wthdidusay82

iTrader: (15)

I have my 5/6 ports and sleeves completely removed and I've heard lots of different opinions about taking them out.

Some people have told me there car revs up faster with them being functional, but is this only true for low to mid revs (2500-4000rpm)? I dont think the car would rev slower from mid to topend (4000rpm to redline) because what I was told by Kahren on here is that it will add more hp and torque to the topend.

heres a video of me redlining http://youtube.com/watch?v=9HLUQxFr700 , one guy i know with an almost stock s4 gxl said his car revs faster than mine, and I was just like no way because his car is stock other than 2 mufflers and an intake.

Mine has streetport, full exhaust, intake, lightweight flywheel, upgraded clutch, removed 5/6 ports, ported tb, tb mod etc

90WhiteVrt

In my experience functional 5th and 6th ports are the way to go. I have a heavier car (vert) and when I reinstalled the sleeves after purchasing the car, I noticed better take off's and easier in town driving. The rotary engine doesnt make alot of torque to begin with, so i think it's best to keep them in.

micah

+1, I removed them on my last car.... drove like that for a while and just figured thats how the car was aftera while. I forgot how it normally felt... I put them back in to sell the car (money problems), and it sucked.... I liked the car so bad, I cried when I saw it drive away.

Man, I'm a walking vagina. But hey.. you are what you eat right?

wthdidusay82

iTrader: (15)

Well I took mine out because I thought Id make more mid end power and top end power. I've never actually driven with them functional though, but I really dont have the money or tools to set mine up with working 5/6 ports.

Maybe someday in the future I will get some 5/6 ports for my car, but if I went that route I was thinking that putting the complete s5 vdi intake on my car with an electronic rpm switch with electronic air pump would be better than using the s4 na 5/6 port intake system.

What do you all think the pros and cons would be to using the s4 system and the s5 intake system.

By the way, to the s5 have the same 5/6 port sleeves as s4 na ? I didnt think they have the sleeves at all ? But I am unsure, can someone tell me ?

Heres a short list for me

S4- Pros - 1. Bolt in install
2. Designed for s4, lower rpm powerband may be slightly better

Cons - 1.peak hp may not be as high
2. 5/6 ports setup not as good as vdi

S5- Pros - 1. Overall better designed setup
2. May give higher top end power and mid end power

Cons - 1. May give lower low end power
2. Harder to install, require grinding of intake to make fit on s4
3. Requires more knowledge to be installed and fuctioning properly

micah

Yep.. Its not really THAT hard... you need two RPM switches and a couple of those solenoid air valves from the stock harness... Wire it up at the right RPM's and blamo!

wthdidusay82

iTrader: (15)

2 Rpm switches ? I was under the impression that you only needed one rpm switch for when you want them to open, why would you need two ?

micah

Well, if you want to use the S5 VDI manifold. you'll need to open the VDI portion at a different RPM than the 6 ports.

wthdidusay82

iTrader: (15)

Explain further please ? Im confused , sounds like there are 5/6 ports to open and a vdi to turn on, I dont know what the difference is between their function.

Another question is does the s5 lim have the same 5/6 port sleeves that turn open and closed by rods like the s4 na?

Im not very knowledgeable with the s5 intake manifold setup so any help would be appreciated.

If I could find good reason to go back to working 5/6 ports I probably would in the future, just because from what I hear it makes the whole powerband have better response because of less turbulence, top end may have a 1 hp + increase (not proven) but down low probably has a 10 hp decrease.

Although with the s5 vdi intake setup I could possibly have just as good of top end and mid power if not better than I would with having my 5/6 ports removed completely and even if it didnt im sure the transition from low to mid end would be much smoother with a working 5/6 port vdi setup.

micah

Well. you might want somebody else to chime in.. I only know the basics... but, I'm pretty sure VDI opens before the 6-ports.

wthdidusay82

iTrader: (15)

Ok thanks, maybe I'll look into putting the s5 vdi intake on my car sometime. I'd want to get the intakes and everything I need for decent price though, Im not gonna spend more than I should on the intake manifold and all the parts i need from the s5.

The electronic airpump and rpm switch should cost about the same price if not more than the full s5 intake. I'm just not sure what I'd need from the s5.

micah

The cheapest rpm switches I've found were 50 bucks each or so...

I'd find a schematic and make one yourself.

wthdidusay82

iTrader: (15)

I just dont get why you need two switches, I guess one for the vdi one for the 5/6 ports. Im just confused as to what each one does since they are turning on at different times.

jdm_emperor

iTrader: (6)

haha that was me,... dont get madd i was jus playing around

slpin

iTrader: (9)

u dont gain anything taking them out. but you do lose the lower rpm.
unless it wasnt opening all the way before....


and to the guy who asked about difference in 5/6th port and vdi

they are both bandaids to the lack of power that the na has

one opens up the auxuary port on the iron
the other changes the lengths of the manifold runners.

micah

Uhh... thanks?

If you have non-functioning 6-ports, taking them out is better than leaving them shut.

Do you know what RPM each of them start/end opening?

slpin

iTrader: (9)

3850rpm for 5/6
5200rpm for vdi

open and shut at same rpm.

anewconvert

iTrader: (1)

The aux ports are a 3rd port for each rotor that open to change the flow and duration characteristics of engine. the VDI is a system by which a shorter set of runners is opened up in the upper intake manifold to change the intake tuning at higher RPM. Further, on a stock or streetport engine, the VDI system causes a natural supercharging effect where the pressure waves bouncing off the face of the rotor when it closes the secondary/aux ports in one rotor is fed into the other rotors intake runner pressurizing the air helping to make the engine breath better.


BC

Rx7TyreBurna

iTrader: (1)

Hmmm, my sleeves have been removed, as far as I know. The guy I bought it from had it rebuilt, and never put them in. He put block-offs, and that's all I can see.

I am replacing mine. I bought a summitracing RPM switch, some LEDs (eye candy) and some relays. To actuate the ports, I bought a lumbar pump off ebay for $15.

I am also doing rats nest clean up, and throttle body mod while I have everything out. So, I bought all the other block off plates.

From everything I have read. You don't gain much more HP if any. You just lose torque. Losing torque is never good. I would suggest keeping them in, and if they aren't working because you got a higher flowing, or free flowing exhaust without the thing to actuate the ports, then get electric activation.

I know as soon as I can, I want to buy all the stuff required to put VDI in mine. Might have to wait though. Standalone system is coming first. And then an aggressive port. Then VDI. Anywho, keep your sleeves in.

NZConvertible

That's an interesting way to describe systems that are now used on most new engines. I doubt BMW would refer to their Double-VANOS cam timing system and infinitely variable length manifolds as bandaids. Both of these are logical progressions of the 6PI and VDI systems respectively.

wthdidusay82

iTrader: (15)

So does the 89-91 model have the same 5/6 port sleeves as the 86-88. If I have to put in the sleeves similar to the 86-88 model has, I dont plan on using pineapple sleeves I'm just going to leave the sleeves stock and using electronic rpm switch activation to control the 5/6 ports and vdi.

What kind of gains can I expect to get with this s5 vdi rpm switch activated system on my streetported s4 compared to the stock s4 na intake ? I expect mid to upper range to have better power and the low end to be better than what it is now since I have my 5/6 ports completely removed at the moment.

The only other things I need to get my full hp potential on my streetported s4 na is to finish my cold air intake by extending it under my headlight with another pipe and to get an safc tuned professionally on wideband dyno , after having these mods done and getting the safc tuned I hope to get 170+whp.

SirCygnus

iTrader: (1)

no, they are logical progressions in meeting the demands of sales. heres why.

some people like in city driving. some people like top end. so you give them both. one is impacted though. in our case, its top end. thats why mazda put in vdi so they can eek out an increase at higher rpms. the ports and the rods hinder airflow. not to mention the ports. simply removing them wont hurt low end too much. i didnt notice anything when i did it to my car. it rane fine, idled fine, pulled from stops on hills fine. however top end was better. i could pass cars that i had a hard time passing before.

all in all, there are people that perfer both, one, or the other. period.

in this case, you ask if they increase top end? yes. do they hurt bottom end? yes. how much so? there are numbers to throw around, but its all speculative. we dont know if you like it one way or the other

putting on a better exhaust and runin stand alone will net you way more hp though. put your time and effort into fixing that first.

all this is just an opinion.

anewconvert

iTrader: (1)

IIRC the S5 has a smaller runner diameter lowe intake manifold, but I dont think the sleeves are any differnet. However im not 100% so dont quote me.

The VDI has been shown to be a roughly 15 hp at the wheels top end improvement over the S4 UIM. You can really feel the difference when the VDI kicks in. Before I knew much about rotaries i thought the 5200 kick in the pants was the aux ports opening, but its really the vdi opening up. Definitely worth the investment in my opinion.


BC

anewconvert

iTrader: (1)

You also fail to take in the emissions implications of such devices. At low load these systems can help to keep emissions lowered to pass government testing without sacrificing top end performance.

Has anyone ever dyno'd a sleeved and unsleeved car? Not two different cars, but the same one, just with the sleeves removed? This would put the whole issue to rest. Somehow I think the differences are intangible.


BC

wthdidusay82

iTrader: (15)

You think 5200rpm is the best rpm for them to open on s4 ? If i put the s5 intake in im not sure what rpm to run the vdi at with the rpm switch or how its even done have to look into it.

Another person told me you can run without the 5/6 ports but still run the vdi and you will see the best results on the top end from doing this, but I am still not sure if I am wanting to keep the 5/6 ports if i use the s5 intake manifold...I want the best overall results improving low end, mid end and top end as well.

The way he made it sound is taking the 5/6 ports out on the s5 intake but running just vdi will not make much difference but everyone is confusing me on here.

I think to have the best streetable car and overall car you would want to keep the 5/6 ports, but im wondering if the difference is less noticable on s5 because youd still have the vdi.

anewconvert

iTrader: (1)

The VDI opens at 5200 rpms, so having the 5/6 ports actuated or not is inconsequential as they are already open at 5200 rpms.

As for whether 5200 is the optimum time to open. Get on a dyno. Close the vdi and dont actuate it. Run it to redline. Then a run with the VDI open, without actuating it, and redline. Overlap the two graphs and have the VDI actuation point be about 200 rpms before the lines cross. (the opening time is about 100-150 rpms) that being said the engines are essentially identical, so if its good for the S5, its good for the S4.

While you are at it if you want to get creative you can do the same thing with the aux ports if you chose to operate them via a window (rpm) switch. Keep the aux ports closed for a redline run (with the VDI either operating at 5200 or wherever you have it opening optimally) then run it with the ports wired open. Where the lines cross is the optimum opening point. In either case I would have the VDI operating properly, or as set from factory, before figuring out the optimum aux port opening time. Since there will be a time when the VDI is closed with the aux ports open having the vdi wired open will throw things off.


If you want the best results, ie most linear torque curve, then you will want the 5/6 port sleeves in and operating. If you are looking for the utmost in upper RPM flow then remove the sleeves as the rods have to cause SOME turbulence and restriction (minimal would be my guess, but some) in the intake flow. The 5/6 port actuation is designed to keep intake velocity up so as to get the most out of low end power.


The VDI only operates above 5200 rpms, so it has no effect on low end power.