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On a completely stock 13B how much hp could you make before you start having issues.
If you setup a flex fuel system with aftermarket ECU along with injectors and supporting mods for flex fuel conversion like ignition coils ect. (Not touching internal engine components) How much Hp could you make and could the stock motor handle?
The benefit of E85 is more precise air-fuel ignition control..., which allows more aggressive tuning w/ respect to timing and afrs. However, it h/b widely established that Mazda didn't leave much on the table as far as tuning goes w/ stock components. Therefore, as Cayman has said w/out FI; I'd expect minimal gains.
Lubrication will also be a challenge since ethanol has a drying effect and you have to use premix specific to ethanol fuel.
But yeah, no point doing E85 conversion on a N/A engine. On a boosted car, you could run more boost than gasohol would normally allow as ethanol has a cooling effect in the engine so you don't run into knocks as easily.
I would like to set up e85, but not as a permanent thing, I will just carry a can of it to the track drain my tank and fill up with e85. I will be premixing whenever I fill up with regular 98 octane so for maybe 4 laps with a decent tune on 85, could I expect performance gains? My whole fuel system would be flushed with premixed 98 octane on the way home from the track so I shouldn't see any issues with seals or lines ect. It would just be for the track, with say a heltech 550 elite ECU and flex filter with professional tune, any ideas as to what gains I would see?
Fit larger injectors and larger fuel pump and tune it ............maybe 10-15whp tops. Maybe enough to get a car length on a stock 8 down the back straight ......
Fit larger injectors and larger fuel pump and tune it ............maybe 10-15whp tops. Maybe enough to get a car length on a stock 8 down the back straight ......
not the answer you were looking for, but the most accurate one so far: not a single person who replied above has any actual direct NA experience or idea.
not the answer you were looking for, but the most accurate one so far: not a single person who replied above has any actual direct NA experience or idea.
You're a funny guy ..... Next time you chime in on the FI forums i'll have to dig up that quote.
I genuinely don't care if they dont have experience, most of the people on this forum know more than me about RX8's so yeah I'm just trying to gauge roughly what will work and won't. The Reason I won't turbo yet is because in australia, you have to be on your Red P plates then Green P plates all up around 3-4 years depending if you pass your tests. On such licenses you can have a turbo car and Id like to squeeze as much power out but keep decent reliability. The ECU is a big invest for a young dude but it would be future proofing the car if / when it gets a turbo.
I genuinely don't care if they dont have experience, most of the people on this forum know more than me about RX8's so yeah I'm just trying to gauge roughly what will work and won't. The Reason I won't turbo yet is because in australia, you have to be on your Red P plates then Green P plates all up around 3-4 years depending if you pass your tests. On such licenses you can have a turbo car and Id like to squeeze as much power out but keep decent reliability. The ECU is a big invest for a young dude but it would be future proofing the car if / when it gets a turbo.
It’s a bad idea, you can’t really squeeze much extra power out of the Renesis simply by changing to E85, and I have no idea what kind of damage running it may do.
It’s a bad idea, you can’t really squeeze much extra power out of the Renesis simply by changing to E85, and I have no idea what kind of damage running it may do.
There have been a couple of dynos on here that back up what i said above ........ sure it's not a lot of power but, yes there does seem to be some gains to be had . As far as running it goes ...I've run high % ethanol blends in my turbo 8 for years . I found it does require more lubrication of the combustion chamber than stock, I know this from going to the extreme limit of what is possible with the omp at high boost. Now that I have lubrication under control ...no further issues.
There have been a couple of dynos on here that back up what i said above ........ sure it's not a lot of power but, yes there does seem to be some gains to be had . As far as running it goes ...I've run high % ethanol blends in my turbo 8 for years . I found it does require more lubrication of the combustion chamber than stock, I know this from going to the extreme limit of what is possible with the omp at high boost. Now that I have lubrication under control ...no further issues.
For me it seems risky to try such a thing. If you have the means to rebuild/replace engines then go for it. Just wouldn’t be for me specifically I suppose.
To run e85 naturally aspirated on a series 1, the only thing you need to do is add a fuel pump with more flow and tune.
You can use a series 2 fuel pump which is probably the easiest solution and what I did. I suspect on a series 2 you would just need a tune.
You will be able to advance timing and find more power. When I did this it was ~8% difference in whp on the dyno.
I also switched to Redline alcohol premix.
well it depends how the question is posed and also where the information is coming from, where/who it’s coming from, and so on.
I’ve qualified statements plenty; like it came from a well established rotary engine builder who’s been doing this since before most people on here were more than a twinkle in their daddy’s eye and specializes in this particular engine. I can also copy and paste where that wasn’t good enough before, but now get a fawning yawn response because the latest dyno proof is the same old ‘better than anyone else is showing’ thing. I also chose not to point out obvious mistakes indicating a lack of direct experience; like stating it needs larger injectors, etc.
It wasn’t so much directed at some as others; though it equally applied. Yet it’s apparently hard for at least one person to admit they have no idea about what they were so quick to state as fact. Just because it’s scary business. There have been a few claims made over the years, but they were here today and gone not too long after and if that’s your proof then I can also copy and paste some quotes that are counter that level of validity as well.
I don’t agree with 15% or even 8%, but I suppose it depends on where in the powerband that may be, what it’s being compared to, and whether both are really all that was truly possible to achieve before the comparison was made. I suppose those kind of details just muddy the water. However, anyone who expects to go from 209 peak whp fully tuned on gasoline to 227 peak whp on E85 might end up being a bit disappointed. I’ve pointed out over the years there’s a lot of information that’s not on this forum.
A young whippersnapper might not care where the replies come from or whether they have any validity, but thats the difference between thinking you’re smart and actually being wise that develops over time with experience.
Here is a dyno plot of the same car that made the 227whp e85 pull, but on 93. The three plots are factory map, one of the maps that comes with versatune, and the 210whp map being one I further dialed in.
I will be dyno tuning a different RX-8 built for STX tomorrow, and while there I will see about getting a plot of the time attack car with both gas and e85 on the same plot.
As far as getting a result of going from 210whp from 227whp -- I personally doubt joe blow will be making 210whp to start with. However I do not think it is unrealistic for a well running renesis to see a gain proportionally in the ball park.
I think you should do your own real world testing with e85 before coming to any conclusions. I am sure another data point would be helpful to the community either way.
Many winning race cars, including RX-8s, are running E85 even when race fuel is an option. This isn't a coincidence.
I might also suggest that post count on an RX-8 forum does not necessarily correspond with ones experience in building and campaigning race cars, or even their experience in developing the RX-8 as a platform specifically.
Team ...ok I'll admit I have no direct experience with doing this ....big deal. I do have a lot of experience with the engine in general though and my comment above about FI still holds water IE you do the same thing .
My comments were made from observation of what I've seen on here over the years. A experienced tuner on here did state that larger injectors were required ............fwiw.
you read too much into it actually, I’m often joking more than serious, newbs being the exception.
however I appreciate Dallas making my point, because I would have expected a racer to have been comparing against 100 unleaded, and still disagree with the variance; which is only to say that imo the gas tune wasn’t fully developed. Those are his results though.
which I still remember back in the day when the forum experts were convincing people to not “waste” their money on premium fuel and to use regular 87 oct. instead. Their compression was so low it likely didn’t matter though. Like I said, not everything gets posted on here. My own position on E85 is known though and the usual malarkey that gets tossed around gets to the point when you just say, why bother.
Just like when I tried to argue against running regular gas. Or the need for more oiling with efuel. Funny enough, Redline recommends lowering the oz/gal ratio. I can only conclude that they think the 33% higher fuel rate is enough compensation, and maybe it is for a go kart or weedwhacker. That’s not what’s under my hood though.
Do you happen to know how much timing advance at WOT/highest load over the stock map is achievable with any other fuel compared to E85? My E85 map had an additional ~3.5 degrees at the point of peak power and 10 degree split.
To be fair I have only tuned an RX-8 on 93 and E85. That being said, the convenience and cost factor with acquiring E85 I am not sure I would care to run anything else either unless there was a substantial output difference. My results do jive for instance with the results here:
Fwiw, here is someone else's plot you may recognize on pump gas on the exact same dyno. There are some notable differences in favor of this car. This is running a 4 inch exhaust and a substantially more open header as well, where I am running 3 inch, turboxs. And there was a budget with more zeros at the end. I expect there is a bit more timing advance as well but I do not know for certain. I only was running 0.5 degrees over the factory map in the 93 plots I posted. So there probably is the potential for a higher whp NA renesis.
Do you happen to know how much timing advance at WOT/highest load over the stock map is achievable with any other fuel compared to E85? My E85 map had an additional ~3.5 degrees at the point of peak power and 10 degree split.
To be fair I have only tuned an RX-8 on 93 and E85. That being said, the convenience and cost factor with acquiring E85 I am not sure I would care to run anything else either unless there was a substantial output difference. My results do jive for instance with the results here:
Fwiw, here is someone else's plot you may recognize on pump gas on the exact same dyno. There are some notable differences in favor of this car. This is running a 4 inch exhaust and a substantially more open header as well, where I am running 3 inch, turboxs. And there was a budget with more zeros at the end. I expect there is a bit more timing advance as well but I do not know for certain. I only was running 0.5 degrees over the factory map in the 93 plots I posted. So there probably is the potential for a higher whp NA renesis.
Do you happen to have your timing maps? I'm curious as to what you were running.
Also, did you try running a smaller timing split on the dyno?
Thank you, I believe I'm going to try E30 and see how it acts. After reading some horror stories about the lack of lubricity with high ethanol contents I don't want to push much beyond that.
I'll see if I can get mine on a dyno here soon to test out 93 vs an E30 blend. If anything, it should lower EGTs a bit which may help with side seal life.
e85 timing maps
I've slept since then but if I recall there weren't any gains to be had going with less split than this. The vast majority is from additional advance on the leading plug. Best power was around 0.86 lambda
e85 timing maps
I've slept since then but if I recall there weren't any gains to be had going with less split than this. The vast majority is from additional advance on the leading plug. Best power was around 0.86 lambda
Thank you very much, I'm going to modify these a bit and run an E30 mix with 93oct fuel as the base. I'll see how it goes from there and post back.
04-21-2020, 05:54 AM
