drago86

Just curious, why does the acv dump at 3800? why not just pump air to the cats and ports all the time?

NZConvertible

I believe it's because the excess oxygen would cause the cat to overheat and be damaged.

FYI, the FD's ACV doesn't need a relief valve because the air pump has an ECU-controlled magnetic clutch (like the A/C compressor), so instead of dumping air it just stops pumping.

drago86

hmm so restricting the dump line with a cat on the car would be a bad thing then?

NZConvertible

What dump line are you talking about? The relief line (the one that does the dumping) goes from the ACV to the silencer under the headlight. The split air line sends air from the ACV to the cat.

drago86

the releif line, i just allways wonderd why it was even there, and i was thinking of restricting it to mess around with some 6 port actuation ideas

HAILERS

Spend fifty bucks on a RPM activated switch from http://store.summitracing.com/defaul...rchType%3DBoth

Grab a RX-7 solenoid off a wreck. A Grey one will do. Buy about three feet of vac hose.

Buy one plastic vac pipe of 3/16 dia from the auto store. VacTite makes them.

Shove the vac pipe in the middle of the large hose b/t the ACV and the air pump. Drill a small 1/8 (are there big 1/8th???) hole in the hose so you can do that.

Run a vac hose b/t there and the solenoid. Run another hose from the other pipe on the solenoid to the air feed pipe for the auxillary ports.

Run a ground to one of the terminals on the solenoid.

Run the output of the RPM activated switch to the other terminal on the solenoid.

Set the RPM acticated switching device to whatever rpm you want.

The actuators will work each and every time the solenoid is triggered no matter whether the ACV is dumping or not.

It never failed while I had it on the car. Its not on the car now, though. The engine was replaced with a TurboII engine.

The wife's 86 is stock and works each and every time with the original setup.

SureShot

I like Kevin's cheap & elegant aux port control for S4's.
(copied from RotaryResurection.com)

Airpump 6pi actuation:

Basically you're gonna get some aquarium parts for this a brass part that joins 2 airline hoses together (union) is used to tap into the air pump supply. Use a small drillbit to make a pilot hole in the hose exiting the rear of the air pump, and insert your brass tap with hose (vacuum hose) on it. You're gonna get an aquarium air valve, one with 1 inlet and 2 valves/outlets on it. Ill explain why in a minute.

Run your airpump supply to the inlet of this valve. Run more hose from one of the outlets to the 6PI nipple on the motor. Open this valve about halfway, and the other about halfway, open-air vented. The reason you must vent/dump some air constantly is because the airpump is always generating some pressure. Since the 6pi system is (supposed to be) airtight, once theyre pressurized (open), they wont want to return shutsince the airpump is still spinning some pressure on them...having an air dump allows the pressure to bleed quicker and allows them to shut more normally.

IT WILL take some adjustments of both valves to obtain a decent working setup. Opening the 6pi valve more makes them open quicker, and opening the dump valve more makes them close quicker, though having them both too far open makes neither work well...it'll take you 20-30 minutes of playing around to get it decent. Grab the throttle and rev the car up to see what happens with each adjustment. You want them to open fairly quickly (1-2 seconds) after reaching 3500-4000rpm, and close fairly quickly (2-3 seconds) after releasing the throttle. You can never obtain a fast/precise operation this way, but it's cheap and a lot better than relying on your exhaust to do the job. IT's also better because you can open them in neutral (as opposed to only under load) and watch what happens for testing/adjustment, and the actuation will be the same in all gears (air pump rpm, not exhaust backpressure).

HAILERS

I wrote my above response just to stir up the Six Port issue up. It's just not normal for this site to not have at leasts one six port question a day.

Just stirring things up.

hugues

here's a write-up for the rpm activation switch thing (I don't know if same as HAILERS approach bit should be same idea)

http://home.rmci.net/panther/6PortSolution.htm

and here's a write-up using that garden hose tee thing (probably similar to what SURESHOT is talking about)

http://home.earthlink.net/~burntoast/6port.html

Hugues -

drago86

Ok, im allready doing the method sure shot described, but it stopped working a month or so ago. so i was going to try using the ACV relif line. I just however, found out why it stopped working ( it would either open them at a lil idle, or not open them at all) my ACV is dumping all the time. Which is also probably why she didnt want to pass smog. ok, 2 new questions i should have probably started a new thread for: are my cats most likly cloged from having little to no air supply? , can i block the ACV dump without doing to much harm to the cats, for a quick run to mr. SMOG? how about perminatly?

jje

Do you know what does not make sense?

You want the aux ports to open at 3800RPM.
The ACV vents at 3800RPM.

Why not tap the exit from the ACV, plug it to build the right pressure, and take your tap line to the aux port acutators?

Why spend all that money, fiddle and fiddle, when the answer was provided for you in 1986?

That is what I did, and wrote it up, and pasted it to the web: http://www.geocities.com/MotorCity/G...1308/rx-7.html

Happy reading.

HAILERS

drago86.....About the dumping all the time. One thing that will cause this is the water temp switch at the bottom of the radiator. If either bullet connector is disconnected, the Blue (Relief Solenoid)will close and not supply a vacuum to the relief diaphram in the acv (causes the air pump air to dump overboard). Check it out when you get the time. Its either that or the ECU isn't putting a ground on the relief solenoid.

Even with the relief valve in the acv dumping air overboard, there is more than enough pressure in the hose b/t the acv and the airpump to operate the aux ports. It only takes a couple of psi to operater them.

drago86

Hailers does the valve get vacume when it is dumping, or when it is not dumping? because both lines going to the acv have vacume at idle. also will plugging the dump line be very harmful to my cats?

HAILERS

Oooops. Both the vac lines just above the acv should have a vacuum at idle. Darn. The vacuum prevents the acv from dumping air overboard. I'll try to attach a schematic with this post.

Get a piece of vac hose. Connect it to one of the two metal nipples above the acv. Suck on it. It should hold a vacuum. If not...the diaphram is kaput. If it does....this does not make sense.

The vacuum pulls the diaphram inside the acv and closes off the path for air to relieve overboard.

I forget right now which of the two nipples is for the Relief. I know with the engine idling, I can stick a piece of vacuum hose on the nipple and stop the air dumping by sucking on the vac hose.

jje

Have you tried this? COnnect your vacuum gauge to the air pump output. Measure that pressure when you're flooring the pedal, and if you got what I got, it's venting when the throttle is floored and there's no pressure in that line. This tells me I can't use the air pump output, because when I need the aux ports, there's no pressure to open them and they're gong to be closed.

iirc there's always going to be pressure in the vent line when the pedal is floored, which is imo OK even at the lower RPM, because you don't get much power below 3800RPM anyway.

I didn't find out why it did that even w/o the solenoids plugged in. I'm guessing that when there's just about zero manifold vacuum, the exhaust pressure gets relieved across the engine - then pumped up by exhaust, the disc valve shuts and pressure pushes open the relief valve as a backup to save the air pump. Was my diaphragm shot? I dont know, I tried two of them and they did the same thing!

But how I see it is... you want these things to open at 3800RPM. This does that without any fuss, expense, or even very much effort, so what's the ongoing (this is 5 years now!) debate about, are you a Royal Commission or something now?

HAILERS

Just talking about what is wrong with your acv for emission reasons:......the Relief solenoid should provide a path to the acv to pull a vacuum on the relief diaphram inside the acv. When a vacuum is pulled on that diaphram, it pulls the valve against the force of the spring and closes off the passage that lets the air dump overboard.





So if you have a vacuum on both hose just above the avc, then there is something wrong with the acv diaphram. If you took the large hose off the bottom of the acv, and looked inside the acv using a mirror, while sucking on the metal nipple that the two hose go to (I forget which right now), you should be able to see movement of a valve and spring. If you can't hold a vacuum on the nipple, then the diaphram is busted and that's why the air dumps all the time. Talking Non Turbo acv. Turbo is different.

jje...uh, no that's not so. I put a Autometer boost gauge in the line b/t the airpump and the acv. When the throttle is wide open there is still pressure there. More than three pounds, less than five. More than enough to make a aux actuator work. It's just a copy cat of the series five that uses that same pressure to open their aux ports. Never a vacumm b/t the airpump and the acv.

jje

No of course there could never be vacuum after the air pump. I was curious and confused why there were openings from the ACV to the block - 2 iirc, one is the split air passage, the other, ???

Anyway, I'm done again, see you all next year!