Running my Car (S3) on E85 (UPDATE - 7/6 PASSED!)
06-02-2011, 06:59 PM
#1
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Running my Car (S3) on E85 (UPDATE - 7/6 PASSED!)
I Have been almost exclusively running the 86.5 on E85 recently. When Gas prices went up I went to the pumps that sold E85 and started doing calculations about mileage, days of usage, gallons, and costs. I have complied some info, but that is not what I am posting about.
As I had suspected, I like it quite a bit. I installed a used FPR that is adjustable so I have turned up the fuel pressure a bit, as when you use stock fuel pressure on the 2.2LH it will go lean at WOT.
Because we have the 24lb injectors, we have more "headroom" for the higher (variable - not always 40%) amount of fuel needed in some cases. So at idle and at part throttle cruise, if you have a nice new MAF and new new injectors (or clean rebuilt ones) you will have enough fuel as the 02 sensor will obviously increase the duty cycle on the injectors to match what is needed.
If one was reading a petrol scale for AFRs only, and did not know that they had E85 in the tank, the numbers under 02 looping would look the same (assuming you have large enough injectors and high enough fuel pressure) - 14.7 for stoich. TECHNICALLY, on an E85 specific scale, that is around 9.5 or so. Power rich is more like 7:1 on that scale, and you would wish to stay down by 11 or below on the petrol AFR scale. .88 or so on lambda iirc.
The engine, which has 255,000 miles, sounds meaner, louder, and has more push at the lower rpms, even though I am still working through whatever the hell is making it stumble in some areas under 3k at part throttle.
I need to get an WB 02 and AFR gauge back onto the car (on a NB 02 now) so I can see what else is happening, but it looks like the stock configuration with stock tune is perfectly fine with slightly higher fuel pressure.
I replaced some of the pressure lines with the 30R9 5-16 line which is a flouro compound rubber - and is good even for methanol. I need to do that front side one as well this weekend I think, even though that is a sort of plastic hard line underneath a rubber cover from what I can see from the 91S4 I am working on right now.
Since I will eventually be doing a top -end refresh on this 86.5 I wanted to run E85 as much as I could until then to see what if anything will be happening to the intake manifold itself, as well as the ports and the back of the valves. Maybe even drop in a camera into the chamber to see whats what.
The pump is just a stock bosch pump. I will be putting in some "Ethanol treatment" to make sure the pump does not have fuel lubricity issues from too much exposure, but that will not affect whatever the outcome will be on the tank and hard lines.
I'm also going to check if I can pass smog with no cats on E85 hopefully this weekend.
As I had suspected, I like it quite a bit. I installed a used FPR that is adjustable so I have turned up the fuel pressure a bit, as when you use stock fuel pressure on the 2.2LH it will go lean at WOT.
Because we have the 24lb injectors, we have more "headroom" for the higher (variable - not always 40%) amount of fuel needed in some cases. So at idle and at part throttle cruise, if you have a nice new MAF and new new injectors (or clean rebuilt ones) you will have enough fuel as the 02 sensor will obviously increase the duty cycle on the injectors to match what is needed.
If one was reading a petrol scale for AFRs only, and did not know that they had E85 in the tank, the numbers under 02 looping would look the same (assuming you have large enough injectors and high enough fuel pressure) - 14.7 for stoich. TECHNICALLY, on an E85 specific scale, that is around 9.5 or so. Power rich is more like 7:1 on that scale, and you would wish to stay down by 11 or below on the petrol AFR scale. .88 or so on lambda iirc.
The engine, which has 255,000 miles, sounds meaner, louder, and has more push at the lower rpms, even though I am still working through whatever the hell is making it stumble in some areas under 3k at part throttle.
I need to get an WB 02 and AFR gauge back onto the car (on a NB 02 now) so I can see what else is happening, but it looks like the stock configuration with stock tune is perfectly fine with slightly higher fuel pressure.
I replaced some of the pressure lines with the 30R9 5-16 line which is a flouro compound rubber - and is good even for methanol. I need to do that front side one as well this weekend I think, even though that is a sort of plastic hard line underneath a rubber cover from what I can see from the 91S4 I am working on right now.
Since I will eventually be doing a top -end refresh on this 86.5 I wanted to run E85 as much as I could until then to see what if anything will be happening to the intake manifold itself, as well as the ports and the back of the valves. Maybe even drop in a camera into the chamber to see whats what.
The pump is just a stock bosch pump. I will be putting in some "Ethanol treatment" to make sure the pump does not have fuel lubricity issues from too much exposure, but that will not affect whatever the outcome will be on the tank and hard lines.
I'm also going to check if I can pass smog with no cats on E85 hopefully this weekend.
Last edited by BC; 07-07-2011 at 12:58 AM.
06-02-2011, 07:05 PM
#2
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Interesting ... isn't much of the concern about ethanol fuel that it is prone to attracting moisture in transport and storage? So that before it ever gets into your tank there is an unknown/variable risk of corrosion to flexible lines and other fuel system parts? Like maybe that goofy coupling in the internal fuel pump ;-)
06-02-2011, 07:17 PM
#3
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Tom -
The car does not have an intake pump (luckily) and no rubber is technically, permanently submerged. If it was, there would be problems I would assume. I have the strainer as the outlet of the tank, and will get the "Green Bay" type one as soon as I can (which has stainless screening - best for ethanol)
Ethanol is hydroscopic and attracts water. I may be saying that wrong, but it does attract water. I am in Socal, where is a very dry climate, so even when I tested E85 as it sat out day in, day out in my garage, completely open, all it did was slowly evaporate. Its water content did not change drastically.
The tanks that hold ethanol probably do have water in them. There are systems to make sure that does not become a major amount of what is in the tank.
Ethanol does not corrode, by itself. It attracts water which can cause rusting of untreated steel and other reactive metals. Aluminum is not allowed to create its oxide coating in alcohol, so it sometimes starts to create a white crumbling substance when in certain conditions.
Rubber will soften but not come apart. But with the Flouro- compound lines, there should be no problems.
The car runs somewhat warm on very hot days here (we don't have many at all) and I'd like to see how the ethanol will affect that tempature envelope during that time.
I should ask Ken if he could burn a chip with even more advance on the EZF side, because on the LH side, I am sure the power would be fine even with ethanol, just up the fuel pressure or use his "POT" to increase the duty cycle at WOT.
The car does not have an intake pump (luckily) and no rubber is technically, permanently submerged. If it was, there would be problems I would assume. I have the strainer as the outlet of the tank, and will get the "Green Bay" type one as soon as I can (which has stainless screening - best for ethanol)
Ethanol is hydroscopic and attracts water. I may be saying that wrong, but it does attract water. I am in Socal, where is a very dry climate, so even when I tested E85 as it sat out day in, day out in my garage, completely open, all it did was slowly evaporate. Its water content did not change drastically.
The tanks that hold ethanol probably do have water in them. There are systems to make sure that does not become a major amount of what is in the tank.
Ethanol does not corrode, by itself. It attracts water which can cause rusting of untreated steel and other reactive metals. Aluminum is not allowed to create its oxide coating in alcohol, so it sometimes starts to create a white crumbling substance when in certain conditions.
Rubber will soften but not come apart. But with the Flouro- compound lines, there should be no problems.
The car runs somewhat warm on very hot days here (we don't have many at all) and I'd like to see how the ethanol will affect that tempature envelope during that time.
I should ask Ken if he could burn a chip with even more advance on the EZF side, because on the LH side, I am sure the power would be fine even with ethanol, just up the fuel pressure or use his "POT" to increase the duty cycle at WOT.
06-02-2011, 08:33 PM
#4
Drifting
I ran 1 tank of E85 through mine without really thinking about what I was doing. It may have been a coincidence, but shortly thereafter I needed to have the WUR replaced. Does fuel flow through there or does it just regulate pressure indirectly?
06-02-2011, 09:22 PM
#5
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All the many moving parts of the CIS system does not sit well with me if I am thinking of E85 usage. The WUR is not something i have dealt with extensively, but isn't it just the vac operated Warm Up Regulator attached near the coolant bridge?
06-02-2011, 11:34 PM
#6
Man of many SIGs
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I'm glad to see you are finally burning some E85 in a 928 Brendan. I really don't think you need to worry about the fuel tank though. I've had a piece of a 928 fuel tank in a mason jar of E85 since 12-27-10 and it has not softened or lost any color to the ethanol. I think the tank will be fine. On a side note, just for kicks, I put a piece of fuel injection hose in the E85 and it turned the ethanol brown within a day or two and it is now neerly opaque. Of course I expected that but I thought I would share. Please keep us informed of your progress. 
06-03-2011, 12:53 AM
#7
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I'm enjoying the difference in feeling... Knowing that there is no possibility of knock. I'm running this car pretty hard.
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06-04-2011, 02:34 PM
#8
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Beautiful drive into work today in the sunshine of Socal. Only here for a few hours, and its my birthday. 
I think that if the timing were to be optimized and maybe a bit of fuel pressure adjustment for cold-idle fueling into low rpm take-off, and of course WOT, it could be used by anyone with an S3 or anyone with an S4 that wants to put in 24s or 36s and tune for that. The problem with S4s with 24s, is that then you would be permanently rich with petrol. With the S3's OEM tune file and slightly higher fuel pressure (adjustable) it seems like you can easily go back and forth.
I think that if the timing were to be optimized and maybe a bit of fuel pressure adjustment for cold-idle fueling into low rpm take-off, and of course WOT, it could be used by anyone with an S3 or anyone with an S4 that wants to put in 24s or 36s and tune for that. The problem with S4s with 24s, is that then you would be permanently rich with petrol. With the S3's OEM tune file and slightly higher fuel pressure (adjustable) it seems like you can easily go back and forth.
06-04-2011, 02:56 PM
#9
Nordschleife Master
Happy Birthday Brendan!
06-04-2011, 04:40 PM
#10
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Thank you. Interesting birthday today. Anyway.... This thing sounds great!
06-14-2011, 08:15 PM
#11
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I have just come back this afternoon from a smog test where I learned some new things.
I have attached the print out from the (failed) smog test.
Again, this is a non-cat 86.5 running ethanol, actually E85 for several weeks now. Air pump is hooked into exhaust pipe, but he could see there were no cats. He didn't like the no-air cleaner top, but if the car had passed, I think I could have sha-moozled on the "vacuum lines disconnected" issue.
As you can see, the car is technically seen as running rich. I really have thrown this guy for a loop. He cannot understand why the o2 is so high if its running rich!
The 02 sensor is in the loop during these tests, and at steady state, the computer is obviously trying to increase fuel to gain a stoich lambda, which for this fuel is around 9.5:1 - but it would look like 14.7 on a non-ethanol wide band readout.
What I do not know is whether the 24lb injectors which are new are at a very high duty cycle in this 02 loop.
I am trying to research this new information in reference to what it means in terms of the current state of fueling with the ethanol. Under 02 loop, there still is not enough fuel for the engine to feel or sound proper. As I have raised the fuel pressure to around 50psi base (jumpered pump, no vac), it goes to above 60 on vac. I need more info to go on from here with reference to whether the fueling is actually correct or not at WOT and transitions.
I have attached the print out from the (failed) smog test.
Again, this is a non-cat 86.5 running ethanol, actually E85 for several weeks now. Air pump is hooked into exhaust pipe, but he could see there were no cats. He didn't like the no-air cleaner top, but if the car had passed, I think I could have sha-moozled on the "vacuum lines disconnected" issue.
As you can see, the car is technically seen as running rich. I really have thrown this guy for a loop. He cannot understand why the o2 is so high if its running rich!
The 02 sensor is in the loop during these tests, and at steady state, the computer is obviously trying to increase fuel to gain a stoich lambda, which for this fuel is around 9.5:1 - but it would look like 14.7 on a non-ethanol wide band readout.
What I do not know is whether the 24lb injectors which are new are at a very high duty cycle in this 02 loop.
I am trying to research this new information in reference to what it means in terms of the current state of fueling with the ethanol. Under 02 loop, there still is not enough fuel for the engine to feel or sound proper. As I have raised the fuel pressure to around 50psi base (jumpered pump, no vac), it goes to above 60 on vac. I need more info to go on from here with reference to whether the fueling is actually correct or not at WOT and transitions.
Last edited by BC; 06-14-2011 at 08:22 PM. Reason: Adding info.
06-14-2011, 08:32 PM
#12
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I'm going to put cats on the car this week and run it again. The top of the airbox thing is irritating but I guess I need to get a used one from 928intl or something.
I think at those levels, I could easily run some very cheap cats if I chose to do so and be perfectly passable even with a much richer running engine than this.
I think at those levels, I could easily run some very cheap cats if I chose to do so and be perfectly passable even with a much richer running engine than this.
06-14-2011, 08:33 PM
#13
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Does someone have a non-cat emissions sheet like mine to compare?
06-14-2011, 08:55 PM
#15
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Jeez. Thanks for that neil. Looks like your CO was WAY WAY low on that run. I wonder what that means compared to mine.