X605

ok so i installed my header today (i had an o2 bung put in it, 30 bucks damnit) it took a while, about 2 hours, from finish to end and i wired the 5th and sixth ports open one was sticking......so i have an idea.....im gonna have a tube welded into the header to run one of the actuators, to get a little low end power.......but right off the back rotor housing header pipe...not after 2 catylitic converters..i think thats why they dont get enough vaccum pressure. cause theres no pressure after a cat back and then going half way through another one.....has anyone done this if so how does it work? i got dips on all the credit if this works oh yeah and the tube that goes into the air box is that necesarry??? i didnt think to so i left it...so far iv taken off the air pump all the cats, and the cruise control tomarrrow i take off the a/c(i just cut the belt before)

Jeff20B

iTrader: (13)

I've cut my airpump belt before. Anyway, yes, try this exhaust pressure mod and let us know when your secondaries (5th and 6th ports) open.

Manntis

In a complete Racing Beat system there are no cats at all, and the pressure is sent from the presilencer back to the actuators. Works like a damn!

X605

i think im gonna do this
have the best of both worlds low end, and some high end on tap

X605

wich tube in the bay opens the atcuator closest to the air cleaner.? which one is that? 5th or sixth? ill check it out after a bit, but i want to run the one closest to teh firewall sincse that one doesnt stick

onepointone

i know this idea is FAR fetched... but wouldnt it be cool if you could take the internals of a **** lite that autometer sells, and wire it so that instead of the light turning on at a set rpm, it turns a motor that opens the 6th ports? like i said, thast probably far fetched, but it might be a start

Jeff20B

iTrader: (13)

Yeah, why not? Just use a relay if the motor draws more amps than the light. Set the shift light to 3500 or 4000RPM. Hmm, but how would you close the ports? Maybe set it up so the motor is always in a closed position, untill the shift light comes on. Then it stays open only as long as the shift light is on. Then it closes automatically. Like an electric radio antenna (which some models use relays to accomplish this).

nosajwrx-7

Some one should design and market this, I bet it would sell quite well.

onepointone

to solve it closing, you could have a spring on it, so when power isnt goign to the motor, it would pull it shut, but when the motor is on, it would open it. the only thing is.. if you are racing, the ports are going to stay open for a while, which might burn out the motor since it wont be moving anywhere, but it will be trying. glad it wasnt as far fetched as i thought

Manntis

easiest way I can see is using solenoids - when the engine is over 3500 RPM, the solenoid receives power and opens the ports. When it drops below 3500, the power is cut, the solenoid snaps back into place, and closes the ports.

onepointone

good idea mantis.

i think going to an electrical method would be more reliable, and alot easier to tell if its working properly

Manntis

for simplicity sake you could hook both ports to one solenoid actuator, eliminating synch problems.

onepointone

yea, thast what i was thinking. you should come up with something like that and sell it on your site *hint hint*

Zach McAfee

Electronic 6-ports
https://www.rx7club.com/forum/showth...hreadid=147853

onepointone

well damn zach, i thought i came up with something original... i kinda would like to see what you have done in person if you dont mind. i think its a very interesting thing, i know alot of the guys in here seem to be having problems with the 6th ports, theres probably 4-5 thread going on right now about them.

Manntis

Good start, Zach - what's your progress like?

brownmound

Just wire em to a button and label it "NAAAWZZZZ!"

Right on.

hornbm

the idea I was thinking of doing down the road, was just getting an electric air pump, connect it to both acutators, and have it be controlled by an RPM switch.

The idea seems simple enough doesnt it? Mabey its because I have s5 actuators, they may work differently than the s3 and s4 ones. The s5 ones look alot different and have an air hose on them.

X605

yeah well has anyone done one working and one completely open...i like the idea

Directfreak

iTrader: (2)

S5 ones are electrically controlled.

ioTus

iTrader: (5)

No s5 ones are controlled by the air pump... thast what the 2nd gen guys told me.

I'm developing a mechanical method based on the throttle position. i dont know if i'll complete it or not because i may need a new engine soon.

X605

there not mechanically opened i check after i read this on my s5 n/a 1990 gxl, it has the same exhaust setup as my 85 gsl-se.....sorry man

Mark S

iTrader: (1)

I don't think S5s will work on an S4 or SE

The S5 Actuators pull instead of push.

I played around with adding tubes to custom exhausts and found that it's the position of the pickup tube that's most important to generating the pressure.

If you just drill a hole in the exhaust and weld on a tube, it won't actuate the ports unless you have a ton of backpressure.

If you look at the RB presilencer, you'll se the pickup tube extends into the pipe and then curves in the direction of the exhaust flow. If you try to do this yourself, you have to make sure it's aligned perfectly, or the differential speed of the exhaust flow over the misaligned lip will cause the exhaust to bypass the pickup.

Once you get the tube aligned so it points into the exhaust stream, you have to play around with tubing sizes or the adjuster screw on the bottom of the actuators to get them to open at the right RPM.

Remember, the car has to be under load when you make your adjustments. I'll let you be creative to figure out the best method for this.

The other option for a pickup is the one Mazdatrix uses on their true dual 2nd gen exhaust header. Remember how I said a pickup welded on the side of the exhaust tubing won't generate any pressure unless it's curved into the exhaust stream, well if you weld the pickup right at the right angle bend of the header as it exits the engine, the sidewall of the tubing gets a direct shot of exhaust as it exits the engine. This setup will work even if you run an open exhaust. The pickup is about 5/8ths of an inch in diameter, and then funnels down to the size of the pickup tube hose (I think 5mm) using a bung attached to a piece of brakeline. This seems to be the best method for actuating the 6ports, as it works pretty much no matter what.

I agree if you don't have access to metal working equipment, it is much easier to set up some sort of electric actuation, but an RPM switch does not sense load, whereas exhaust flow is directly related to load...

However, either method of actuation is much beter than wiring them open...

Directfreak

iTrader: (2)

You know, I screwed up. I was thinking of the OMP on the S5 ones.

Mark S

iTrader: (1)

No, you didn't screw up.

The S5 actuators are kicked off by an electronic switch controlled by the ECU. The switch opens a valve on the ACV which lets positive air pressure in from a circut attached to the airpump. It's the air pressure from the Air Pump that works the actuators. There is no exhaust backpressure involved. The ECU looks at load and RPM to decide when to switch the actuators.

This same system is used to control the VDI actuator (switch from long intake runners to the short ones). It's located on the right upper section of the S5 intake.

While the actuators may look similar, the S4/SE ones Pull (Arm Retract) whereas the S5 push (arm extends) or vice versa I never remembrer which. Bottom line they move opposite directions.

And like I said, the S5s run off air pressure from the Air Pump and are computer controlled