Interesting PDF on Formula Mazdas (Renesis Engine)
 

Interesting read, I have never seen this before. Just thought I would share, I couldn't find it linked anywhere. Looks like they use the S2 Renesis? The page on engine speed limiting confirms what other builders have stated.

http://www.starmazda.com/competitors...isTutorial.pdf

What have other builders stated? Good find by the way, thanks!

That basically redlining to 9k is pointless and damages the engine. Also that coolant temps above 220F is where damage can occur.

Fantastic read.

I agree with the >9,000, though I would interpret that page as 8,800-9,000 "slow engine damage" as related to the "fuel cut over 8,600 so the engine isn't getting the lubrication from the fuel"

This also implies that the fuel is premixed :)

Lots of great info for even street cars in there, like the EGT info, how to detect something is failing, etc...


And note that the coil testing procedure isn't OEM Mazda's, even though it's the street coil. It uses the spark tester.

Yep, I caught that as well. Their oil change intervals are telling as well.

Thanks 9k for posting this, i completely understand how the intake ports work now

was a great read

Word. Yeah, I saw the premix part too haha. Good to know about the engine damage. I've been doing some research on raising the redline. Definitely not something I'll be doing. So is it the bearings that get worn from high rpm?

Great information thank for finding and sharing. I will stay below 9000rpm from now.

They also talk about having an o2 sensor for every port. I am not sure if the current computers have the capability of handling extra sensors

Skc I'm sure you have read it since you have been here longer than me but you know when the tach shows 9k rpm you are really lower than that by at least a few hundred rpm already.

I was going to say that...

Also that info is for a formula car not a daily. Just sayin bro's.

Yes, I did read that earlier. I had a habbit of staying in the same gear on the track on the straight and then bouncing off the rev limiter for the last 100m or so before brakeing. It did the same on the down shift.

I am trying to listen to the buzzer now for gear changes. Driving on the track is so demanding on the car and driver.

I'm wondering what the difference would be? At least as far as internal stuff.

A fascinating read....

I think the redlining rule only applies to formula rotaries. It also talks about changing the oil every 500 miles or 2 hours.


Yeah, I heard about that.
Our cars don't even really idle around 900 right?

No, I would say that the >9,000rpm damage is not just for the race cars.

If you read through the section:
I presume that this is because of the later section here:
Slow engine damage from no lubrication makes sense.


However, that is a very different implication than the >9,000rpm:
It doesn't note slow, or might, it says 'will'. Even bearing failure would be a 'might'. This is probably a direct reference to rotor tips contacting the housing, and even a single event of this WILL damage your engine. This same effect was shown by EricMeyer. For once I don't even think my argument of proper balancing would come into play here, because I would believe that these engines WOULD be properly balanced. So this is probably e-shaft flex allowing the contact to occur.

Great read 9K, thank you for posting.

My car is a race car dude.



Yes it does idle at 900RPM (give or take). The factory tach only becomes inaccurate as revs increase.

An interesting read. It would be good however to have more information on the engine installed and how it's used.

"The ECU cuts spark above 8600 rpm, but it also cuts fuel at zero
throttle input. Therefore the engine is being starved of the lubricating
oil in the fuel at high rpm for long periods of time when running above
8600 rpm at zero throttle"

Is this over-revving on downshift any different than running to 8-9k rpm and simply letting off the gas when in gear? (which also does a fuel cutoff, but is encountered much more often than overrev). Any premix is cut off, but the OMP continues to inject oil.

Hiflite,

I think the difference here is the ECU, since they don't run a street ECU. That portion of the comparison makes it harder to determine. You are correct that if the ECU cuts fuel with zero throttle input, then just letting off the gas anywhere in the rev range would be cutting off the premix. Although perhaps if there is not an active combustion, the residual fuel left from the last fuel injected provides enough lubrication for short periods?

There is no indication of if the Star Mazdas use the OMP in that document, but I have to believe they do. The street ECU injects OMP rate based on load, but I don't know what off throttle decel injection rates are like.

Yeah I'm not sure about the exact setup but I think they are running an S2 engine (based on injector colors mentioned) and they are likely using the new OMP setup on that engine.

good read
guys just use common sense---i have been saying for years that this is NOT a 9K rpm engine.
I redline at 8.2 K even though I have increasing power above that.
At that high rpm two things can happen--rotory tips can touch the irons etc ot the e shaft can flex. I have had a builder to tell me if you miss a downship and accedently get to 10K rpm--then just drive the car to the pitts or home, park it and remove the engine because the e shaft has flexed and damage has been done.
Besides the heat and the friction that increases dramatically between 8-9K is amazing.
What caught my eye is the oil temps. Everyone I know with rx8's on the track ( not dedicated race cars) are running too high oil temps. Most of us are measuring on the cool side and 220F is very very common. 230F is not unheard off and I have seen 240F on a few when I was riding with them.
Pause for though.

Great post, receiving reliable info like this from a reputable source is rare and invaluable. I found the oil change interval and 9k point rather surprising, but it's great to know.

Ii posted the S1 version quite a few years ago

So to sum this up...no more "redline a day" at 9500 on the tach (about 9000 actual)? Doesn't this just reinforce what Meyer was saying about there not being much reason to go above 8500 rpm ?

I don't think many of us have ever encouraged >9,000. "Redline" is more of just the high RPM, and technically the red part of the tach starts around 8,500. Just going till the beep works too.

yea I just meant for myself lol.

Posted From RX8Club.com Android App

10W30W engine oil hey...so where is Jackson!..:)

Glad to know someone else (Star Mazda) knows which coloured Injectors go into an S2, as MNAO DON'T, their advice to their Mazda Dealers is appalling wrong (yet again)....been this way for over 10 months..

I did not want to post this 'M-tip', I have been sitting on it since January this year in the 'hope' it will be fixed, but, communication from myself and a few US Dealers I know have tried, it all falls on deaf ears @ MNAO, including the useless J Barnes...is it any wonder this Upper Managerial mob at MNAO all need sacking!....and yeah it make me mad!.

You have a "President" that is an old FORD hack!
The old Ivory Tower of management...BS castle!

You guys pick the error in this M-Tip..

BTW, Unless Star Mazda uses a different Injector in the Secondary LIM Ports (N3R2-13-250) in production S2's RX-8's are actually Dark Red, not Brown?

Lotsa good tidbits of data there... this slide jumped out at me moreso than the others. Hopefully it dispels the belief that there some magical combination of events controlling the SSV in the stock ECU.

https://www.rx8club.com/attachment.p...1&d=1349553659

Ash...

I have no idea what you just said.

Edit: apology to Ash, thought you were referring to Shelldudes statement about the SSV, which is incorrect.

They are using a MoTeC racing ECU, not an Rx8 PCM. So they are controlling everything directly, not something that can be done on an Rx8 with the Cobb AP etc.


.

^^^ this ... I'm not sure it was obvious to everyone ... didn't see it called out previously. team can you link back to the S1 version?

Shell, here is the information regarding the OEM operation of the valves for the street RX-8 (original pdf attached).

The street RX-8 is RPM only according to this.

https://www.rx8club.com/attachment.p...1&d=1349558006

Load and rpm, you are assuming that 1 + 1 = 3

What is so hard to understand...:)

The Star Mazda PDF says secondary Injectors are Brown, well in factory S2's they are Dark Red,
perhaps they are using a different secondary injector...obviously...but they are using the S2 green Primary's..so I hope their information is correct.

I have genuine (OEM) parts stock of S2 Injectors for Series 2 Engines...they are Red and Green...
not Blue with Red or Green with Brown.

The MNAO 'M-Tip" I just uploaded has the wrong color Injectors listed for factory S2, Primary's are GREEN, not RED...Secondaries are Dark Red not Blue.

Not making any assumptions, especially about math.
Engine speed does not equal load.


As I said, "The street RX-8 is RPM only according to this."

They make it a point to mention the 4 port in that slide so I dunno if it's even S2 specific.

The PDF I attached is for S1, and they detail both 4 port and 6 port. Only place where both aren't referenced is in the RPM-opening chart at the bottom, which only references the 6-port. The PDF doesn't have a similar chart for the 4-port.

Your assumption is that they are telling you ALL the details, which they aren't

Raise your hood and have some start and run the engine from the driver seat while you watch the SSV actuator assembly. Tell them to slowly raise the rpm above 4000 - SSV doesn't move. Then tell them to wail on the engine hard with sharp WOT bursts - SSV actuates.

Here is a later post I made with several documents from the original Pro Mazda series using the S1 engine

https://www.rx8club.com/engine-tunin...3/#post3907774

You are assuming that because I am posting a document and pointing out things that it says in the document that I am making assumptions about it. I have done nothing more than point out what it says. I'm not even making a statement of if I believe it or not.

No assumptions made at all on my end. Just yours.

I was referring to the injectors slide in the star mazda pdf regarding injector colors.

I've referenced the diagram you posted previously ... didn't help to convince some otherwise .... thanks RIWWP!

I agree with team to an extent here. Load is certainly taken into account but I'm not sure to what extent.

Agreed, I expect that load can prompt them to open before the stated RPM, but also that they will open by the stated rpm regardless of load.

Shell, here is their (SM) PDF where they say they are phasing out the 6 injectors in 2010 to the 4...I assume it is S2 (most of it) as S1's never had green injectors...but yeah..agree.

Got to go, Bathurst 1000 is about to start now..50 years old.:)

Edit...Even this 2010 info on the use of 4 Injector colours is back to front to what is in the August 2012 PDF??

The debate about the load dynamic on port actuation seems to defy common sense. Taking load into this equation is useless, I'm not saying it does or does not differentiate between actuation of the ports or not I'm saying it is useless to worry about it. When acceleration of a certain rpm is achieved it will trigger the solenoids to engage opening the different ports at different ranges, from readin the PDF it notes that these actuators have about a 500rpm buffer meaning the close at a lower rpm then they opened. With all of this in mind if you are entering the given rpm range of these ports it is due to acceleration which in turn is a load. Who cares if these actuators open or close during none load revs your not going anywhere if your not under load why do you care how many ports are open. In this instance both variables go hand in hand. And it seems unnecessary to be concerned with load, fact is if your not under load your not doing anything relevant to require additional intake volum.

For the Star Mazda cars, yes, I'd say that anything dealing with partial load activation of the valves is pretty much a moot point. If you want full power, you have the pedal to the floor. Anything other than full power needed and the valve alignment isn't really all that important, since you are still going to use the gas pedal by feel of how much power you need at the moment, regardless of what the valve configuration currently is. If it's not optimal configuration, you will just have the pedal down a bit further is all.

For the OEM ECU, Team is correct in that there does appear to be a load based component to the activation, simply because of how the valves respond. Mazda's official documentation doesn't appear to back this up anywhere that I have found, but that is probably because they didn't feel that it needed to be published. For street cars, I would think the only reason partial load valve configuration would matter would be for cruising economy.

oh geez... I'm sorry Ash8, but now that you pointed it, I do remember reading about there only being 4 injectors at some point with the S2s.

I'm wondering if the engine damage is solely from the fuel and spark cut on throttle lift? I can't imagine Mazda would put a car out that can damage itself by going through the normal rev range. I think I'll be keeping it below 9k on the dial just in case....

Did you not read the whole statement about fuel and spark cut?

And this is referring to the race car still, which has a different ECU and different rev cut point than our street cars. That being said, shifting in the 8,000s and not crossing 9,000 is still a good idea for us.

Thoroughly enjoyed reading the PDF and the thread while having my morning coffee.

Thanks all

Since you clearly have noted a personal expectation I can then concretely inform you that your expectation is wrong. I previously informed you how to confirm this for yourself. The SSV will not open prior to the condition occurring that requires the secondary P2 injectors to come on line. Regardless of the rpm, if there is insufficient load, such as revving the engine slowly higher and higher in neutral, the P2 injectors will not come into play and the SSV will not open.

Instead of hiding behind silly word games and making guesses why not try doing something productive like trying it out and then come report what you observed ....

according to your expectation the SSV will open at 3750 rpm regardless. Maybe every Renesis I have personally observed free revving above this is malfunctioning

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