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      10-31-2012, 02:19 PM   #23
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Originally Posted by M3PO View Post
Some of the supercharged guys are running 180+% of stock power with the stock pump. It's safe to assume that they need at least 80% more fuel to do that. Running E85 on an NA car is going to require much less than that (~25% more) so the stock fuel pump will not be overworked.
must remember that on a SC car boost and the required fuel for it is linear/or fuel pressure is directly correlated to boost. This is why FMU type regulators work fine. As boost increases, extra fuel pressure is increased. It's not really an apples to apples comparo for tuning on a turbo or e85. That being said, rather than worry, why not throw a 100-200 dollar pump in to be safe. It's safety margin. Again I would rather underwork a larger pump than push a smaller one to keep up.

E85 is more of a constant demand, on a SC car the car is not always in boost.
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      10-31-2012, 04:40 PM   #24
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So where does the constant demand for E85 come from? If the throttle position is calling for fuel, it's going to deliver it. When you go part throttle or WOT, fuel is delivered accordingly. Why would this be different for E85 vs NA vs FI?
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      10-31-2012, 05:04 PM   #25
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So where does the constant demand for E85 come from? If the throttle position is calling for fuel, it's going to deliver it. When you go part throttle or WOT, fuel is delivered accordingly. Why would this be different for E85 vs NA vs FI?

your a little off; throttle position (TPS) is amount of input applied; not volume of fuel which is dictated by the max injector flow rate. E85 burns at a totally diff rate than gas and requires @ 48% more volume of flow.
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      10-31-2012, 05:28 PM   #26
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your a little off; throttle position (TPS) is amount of input applied; not volume of fuel which is dictated by the max injector flow rate. E85 burns at a totally diff rate than gas and requires @ 48% more volume of flow.
Thanks. My comment was in response to yours on the constant demand for E85 vs standard. I brought in throttle position as a way to illustrate imposed demand that is common regardless of the fuel.

Volume of dispensed fuel is not dictated by the max injector flow rate - it is a direct response to the input of the throttle. The max injector flow rate is a limiting factor used to determine the maximum volume of fluid it can dispense in a given time frame.

I didn't know that E85 requires 48% higher flow. Thanks for that. These are figures that are useful.
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      10-31-2012, 05:43 PM   #27
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Quote:
Originally Posted by CarbonFoot View Post
Thanks. My comment was in response to yours on the constant demand for E85 vs standard. I brought in throttle position as a way to illustrate imposed demand that is common regardless of the fuel.

Volume of dispensed fuel is not dictated by the max injector flow rate - it is a direct response to the input of the throttle. The max injector flow rate is a limiting factor used to determine the maximum volume of fluid it can dispense in a given time frame.


I didn't know that E85 requires 48% higher flow. Thanks for that. These are figures that are useful.


yes, semantics but you get it. You need to compensate for the additional volume needed.
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      10-31-2012, 06:07 PM   #28
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yes, semantics but you get it. You need to compensate for the additional volume needed.
Thought it would be interesting to share the visual differences between the stock injector nozzles and the upgraded injectors for an SC application.
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      10-31-2012, 06:26 PM   #29
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while just looking at pics is really a moot point, what is interesting is the actual pintle design; the OEM is a 6 point design the A/M is 4
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      10-31-2012, 07:14 PM   #30
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Lol...yes, that would be the interesting part.
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      11-01-2012, 11:38 AM   #31
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Well this is easy to clear up for the OP as I experimented with e85 in all types of mixtures on a completely stock car, with no injector or pump upgrade, no tunes or nothing, simply for the octane and cooling effects.

It makes a HUGE difference and the car is really noticably quicker with 3 gallons of 85 and the rest 91.

The problem however is our injectors and pump simply cannot handle it. Car could not be driven over 7k rpms and would simply sputter like crazy during wot higher than 7k. Or even at 6500 k when going up hill or any additional load on the car.

I tried 2 gallons but essentially did the same only took a bit more load. Higher than that was not even tried.

I was a bit baffled as I know the n54 guys and many cars run it stock without upgrading injectors but I realized the key is that en engine running to 8400 rpm, requires such a mass amount of air and fuel at that rpm that since using e85 requires more fuel to be put out for that air than normal gasoline, it simply could not keep up and sputtered like crazy.

Sad part is the car did feel really damn strong until the engine temp got a bit high and rpms climbed. Took the fun out of the driving for me as I love going to 8400 all day.

Now if you are someone who does not rev the car, you will see a nice pull under 6k rpms. HOwever 1st and 2nd were not usable under WOT. THe load in 1st and 2nd would cause sputering at 4-5k rpms

A high rpm engine in the 8400 range simply has a much more enormous air requirement and such little time for fuel pulses to shoot fuel in, you would need bigger injectors and pump. Which then require a tune etc.

So if you know someone that can tune and someone who can upgrade injectors and pump, i promise you that it makes a huge difference even on a stock car.

I said screw it and now I order 55 gallon drums of 108 unleaded race fuel and mix in 3-4 gallons.

When first doing the e85 and seeing sputtering I went back to normal gas and it went away and then I tried e85 again and same sputer. So it was not a bad batch of e85 or anything.

Essentially our cars cannot run on e20 which is what that mix essentially was. N54 guys are running like 50 percent mixes on stock parts but low revving engines to 6500 really probably requires half as much air and fuel per cycle than does 8400 m3.

So bottom line, can't be done if you want to at all drive the car beyond 3-4k rpm!
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      11-01-2012, 02:25 PM   #32
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^^Thanks for sharing the results of your testing.

I was thinking of doing pretty much what you did in order to determine if the increase in performance was worth it and if the fueling system would handle it in stock form. Based on your experimentation, it doesn't seem feasible or practical to limit the effective rpm range to prevent sputtering.
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      11-01-2012, 03:14 PM   #33
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Heed others advice at caution; I for one would never just run e85 in my tank w/out setting the car the prop to make power.
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      11-01-2012, 04:36 PM   #34
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Heed others advice at caution; I for one would never just run e85 in my tank w/out setting the car the prop to make power.
Why would he take my advice with caution? I am telling him not to do it because I have experience with it.

You actually don't need to "setup the car for power" Cars, such as the n54 engine cars make gobs of more power from simply running e85 on a stock motor and tune. Its just simply that the m3 fuel system cannot keep up with demands so its useless even at very small mixtures.

If you want to do it on the m3, you need injectors and probably a pump, which then in turn requires a tune to properlyoperate them.

But e85 does not require a tune to benefit just like race gas, if the fuel system can accomodate.

I am a bit surprised that our fuel system cannot compensate for a mix of e20. That is not far from where we likely will be going in this country in 5 years. Atleast e15 will be here. I am surprised the fuel system does not have more reserve built in
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      11-01-2012, 05:44 PM   #35
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Of course this is just a theory but. I think because of the slower burn rate of the E85, people need to consider piston speed and flame speed. In a high reving motor (ie 8400rpm S65) the piston speed simply outruns the flame. Thats when you get sputtering detonation etc occurs. I don't have the specs, but I think the N54 has a lower piston speed (shorter stroke) than the S65. This could be one of the reasons why those guys can run higher mixes. Also the turbo helps with moving more air.

That being said, I don't know how those HPFP are survining. I changed my HPFP 3 times under warranty on my old 535
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      11-05-2012, 04:06 AM   #36
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Quote:
Originally Posted by Munit View Post
Well this is easy to clear up for the OP as I experimented with e85 in all types of mixtures on a completely stock car, with no injector or pump upgrade, no tunes or nothing, simply for the octane and cooling effects.

It makes a HUGE difference and the car is really noticably quicker with 3 gallons of 85 and the rest 91.

The problem however is our injectors and pump simply cannot handle it. Car could not be driven over 7k rpms and would simply sputter like crazy during wot higher than 7k. Or even at 6500 k when going up hill or any additional load on the car.

I tried 2 gallons but essentially did the same only took a bit more load. Higher than that was not even tried.

I was a bit baffled as I know the n54 guys and many cars run it stock without upgrading injectors but I realized the key is that en engine running to 8400 rpm, requires such a mass amount of air and fuel at that rpm that since using e85 requires more fuel to be put out for that air than normal gasoline, it simply could not keep up and sputtered like crazy.

Sad part is the car did feel really damn strong until the engine temp got a bit high and rpms climbed. Took the fun out of the driving for me as I love going to 8400 all day.

Now if you are someone who does not rev the car, you will see a nice pull under 6k rpms. HOwever 1st and 2nd were not usable under WOT. THe load in 1st and 2nd would cause sputering at 4-5k rpms

A high rpm engine in the 8400 range simply has a much more enormous air requirement and such little time for fuel pulses to shoot fuel in, you would need bigger injectors and pump. Which then require a tune etc.

So if you know someone that can tune and someone who can upgrade injectors and pump, i promise you that it makes a huge difference even on a stock car.

I said screw it and now I order 55 gallon drums of 108 unleaded race fuel and mix in 3-4 gallons.

When first doing the e85 and seeing sputtering I went back to normal gas and it went away and then I tried e85 again and same sputer. So it was not a bad batch of e85 or anything.

Essentially our cars cannot run on e20 which is what that mix essentially was. N54 guys are running like 50 percent mixes on stock parts but low revving engines to 6500 really probably requires half as much air and fuel per cycle than does 8400 m3.

So bottom line, can't be done if you want to at all drive the car beyond 3-4k rpm!
This was not due to a lack of capacity in the fuel system, but due to the different stoichometric ratios and the engine not supplying the proper amount of fuel because the target AFR was not changed.

Gasoline expects the AFR to be mid 14's, and that is what the car is told that it has so that is what the car delivers. E85 expects it to be high 9's, but the car doesn't know that so it still delivers mid 14's. Dangerously lean, but with no load not as noticable. This is worse at WOT when the required AFR is a few points richer, and that is where your stumble shows.

That's not to say that just because S/C guys have fuel supply that the N/A guys will, because various setups all tax the fuel system in different ways, even at the same power level. On a mostly stock/bolt on car though, fuel supply is not an issue with either fuel.

Also, there is FAR more to the injector that determines the IFR (Injector Flow Rate) than just the tip or number of holes.
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      04-16-2013, 05:13 AM   #37
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To clarify things, the N54 cannot run any form of E85 mixture using stock parameters.

The guys who run E85 mixtures have tunes to up fueling needs up to an E50 content. Power is made from allowing it to run more boost, cleaning up ignition corrections, or advancing ignition in some cases. No other upgrades are needed. I ran an E50 mixture running over 400rwhp/tq for a good year, using methanol on top to cool IAT's only; I would otherwise max at 375rwhp range with just a tune + methanol (to give an idea how much an E50 setup helps with power) No hiccups, no issue's, and I feel was a reliable source of power. But N54 guys also have DI.

Any mixture beyond E50 requires either a 1) Walbro inline booster ($100 or so) or 2) upgraded Walbro LPFP ($300).

Another plus I see running either straight E85 or an E85 mixture is that it cleans up exhaust gas smells, perfect for anyone who wants to run test pipes+X-pipes (catless) and worry about gas smells, it almost eliminates it

I'm thinking of picking me up a Procede Piggyback system that allows logging of a/r ratio's, adjustments of fueling, ignition timing control advancement + more through a laptop to see if I can "tune" things for an E50 mixture. Procede is well-known in the N54 world and have e85 tunes for them. I'd like to go with a real tune/flash system, but none seems to offer the ability to log the car, which I'm OCD about, so Procede may be on my list.
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