme upper end benefits. Since my restriction is no longer there I wanted to keep the intake velocity as high and constant as possible. I filled back in everything that I had ground out. I even added epoxy in farther up the intake runners to make the port shape as constant for as long as possible. The result was less runner area with more airflow and therefore greater intake velocity. If you look at the middle intake manifold long enough you'll eventually figure out what I mean. The result of this work was not only restored low to mid power that was lost after I (and everyone else porting these manifolds) hogged it out but also the gain on the top end that the original manifold porting job gave.
As far as the damn plenum (dynamic chamber) goes, I felt that if air could flow through it better then more power could be had (duh?). As it turns out in flowbench testing the plenum is the least restrictive part of the intake manifold. This doesn't mean that changing airflow through it won't give us more horsepower. Since I now sped up the air through the entire manifold, it is only appropriate that I improve the flow through here as well. By hogging it out I did change the way Mazda tuned the car. Then again I also removed my actuators permantly and did the same thing there too. So what! If you look into the plenum you can see that while the upper flows good the lower has some wierd internal shapes and air has to turn sharp. By hogging this out to one open area, the air doesn't turn near as sharp entering the primary intake runners. Since the secondary runners are still in line with the throttle body their airflow isn't really even affected. I added the single throttleplate because it can flow more air and without a dual plenum why be so complex with 3 plates? The result is a car that revs much faster, and responds better to throttle inputs. I don't have a problem with bog anywhere. I don't know how gas mileage was affected since I'm always on it pretty good (not my daily driver!) but I know it really isn't affected all that much. FWIW someone once commented that going with a single throttle plate on a rotary is bad for gas mileage and drivability and there was a reason that Mazda designed that system that way and by changing it I undid all of their hard work, time, and money spent on the project. If it were so good stock then they wouldn't have changed it with the Renesis. Incidentally the Renesis has 1 throttle plate and still has VDI. Sound familiar?
For any other specific questions please PM me so I don't waste pages upon pages of thread with my responses!
Last edited by rotarygod; 02-06-03 at 12:29 AM.
02-06-03, 01:01 AM
#10
Nope actually power will be the same up to about 5500 rpm when VDI kicks in. After this you will gain about 15 hp up to 8000 rpm or so. The midrange loss applies to modded S5 manifolds. Since the manifolds exibit about the same power up to a point, and power and torque are directly related, torque remains the same as well. Since top end power is increased, top end torque is also increased. You can't increase or decrease one without doing the same to the other.
02-06-03, 01:14 AM
#11
boost on the way(GTU II)
ohh i c rotarygod... u have shed some light on the matter for me.... one last thing... if i switch my mani. from the stock s4 intake mani. to the s5 mani. should i port the s5 mani? or should i keep the s4 mani. and port that ?? i have heard of people thinking it is better...
thanks
jack
thanks
jack
02-07-03, 12:09 AM
#17
OK sorry about being so slow to respond. If your motor is stock then definitely switch to the S5 intake. Supposedly porting the manifold (S5) will give you top end power and I have found this to be true but only extreme top end over 6K or so. I found that the midrange on the ported manifolds suffers a little bit though. It is up to you whether or not to port the intake. The guys that have done it on here swear by it and since I haven't seen their cars I can't say it doesn't work for them. Just swapping to a stock S5 manifold will be a noticable improvement though. There isn't really anything significant you can do to port an S4 manifold. Supposedly they work best on ported engines though. This one I can't verify.
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