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E85 Naturally Aspirated Tuning Thread

Hey dudes, I just went through the process of throwing a VVT motor in my NA, and finally got around to getting the flexfuel sensor set up. I followed Savington's procedure for tuning fuel for MS3 last night (copied below).

Quote:

Originally Posted by Savington (Post 1340112)

Here's how I would set up a fresh MS3 flex fuel install.
1. Dial everything on gasoline and save your tune.
2. Install the flex fuel sensor and set Baseline Ethanol% to the value you get with "100% gas" (in CA this was ~8% for me)
3. Turn on flex fuel, but leave all the alternate maps off. This just leaves the global blend, but doesn't allow blending between VE1/VE3 (or Spark 1/Spark3, etc)
4. Drain the tank and fill it with E85. Tune the spark/fuel, AFR target, ASE/WUE/Accel maps, and all the other maps that have switching available in the software. Tuning all these maps on VE1 will let you use Autotune like you normally would. Put a few tanks of raw E85 through the car to get the content up as high as you would ever see it, and make sure the tune is dialed in.
5. Load the set of E85 maps into the alternate map positions, load your gas maps from step 1 into the primary positions, and turn table switching on. Set the flex blend curve so that the ECU switches over to the alternate maps by 80%EC
6. At this point, you're about 95% of the way there. The only setting left to dial in is the flex blending map, and that will happen by trial and error with varying levels of ethanol content in the fuel.

At this point, my intent is to deck the head and install my 264/264 Maruhas over winter, but I'd like to semi-optimize the tune for the moment (planning on hitting the dyno in the spring post-headwork). Does anyone who has tuned an E85 car on a dyno have any idea (approximately) what sort of timing changes showed results? Currently my car is a BP6D, RB headers, Squaretop, properly sized intake & exhaust, MS3Basic. I realize this question is in a lot of ways, a bad one, but I'd like to know if the E85=faster flame front phenomenon actually necessitated adding timing on cars that were already hitting MBT on gasoline. My ignition map is below, and is more or less just the Reverant basemap. Ignore the fact that I threw away half my resolution by leaving in boosted rows.

Attachment 231748

Thanks!

edit:
Non-sequiter, but this is a pretty neat note about E85 cruise tuning
http://e85vehicles.com/e85/index.php...soline-vs-e85/

I don't have any answers, but as the owner of a cammed engine considering E85 I'll be watching closely

IMO tuning strategy wouldnt change. You'd still try adding timing until you found MBT or back timing off if adding didnt gain anything. Then lean the fuel out until it either stops making more power or starts knocking, and if you got to the stops making more power point try adding ignition back in.

I have a N/A engine that was tuned on Aussie 98 octane (93 ron?) and then tuned on E85. I run a Haltech so the maps might be slightly different but I can post the timing maps and the fuel composition blend map when I get home.

From memory, I think the E85 timing map ramps up to 8-9 extra degrees of timing by around 50% ethanol... from there it stays fairly flat up to 100%. My tuner said with N/A you really only need 40% ethanol to make the most power, after that you're pretty much at MBT and any more timing doesn't help. I suppose that will depend a bit on compression / cams / headwork etc which mine are all excessive.

For me I saw a consistent 8% power increase across the board from running E85. Plus it smells so nice! Interestingly, another side effect is a fairly substantial increase in noise from the exhaust.

I can run full advance with 30% E with no det. I tried everything from 27-32* @ 100kpa/wot on the last bp6d and saw almost no changes. I'd bump up your whole map by at least 2-3, and even out the 97-116 rows so you stay in the 27-30* range at wot.
Just my opinion

it's a lot different with boosted cars where the difference is like 10* over knock limit and you pick up giant gobs of power/torque

Any opinions on ideal AFR? Have heard that going richer (high 11s) is better for power VS the usual 12.8-13.1 on gas.

Nope. In fact it will be slower

i would rescale the breakpoints for some more resolution down low. this is how my dyno tuned timing map looked.

Stupid question time, since I can't find the answer. If running without a flexfuel sensor can you still run a blend? Such as 50% 93 - 50% e85. Logically I'm thinking it's all or nothing since you're guessing octane and req_fuel at that point, which could go poorly even for an N/A car. I'd like to run e85 for ALLOFIT power in TTE, but the closest e85 stations to every track are about 30 minutes away in Texas region. Figured the easiest fix would be keeping a 5 gallon sunoco jug with e85 around and put in equal parts 93/e85 since 30-40% ethanol is all that's needed for all the gains in this application.

I have no intention of running e85 on the street so don't really need to run flexfuel (I think). Too lazy to drive 15 minutes up the road to H-E-B for e85 when I have a shell across the street. I'm also three days in to MS3 Basic life and still smitten with all the hamster powers and torques on 93.

*dons flame suit*

Many cars (Mazdaspeed 3/6 tunes come to mind) with aftermarket tunes run a fixed blend map. As long as you can confidently mix the fuel it'll be fine. Think about it mathematically. E85 has about 80% the power density of gasoline. So, if you put E85 in on a 93 tune, you'll be about 20% off. If you can consistently mix within say 5% of ethanol content (not sure if this is reasonable) then your tune will be about 1% off. EGO control should be able to handle that no problem.

Personally, I would not want the hassle of mixing. A flex fuel sensor would make life a lot easier.

If you already have MS3Basic, you're talking about a $40 sensor, $15 worth of high pressure fuel hose and a bit of wiring to make your wildest dreams come true.

It's really nice not to ever have to worry about what you're actually throwing in the tank.

Do it once, do it right. Roger that.

lol 5hp. "wildest dreams"

But yeah, he's right. It's so simple that it's a crime not to do it right.

Quote:

Originally Posted by 18psi (Post 1387085)

lol 5hp. "wildest dreams"

But yeah, he's right. It's so simple that it's a crime not to do it right.

...but it's a naturally aspirated 5hp, so it's faster. If I add ITB's and paint it red it'll be equivalent to 200whp boosted.

So I was under the impression NA8 injectors had the headroom for e85 N/A, but after a shitload of street tuning I've run into a ceiling past 6000rpm. Right now I have everything before ~4500 set to hit high 13's afr, then it switches to low 12's by 5000, which is all fine until ~6200 where pulse width is pegged and afr's steadily climb to 12.8-13 at fuel cut (7200). Looking at logs it also corresponds with the pulse getting pretty haggard, jumping up and down and adding more PW does nothing for AFR's. Is this expected or likely just haggard old injectors that need some love? Running straight e85 at the moment.

I'd say expected. :dunno:

Guess I'll just lug it around like a Mustang at MSR-H. It feels ridiculously good up to that point, then falls flat. Went back and checked a 93 octane log, the pw actually goes down a bit, but it maintains target AFR. Sigh.

EDIT: Friend told me to take a peek at duty cycles. Yeah, no bueno. Back to 93.

12.8-13 (gas scale) seems about right for E85, maybe try a little leaner.

I run 2001 injectors in my VVT swapped NA8 but I use the NB FPR so the 300 cc rating should be close. I hit 92% DC with those with ~e70 on a stock longblock. I'd like to test ~e100 in the car just for shits and giggles but not with those DC's. Probably going with FF 640's unless I can find real EV14 440's. I know the 640's supposedly idle very well but it's 50% more injector than I need. Although it would be tough to go anywhere else considering the great reviews they have.

I believe you need the NB 60psi fpr setup to be able to run e85 on stock injectors