swoope

iTrader: (5)

yea for us..

scan and post!

and thx for the work.

beers

ASH8

I have already..back when I bought my car...I think you even commented at the time..
Jeez..I will have to go and SEARCH!...

madcows

This has been my thought as of late, too.. Because of the oil pressure limit on a stock S1, it may be reducing flow significantly with higher vis oils. So it may possibly be imperative to increase the pressure limits if you go over a Xw30. Who knows?

SARRAS

Yeah but don't forget - outside the US - eg Australia - 10-40 is ON the list in the handbook - so its recommended by Mazda as well - pressure effect or not.

bse50

Really? Here the manual shows 0w30, 5w30 and 10w30.
Are there any other gradations listed on your manual?

HiFlite999

iTrader: (2)

And engines are failing outside the USA as well, in spite of using the heavier oil.

dannobre

iTrader: (3)

Why do people fixate on the numbers on oil bottles....


Back to your regularly scheduled programming

Flashwing

Engine failures are due to a lack of OMP volume and have nothing to do with the overall viscosity of the oil itself. You could run a 60wt oil and still suffer a failure if there isn't enough volume being put into the engine to protect the seals and housings from wear.

bse50

HiFlite999 comment's a bit misleading: it is true that engines tend to fail here as well but our average car use is much different. We have got a lot of stop and go traffic and mostly drive short trips (something around 3-8 miles IN traffic). That's what wears our engines
Carbon build-up and rear bearing wear are the biggest causes. Apex seals wear was an issue that killed many engines before the 50.000km mark, the OMP before the famous reflash was barely injecting oil around 3000rpms. Imagine what would happen driving all day around that spot

I agree with Todd's comment about the OMP volumes but have we proof that an engine with the OMP properly set-up doesn't show wear in the middle of the apex seal tips?

HiFlite999

iTrader: (2)

The point I was trying to make is that switching to a heavier-weight oil, while likely a good idea, is not a one-step cure for all Renny lifetime problems. I wish it were so simple!

bse50

I agree, a higher viscosity oil is not a panacea but will surely help
The cause of engine failure seems to be lubrication related but needs to be addressed in different ways and even then you will not have a bullet proof engine. Viscosity is just part of the puzzle. Main part? maybe, depending on the use.
We often forget to mention that and that's why i stress the word "use" so much.

From my little experience the bypass pellet is a nightmare for the guys from my nation, OMP rates play a huge role as well. However, when you address (or exclude with long trips, higher rpms etc) those factors the viscosity still stands up as another point to be concerned of.

Your "factory recommended" 5w20 is worse than our 5w30 one and a lot different from any 10w40 oil in commerce. It may look like a paradox but that very 5w20 oil would probably work better in our environment (traffic, short trips) than in yours! I know that i switched back from 10w40 to 5w30 in my bike. Would i tell to a friend in italy to use a 5w20 anyway? No! It would be better to buy a daily driver or modify the engine to run a higher oil pressure and possibly shim the e-shaft pellet :p

ASH8

There is obviously an issue with the S1 MOP set up even with the later flash, why would Mazda move in a new direction with S2 if it wasn't, plus add the middle nozzle.

Remember the 6 Nozzles themselves are also different/new in S2.

On a side note it would be interesting to see the "volumes" of engine oil injected/dribbled in S2 set up.
Having said that the S2 is meant to use less engine oil not more.

Flashwing

I don't know of any specific engine tear-downs that fit the necessary conditions to show that the housing was still wearing in the middle of the apex seal area when increased OMP volumes were used. While I do not know the specifics of what Jeff is including in his tunes I know I am running my OMP injection about 3x what the stock map was utilizing in some areas including idle and low RPM cruising.

As Giorgio pointed out, the "solution" is going to be a combination of elements because the problems stem from different sources. Seal failure is a volume issue and not viscosity related. Middle apex seal wear might be solved by premixing but premixing isn't nearly as controlled as a middle OMP nozzle would be. HiFlite explained the pressure vs. pumping very well and articulated how there is a compromise between flow and barrier protection.

The S1/S2 relationship in terms of fixes will obviously be different and I am confident the S2 will see less of these issues if any at all.

ASH8

Yes...time and mileage will tell Todd in S2...

IMO I still believe Carbon is going to be an issue in S2 engines like S1...

I wish there was a Cobb AP out so I could slightly lean out my car..

RIWWP

iTrader: (2)

I had a thought occur to me on the way home today (i know..scary...almost made me crash)

The OMP is tied to RPM correct? Solely RPM?

So off-throttle deceleration, gears engaged, is pumping oil into the engine? Oil that isn't being burnt off because the throttle is closed when RPM > Idle and no pedal input? Oil that is being spread around the housing, rotor, and seals quite a bit?

Or am I thinking about that wrong?

It makes me wonder if people that tend to let the engine slow them down (even ignoring downshifting, just leaving it in gear and not using the brakes), might have better/more lubrication of the seals than people that don't (either lots of braking and/or lower RPM in ATs, shift to neutral to clutch in for MTs)

Initially, it doesn't seem like it would be a drastic difference, but the more I think about it, the more I think that it would be quite a big difference. I've never seen it mentioned on here.

madcows

Water/Meth injection should take care of this!

ASH8

Well will see/hope my friend!

Brettus

iTrader: (2)

This is one good reason to retain the OMP in addition to premixing IMO .
Off throttle deceleration oiling in a premix only car would be non-existent

Onyx57

isn't premix going to increase the "carbon" build up as it's lovingly called here?

madcows

Good premix oil will reduce this as much as possible while providing necessary lubrication. Those are some tough shoes to fill.

ganseg

iTrader: (5)

This is why I come here! I would have never thought of that but it's very improtant! I will have to check my reader when I get it back. I imagine it is going to give a reading like at idle - mine shows 3 for the omp setting. Even having some oil being pumped when you are decelerating from 6,000 rpm may not be enough. This happens on the track repeatledly.

I think the omp takes load into consideration - I hope it considers RPM even with closed throttle.

bse50

That's why many 2 stroke bikes are driven with partial throttle during long downhills and not without throttle at all
Anyway in the RX8 the OMP should not be only RPM related but i'm not 100% on this one. My memory sucks.

robrecht

Yes, it's also based on load.

RIWWP

iTrader: (2)

Ah, ok.

Next question that would come to mind... is it possible to adjust the amount based on load? And set closed throttle to full 100% values? I don't think you would want full oil amounts getting pumped in during idle, but idle has more throttle input than no-throttle when RPM > Idle right? Or is no-throttle actually just idle throttle amounts, which are the minimum 'closed' possible?

Brettus

iTrader: (2)

Yes omp is both rpm and load based .

FWIW I have my turbo setup like this :
high load areas at 1/2 stock omp values
low rpm and idle at 3/4 stock
premix at 200:1

after thinking about this I may increase omp in the no load /high rpm areas back to stock .