1987RX7guy

iTrader: (3)

Ok since there isn't a write-up I think I am going to make one myself for others to not have to go through the crap I am going through right now.

I have started with the basic Engine Vacuum diagram and have started marking things that need to be removed or can be removed along with the rack and what needs to stay.



Here is what I have so far. The red has to go or can be taken off along with the rack. The blue is what I think I need to keep.

In red are: The ACV, solenoid valve, purge valve, the three solenoids on the rack itself,BAC(because I don't have any accesories anymore)

What needs to be kept is: Duty solenoid valve, vaccume line to FPR, line to oil injectors(until I go pre-mix).

If anyone wants to add to this please do so. I am still working on the car and will be adding things on and off throughout the night and tommorow.


Santiago

RotaryResurrection

iTrader: (8)

I dont know how many times I have to say this. IF you want to remove everything, then go right ahead, remove EVERYTHING. HEre is the list of things you HAVE to keep:

-vacuum hose to the boost sensor, should see manifold vacuum and boost
-vacuum hose to the BOV, should see manifold vacuum and boost
-vacuum hose to the fuel pressure regulator (upper fuel rail, rear), should see manifold vacuum and boost

That's it. That's all the engine needs to run, other than the AFM, injectors, and TPS. EVERYTHING else is optional. Same for an NA, except you have no BOV either. Cap everything else off with vacuum caps, blockoff plates, or jb weld as desired. I do the TB mod at the same time I do emissions rack removal. The TB mod involves removing some unnecessary stuff, including one set of secondary throttle plates that restrict top end airflow.

For the required parts listed above, I use the SINGLE nipple on the upper intake manifold, where the BOV used to plug into (pressure sensor for NA models). Run a short line off that, use a vacuum tee to split to 2 or 3 other hoses, and run them where they go. This way, you can easily check for deteriorated hoses or vacuum leaks.

Things that are optional, that you may want to keep depending on your driving habits, maintenance habits, and needs.

-stock oil metering setup. OMP, lines, and oil injectors, as well as the 4-into-1 vacuum hose spider. This needs to draw air from the original nipple it was connected to.

-warmup idle assist. The thermowax and coolant lines from the back of the block to the back of the water pump. IF you remove this (in conjunction with the TB mod usually) the car will not idle cold, you'll have to keep it running for the first minute or 2 each day. Afterwards, you'll have a rock solid (unles there are other problems) idle per the setting of the throttle plate clearance set screw.

-BAC valve. Helps with idle under load such as a/c, headlights, p/s, etc. IMO s5's should usually retain this, s4's should usually get rid of it.

NZConvertible

If you want to do this that's cool, but don't claim it's because the info isn't available here. There is so much info on this forum about doing this it's not funny. It's been covered many times, and you won't be posting anything new.

Kevin, why wouldn't you keep the injector air bleeds? Seems they're there to improve injector performance, and there's no advantage to removing them.

It also seems smart to use the correct nipple for the FPR (inside of the LIM). Mazda could've just tee'd off the metal spider like the others, but they kept it seperate from everything else instead. I figure they had a good reason.

Scott 89t2

RotaryResurrection

iTrader: (8)

For simplicity, the same reason you don't keep everything else. IF you're one of those "the factory knows best" types, then leave the car bone stock and don't worry about it. To me, there is no point in modifying half-assed...either leave it alone, or remove most everything. Besides, if the factory knows best, explain twin scroll turbo manifolds, fuel cut under boost, and plastic interiors panels.

I'm being totally honest, this is no bullshit. I cannot tell ANY difference in the car's response, idle, low end, under boost, anything with and without them connected. I do this on a weekly basis, remove emissions/etc. from engines, and everyone is always exceedingly happy with the results.

Besides, that's just one or 2 lines that you don't have to fool with to get under the intake. I can have my UIM off my turbo convertible in about 2 minutes if I want, versus about 20-25 if bone stock.

Wankel7

I was reading somewhere that one of the three solinoids might serve a postive purpose. Anybody know about that?

James

Ni5mo180SX

RotaryResurrection

iTrader: (8)

Other than emissions, the only "useful" one on a stock engine is the s5's boost control solenoid. The s5 turbo uses the same 5.5psi wastegate spring as the s4 turbo, however the s5 car runs at 7.5psi. It accomplishes this by using what amounts to a stock, ecu controlled, electronic boost controller, which is the boost solenoid. This keeps boost a bit higher on a stock car. IF you modify almost anything, you're going to exceed that 7.5psi anyway, and after that it is no longer needed.

Wankel7

Originally posted by dcfc3s
FUEL PRESSURE REGULATOR...
...The only thing the solenoid does is switch the FPR's vacuum reference from vacuum to atmospheric pressure. There is NO DIFFERENCE in driveability or starting with the solenoid not there.
--------------------------------------------------------------------------------

This is the Hot Start Assist System. Opening the solenoid means the FPR doesn't adjust fuel pressure according to manifold pressure, but keeps it at the a fixed pressure that's higher than the normal idle fuel pressure. This only happens if the coolant temp is over 150degF and intake air temp is over 140degF (i.e. the engine's been run recently), to stop "percolation of the fuel" according to the FSM (I think they mean aeration). After ~50sec the solenoid closes and manifold pressure then controls the FPR.
Removing this solenoid won't affect driveability, but I have heard people complain about having poor hot starting/idling without it. I assume Mazda had a good reason for going to all that effort...

That is what I am talking about. NZ wrote that. Which solinoid is it? 1 2 or 3?

James

HAILERS

FPR is the orange one.

Aaron Cake

iTrader: (1)

You know, I could swear there's already a thread like this in the archives....

https://www.rx7club.com//showthread....hreadid=112251

Bottom line is that unless you can figure it out yourself, you shouldn't be making these modifications. Everything in that system is there for a reason. You won't gain any additional horsepower, and for 9 people out of 10, the car will run worse because it has other problems. Now obviously if you're going for huge power or to a aftermarket EMS system it's another story, but for the average mildly modded street car, there's just no point. And it goes without saying that you will have a hard time passing emissions after this mod.

Also, why not keep the purge valve and charcoal caniser? So you don't have to mess with catch cans and open vent lines that basically run directly to the gas tank. If that little purge valve and related hoses really bother you that much, then you have too much time on your hands.

Just my opinion, take it for what it's worth.

1987RX7guy

iTrader: (3)

I wanted to answer this post first. For one I KNOW about the thread in the archives but I want to do a specific one for S5 TII's. If I had each series in N/a and turbo I would do separate ones as they have slightly varying systems. I don't like universal or general info to be said or called a write-up. A write-up should be exact and precise preferably with diagrams and photos of what you have to do, where things are located, and all that.

I perfectly well know this modification does not add HP but what it does add is simplicity. I live in an area that has ZERO emmissions tests that means no visiual either. With as little systems on the vehicle it becomes increasingly easier to trouble shoot a problem because there are less things that could possibly be broken. That is my reason for doing this.

The fact that I or others can't figure it out is not a good reason for not doing something. It is a good reason, however, to stop for a minute and try to find a good read about doing the procedure. This is what I am trying to provide specifically for S5 TII owners. It is far better that this be here than it not be here. Without something to go by people might just try hacking things off and end up destroying vital electronics or other essential parts.

Purge Valve- I don't have a purge valve on my N/a and it works perfectly every day, night, what have you. I have zero starting problems eve in the colder months of the year. I usually don't even have to hold the idle for her.

I do however have the charcoal canister in place on my 87 because the thought of fuel vapors around my car is not a good one at all. I have yet to descide if everything will go on my car but I will see how things go.

1987RX7guy

iTrader: (3)

Thanks for the input. I have two questions though.
#1- Why in your oppinion do you think S5's should retain the BAC?
#2- Doesn't the "Duty Solenoid Valve" Have to stay also? It says in little parenthesis it is for Turbo Boost Pressure Control.

1987RX7guy

iTrader: (3)

To reitterate(sp?) what I said in response to Aaron's post I for one and I know many others would appreciate a step by step procedure and diagrams and perhaps even a couple of pictures to show where things go hooked up to and such. You need specificity in a write-up not just general information on what you have to do. I don't undestand what you guys are worked up about. WHy didn't you do this to the guys with the grounding write-up? I just want to have an organized and specific thread about one series one model. S5 TII. I am comming from an S4 N/a you can't get much more different than that. Others will and are in my position and they are probably perplexed by the differences in the systems from one car to the other.

In any case it will take me a bit longer to finish this as I think I have an eye infection from rubbing my eyes with dirty hands(I know stupid) so hopefully by mid-week we should have a good read setup for our fellow forum members to be able to go off of.

RunningDeer

I appreciate what 1987RX7guy is doing. Wish there was a UIM write-up for S4 N/A's and one to remove the Exhaust Manifold. I don't have the "know-how" nor work on my car as frequently as guys, but I can follow "good" directions and have a garage full of tools

J-Rat

iTrader: (2)

WHATS NEXT? A WRITEUP FOR REMOVING THE GAS CAP?

sheesh!

ddub

rofl!!

poor_red_neck

OUCH!

lol


Well, while I might agree with aaron cake that there are writeups for almost everything, I have noticed that SOME of them are pretty vague in certain areas. Now the entire purpose of these write-ups are to teach beginners; such as myself, what exactly needs to be done.
If I'm right in the middle of yanking vaccum hoses, and --OOPS-- My S5 TII has 2 hoses coming out instead of ONE like this write up is made for (not speaking from experience, just a hypothetical situation) then now I'm stuck. I have all these vac hoses hanging out or taken off, the car won't run now because I dont know what to do since 1/2 the system is out.
Now I have to go and make a thread about what to do. Get yelled at for not following the write up ( ) then followed by the "search ****"...... see where I'm getting at. It would be PREFERED by a beginner such as myself to have the most PRECISE write-ups possible. And the fact that Santiago isn't ASKING for a SPECIFIC write up, but the fact that he's DOING it should be appreciated.

Jonathan

NZConvertible

That must be an old post because I've posted more info since then. Because the primary fuel rail is bolted to the hot engine and buried under the manifolds, it gets very hot after the engine is turned off (heat-soak). Piston engines generally don't have this problem because the fuel rail sits on top of the manifold. That heat soak can cause vapour lock, resulting in hard starting and rough idling. Once the fuel is flowing through the rails they cool down. FD's took this system one step further by adding a fuel temp sensor in the primary rail to trigger the system.

Depending on climate and driving style, some people will not miss this system at all. It's no big deal, but I personally hate it when an engine will not just fire up and idle smoothly no matter what the situation.

The purge valve has nothing at all to do with starting or idling. It does however control the removal of those fuel vapours from the charcoal canister. Without the purge valve the charcoal canister is useless, and vice versa. Unplug the vent line at the tank so any vapours are vented outside the car instead of in the engine bay.

This is exactly why you research and plan what you want to do first, so you avoid getting stuck halfway through. It seems common sense, but I'm constantly surprised how many people don't do it.

1987RX7guy

iTrader: (3)

Ok I have two questions to those who know. and yes I already searched in the FSM and found what they do and what the are responsible for and yadda yadaa.

First is the Duty Solenoid Valve and second is the Line that comes off of the top of the turbo inbetween the compressor and the turbine.

The Duty Solenoid Valve is to control boost pressure so obviously I need the damned thing or else I could have dangerous overboost. Unless some of you S5 guys have just tossed it? Kevin didn't answer to my question about this so I ask again. Does it not matter?

NOTE: the car has no manual or electric aftermarket boost controller.


I asked J-rat about the line and he things its for coolant or oil as those are the only lines that are on the turbo. It is ON(connected to) the rats nest and goes to the driver's side of the engine and is connected via a banjo fitting.

I have two options here: Cut it out of the rats nest and re-use it or fab up my own line. But I am not that good at fabbing lines specially ones that are crucial to a turbo's life.

Santiago


PS- Any thoughts or comments please?

Templeswain

I agree with what PRN said.

I'm very gald that santiago is doing this. I don't have a turbo two, but so what.

People think sometimes that the search function on here is great. Yeah, I have done my fair share of searching and in my opinion the "search" isn't that great. In fact I think its engine sucks. Hey no insult I just don't like it and you're certianly welcome to think I have no idea how to use it....

This is after all a forum. Not an archived help desk.

So if anyone thinks that you're ever in a million years not going to see different people talking about the same thing time and again, then you need to come back down to earth with the rest of us idiots.

If data storage space is an issue, why the hell would anyone offer a forum about a Major automaker's 3 different models, and not expect to have a shitload of people doing exactly what is supposed to be offered: Conversing.

NEWS FLASH: Not everyone is as smart as the moderators. Who are required to sit and monitor all the stupid pathetic postings of us poor idiotic individuals. Should we dare talk about our stupid problems or ideas? Sometimes no, I guess, because it has such an profound power over other people they might have a corinary reading it.


Go santiago.

Thanks for your consideration. And I look forward to reading about your exploration into this subject.

EVEN IF THE SUBJECT MATTER IS ALREADY SOMEWHERE IN AN ARCHIVE!

RotaryResurrection

iTrader: (8)

The s5 turbo's boost solenoid's function:

the s5 turbo uses the same 5.5psi wastegate spring as the s4 turbo. However the s5 turbo runs 7.5psi boost stock. how?

the boost solenoid is basically an ecu-controlled, electronic boost controller. Tha's it. For a stock car, it's good. IF you modify most anything on the intake or exhaust, you'll exceed that 7.5psi anyway, and at that point the solenoid becomes nearly useless.

NZConvertible

Do I really need to say this? Boost controllers cannot lower boost, so removing one cannot increase boost. Kevin already explained its purpose much earlier in the thread.
It's not part of the rat's nest; it's a separate pair of solid lines for the turbo's oil supply and the PCV connection to the TID. Leave it in place.

Someone else complained about the search function during a similar rat's nest thread only a couple of weeks ago. I searched for the word "rack" under my username and found dozens of useful threads from all the other times this has been discussed. So the search function works fine for me.

1987RX7guy

iTrader: (3)

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It's not part of the rat's nest; it's a separate pair of solid lines for the turbo's oil supply and the PCV connection to the TID. Leave it in place.
-----------------------------------------------------------------------
Really?



That is where it goes to the engine block via a banjo fitting.



This is where the hose hooks up to the other peice that bolts onto the turbo.

.

This is where it is...umm.....separate from the rats nest.

Please don't tell me I am wrong when I just saw and removed the damned thing from my car.
-----------------------------------------------------------------------
Someone else complained about the search function during a similar rat's nest thread only a couple of weeks ago. I searched for the word "rack" under my username and found dozens of useful threads from all the other times this has been discussed. So the search function works fine for me.
------------------------------------------------------------------------
There goes that subtless about you again

NZConvertible

I stand corrected. The FSM clearly shows it as a seprate piece (page C-23). You still need the oil line, so you'll have to cut it out.

Subtless?