I'm currently running an MS2 on premium unleaded fuel (98RON) and am looking to go to E85 (104RON )
I realise I'm going to have to make some changes to AFR and fuel maps, but my question is; is anyone else running E85 who might be able to help me with how the AFR map will look? I've had everything from 'don't change a thing' to 'you'll have to base it on an AFR of 9.7 rather than 14.7' and so Im confused as to what's needed before I fire it up. I realise also that it needs more fuel and my injectors can handle that, but I'm hoping for a starting point so I don't run too lean and burn things, and conversely don't run so rich it wont run!
Any advice would be appreciated.
Cheers, Marc.
1968 VW Type 1 Baja 2332cc, Borg Warner K16 Turbo, Quad throttle body injection, MS2
while the "real" AFR is different for E85 and standard fuel, you can leave your AFR-map as it is. The reason is that your lambda probe is measuring lambda instead of AFR and does the job for you!
You will need to increase your req_fuel by 25...30% and maybe have a slight retune of your VE-map. The next step is to play around with ignition timing to gain some torque - mainly in the lower revs.
The only bad thing is starting when it is cold outside. Here you need a LOT more fuel for cranking and the first seconds after starting. Also AE can get a little bit more tricky. (or a real mess on SPI-engines)
Best Regards, Mario
Peugeot 106 Sergio_Tacchini, 1124cm³, MS2/Extra pre3.3alpah15, E85
Citroen AX, 954cm³, MS2/Extra pre3.3alpha15, E85
Peugeot 106 Rallye, 1298cm³ ... waiting for ITBs and full sequential injection
Thanks so much for that. The whole lambda/AFR confuses a simple carburettor guy like me! But my thinking was along similar lines, so that's good to have that confirmed!
I'll take that advice into account when I'm doing the set-up, and hopefully it doesn't get as cold here in Oz as it does in Germany so I can get the cold-starts set up too.
Thanks again for your help.
Marc.
1968 VW Type 1 Baja 2332cc, Borg Warner K16 Turbo, Quad throttle body injection, MS2
The good thing is, E85 burns alright (read: safely) over a much wider AFR than gasoline, so getting it started and running isn't much of a hurdle. I just used some fuel maps based on my engine and gasoline, and added 30% to start. I was having trouble with cold starts, so I know I've got to get the idle tuned for more stability before moving on to that, but overall it wasn't a huge deal to make the switch.
I started running mine on e85 recently. Mostly, I wanted to use it on the race track. I have been using Sunoco 110 leaded. Now that's up to about $10 a gallon; e85 is still $3.19. I burn about 30-35 gallons of fuel on a race week end.
Creating the new maps was not difficult, but not a simple swap either. Alcohol has some different characteristics. I started out by increasing the required fuel by 25%. That wasn't nearly enough. I had to play around with that until I got it close. I set the fuel map using data logging and MLV just like gas.
You certainly need to add more fuel, usually done by increasing the pulse width. Be sure and check your data log. At max load, make sure your duty cycle remains <85-90%. If your duty cycle is too high, consider increasing fuel pressure, or multiple squirts per engine cycle.
I'm still playing around with the timing to get it where I want it. Because e85 runs cooler and is about 100 octane, you can run more ignition timing, especially at low rpm and heavy load.
Cruising AFR can be a lot leaner. My engine is pretty radical, and cylinder pressures are pretty high. For protection, I tend to run it a bit rich on the street. with e85, I can run as lean as 15.5 on light cruise, so I burn less fuel on the street. I also added more vacuum advance, which also helps.
I went racing a couple of weeks ago. The car ran great - very smooth, very fast. I burned a little more fuel than I had in the past, but not as much as I thought I would. Definitely saved me a bunch of money on fuel.
All in all, I'm pretty happy about the way it runs. And the exhaust smell is certainly different.
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.boB
LS6 Track Car
Mostly stock. Sort of.
MS3X- Built by DIY AT
.boB wrote:...If your duty cycle is too high, consider ... multiple squirts per engine cycle ...
Actually, that's the opposite. Running more squirts will give you less fuel because the injectors will spend more time in the opening phase which doesn't provide fuel. To get the maximum out of the injectors, you want a single squirt per cycle (which is what you get if you run full sequential).
Not in my car. My injectors are too small for the power I make; especially with e85. Using a single injector event puts the injector duty cycle up around 95% on racing gasoline. Going to 4 injector events per engine cycle (720*) feeds the engine really well. With alcohol under a full load, it doesn't go lean.
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.boB
LS6 Track Car
Mostly stock. Sort of.
MS3X- Built by DIY AT
If you car doesn't behave that way there is something fundamentally wrong somewhere. Think about it: how can you provide more fuel if you spend 4ms (assuming a dead time of 1ms) of the available time not injecting fuel instead of spending 1ms. That doesn't make sense. So something in your fueling system is not behaving correctly. Make sure you're not losing fuel pressure somehow.
Saying that it works for you and what I'm saying is just theory doesn't change the facts. I just shows you don't understand the issue and that there has to be something wrong with your setup. I don't care if you don't understand and it won't affect my sleep either way.
Just thought I'd update on how the E85 is working.
I went for the 'upping the req_fuel' option and it's working a treat.
When I first filled with E85 I only was able to do about 2/3 of a tank so I wasn't going to get the full effect, more like E55 I guess. Rolled out of the gas station and within 100 yards she was coughing and playing up, so I pulled over, plugged the laptop in and bumped the req_fuel 25% to start with. Engine instantly ran sweetly (man I love tuning with an MS2!) so I set the auto tune and went for a run. It didn't change the VE map much so I think I fluked it with the 25%. When I next filled up it took nearly a whole tank so I'm pretty close to true E85 now (it's autumn/fall here now so the E85 is pretty much still E85, not the E70 that it will be in full winter) and I had to do the same trick with the req_fuel but this time only about 8% on top of the 25% I'd already done. Again with autotune but this time it richened very slightly across the table so my 8% maybe should've been 9% but it seemed to handle it.
With the higher octane, I've also been able to add a degree of advance across the whole table and she runs like a rocket.
So I now have a car that runs very smoothly and strong on cheaper fuel! All good! My only issue now is planning my driving so that there are gas stations with E85 along the way!
Thanks for the advice on this topic everyone.
Cheers, Marc.
1968 VW Type 1 Baja 2332cc, Borg Warner K16 Turbo, Quad throttle body injection, MS2
There's a little more to it than simply change the required fuel. That's a pretty good start, though.
- Higher octane and cooler intake charge means you can sometimes run a leaner mixture, especially at light throttle cruise.
- just because you can add more timing, doesn't mean you should. Sometimes more timing will cost you power and economy.
If you don't have access to a dyno, you'll have to experiment a bit to get what you want.
- E85 isn't always cheaper to run. It all depends on conditions. The alcohol is cheaper, but you burn more of it. I switched to E85 for track use, because Sunoco 110 is about $10 a gallon. It saved me a bunch of money on the last race week end. For the street, I don't plan to use it very often.
The biggest problem with using E85 is it's inconsistent mixture. It could be 85%, or it could be 70%. If you mix in some regular pump gas, it could be as low as 55% - like you said. The tune really changes depending on the mixture. You need a way to adjust the pulse width accordingly.
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.boB
LS6 Track Car
Mostly stock. Sort of.
MS3X- Built by DIY AT
here in my area i can even see different mixtures at one gas station in short periods of time. If you take some glass, put some E85 in it and look at it a few days or weeks later, you can see the mixture falling into its fractions. If you give a small (and known) shot of water to it, you can check the percentage quite easily. (water + alcohol = fine, water + pump gas = bad)
On the weekend i had my first try with E85 on an old motorbike with carburettor. (based on an Awo / Simson 425 Sport, 1957, 250cm³, tuned to around 25hp@8500) As expected, i had to mount bigger jets for idle and full load. What i did not expect, was that i had to hang the needle for part-load that much higher. (i had to mount another needle and needed to mount it in the top position - that means the cone was sitting nearly 2cm above the position with pump gas) The bike was already running on a MS-based ignition-system but i am still having trouble with the reliability of the pickup and cables - so it was running on the stock magnetic ignition last weekend. Although the setup in lower loads is still ugly, it is running really powerful on the track.
Best Regards, Mario
Peugeot 106 Sergio_Tacchini, 1124cm³, MS2/Extra pre3.3alpah15, E85
Citroen AX, 954cm³, MS2/Extra pre3.3alpha15, E85
Peugeot 106 Rallye, 1298cm³ ... waiting for ITBs and full sequential injection
Started running E85 for the first time today. Tuned and think it's pretty good. Watching my AFR - looking to be safe in boost. The 96lb injectors are miracle makers.
joeyb wrote:Started running E85 for the first time today. Tuned and think it's pretty good. Watching my AFR - looking to be safe in boost. The 96lb injectors are miracle makers.
Are those low impedance?
Also you guys talking about inconsistent E85 blends (I've read about this) wouldn't a flex fuel sensor help?
1995 Ford Lightning. Dart based 427 Windsor, Novi 2000, full sequential, E-85, etc. MS3X/v3.57 http://www.buildpics.org/
joeyb wrote:Started running E85 for the first time today. Tuned and think it's pretty good. Watching my AFR - looking to be safe in boost. The 96lb injectors are miracle makers.
Are those low impedance?
Also you guys talking about inconsistent E85 blends (I've read about this) wouldn't a flex fuel sensor help?
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