Interesting so it can react very fast to a fresh tank of E10 that now is E35-E85? No issues with E85 (lower air flow but much higher fuel flow requirements to the engine) to maintain richness to repvent misfires?

Going from E10 to E85 is too much of a difference for the ecu to cope with . Any concentration of ethanol higher than around 15% should be tuned for.

Like Brett said....

You are limited to about +20% fuel trims.....in an NA stock ported motor that would allow E15 to be trimmed out OK. Anything else you will want a tune. Really you want a tune anyway 😎 otherwise what's the point of playing around at all 😉

In the US , is Ethanol added to a base fuel with an octane of lower than that rated at the pump ?

EG : for E10 91 octane fuel is the actual octane 91 or is it higher than 91 after the ethanol has been added ?


I did do a google search but couldn't find an answer to this .

If they blend it with ethanol the final mix is the octane at the pump.

They get to use crappy fuel and improve the octane # with the Ethanol 😐

Thanks Dan . That sucks !
Here they mix 95 with ethanol to get 98 and advertise it as 98 (your 93) .

Ya...that's basically what they do here.....they take 85 and mix in 10% to get 87....

We can get non-ethanol 94 here though......and mix that with 50% ethanol and you have my go to fuel ;)

im new to rotary scene. are there major benefits to running e50 or higher on renesis NA motor. ideally i want to setup for flex fuel but dont want to go with stand alone ecu. this will be mostly track car. i ran e85 on my Evo. it's cheap, burns clean, and run cooler. is it worth the hassle for NA renesis. how much more power can i expect running e50-85

It’s worth some hp for a race engine, nothing huge though

There is a thread on here where someone tuned a race engine for E85 ... I think the gain was around 10whp.

Would love to see the dyno graph of before and after to see how much he gain under the curve, that's more usable for me on track than peak number gain.

Found it : https://www.rx8club.com/series-i-eng...ciated-247223/

It will depend on a lot of variables and my car is mostly custom mods rather than off the shelf parts. I dyno’d higher on gasoline than anything I’ve seen for E85 from anyone I’d trust to provide a good number. The potential is quite significant for FI, but for NA it’s pretty much what I previously posted.

looking at that graph, the gain is from 6500-9k rpm, not great but not horrible.

https://cimg2.ibsrv.net/gimg/www.rx8...d1b2270c11.jpg

well again it depends on a lot of things besides how well tuned it was before vs after among others

ok, ill stay with 93 pump for the first season and see how close i can get to max hp/weight ratio for the class. running a turbo car for the last 7 years, i'm spoiled with having max power from 4k to red line :D

the 8 is a somewhat a momentum car. definitely different from driving the evo. you'll never be below 4k on most tracks, but when you are IT SUCKS

pay you to read the narative that goes with it . My understanding is that both of those plots are with e85 ... one tuned one not . There is no actual E85 vs 93 dyno as far as i can tell .

ah i see

Actually he stated in text at the very beginning of the thread that it dyno’d 179 rwhp before mods including the fuel change. It still doesn’t define it exactly, but if you figure in the usual expectation for the tuning and mods it more or less mirrors my general assessment.

The only mod there that would see a hp gain was the exhaust system which would maybe free up 10-15whp . So that leave somewhere around 15 for the E85 alone . Not too shabby really .

well if you want to see it that way then fine, but the actual numbers for the Renesis IME are smaller than that all else being equal

Not seeing it that way because i "want to" at all . I've never seen more than 15whp for just some ordinary headers + a catback ?

For anyone turboed that runs a high % ethanol mixture . The omp oil cranked up is insufficient to properly lubricate the apex seals past about 10PSI .
I now run Motul micro 2T premix (150:1) as well as omp for any hard abuse situations when running an ethanol mix.

I run Redline Ethanol 2 stroke. It is formulated for alcohol mix. Ive run Castor type oils as well. it smells like french fries when it burns

I looked at the Redline ...but it's $40 for 350mls whereas the Motul is $75 for 2L .... so it's no contest .