You forgot the most important aspect of the SCCA rules though; if it doesn't say that you can, then you can't. Plus anything over E15 will not be permitted below SP beginning in 2014 unless specifically approved by the manufacturer i.e. factory-rated flex fuel vehicles only.

subbed

How has the car been running? There is plenty of access to E85 around where I live, I would be interested pursuing the same course of action.

That's another reason I like NASA. They have a rotary specific bulletin that says mixing 2-stroke oil into the gas is allowed. Also fuel type is pretty open, so pump gas, unleaded and leaded race gas, and E85 are all under the no-points modification category. Methanol and alcohol are not permitted and neither is nitrous.

If I can't make enough power for my class I am heavily considering trying E85... there is a local place that has 550cc injectors for very cheap, there is also E85 specific 2-stroke oils, then swap two yellows into the red positions and give it a go. The thing that had me most interested was possibly using the baro input to modify the maps. Instead of having it hooked up to the baro sensor, hook up a flex fuel sensor and have it scale the map so you can run any mixture of E85 and gasoline and it will self adjust. (Please note I have no clue if this is even possible.) The more concentrated the E85 mix, the more power it will make, but if I run out of E85 then no sweat and no having to wait forever to flash a new tune onto the car.

The car has been running well. About 10k miles on E-85 so far (I drive A LOT) with no problems other than the usual cold start issues now that the temps are below 40F in the morning. All E85 cars have this problem without intake preheaters.

Arca_EX,

Take some logs from your ECU, you will end up adding about 22% to your injector duty cycles. As long as that won't push you beyond ~85%, you can use the stockers. I'm running on the stockers without issue. Really cold nights can push IDC's up to about 87%, but AFR's stay healthy. This is with a walboro though. It wouldn't be hard to bump fuel pressure up by a few PSI by tinkering with the regulator inside the tank.

E-85 is great in a track environment due to the decreased coolant temps. I'm about 10 degrees lower vs. gas.

Unfortunately, the stock ECU doesn't really let you play around with barometric compensation. You really want to leave baro. compensation intact, it's super important.

Any alcohol compensation you do really needs to make timing changes in addition to fueling changes to be effective. On these engines it's about a 3 degree difference for MBT between gas and E-85. The power gains really come from timing changes. If you have an E-85 timing map on gas, you will detonate. If you have a gas timing map on E-85, you are leaving a lot of power on the table.

I have had very good results with Autronic ECU's and scavenged flex fuel sensors. The autronic has provisions to interpolate between different timing/fuel maps based on an analog sensor input. Going to a full standalone has some class implications.

Honestly though, the reflash times aren't bad. If I'm switching fuels, my routine is: Grap AP, Start reflash. Pump gas. Finish pumping gas. Reflash is done by this point. Turn key off and drive.

Yeah the better cooling with e85 is another thing that is pulling me towards it. I think if I went to E85 I would just end up doing a complete overhaul on the fuel system. Also I would go to a castor based 2-stroke like Maxima that will actually blend with E85. My biggest concern is the E85 gunking up everything since I've been premixing my gas for so long. Wonder how long it would take to get rid of that crap built up from the years. Like 3 tanks of gas and some seafoam or fuel system cleaner?


Here's a rough idea that will also fix my fuel starve issues when I'm at a little over 1/4 tank.
Install another stock pump and bucket assembly to the passenger side.
In tank pumps lift to a 1 gallon surge tank in trunk.
External bosch 044 pulling from surge tank.
-06 AN lines everywhere, replace front to back.
Convert to return style fuel rail.
Aeromotive adjustable FPR.
New 550cc secondaries and move two yellow 380cc to primaries.


A standalone doesn't affect my classing because I'm on a dyno reclass, but it's just a lot more money lol.

There should't be any buildup other than the residue in the engine.

Your biggest issue for track racing is fuel tank capacity since mileage will decrease by approx. 40%

[QUOTE=Arca_ex;4562438]
Here's a rough idea that will also fix my fuel starve issues when I'm at a little over 1/4 tank.
Install another stock pump and bucket assembly to the passenger side.
In tank pumps lift to a 1 gallon surge tank in trunk.
External bosch 044 pulling from surge tank.
-06 AN lines everywhere, replace front to back.
Convert to return style fuel rail.
Aeromotive adjustable FPR.
New 550cc secondaries and move two yellow 380cc to primaries.
[/QUOTE

Thats basically what I have done...except the surge tank is bigger and the 044 is mounted inside...the pump is quieter and runs cooler that way...although it warms up the fuel more I guess :)

You can use the stock fuel line for a return with no worries....-6 minus the fuel used will return down -5 no problems. Make sure you return the fuel to the surge tank though and not to the drivers side cup...or the 044 will outpump the OEM side and you will empty the surge. you can plumb the return from the surge to the OEM suction and leave i for transfer if you want...that way you can turn the passenger pump off if you are street driving so it doesn't run dry

The baro sensor will respond to pressures up to about 3 psi after which it flatlines.


Actually ... it isn't that important at all .But it is important to know how to deal with it . All it does is provide an input into the Max calc load calculation - nothing else .

See what you need to do with Max calc load for tuning purposes here :

https://www.rx8club.com/series-i-eng...erride-248857/

That's a non-issue for me. The surge tank will increase capacity a bit, and I only need to be able to do a 20 minute run at the most. Plus with the surge and dual lift pump setup I will be able to use almost all of the fuel capacity with no starving issues. Usually I use just enough time to set a fast lap and then get off the track which is maybe 10 minutes or less. If I can go out and beat whoever is in front of me in the standings by a decent margin (I have a QStarz GPS lap timer that is always within +/- 0.05 seconds of the transponders) I will just come off track early to save consumables.

I don't ever see myself racing this car wheel to wheel where fuel capacity and fuel economy would start to be an issue with longer sprint races (30-60 minutes). If I decide to do wheel to wheel racing it will most likely be in the Miata. Cheaper to operate and cheaper to repair in case anything happens, and a LOT less money invested.

Yeah noise isn't really an issue for me so mounting externally won't be a problem for me. As far as if it runs cooler submerged, I think it's kind of a wash since having three pumps will be adding a decent amount of heat to the fuel on top of having it be a return style system that dumps back into the surge tank after taking a visit to a blazing hot engine bay.

Thanks for the input on the routing, I'll have to keep that in mind. :icon_tup:

What I meant was, the AP working with the stock ECU doesn't let you play with baro compensation in the way that Arca_EX was wanting. You don't have a table to alter fuel delivery based on baro pressure. It would be pretty sweet if this were the case. At a sensor value of say 0 volts, no fuel trim. At a sensor value of 5 volts, 22% enrichment.

Baro compensation should make small changes based barometric pressure changes. It's part of that behind the scenes ideal gas law calculation that's constantly ongoing. It's not going to be a huge change, but it's still there.

I would actually like to see what happens if someone zeros out the baro tables and disconnects the sensor. I'd be willing to bet you saw a deviation of a few % points from the base tune, especially in an area with baro pressure that differs wildly from sea level.

It would be cool. I've done some experiments with the bario sensor.

With the Bario unpluged or pressurized your traction control becomes disabled and can cause some troubles.

The sensor makes a small differance in the load. Pressure will raise load, and vacuum will decrease load.

1.0 on the bario table is zero adjustment.

I believe it defaults to 1.0 if it is unplugged. I've never tested that.

Edit:

The differance I saw in load from the Bario sensor was with the MAF unplugged.

No it doesn't .I thought you read the max. calc. load thread ?

Fixed

The sensor makes a difference in 'max. calc. load' . Not actual load .

As far as what the engine sees it makes no difference to fueling .....................unless max. calc load is surpassed. Which is why you need to ensure 'max calc load' is higher than actual load .

@no-coast-punk
could you please post your ignition timing tables?
I drive with E85, too ;)
My Ignition setup is only trailing about 6-8deg advance. Leading is stock

The entire map is available for download on the first post.

Still running on E85 NCP ? All good ?

thinking of switching brettus?

I know a local mazdaspeed3 owner who mixes e85 and regular either 40-60 or less, has huge gains from timing adjustments!

I ran E60 all last year without issue. With a new fuel pump my engine would go lean on the top end with 'true' E85, hence the lower mixture (had to run the correct OE model year fuel pump per the class rules).

New class this year that allows full fuel mods etc., but due to life situations I'm out for pretty much the entire race season this year:

https://www.rx8club.com/series-i-eng...7/#post4604623

Hi but I cant open it with the access tuner... not allowed it says...
or is there a trick?

Or could you make a screen shot of the igniton tables

Thanks

its probably a different year of atr race.

Right now, I'm actually running on the F-76 diesel fuel that is powering the warship I'm currently riding around on for the next several months.

Before the car got parked, my fuelio app showed me I had burned almost 1500 gallons of E-85.

Ass dyno makes me think that the car was actually running a bit better by that point. I switched to E-85 like two weeks after I picked up the car. The alcohol had probably slowly burned all of the carbon out of the motor.

Datalogs showed it was using a few more grams/second over the initial dyno tune. Once I get back in the world, motor will be opened up so I can dabble in rotary porting. I'll take some pics then. Should be interesting to see what a motor that ran on gas for ~80k miles, then E-85 for ~15k looks like when opened up.

Hi No-coast-punk

please make a screen shot of the two ig tables L+T. I have no chance to open your map.
Thanks in advance. I´m running at the moment +2 deg more than stock Leading & +5 deg more then stock Trailing

us mazdaedit guys would like the maps as well.