Couldn't this be a 2004 vs 2006+ deal? At the time of engine recall and CPU reflash, didn't the new flash increase the oil injection above 6500RPM in order to improve lubrication. Maybe that makes a difference?

 

And, if it did go up, why was it low for the early models to start with, there must have been a reason...

 

You asked for 09 Numbers...this is about the 4th time I have posted...

As I said it is a different system, no rear valve, totally different oil filter location, and the "front" valve is part of the Oil Pump casing now (156 PSI), so where do you want PSI figures taken from,,at what point???

 

If you look at the Oil Pressure Reference Value @ 3000 RPM @ 100C.

The 09 shows 72.5 PSI the Series 1's 50.8 PSI..

As I have said before IMO you can be confidant to increase OP by 20 - 30 PSI, ALL internal engine parts are the same for ALL RX-8s.

But what do I know..

 

My second engine failed and it ran the updated flash from day one and 10W-30. The flash was an issue but I don't believe it was the only issue.

 

Ash-- what i am looking for is an actual engine running pressure range--from idle to 9K. And at what temps with what viscosity oil?
The pre 09 could not maintain its spec pressure (taken from an oil filter plate) with 5W20 oil--also wondering if the 09 is getting that high a pressure with 5w/20 wgt at 100C temp? I dont think it can--but i also know nothing.
I guess taking this from a plate below the oil filter will be the most likely spot?
OD

 

Yes mate, as we know the PCM (ECU) Flash was for Internal Lube of Apex Seals from the Metering Oil Pump.
As far as Engine Oil Pressure goes that is maintained mechanically not electrically.

 

Understood OD...

I have had a look (or tried) to find room in my 09, it is in such a damn hard spot to look at, particularly when you can't put the car on a full hoist, the Oil Filter is actually above and slightly to the front of the Cross Member, with the Air Con Compressor right next to the filter!!..

I guess all the US specs I have shown are for engines running "recommended" 5W20 oil.

As we know the Oil Filter by passes if filter becomes restricted or blocked, which has gone from 17 PSI (S1's) to 26 PSI (09's). And the Filters are both 100% Full Flow so all the Engine Oil is Filtered.

I know you want OP Numbers over the entire RPM Range (not sure where these could be found on an 09 or S1 for that matter, has anyone done this?), because as we know most guys here are monitoring OP at the Filter AFTER Oil has gone past Rear BY Pass Valve, so give or take a few PSI surely the actual OP would be maintained at fairly constant PSI Levels??...say the 70 PSI range...but what do I know.

SO say at 3000 RPM the PSI would be the same at 6000 and even 9000 RPM, as wouldn't the Rear Valve Piston be just more fully compressed then by passing oil into sump pan??..what do I know??

I am pretty sure the Rear Valve's orifice or bleed off hole is larger that the front OP Control Valve's orifice. I think the rear one is about 5mm and the front about 3 mm.

 

Just trying to entertain an idea, ash.. Can you find out and see if there are any differences between the oil coolers of an S1 and S2?

I'm not sure if there would be any significant difference in OP if measured directly after the oil coolers, or right behind the rear OP regulator.


"And, if it did go up, why was it low for the early models to start with, there must have been a reason... "
I wonder it was done in attempt to achieve the highest possible emissions rating they could obtain with the rotary.

 

No problem..

YES, the Oil Coolers between series are different by Part Number, so are all the OIL Hoses and Lines, even the O rings for hoses are now Series II Specific.
There fixing Locations on engine could also be different.

Although physically the Oil Coolers look the same, there is a possiblity the Thermal By Pass Pellet opens at a different Temperature...I don't have data to confirm this, and it was not listed in the 09 Service Highlights/Changes.

Here are the Part Numbers.
S1
N3H1-14-700D Oil Cooler LH
N3H6-14-700D RH

S2
N3R1-14-700 LH
N3R2-14-700 RH

As far as your OP question are you talking S1 or S2?, S2 does not have a rear OP Valve.

On S1's if there is no difference, why are two PSI stats listed above, the Oil Pump 156 PSI and Rear BY Pass at 60-70 PSI, leaving about 80 PSI of oil pressure/oil not used and returned to sump...or am I wrong??

Or is there OIL of about 156 PSI going from pump through coolers then to rear by pass valve, with a lower pressure to engine?

Or is the Oil Pump actually at about 236 PSI, with 156 PSI By Passed with the remaining 80 PSI going through coolers and to the Rear Valve and by passes yet again...so why would it be done twice at a similar PSI..??

I would really like to know the Oil Pressure actually out of the OIL Pump into the first Oil line then into the Oil Cooler, is it 156 PSI or about 80 PSI???...does anyone REALLY Know??

I guess I am wrong again...
Remember the FC and FD and S2 say Oil Pump Relief Valve (Front) Opening Pressure Reference is 156 PSI.??..but what do I know?

 

Changing the spring or use shims only will raise the maximal pressure number. The pressure at 3000 rpm won't change if we don't raise the oil pump's performance.
Of course to raise the max pressure is a step forward, but maybe not enough big step.

 

Rather 71-80 PSI !!!
I took here my simple drawing again. Please take a look on it!
If we would have 156 PSI max pressure in the "coolers section", we would have to got the 71-80 PSI ALWAYS at very-very low rpm in the engine (e-shaft section)!!!
When the coolers section (pump-cooler) would reach the 71 PSI (at very low rpm) we would have the 71 PSI in the e-shaft section at much lower rpm than now!!!

Think about it!!!
I'm sure that the rear regulator determines the pressure in the coolers section too.

 

and that contains some of the questions in my little mind.
Since we dont spend most of the time in the 7-9K rpm range, i am wondering how the oil pressure "builds" in the 09.
In the 04-08 with a 5w/20 oil at 212F you have around 48 lbs of pressure at 3K, with a 20w/50 it is around 55-60. Almost in the rear regulator range. If you are cruising at 4-5K with 20w/50 oil then you are in oil pressure relief range. That means the volumne of oil is reduced going to the filter and to the e shaft. I dont think that is a good thing? So if you do a lot of interstate driving at 70-80mph you are bypassing some oil to the filter most of the time and have reduced flow (volumne wise) to the e shaft as the pump is capable of providing more.
Now on the 09's I think it would be safe to say that they are not reaching any of the bypass limits? So their oil is filtered ALL the time (so a change in the filter to further increase this).
I am not concerned with the pressure at the pump or to the coolers---(although if fittings etc was changed then i dont want to blow any lines if i up the relief pressure--thanks again Ash!)---i am concerned about the pressure going into the e shaft.
We are starting to get into this good and it will be important to understand the real world differences between thiese 2 systems?
OD

 

Denny,
I recently rewired my oil pressure gauge and i can confirm that it sits at around 4bars while cruising\driving with peaks of 5 bars when having fun

I still think that we must, provided that we don't modify the pressure regulators, find a compromise in oil thickness. I use a 10w40 in a mediterranean climate, a bit thicker than our stock 5w30 but not as extreme as a 20w50. I think that we had the same guesses

G

 

That is what counts, all of the pressure working for oil flow in the engine! That is the ideal situation.

 

One more thing is confusing.
There are in the table in Ash's thread:

- S1's oil pump relief valve opening pressure is 71 PSI
- S2's oil pump relief valve opening pressure is 156 PSI

So, is the S1's oil pump relief valve what we call rear relief valve?
If it is, where is a 156 PSI regulator in the S1?

 

My 2005 has 75PSI by 3K rpm.

 

As you can see our pressure vary a bit. I am going to start taking more specific data in a week or so and I will post it up. I am going to track RPM, Coolant Temp, Oil Temp, Oil pressure, AMB Temp, and Intake Temp. Here is some data from a month or two ago.

 

Lemme do something like what 9K did.

 

It's important to realize that there will be a drop in pressure between ends of the oil coolers. So, the OP going into the coolers will have to be at a certain pressure in order to to obtain a certain flow rate.. Mazda then used the rear pressure regulator to establish the oil flow rate going into the engine.

Now if the S2 no longer has a rear regulator, I wonder if it would be a bad thing to just eliminate the one on the S1, replacing it with a solid bolt. So whatever pressure is coming out from after the coolers is going to the engine.

Ash, another parts questions - have any of the e-shaft seals changed?

Also, I can't seem to find the S2 oil circuit pic you posted, but wasn't there some sort of oil distribution unit? If so, I wonder if there is some regulator in there.. Hmmmmm...

 

Gee Man, I think I have typed this a THOUSAND TIMES....

There are NO internal changes between the last 2008 Series 1 RX-8 and the 09-10 Series II RX-8, apart from the usual Letters on the end of part numbers Mazda does over the years.

But say if you wanted Apex Seals for a 2004 RX-8 you would be supplied the 09 (latest seal)....as far as the engine internals, don't look into this too far.....

To put it another way if you replaced ALL internal engine parts attached to the eccentric shaft and the rubber OIL Seals (rear main, and timing cover), they use ALL the same parts.

 

BTW, The S2 does not have a rear valve, but has an external OCV Oil Control valve.

And No I would not recommend you "Bolt Up" and remove the rear valve, NO one including the experts have recommended this...I certainly would not.

 

I wrote it again:
If there would be higher pressure in the cooler section than in the engine section (S1), why don't we get the 71 PSI (about) max. pressure at lower rpm?
Or our pump can't build up higher pressure at lower rpm than what we see on the gauges now?

 

Looks like 30W oil numbers.

Move up to 40W or 50W for 75 psi by 3k.

 

Oil control valve you say? Is it possible that this valve also regulates pressure? If so, I wonder what that pressure would be.