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As far as I can tell, there is not much info on pre-mixing S1 vs S2 engines. I understand that the S2 engines lubricate better, so I've been told that you don't need to pre-mix them like you do the S1s but if it adds any ounce of extra life or reliability to my R3, I'll start doing it.
Do any S2 owners out there pre-mix, and if so, what ratios are you using?
It won't hurt. Don't know the omp rate in s2s but I guess due to emissions, it will have certain limitations.
A 200:1 ratio for street use?
Rotary Performance has a guide https://rotaryperformance.com/blogs/...-not-to-premix
Last edited by peloponisios; 01-03-2022 at 09:30 AM.
As far as I can tell, there is not much info on pre-mixing S1 vs S2 engines. I understand that the S2 engines lubricate better, so I've been told that you don't need to pre-mix them like you do the S1s but if it adds any ounce of extra life or reliability to my R3, I'll start doing it.
Do any S2 owners out there pre-mix, and if so, what ratios are you using?
I've premixed both my 2010’s. Half an oz per gallon of gas on the street and 1 oz per gallon on the track. When I got rid of my first 2010 at 75XXX miles it had slightly better compression than my current one with 25XXX miles. Original CAT on both. As is often recommended around here any JASO spec’d will do (JASO FD).
It won't hurt. Don't know the omp rate in s2s but I guess due to emissions, it will have certain limitations.
A 200:1 ratio for street use?
Rotary Performance has a guide https://rotaryperformance.com/blogs/...-not-to-premix
Great link ^. Chris Ott and the crew at Rotary Performance are one of the absolute best rotary shops in the country
Last edited by GoodfellaFD3S; 01-04-2022 at 06:42 PM.
Sure, but why? Owning an S2 I'm genuinely curious. I just assumed it was effectively an S1 and I've been premixing it at 1/2 oz per gallon, or 1-1.5 oz per gallon for autocross/track stuff
I was also wondering about premixing on S2. I premix 0.5 oz per gallon on my car or 256:1. I mainly track my car and I noticed that is uses more oil on track than my S1 did. I use about 1/2 quart of oil per track day ( which is usually 4 25-30 min sessions) and about full tank of gasoline. so 17 gallons of gas and 16oz of oil gives oem gas to oil injected ratio of about 136:1.
now when you combine premix with oil injected/consumed you get 24oz of oil per 17 gallons consumed which gives you about 90:1 effective gas to oil ratio. I wonder is that a bit to much?
from that website:
"it is not uncommon for many racers to run 1oz of premix per gallon of fuel. This is a lot of oil and can foul spark plugs easily. Many begin premixing rich and back off slowly by reading the spark plug deposits. Excessive oily deposits on the plugs are a dead giveaway that the mix is too rich."
remember what my spark plugs looked like, lot of deposits on lead plugs:
Last edited by Nadrealista; 03-08-2022 at 07:19 PM.
typically at least 1 oz./gal is standard, but up to 1.5 oz. is fine
Racing Beat had tested up to (edited) 1.67 oz. on the Renesis and claimed a slight performance benefit, but that likely had more to due with it already bleeding too much past the rotor seals imo …
sometimes it can depend on aftermarket seals, Iannetti recommends quite a bit more for their newer “steel” (non-ceramic) forced induction apex seals with e-fuel; 2.5 oz./gal minimum.
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here is Racing Beat premix recommendation for RX8:
RX-8 - Race Tips
While undertaking development work on the RX-8 Renesis engine for SCCA T2/T3 use, we decided to introduce extra oil into the fuel to monitor the effect. To our surprise, this additional oil increased power! Further dyno testing found that by adding 10 oz. of Royal Purple 2-Stroke Oil to 6 gallons of fuel, we gained an average of 1.7 HP from 2000-9000 RPM, along with an increase in peak power of 4 HP. We validated this increase by changing back to a "non-oiled" fuel - and the power returned to the previous level. Later, we tried the same test with another brand of synthetic oil with nearly the same results.
For racing applications, the addition of a high quality synthetic oil increases power and most certainly decreases wear. The only negatives are the cost of the oil and an increase in the tendency to foul the spark plugs.
Some good info shared already club. Idemitsu and Racing Beat's description are good imo. Rotary performance has a good read on the subject as well
I used to pre-mix my old s1 and pre-mix my s2 regularly. For street driving, I typically eyeball about 4oz per full tank of premium gas (91) while at the pump. Track use I'll add approx 8-12oz per tank (depending on conditions, etc). I also run Motul 300v 15-50 with NGK racing plugs (I forget if it's 9-10 or 10-11 heat range). Runs well in CA climate and no issue with fouling or cold / hot starts, etc. Rotary fuel consumption is atrocious on track though. I even bring multiple gas cans with me (so I don't have to pay track prices, etc) and go through around a tank and a half throughout the entire day. I also prefer to drive with a full tank, so I top off after every session.
With the way gas prices have been these going days, the cost of rotary ownership just went up big time. Bummer.
I’ve been running amsoil 5w50 in the car. And add a 8oz bottle of amsoil 100:1 premix for street use. When I head to the track I have the 12.8oz bottle I pour in.
I’ve been back and forth with either staying with juts adding a 8oz every time or the12.8oz bottle every time.
Not sure it would really matter but I keep ending up at what my original ritual was.
here is Racing Beat premix recommendation for RX8:
RX-8 - Race Tips
While undertaking development work on the RX-8 Renesis engine for SCCA T2/T3 use, we decided to introduce extra oil into the fuel to monitor the effect. To our surprise, this additional oil increased power! Further dyno testing found that by adding 10 oz. of Royal Purple 2-Stroke Oil to 6 gallons of fuel, we gained an average of 1.7 HP from 2000-9000 RPM, along with an increase in peak power of 4 HP. We validated this increase by changing back to a "non-oiled" fuel - and the power returned to the previous level. Later, we tried the same test with another brand of synthetic oil with nearly the same results.
For racing applications, the addition of a high quality synthetic oil increases power and most certainly decreases wear. The only negatives are the cost of the oil and an increase in the tendency to foul the spark plugs.
Wow, what a breakthrough!!
I have been saying this for years (over 15 years on here).
Have also premixed my S2 from day 1 of ownership, I actually filled up tank on way home off the showroom floor and put in my Amsoil mix at gas station.
Not only does it reduce wear and friction on ALL of inner engine surfaces,
but the reason you see an improvement in performance is that engine compressions are optimised.
Edit... and yes must monitor ratios as too much can foul plugs, but that is easily rectified (add more gas) and a few high RPM runs.
Ok yous guys have made me think more about this. Thanks Ash and Team (amongst others) for keeping this point coming up. Will start premixing once this latest work trip ends and my car and I are reunited. Oh ya, and my family.
Team do you use the handy 8oz bottles or 12.3oz
hope I got those right off memory.
Or do you use quart and measure?
Also are you using saber?
I know some people prefer the dominator oil. I know I always had the best luck with the saber in all my mod sleds. Based off that I keep running saber. But that dominator would probably be a very good oil to premix also.
Team do you use the handy 8oz bottles or 12.3oz
hope I got those right off memory.
Or do you use quart and measure?
Also are you using saber?
I know some people prefer the dominator oil. I know I always had the best luck with the saber in all my mod sleds. Based off that I keep running saber. But that dominator would probably be a very good oil to premix also.
Both Amsoil Sabre Pro and Interceptor are JASO FD rated, Dominator is not.
I highly recommend Sabre if using an Amsoil product with gasoline based fuel.
E-fuel use (E30 or higher) is going to require a pre-mix made for that. Although Redline recommends their standard 2-stroke oil for up to E-50. So you always need to verify this and the use-rating with the manufacturer. I would also recommend an additional 1/2 oz. gal of an e-fuel specific top end lube in addition to premix to combat the “dryness” of e-fuel for pumps, fuel injectors, etc. Not sure what the long term effect is for a cat converter, but the fuel system and engine will be better off with it.
.
I’ve always thought saber was the best amsoil they made. Even when running 800cc 240hp race sled engines it seemed to do better than the dominator.
I’m curious now though to why the dominator does not meet those specs. Wonder what part it does not. Wonder if it is based on ash maybe. Maybe better protection but more ash. Now I’ve got some research to do.
Not that I will
run it as the saber is to handy and has always been fantastic. But good know for knowledge sake.
I wonder if the newer year cars need anything for higher e content. Or if they fall into the modern set that allows it with no harm to pump or injectors.
Not sure what year it was but I know 15 plus most cars could handle e85 even if not tuned for or flex fuel. I won’t be running a mix anytime soon as I’d have to tune and never heard back from Steve at versa tune for a dyno day.
I do have a great e station right by my house that does e15,e30 and 85 at the pump. But I’d like to tune for it first then I’d have to move away from my favorite oil. So I’ll be staying stock.
01-03-2022, 08:17 AM
Pre-Mixing S2
