chohakai

iTrader: (1)

I've just spent $50 dollars on a K&N filter with 4" opening and a place for nipple, will the rubber part hold up if I just clamp it onto the turbo inlet (4" 60-1 comp. housing)?

also will the nipple in the picture offer enough vacuum for the oil injectors?

TIA!

Fred

FourtyOunce

iTrader: (15)

i think that when you go single, you cap off the vaccuum port on the oil injectors... i could be worng ..

nd4spd

First, this is not an accurate vaccuum source if at all. You will need to get vaccuum from your intake manafold after the throttle body or before. I don't remember anything needing a real vaccuum source that came pre turbo. Unless you eliminate the oil injection and go premix, you will need to keep vaccuum to them.

Even the compressor gets very hot so a thin layer of adhesive backed thermal insulating tape will help. Just make sure the filter is clamped on well.

es

Not to flame, but how can the intake manifold or IC pipe be an accurate source of vaccuum if it's pressurized on throttle?

The factory configuration had the vaccuum hoses from the MOP injectors running to the plastic INTAKE pipe of the primary turbo. Filtered air, never pressurized...

94SR2

Do a search on this, Someone had the right answer posted which is how I ran it:

T'd them together and ran them open to atmosphere with at vacuum filter on it (like the one's found on the stock seleniods)

-Ed

chohakai

iTrader: (1)

thanks for all of your input!

But no one has said anything about the durability of the rubber opening of the filter. With the filter mounted directly on the turbo, will it crack after some use?

Also, I've search the archives, it seems that no one really explained how the oil injectors functions. My guess would be that air and oil are injected/sucked into the engine through the little holes on top of the rotor housing. I guess that without the vaccum too much oil would be sucked into the engine or something?

Fred

nd4spd

O.K. es try this, hook your boost gauge to that port on the air cleaner element and see how much vaccuum you get and then compare it to its stock attachment. All devices that need vaccuum or boost get it from the intake (i.e. your rats nest of vaccuum lines). The wastegate (and maybe other items) from pre throttle body. If the injectors need the source you describe, it is for reasons other than actual vaccuum. I am not sure of why the injectors need this source, but if that was the stock location, keep it there.

Also, its only under pressure on boost. Otherwise it is either 1 atmosphere or vaccuum.

stevenoz

iTrader: (27)

Oil injectors 101

Ok the ONLY reason for the the vacuum source on the other side of the oil injector is to keep the motor from sucking in oil when you shut it off ( It also creates good suction to spray in the oil in the rotor housing but you could do this without the opposite nipple ). I'll explain how this works.

Lets start with the oil injector. The injector has a nipple on one side for a vacuum source and on the other side are the threads. On the threaded side there are 2 small openings for the oil to come into via the oil metering lines/pump and then one opening on the bottom to "shoot" the oil into the rotor housing.

From the nipple side you should be able to "blow in" but not "suck out". If you can your injector is bad and needs to be replaced.

From the threaded side you can "suck in" ( as long as you block the 2 small openings ) but you can't "blow out".

Now try sucking in and as you do put your finger over the nipple. You can't suck in now. This is what happens when vacuum is applied to the nipple...you have and opposing force stopping this. What this does it provide a sealed oil line so it can be sucked into the housing with force, therebye creating enough force so it kinda sprays when it goes through the oil jets down in the rotor housing.

So the motor is running and oil is being injected in the rotor housing ( the oil metering pump dictates how much but Im not going into that ). We have our vacuum source on the other side providing a sealed enviroment. Now we shut the motor off....we lose our vacuum on the other side and the motor ( which loses its spark the instant you turn off the key ) turns out its last revolutions. Remember when we don't have our finger on the nipple you can suck through the injector...well that is what is happening now. The motor won't suck the oil that is in the lines but will suck out through the other side of the vacuum line ( attached to a vacuum source only ).

Suppose the nipple side was capped off. You would have constant suction in the oil injector lines and when you switched off the car it would suck the remaining oil out of the lines ( and the lines are pretty long ). Considering you have no spark ( you lost it when you turned off the key and the car will still turn out its last revs ) the oil would just sit in the housing until you go to start the car again. Then when you started it you would have a bunch ( or a little ) of oil smoke at first. So this is why Mazda came up with this idea for the oil injectors. Phew!!!

So basically remember always apply a vacuum only source to the oil metering injectors !!!

chohakai

iTrader: (1)

Thanks, stevenoz, for such an informative answer. So the answer to my question is that yes, my vacuum source would work, even if it may not be a very strong vacuum souce.

Fred

rx7tt95

Theoretically, what would happen, however, if the vacuum source used also produced boost, ie. a nipple coming off the intake manifold after the throttle body, and you'd been doing this for say, oh, two weeks now? Would this cause excessive oil injection or possibly an oil leak in the oil metering system?
Michel
(guilty of the above)

stevenoz

iTrader: (27)

Your vacuum source should be fine.

One bit of advice is to clamp the K&N on there once and don't overtighten it. That rubber will get real hot and if its too tight the clamp will just eat through the rubber of the filter and tear. Also don't retighten it when its hot too.

stevenoz

iTrader: (27)

rx7tt95

First of all you can't make it inject any more oil than the oil metering pump will allow. Thats controlled by the ecu and it dictates when and how much oil to inject.

As far as letting boost get to it, I guess it is possible for the boost to "push back" some of the oil but don't hold me to that one. With all those nipples on the intake Mazda went and made one just for it on the primary compressor side so that it had vacuum only. I would somehow switch it to vacuum only. But thats just me.

rx7tt95

I wholly agree with you steve :-). Just curious as to whether or not I've possibly done damage, blown out oil seals, etc...It's being switched to vacuum tomorrow morning first thing.
Michel

suganuma

stevenoz - so if you just leave it exposed to atmosphere or capped off instead of vacuum, the only draw back is after you shut off the car the little oil being sucked in before start-up the next time, a little smoke at startup and thats it.....correct??

stevenoz

iTrader: (27)

Looking from the injectors as they are mounted on the car you can push air down into the motor but not pull air out. So if you leave it exposed everytime your car is under vacuum ( meaning not making boost ) it will suck air in through the injector into the motor. Since you have no filtering on it, it would suck in dirt and trash into the motor. I wouldn't recommend this.

You could just cap it. All that would happen is you would suck in a little oil everytime you shut off the car. You would see a some oil smoke at first but it should burn-off rather quickly. But hey most do smoke at first anyway. Its just usually fuel related due to the accelerated warm-up system overloading fuel at initial start-up.

suganuma

since stock it is only connected to one turbo inlet, for those of us who are single turbo and still running this system, what would be the effects since it is seeing twice the vacuum if not more due to the turbo sucking more air than the twins ever could....??

es

OK, lets imagine we just stick a small filter on the end of the MOP injectors.

When the MOP is pressurizing the lines air wont be sucked into the chamber (idle, light load), and when you shut it off oil wont get sucked in... Sounds like the way I want to run it.

I've never liked the idea of charging that line wtih boost. And nd4spd, yes the vacc source for the nest is from the UIM, but it's isolated by check valves. If you just hook your MOP injectors to the UIM there is no check valve & your pushing boost through the injectors. And hooking it up before the throttle body will give you constant pressure with no vac...

nd4spd

Thanks for this lesson. It all sounds reasonable to me. I just didn't think you would see a usable amout of vaccuum at the filter. The intake pipe to the turbo makes more sense as in the stock set up. And Chohakai, try the single layer of Thermotec adhesive backed heat insulation tape on the edge of the turbo. I have done this and it seams to insulate the rubber somewhat from the hot turbo. It will need replaced once a year or so. Before I did this, the rubber wanted to stick to the turbo after it got hot a few times. I could see it dry rotting and cracking in very short order.

stevenoz

iTrader: (27)

No matter what turbo you are using I don't think you could ever get too much vacuum on the nipple side. The injectors actually leak down a little from this side. If you hook a vacuum pump to them you can see. What you are wanting is a little opposing force so that you 'seal up' the oil lines. The jets in the rotor housing are really small so I think that it would benefit the injection of the oil to have the vacuum source on the other side. This would help to create a force to help suck the oil through the injectors instead of relying on the oil metering pump to push it through. It would probably help to spray it a little too. If you had a filter on the end of the injector you would stop the oil from being sucked in when you shut it off but you will lose your sealed enviroment. Therefore IMHO I think its best to run it to the front of the turbo.

There is no possible way to use a check valve and make this work off one of the manifold nipples. If the arrow on the check valve is facing the manifold, then its just like capping it off so you might as well just cap it. If the arrow is facing toward the injector, then you are supplying boost to it and I've already stated how I feel on this.

In the stock setup the two injectors connected into a line for only them and ran down to the the primary turbo. No check valves.

suganuma

maybe i am not reading this right

i dont see the big difference between just putting a filter on the line versus it going to the turbo inlet which sees a filter in the same way besides the fact that when the car is started the line will see vacuum.

From what I am understanding vacuum pulls on a valve in the injectors which opens or closes them more (dependant on vacuum) and allows more or less volume of oil to pass through to the engine. That is why i asked about increasing vacuum when you have a single turbo - whether or not that valve can handle the extra vacuum, pump can handle the extra work load to pump that amount of oil, collapsing of lines or other parts, etc

am i misunderstanding how the system works?? - the above makes sense to me.

-Nic

stevenoz

iTrader: (27)

I made a video to explain how the oil injection works. You can download it here . Hope this helps. Its about 5 megs.

rx7tt95

The check valve thing is what I did today...With the arrow pointing away from the injectors and towards the manifold, vacuum should be allowed through (I tested this). But under boost, it can't get past the check valve. What am I missing?
michel

stevenoz

iTrader: (27)

If the check valve is pointing toward the manifold then this only works if you are under vacuum.

Its almost like having a cap on the nipple of the injector with the exception of when you are under vacuum. When you are under vacuum it works like its supposed to...meaning vacuum is applied to the top side of the injector. Under boost the airflow stops at the check valve, which means on the other side of the check valve there is nothing ( no vacuum being applied ). Also when you shut off the car it stops sucking at the check valve, so it pulls from the oil lines.

If you can't get a vacuum only source then just cap it off. All that will happen is a little more smoke at startup. No harm done unless it fowls out your high dollar sparks plugs.

turbostreetfighter

ok guys here is my take on this whole thing: first off you dont want to put a check valve on the line because when under boost the valves will basically not inject enough oil to supply the engine under power. the only time you eill get oil in there is at idle or light cruise. the point of injecting oil in the first place is to lubricate the insides on the cumbustion chambers. the injectors are basically check valves already and you need to have a constant supply of vacuum whenever the engine is running, so putting the line at the intake ( like the million dollar mazda engineers do) this way the faster the engine runs the more vaccum is applied to the injectors.
now if you run the lines to a source in the manifold then everytime you got into boost the valves/injectors will shut. thus not oiling the CC and wearing out your precious rotor housings!! actually the best thing for you to do is disconnect all of the oil injection CRAP and premix!! there is something about injection oil that is not designed to be burned in to your engine that makes me ill!!! i have taken engines apart that have been premixed since birth and they actually look good when you take them apart. how many of you have taken apart a stock 100k mile engine and seen what the rotors and internals look like? pretty nasty at best!! 6oz of normal premix per tank of fuel is perfect and if you use the Royal Purple race formula you only need 4 oz per full tank. i have to run 10oz per 5 gallons in my methanol burning race car!!

i am sure some of you already knew what i just posted but after reading the confusion i just wanted to give my opinion


MWW

rx7tt95

Much appreciated! Luckily, I run a bit of premix as well. My current problem is that I do not have a filter on the turbo inlet and thus, I do not have a spot to run a line to. I'm fabbing up a carbon fiber adapter tube that will allow me to use a filter (there's an interference problem with the T78 and my CWR IC) and I'll run a nipple or two off of the tubing to provide vacuum to the metering nozzles.
Michel