Doblegota

wow!

so here I have the middle position.

- for those who says that sohn is not a good idea and defending 10/30 idemistsu with premix.
- for those that sohn is correct forcing 2stroke for one thing and 10/30 for other think.

its the combination of the same system as standard but with a new option.

the 10/30 becomes quite inmidiatly dark when moves through the system and part of that goes to the omp and to the oil nozzles letting deposits every way.
So now I will have pure clean 10/30 in sohn.

and as I said no one recommends mixing premix with a bit of fuel in the sohn tank kit.

thanks a lot Acid22 because my idemitsu Spanish dealer does not accept the sohn and says to me the same with pure premix. Also asked me why there is no competition Rx8 with sohn adapters.

its these correct?

Brettus

iTrader: (2)

Thanks Acid , this makes perfect sense and adds weight to what I've been saying for years : forget the Sohn,forget premix, change engine oil often, increase omp rate.

Doblegota

well i think he is not saying that.
premixing it's important.
Idemistu says that that's the proper oil for rotary mazdas (including renesis?). Of course they have to defend that.

what it felt here for a 10/30 combination with sohn is the temperature oil and thickness.

But, I suppose that the omp works in opposite form as I have red. For me:
the more oil pressure the less oil admitted to the nozzles ( omp closes ).
And also, the more heat oil combined with the oil pressure the less oil entering to the nozzles.

When the car is cold and starts for first time, cold al thickness has to be considered in the omp work. Could be the moment when omp opens at maximum.

i don't know how thin becomes the oil when it's hot inside the system, but there is a system that tries to mantein constantly a "normal oil temp" (radiatiors)

so, the idea now says to me that in cold conditions idemitsu 10/30 in sohn wil enter as open omp. But then, the omp has the information to close when pressure increases when ecu calibrates.
In these case, idemitsu 10/30 is not so hot as should be and has no pressure to force omp to close if it's ecu who says open o close or are the mechanics of the omp they move in order the pressure ( not hot).

in these case these clean an warm oil could work better because it's clean and also refreshes the housings from the inside because not all the oil it's burned.

could be new option putting a oil heater in the sohn kit reservoir.

sorry If i am saying stupid things. Only learning.

bie bie.

Brettus

iTrader: (2)

No he wasn't saying the same thing ..... but looking at it logically ,his post adds weight to what I said.
Premixing is only important if the omp isn't able to do the job properly. I would rather just add more oil via the omp than premix .

I have seen loads of worn out rotor housings and they all fail at the edges . Mazda designed the injectors to concentrate oil in that area because they obviously knew it would be an issue . Premix isn't going to help with that anywhere near as much as just adding more omp oil via the ecu program.

Cannot understand the rest of your post ........ looks like you auto translated it from a foreign language ?

Doblegota

yes! My fault. Bad Spanglish. :-(

well, my premix calculation is 100-120ml for 61L of fuel. It's quite nothing.

So, what you are saying is that the injectors are inyecting to liquid (thin) oil and they are not able to seal properly. So we can consider that it's better to have warm and not hot oil to force the consistent of the oil.

With premix you don't need to spend part of 10/30. Diluted oil burns quicker than 10/30. Increases temp during the combustion process but doesn't need to much 10/30 in the combustion process.

so sorry. I hope you understood me.

Loki

iTrader: (1)

OK but is using straight 10w30 any better? Do they explain what the problem with straight premix is? Fuel is not an active ingredient in mixed 2-stroke oil for 2-stroke applications, it's just a delivery vehicle. I don't consider Motul, RP, etc, experts on what is best for a rotary application. 2-stroke injection systems have literally nothing in common with the Renesis injection system.

TeamRX8

iTrader: (25)

Maybe you need to speak with Redline again, this is straight off their webpage for 2-stroke oil


.

Acid22

I absolutely agree with Brettus, but when we talk with a customer "falled in love" with Sohn, the best advice we can give him is this.

Doblegota

Thanks for the reply! ;-)

So, you don't see a good idea to feed the omp always with clean and new 10/30. That darkness starting very very soon as I see it everyday says to me that 10/30 starts soon to fail.
Of course, the good thing is that we have to refill constantly with fresh 10/30 mixing it with the old one, but that doesn't mean we have not to change the oil. The lubricant properties and the refreshing properties decreases soon even with new mililiters.

I do the premix because it was recommend to me. At the moment no problem with fuel pp

Brettus

iTrader: (2)

It seems like a great idea theoretically , but in practice, it has never shown to improve engine life by any measurable amount.

Doblegota

That's what I am reading here in the club. Oil it's a must but there are so many factors that destroys the engine that we can't say "it's because you used a bad oil"

Only thinking in the water pump or cavitation it's a headache.

Acid and his friend are my dealers and all what I did are only
By their recommendations. Public thanks for renesis essential parts. :-)

I Know theory is theory and there are no magic solutions.

Thanks to everybody for the help.

Great people!!

;-)

Brettus

iTrader: (2)

If you look at all the high mileage Renesis owners there is one common theme among them . They all change the oil regularly.......
Some at the Mazda recommended interval and others more often.

Doblegota

Oil and oil filter.

Yes, I was really surprised how quick was getting dark the oil.

9krpmrx8

iTrader: (46)

You can do whatever you want, there is zero evidence that premix or no premix, sohn or no sohn, that it will increase the life of a Renesis. I have seen well maintained engines die with less than 25,000 miles and I have seen poorly maintained engine last to 100,000 miles and up.

I run a sohn because in my mind, clean 2 stroke just makes sense. But like most here, I am also not an engineer or a scientist.

Doblegota

Let me please say it's a pleasure to talk to you. I'm reading you months ago even before I bought the car. Great story with your car.

One of my first posts talks about these things till acid22 came to put the third option: idemitsu 10/30 in the reservoir.

What to do? And the answer is:
Doesn't matter. The car will fail because another thing.

So far to meet all of you guys! :-(

Kind regards 9k!!

Doblegota

My toy with 19" 5zygen Hyper 5ZR. <br/>74000km.

9krpmrx8

iTrader: (46)

Clean car. Just drive it and enjoy it.

Doblegota

;-)

I do that everyday.

Kind regards.

Alexandru Ciureanu

hi, guys!

I just read my 5th thread on the sohn... but ths is where i found the most info!

a week ago i bought the low power rx 8 with a new engine changed on warranty (in 2010, but the car was deregistered and was not driven since).

I am aware of the issues of ths car so I decided that i would install the sohn adapter.

I guess Thomas (?) said that in germany they use motul 710 2t for the sohn, motul 800 2t for premix and some synthetic in the engine.

I searched about the difference between those 2 oils and i found out that motul 710 is 35 cst while the 800 is 135 cst. Dexelia is 236 cst. This means that Dexelia 5w30 is almost twice as thick as the 800 and 6-7 times thicker than the 800.

The recommended ratios for premixing for both motul oils is between 2 and 4% for 2 strokes engines.

The 800 is not recommended for the oil injection (i know ours don't actually inject), so I will run the 710 in the sohn which is 35 cst. I will also premix to insure a better spread (710 or 800?)

A higher ratio means that it might not burn properly and create deposits both on the rotors and in the exhaust. A leaner ratio means engine failure.

PROBLEM: What is the total ratio of motul 710 (sohn and premix) i should run to get it right? Or what mix of 800 and 710?

My thoughts: If the engine was build to run on Dexelia 5w30 or thicker, and the sohn will inject just as much 710 as it would Dexelia, than i should premix at a higher enough ratio to compensate for the thickness. That would mean waaay to much 710 oil. So i should use thicker oil for premix. That could be the 800. Being almost 4 times thicker than the 710, i should use 4 times less 800 in the premix than the 710. As the recommended ratio for a proper burn for both is between 2 and 4 percent, than the question is for what intended ratio was the OMP calibrated? so i can calculate the amount of premix i can run.

Example: if the OMP is calibrated for a ratio of 2 percent it means that i have 2% spare ratio percentage to compensate with the 800 without compromising on the carbon deposits...

ANY IDEA ON THE OMP RATIO CALIBRATION? What is the average gas/sohn-oil-used ratio for you car (please state if it is the 192 or 235 hp)?

Alexandru Ciureanu

Idemitsu Premix is 135 cst, and the producer recommends a ratio of 1:200 for daily use and up to 1:100 for racing with the OMP and no sohn...


Oh... and the Idemitsu is JASO FC and not FD as the motul.

TeamRX8

iTrader: (25)

Loki

iTrader: (1)

FD is just FC with more detergents. For the purposes of lubrication the specification is the same.

The OMP isn't really calibrated for a set ratio, it gives more under some regimes and less under others (like idle). But if you insist, I burn about 1L through the Sohn per 50L of fuel at the track, for a ratio of 1:50 or 2%. In regular street driving it's about 1L in 150L, so 1:150 or 0.6%

But you need to also realize that oil you add as premix ends up in all kinds of places and only a fraction of it does any useful lubrication. A bunch of it burns without doing anything, a bunch condenses on the rotor and goes for a long ride before burning up, and only a little ends up ever touching the apex and side seals. So the OMP ratio, while lower, is more effective at delivering oil to the apex seal.

Usually the recommended premix for a rotary is between 1:200 and 1:100, I suggest you stick with that range.

Alexandru Ciureanu

I really appreciate the quick reply!

I kept reading about the sohn overnight and the issue with the oil heater for the sohn looks even more relevant to me. I plan to daily drive (I drive kinda spirited!) my rx-8 and here (in Romania) during winter, temperatures can drop to -20 Celsius with an average of 3 Celsius.

1. Is it too cold for the sohn oil to flow/get pumped?
2. Is a 2T oil for the sohn too light for the lubrication compared to Dexelia? What do u use in the sohn? Idemitsu suggested in the comments here that we should run the 10w30 4t oil in the sohn,..
3. Should I beter run a thicker 10w40 mineral oil in the engine (to protect the stationary bearings), use the standard omp and premix some motul 800/idemitsu (they have the same weight)?
4. What oil do you use for the engine when the sohn is installed?

Brettus

iTrader: (2)

There is a really cunning piece of tech. to preheat the oil injected into the engine .................it's called ............... the Engine !

A lighter oil is for winter ... 0w30 would be a good choice for that climate.

TeamRX8

iTrader: (25)

Lol