Iluvrevs

Ah, ok. Makes sense. FWIW just about every run I’ve done on RP over the years has it shearing to barely still in grade so I don’t think its the most shear stable oil. But, the couple of engines I’ve seen torn down that used it looked much better than comparable engines torn down that used other oils such as M1. I haven’t used it in the 8 myself yet though. My experience with RP has been in BMWs, Audis, Nissan VQ3.5s, and an EVO VIII.

REDRX3RX8

I realize we're off topic, but this is what I like to hear!

The feel of the 8 is so good that I go to track days to tune my tires and suspension to street conditions, and since the 8 is underpowered, I tuned the suspension to light wheels, and tires.

I'm running a lowly Hankook Ventus V12 225/40r18 that weighs 23#, and is pretty good for a street tire that gives some predictable grip on the track. In RE11's I'd probably have a little more dry grip and 2# heavier.

I noticed that Continental ExtremeContact DW is way lighter, tested at 1.01 G dry skid, and I'm looking forward to tracking on them with a 4# lighter weight.

I don't dream of having a supercar even if I could afford it, but I like to feel the 8 at the limit, and tweak the tires and me; I don't want to program any sense of extreme grip into my brain with R comp, since my subconsious might forget which tire I'm on.

ganseg

iTrader: (5)

Input please (from Blackstone re Eneos in manual trans for 20k with one track day):

GARY: Your RX8's manual transmission put more aluminum into the oil than the average Mazda 6-speed we've
analyzed. We aren't sure of the exact source of the aluminum, but this amount isn't anything to go tearing into your
57,000-mile transmission over. We'll look for aluminum to improve next time. The viscosity was quite low, and the low
flashpoint may be to blame if it was caused by some sort of contamination in the oil. No moisture was found. Check
back for more information about your RX-8's transmission


Aluminum 72 Universal Average 31


SUS viscosity @ 210 degrees F 51.4 (range 67 to 80)

cSt Viscosity @ 100°C 7.69 (range 12.1-15.8)

maskedferret

iTrader: (1)

ganseg

iTrader: (5)

Exactly what I was thinking of, but figured only one person would get it!

9krpmrx8

iTrader: (46)

Johnny 5 is alive!

I guess that Eneos is not all that it's cracked up top be huh? I never thought of sending in my tranny oil, I'll have to do that next.

ganseg

iTrader: (5)

I ran the test for the person who bought it from me. What aluminum parts are likely going away and does this relate to the common grinding problems reported (including cars nearly all of which don't use Eneos?

He switched to redline with this change. (half and half MT90 and MTL)

9krpmrx8

iTrader: (46)

I have always used Mazda gear oil. My tranny has 128,000 miles on it and occasionally it will grind downshifting to first gear but it only happens rarely. other than that my transmission has been perfect. i wish I could say that about the rest of my car

olddragger

iTrader: (3)

trans can get very hot during tracking and regular trans oil may not take that? IDK for sure.
All I do know for sure is that the redline is great and its an obvious difference.

ganseg

iTrader: (5)

He said it shifts smoother with the redline.

dannobre

iTrader: (3)

Tranny temperature is only mildly high compared to ideal....mine runs about 260-280 with really hard tracking. It is the diff that gets really hot. In 72deg weather after 15 minutes of hard tracktime mine got to almost 400degrees. This is something that I picked up from Eric Meyer as well....the diff needs a cooler to survive long track sessions

Nadrealista

20k miles and one track day doesn't sound like a lot of stress on the gearbox..I would persoanlly stick with motul 300v or redline..both ester based lubricants

ganseg

iTrader: (5)

So what parts in there are aluminum? I wouldn't think gears and synchros would be. I am sorry - it is 37,000 on the fluid - I edited above.

ganseg

iTrader: (5)

I emailed Blackstone about my results. Here is what they said: I have no idea where the aluminum is coming from, but this amount is not normal for your type of transmission.

I will check with the current owner to see if he saw the sample being pulled. Just want to verify it was a clean sample. (I know the sample bottle was clean because I provided it.

mikimazda

used oil Analyse after 2700km and great Track Day
what do you guys think about it?
thx
Miki

40w8

^With a 10.3 TBN this oil hasn't been stressed, and is ready for another track day.

The wear metals and silicon are very low since it was only 2700 km.

This Motul 5w30 is a very good uoa with a massive antiwear moly additive, so you can run this a lot longer without harm.

mikimazda

i already took it out,no chance that oil stays longer than 3500 km in my engine
and i change my diff and gear oil every year.in that attachment you can also see the oil analyse from the last year.can someone explain where the aluminium and iron comes from(which part from engine)?
thx
miki

Iluvrevs

Series II GT 6spd, Valvoline 20w50. 22,500 on the car, 2,200 on the oil. No track time but car is run way hard once warmed up. Oil was double flushed 5 qrts each time so the viscosity is way sheared.

Nadrealista

yes oil shared down a lot but your wear numbers are low so I wouldn't be to concern about it.

but 20w50 is probably overkill..I wouldn't go over 0/5/10w-40 viscosity

Bladecutter

You're right that the oil has sheered heavily.
Probably directly caused by the stationary/rotor gears.

I would bet that motorcycle oil would be the best bet to reduce oil sheering in the RX-8 engine. Have you ever considered picking up some motorcycle 10W-40, 10W-50, 15W-40, or 20W-50?

That would be an interesting set of results.

BC.

9krpmrx8

iTrader: (46)

If that 20W-50 was Mobil1 0W-50 the results would be much different I also saw that Napa now carries Eneos 0W-50.

Iluvrevs

Id thought that too, but here's a UOA in what Id call a less demanding application where the M1 0w50 didnt hold viscosity much better, if at all better than mineral oil.

Iluvrevs

Good bet indeed I think. There's a motorcycle oil study by Amsoil that covers among other things shear stability that offers some good prospects. While possibly biased its probably still of some value in this regard. However, I’m not convinced that shear stability is of much importance beyond extending the OCI.

I’ve actually ordered some Total Quartz 9000 0w30 after seeing a UOA after 5K in a non DI BMW I6 built within the last couple years where 0% shear occurred. I also am thinking it MAY be using some PAG base stocks which might be a good bet for our application in clean burning and bearing protection as well as the other benefits of a heavier oil with its HTHS of >3.5 and 100C of >12 plus perfect start up protection. I am also looking to extend my OCI's since as we see in mine contamination and oil integrity are positive. And for giggles if that doesn’t work or I want to keep playing around they make through their ELF name one of the more notable 10w50 motorcycle oils.

9krpmrx8

iTrader: (46)

12.86 is not too bad but i would expect better. Still way better than the 20W-50 though. I'll be sending in my first sample from my first full oil change interval on the new engine and turbo this weekend.

Iluvrevs

You are probably right. From my calculations the operating viscosity at this used viscosity is only about 10.08 at 100C which is on par with what I calculate for the used 40wt oils we have in our collection. This is assuming a standard 35% viscosity increase realization with the increased heat from oil viscosity frictional resistance as well as other arbitrary inputs used as handicaps. This is why Im thinking the sweet spot for our engines may be 12 at 100C which is in line with Castrol GC, Total 9000 0w30, and used M1 0w40 to same a few.