Premix for racing
 

Re our Racing Renesis project :

https://www.rx8club.com/rx-8-racing-25/renesis-hp-engine-racing-proto-86136/

I'd like to have expert views on the use of premix, especially :
- which oil you recommend
- which ratio
- other aspects

I did a search and found a lot of interesting info (mainly from RG), but no definitive answers about the ratio.

Thanks,

Fabrice

if you're still using the OE MOP and have a cat converter then 1/2 oz oil/gallon fuel = 1:256 max

http://www.idemitsu-usa.com/page_214.htm

or you could probably do the RB MOP upgrade and not have to hassle with it ...

Hi TEamRX8,

No, we'll get rid of the OE MOP. And the cat goes too. We'll have an NTK UEGO sensor in the exhaust though.

Fabrice

Pumpless....
 

With no pump, you would want at least 150:1, and it must be a good synthetic oil to be effective at those ratios. Widebands work fine with a ratio that lean.

The engine is not a two stroke, there are no bearings in the equation, and no rings to sieze, but you still need all the lubricity.

If you get into the 1% range, you start to affect octane, overall power, and exhaust port deposits.

Stay well away from old school castor extracts and anything rated less effective than ISO-EG-D. Any deposits in the ports and on the rotor face will ruin your day.


S

^^ Thanks!

F

Anyone have any opinion on using Royal Purple TCWIII oil for premix? I was thinking about picking up some for the track.

http://www.royalpurple.com/prodsa/tcwiiia.html

Use a name brand outboard (water cooled) 2 cycle oil at a ratio of 1 ounce per gallon.

No, no, no.....
 

TCWIII is EXACTLY what you DON'T want!

1- The "W" stands for watercraft, all residues must be bio-degradable. The oils used are chosen more for their 'friendliness' than for lubrication, and are much less effective than more purpose-designed oils, hence the requirement to stay richer than 50:1.

2- You need an oil that can lubricate very well at extreme dilutions, burn away completely, leave no residues and contain ZERO metals. You don't need or care about bio-friendliness, since your exhaust will not be below the surface of a lake.

The Japanese came up with the definitive tests for 2-stroke oils, their specs call for actual tests to see how lean the oil can prevent seizing in a Yamaha test engine. Then the exhaust is run thru a chamber, where the opacity is measured.
Any smoke at all is a fail, and most of the good oils go well into the 200:1 range for protection. Look for JASO certification at least an "FC" level. When you find it, it will be a synthetic, since no dino oil can meet the demanding specs.

S

It works in the race engines that I have built. Maybee you need to contact people who are actually using it in race situations and ask them what they use. While I appreciate a good book or theory on the subject I prefer what is tried and true. I just finished 400 high rpm race miles with the same recommended premix. Call some of the Grand American teams who are running RX8's and ask them what they suggest.

One last time. You CAN use synthetic in the engine if you are not using the oil pump to inject it into the engine. Use premix at 1 ounce per gallon. Synthetic does show a slight power increase. So does diluting high octane fuel with premix. Some people use more than 1 ounce per gallon.

Well now I'm confused. The Idemitsu Premix is also a synthetic, so what would be wrong with the Royal Purple?

Hogcar, have you specifially used the TCWIII?

No, I have not. Just run down the Wallyworld and get a name brand 2 stroke oil. I think I used Havoline last time out. I also used 20w/50 Havoline Race oil in the engine.

Has anyone tried the Red Line "Two-Cycle Smokeless Oil"
http://www.redlineoil.com/products_m...72&subcatID=16

In other words, you're saying it's ok to use synthetic oil in the engine but ONLY if you disable the injection pump and premix with 2-cycle?

Ok.. and what if you ARE using the oil pump to inject synthetic oil into the engine? Would there be any added advantage to premix 2-cycle in addition? If I read you right - you're implying that injecting synthetic is bad in someway. Can you clarify?

I use synthetic in the engine if the oil injectors are disabled, such as a weber carbed engine. In the renesis I have not altered the oil injection so I use Dino oil in the engine AND add premix for high stress :SHOCKED: events ie racing. Using synthetic in the renesis can/will cause problems with your cat. The flash point of the synthetic is higher than dino or two-stroke oil.

I like Yamalube R for all of my rotaries and Professor Engman uses a ratio of 125 to 1 in his racing versions. I don't see the need for more than half ounce per gallon when supplementing the existing system.
Paul.

I dont either if you are using "street fuel" Rick uses 125 to one, hold the phone that is 1 ounce per gallon. (128/1)

In other words, the oil won't ignite properly or completely burn and will end up flowing into the cat and clogging it up with oily residue?

Close enough. :ylsuper:

Your Flash point.....
 

The flash point quoted for an oil has ABSOLUTELY nothing to do with whether it combusts completely or not. Nothing. Zero.

The number quoted is the ASTM Closed Cup flash point, a test I do every day at work. The oil is heated in a sealed brass cup and an ignition source is put in the lid every degree of temp rise. When enough vapor accumulates, there will be a tiny "flash" detected by the UV sensor, and you have your flash point.

An oil that is composed of many sizes of molecules will let its "light" stuff out, and flash sooner. An oil made of one engineered molecule (like a synthetic) won't have any light material to release.

No dinosaur juice can lubricate like a purpose-built synthetic 2 stroke oil - none.

S

the only pre mix oil to really stay away from is a castor based pre mix--that one will mess your cat up. Some 2 cycle engines that run pre mix(duhhh) actually have cats and use a synthetic pre mix. Respect your experience and knowledge hogcar but many 8 owners have been running a low dilution pre mix for some time. I run a blend of Lucas top cylinder lube/fuel injector cleaner/ yamaha full synthetic race pre mix--mix to a 50/50 ratio an add 1/2 oz per gallon. With the mop in place dont go over that. Engine has been running better than ever since I have started that and changed the oil viscosity to 10w/30 in the hot georgia weather. (5w/30 in winter months) oh and i use royal purple.
olddragger

I hope it's not too late to bring this thread back, but I had a few questions in regards to olddragger's last post:

-Is olddragger saying that some 8 owners are using a combination of oil and gasoline to whatever dilution, and also running synthetic engine oil WITH the OMP in place?

- olddragger: Do you add this 50/50 Lucas cylinder lube and yamaha premix to your gasoline every time you add gasoline, or is this something you do only when you know the engine is going to experience high stress levels [maybe an autocross or track event]?

- Also, would switching back and forth between running this premix, and then running normal gasoline through the engine have any kind of detrimental effects? I'm not sure if I want to go through the hassle of having to add premix every time i add gasoline.

BTW: I am running Royal Purple 5W-20 in my car along with a few very minor modifications.

Apologize in advance for the question whoring.

NP man--that is one reason why this forum is so good.
to answer
1- yes i added premix everytime i put gas in the car.I will not go pass 1/2 oz to the gal. keep a little bottle in the truck.
2- switching will not have any detrimental affect, except imho this engine doesnt get enough oil in the combustion chamber(one of the things the S flash per mazda address's). Street driving can actually be harder sometimes than a track event--(if you drive the car correctly at the track!)
RP is good oil, I also use it--but if you live in a hot climate or heck even if you dont I would hightly recommend 5W/30 AND the prelube.
Dont worry be a whore all you want!
Olddragger

keep a little bottle in the TRUNK,, that other bottle ---errrrr No honey I havent had a drink!
OD

Thanks OD.

Where is a good place to get something like Yamalube 2R?