Simplified Sequential

[David Jerome]

For those who know me very well at all, they know I pretty much despise the stock sequential setup. I love it the 10 minutes of the year it performs correctly and Im sure it was probably great in 1993-1998 before people started pulling these cars apart, however, it is very rare to find them working correctly these days. Since I buy and resell fds and try to sell them as properly running cars, I almost always convert them to Non-Seq if I am doing a rebuild on the car also. This minimizes my headaches during the rebuid period and also the period after I sell the customer the car because if they have any boost issues or really issues at all it is pretty simple for me to diagnose over the phone.

Well, for whatever reason I decided to put the last car I bought back together as a proper running sequential car(shocking I know ) As I have been looking over the simplified sequential chart I have ran into some questions about the necessity of some of the simplified setup.

The lower vacuum nipples on the wastegate control solenoid and turbo precontrol solenoid are "T'd" into the vacuum lines for the oil injectors for the oil metering pump and ran into the plastic primary intake elbow. What is the reasoning for these lines being ran into the plastic elbow. I know it provides a slight source of vacuum, but is this really necessary? This is one area of the FD I can honestly say I could stand to do some more studying and learning. In the past I have only dealt with the Sequential setup when a customer wanted me to and that was it.

Hopefully some of the experts can chime in on this and this thread may provide some helpful information to forum members in the future.

I will attach the pic below.

[Brent]

*runs outside* Nope, Hell has not frozen over That is a good question David. I'll be putting a set of 99spec Twins on my VR FD soon and will be going through the entire system I'm sure. Kevin have any input on this? I'd like to learn the sequential system better as well. I have done troubleshooting over the years on a few cars that I have purchased to resale, but never really looked into what each component does and why. I understand the general concepts of each piece, but I'd like to know exactly what each component does and why. The only trouble mine has ever given me is the wastegate hose popped off once back in 2002 or something *knock on wood*. My turbo's still boost fine after 8 years of ownership, but I have an oil seal that is starting to go bad. I bet Garfinkle could prob. break it down for us wrench twisters David.

[SPICcnmFD]

I would say it's probably not necessary because mine are capped and mine runs fines, always has. I do have a Profec B but that basically just takes the place of the stock solenoids. I did leave the OI lines hooked to the elbow.

[Herblenny]

David,

I know I had also wondered about that before...

What I know is that oil metering jets are one way jets. I also know what when air is being pulled by the turbo, it will create vacuum by the intake nipple. I'm assuming the vacuum lines on the oil jets are facilitating oil injection at higher load (under boost). I've seen people run this line to LIM manifold nipple, but I think when you do that it does the opposite affect and could also distroy the oil injectors. Why?? Well, because intake manifold create higher vacuum and pressure and I don't think these oil jets are made to handle big changes in pressure and vacuum like that. I've checked over 20 jets in my life time and I have to say, about 50% of them were bad.. Either I couldn't blow thru them or it would flow both directions... As we all know these little things are there for a reason...

[David Jerome]

Would any one care to share with me why in the Simplified Sequential setup there is an extra solenoid pictured but not listed. It is below the (E) turbo control solenoid. Looks identical to the above (E) turbo control solenoid and is even labeled as such. However, the simplified setup has two pics of this solenoid and is unclear about how the lines should be ran. There are only two vacuum nipples on this solenoid and if you were to assume the two solenoids are indeed the same (E) rurbo control solenoid. It doesnt make sense as to why the simplified diagram has the red vacuum line getting T'd back in wiht the vacuum chamber and the other solenoids.

The factory non-simplified setup in no way has the (E)turbo control solenoid connecting with the vacuum chamber or going back into the UIM. Just a little confused since there is an un named solenoid on the simplified diagram.

I know there are sequential experts in her that can chime in.

Thanks
David

[Herblenny]

David,

Its a different solenoid. Its the solenoid with two nipples facing up and a filter like thing in the back (rectangular box on the back of the solenoid). It actually looks VERY similar to purge control solenoid except the purge control solenoid doesn't have the little box thing in the back of the solenoid. If you use any other solenoid you WILL have issue with your sequential system.

The diagram is correct and you have to use the correct solenoid! The "E" solenoid is the same ones as the "F", "H", "I", and "J".

[David Jerome]

Im an idiot, I figured it out. I am still going to find a way to simplify this mess even more if it kills me

[Herblenny]

Well, To be honest with you, you can't get any simpler than that if you are going to use stock system to control boost. If you go aftermarket boost controller, you could get rid of the Solenoid "I" and "J". And some people run their car without the purge control solenoid so you might be able to get rid of that also... But thats the simplest you'll get..

[Garfinkles Motor Works]

You will not need to put lines on the oil meter injectors and the line from the front elbow to the oil fill neck can be gone as well .Cap the nipples on the front elbow and put a small filter on the oil fill neck or cap it .I run a small filter out of the top of the oilfill cap .

[SPICcnmFD]

FWIW the simplified sequential system is just the normal sequential system minus all the the emissions solenoids and vac. lines. I thought it was some great thing to make it alot easier to work on, which it does because it's not as cluttered but when I did mine 2-3 years ago I found out that was all it is.

And like Phil said make sure you use the right solenoid they flow only certain ways even thought they look the same. But there is only 2 or 3 different kinds.

[Whizbang]

Originally Posted by Herblenny

David,

I know I had also wondered about that before...

What I know is that oil metering jets are one way jets. I also know what when air is being pulled by the turbo, it will create vacuum by the intake nipple. I'm assuming the vacuum lines on the oil jets are facilitating oil injection at higher load (under boost). I've seen people run this line to LIM manifold nipple, but I think when you do that it does the opposite affect and could also distroy the oil injectors.

i would have to disagree with this partially, at least in terms of what is happening. When a volume (the intake manifold) is pressurized, the pressure WILL go in the direction of lower pressure. Which is the reason the air is moving in the first place (towards the engine). The air on the wall of the intake plenum increasingly approaches a "0" velocity.

Now, what is probably happening, is that there is pressure working against the oil jets. This is probably the reason that there is a line running to the oil jets (at least on all the FBs, and FCs i have seen). It probably is to help equalize the pressure.

If you read my thread on air and its working, you might remember this formula. M=DVA (mass flow = density x velocity x area)

Mass flow must remain constant in this situation. We shall assume that for a given density (due to pressure and heat after turbocharger), you have velocity and area as a variable. The air moving inside of the smaller lines and vacuum nipples will be moving faster to make up for the decrease area when compared to the intake manifold.

Meaning that any of that pressure in the manifold is compensated for and if anything, a pressure differential may form in favor of moving air/oil of the jet and into the intake plenum. This, coupled with the pressure of an assume good metering oil pump, will mean oil is exiting the nozzle.

Without good testing, this is the best i could reason.

[David Jerome]

I never run the lines on the OMP injectors and I always delete the purge solenoid also. I am considering making an aftermarket set of hardlines(rats nest) that would make the simplified seq a much cleaner setup underneath the manifold.

[Herblenny]

Ok.. Well, again, i have to put a disclaimer as I'm no expert..

But you have to look at the reason of oil metering and why mazda would have gone extensive length to put a "jet" and vacuum lines to a intake source.

To start, we all know as rotor spins and after apex seal passes exhaust port, it start creating vaccum (expansion of combustion area) to suck in air/fuel. If you look at the position of where oil metering jets are, its just before the primary fuel injectors and intake (I think??). By this, oil is drawn easily into the chamber by vacuum created by the engine. We also know as higher the load and engine speed more oil is needed. This was one of the reasons of why Mazda has been spending money on R&D... and why Renesis had 4 oil jets instead of 2 on 13b-rew (someone told me new one has 6!). I believe that the reason for vacuum source on the jet is to provide and control oil level flow.. As more air is being sucked in thru the intake passage, it creates higher vacuum pressure, causing higher flow of oil to be injected into the engine. By not using the vacuum source for the jets, you might not gain the benefit of increase oil flow thru the jets.. I guess you could get away by premixing.. but why pre-mix and go thru more hassle when just simple vac lines could do similar job.

bottomline, I think certain things mazda did it to save money and certain things mazda did it so it will increase the life span of the engine.. In this case, we could clearily see the reason behind the jets, location of the jets, and why mazda put it. Otherwise, why would they increase the number of jets to 4 (6) on the new engine?? That's more money for them and labor they have to pay...

[Whizbang]

Mazda is also very concerned with making the engine last. Sorta to prove a point. Plus with there being a larger rotor, there is more surface area and more nozzles who give a better spread to help reduce that wear that seems to prevail at the edges of the rotor housing.

[Herblenny]

Yeah, but I think we all want our engines to last longer.. not just mazda Hence some people running premix on top of working oil metering...
I was told by local dealer mazda tech that new 09 RX8 had 6 oil jets (not just the 16x).