Running e85 in 3.4L 3rd gen 4runner Supercharged

[CASPRO]

Whats up everybody I'm new to this forum. I have a 1998 supercharged 4runner. I was curious if anybody out there is running e85 with a supercharged 4runner. Would it be possible? Would it be safe without any conversions?

 

[fish0281]

Not sure, but I think you would have to at least run bigger injectors and re-map the ECU for optimum performance with an E85 blend...

 

[badattitude]

I think e85 is 85 percent ethanol. No, we can't use that. You need 92 octane in a supercharged 5vz.

 

[Greg_Canada]

I think e85 is 85 percent ethanol. No, we can't use that. You need 92 octane in a supercharged 5vz.

Don't listen to this guy. He has no idea what he is talking about. E85 is about 95 octane...

However, you need to tune the ECU for E85, and you also need larger fuel injectors. Do you have a programmable piggyback computer, or a standalone ECU?

 

[Dous]

Well also keep in mind these vehicles were not designed to run E85 so I would be hesitant to use it. The fuel hoses are already old, and the E85 degrades rubber lines, so something to keep in mind

 

[CASPRO]

[MENTION=85423]Greg_Canada[/MENTION] I dont have large fuel injectors just stock. But i was thinking about getting the 7th injector would that help? It's stock ECU.

 

[Greg_Canada]

Well also keep in mind these vehicles were not designed to run E85 so I would be hesitant to use it. The fuel hoses are already old, and the E85 degrades rubber lines, so something to keep in mind

It's been shown that's a myth. Many 95.5 - 04 tacoma guys are running e85 in their boosted builds, same fuel system.

[MENTION=85423]Greg_Canada[/MENTION] I dont have large fuel injectors just stock. But i was thinking about getting the 7th injector would that help? It's stock ECU.

You'd need both. Best would be to first research forums, then to call gadget at urdusa.com and he can steer you in the right direction. We dont have e85 up here or i'd be trying it.

 

[Chandlerdoom]

Would be sweet but I don't see the real advantage. If your looking to make more power you need to know what the breaking point is for these engines.

E85 is great, it's cheap,105ish octane rating*, burns cooler, and you can run tons of boost. But mpg will drop because our compression ratio isn't ideal for fuel economy and running e85.

But you'll need bigger injectors, bigger fuel pump, or two fuel pumps, and a tune


I see E85 as a poor mans race gas, although many shops have proven to make more power on E85 against race gas (vp117)

So what's the reason why you want to run e85?

 

[S14]

Don't listen to this guy. He has no idea what he is talking about.

:whipping2


Ethonal blends cannot be easily converted to octane numbers due to the way octane is rated, and the different properties of ethonal/methonal.

A fun read that might need an engineering student to translate:
http://delphi.com/pdf/techpapers/2010-01-0619.pdf






OP: Long story short is that E85 is great for engine with high compression or high cylinder pressure (turbo). the little 2 liter turbo guys love the stuff because of the way ehtonal sucks the heat out of the intake temperature, they can safely run more boost(one of many of E85's advantages). I think the TRD supercharged 5vz would welcome E85 nicely, but the engine should be tunned on a dyno by a reputable tunner.
Be advised though is that E85 reportedly has worse fuel economy over regular fuel. Approx 30% more E85 needs to be pumped into the motor, so often higher rate fuel injectors and sometimes higher output fuel pumps are needed.

 

[S14]

@Greg_Canada I dont have large fuel injectors just stock. But i was thinking about getting the 7th injector would that help? It's stock ECU.

6 correct injectors for the flow rate the engine requires and a correct tune is what you need.

 

[98OzarksRunner]

I burned E85 in my 65 Mustang with 4.6L motor (and tuned it myself, with Special Forces software). With high compression (10.5:1) and roots/Eaton blower (10# boost) it worked great. E85 is between 105 and 108 octane (depending on winter or summer blend - winter is 70% ethanol, summer is 85% ethanol). It is a great fuel - the poor man's racing gas (or the thinking man's racing gas!).

The advantage to E85 is higher octane, and it burns cooler to boot (since it's mostly alcohol). It is great for supercharged or turbocharged motors. The downside is fuel economy is not as good as gas - typically about 20-25% less, due to the fact that ethanol contains less energy per gallon than gas.

To burn E85 you have to increase the fuel flow, since E85 has a richer stoich point (about 9.? - don't remember off hand - to 14.7 for gas). The rule of thumb is 50% increase in injector size. You usually have to increase the fuel pump capacity as well (I ran 60# injectors and dual 255 LPH pumps @ 550 HP in my Mustang, that fuel setup would support about 650 HP), and often the size of the fuel lines (I ran 1/2" feed with 3/8" return line). You can run more timing, to make more power. It is also almost impossible to get detonation with E85. Tuning for E85 is tricky and you'll need to do it on a dyno, since you can advance the timing past peak torque (and actually lose power) before detonation (gas tuning is easy - push the timing until it pings and back it off a bit). You'll have to remap the fuel tables as well, which will require tuning software.

In short, burning E85 will do away with spark knock and let you run a little more timing (actually quite a bit more). Typical supercharged engines (e.g. 4.6 Cobra Mustangs) make about 10% more power due to the more aggressive tune. But it's is expensive to do - injectors, fuel pumps, maybe fuel lines, tune. Unless you're running a lot more than stock boost (ported blower, pulley) or a turbo, it's probably not worth it on a 4Runner.

The other problem with E85 is availability. I had about 8 stations in my area that sold it so I always knew how much fuel I had. It wasn't bad for a weekend cruiser/stoplight import killer, but I wasn't able to drive it cross-country since E85 isn't always available. I had a backup tune I could load and burn 93 octane to baby it home if necessary, but never had to use it.

Here's Plain Jane (sold it last October): http://www.cardomain.com/ride/3838887/1965-ford-mustang/

 

[FancyPantsMcGee]

my .02:
If your not currently experiencing any predetonation(read knock) then you probably will not benefit from E85. It is ~105 octane(anything over 100 octane is calculated, not measured, hence the variations from different people).
the stoich of e85 is something like 9:1(don't quote me), and therefor requires more fuel to burn properly. about 30% more than gasoline. So you'd need to have approximately 30% larger injectors and fuel pump, as well as a fuel controller. the factory ecu isn't going to figure it all out on its own.
If your at sea level and struggling to get your 5v"Z"fe to run without knocking you should definitely start reading up.

 

[Greg_Canada]

my .02:
If your not currently experiencing any predetonation(read knock) then you probably will not benefit from E85. It is ~105 octane(anything over 100 octane is calculated, not measured, hence the variations from different people).
the stoich of e85 is something like 9:1(don't quote me), and therefor requires more fuel to burn properly. about 30% more than gasoline. So you'd need to have approximately 30% larger injectors and fuel pump, as well as a fuel controller. the factory ecu isn't going to figure it all out on its own.
If your at sea level and struggling to get your 5v"Z"fe to run without knocking you should definitely start reading up.

Untrue, just because he isn't experiencing knock, does not mean the ECU is not pulling timing. The toyota ecu advances timing until it knocks then backs off. With the e85 it will run more timing.

 

[FancyPantsMcGee]

Untrue, just because he isn't experiencing knock, does not mean the ECU is not pulling timing. The toyota ecu advances timing until it knocks then backs off. With the e85 it will run more timing.

Are you sure?
Your argument is the same as 85 vs 91 octane. Prepare for fierce opposition from the masses.:deadhorse:
Factory ecu design and compression ratios play a large role in this, and I do think you're making an assumption. You are saying the factory ecu will advance endlessly to find knock. I doubt this very much. You're going to reach the limits of your camshafts, ecu, and engine design very quickly.
If what you say were true, everyone would run 91 octane. but realistically, most engines just don't have the capacity to "utilize" higher octane fuels.
I have found myself on your side of the fence in this theory. However, it turns out every engine is different, and so some logic must be followed. If your engine knocks, move to higher octane. If no knock.......:shrug:
Now if you had the ability to advance the timing yourself, that would be something.
I'd love for someone running E85 to chime in. If I could buy E85 in my town, I'd gladly do some experiments.

 

[Greg_Canada]

Are you sure?
Your argument is the same as 85 vs 91 octane. Prepare for fierce opposition from the masses.:deadhorse:
Factory ecu design and compression ratios play a large role in this, and I do think you're making an assumption. You are saying the factory ecu will advance endlessly to find knock. I doubt this very much. You're going to reach the limits of your camshafts, ecu, and engine design very quickly.
If what you say were true, everyone would run 91 octane. but realistically, most engines just don't have the capacity to "utilize" higher octane fuels.
I have found myself on your side of the fence in this theory. However, it turns out every engine is different, and so some logic must be followed. If your engine knocks, move to higher octane. If no knock.......:shrug:
Now if you had the ability to advance the timing yourself, that would be something.
I'd love for someone running E85 to chime in. If I could buy E85 in my town, I'd gladly do some experiments.

I will quote Gadget from this thread: Timing advance does not work on Mapecu2 - CustomTacos.com Forum

The MAP-ECU2 does retard and advance timing just fine.

Remember that the ignition timing on these trucks is DYNAMIC and it is always self tuning and adjusting the timing to the knock threshold hundreds of times a second.

Also remember you have taken a normally aspirated engine and have converted it to forced induction. When you jam more air into the cylinder you will lower the knock threshold so it will now be lower than stock.

If your ECU has pushed the timing out to the knock threshold and you have added 5 degrees of timing advance, YOU HAVE NOT ALTERED THE KNOCK THRESHOLD. The ECU will just pull out 5 degrees of timing.

Just because you made 271 HP and add a few degrees of timing with the MAP-ECU2 and make the same 271 HP does not mean it has not advanced the timing. If the ECU is already at the knock threshold it will just take out what you put in.

Now thing will get very dangerous. The ECU only has a LIMITED ability to retard timing to supress knock. Again, remember you took a normally aspirated engine and have converted it to forced induction. The ECU is not calibrated for a forced induction engine.

If you keep jacking in timing and the ECU keep pulling it out you will fast reach the point where the ECU cannot pull out any more and then if it knocks the ECU can no longer protect the engine and the engine will pop.

I know this is a hard concept to understand for some reason, but even very smart people sometimes needs a visual demonstration.

Peter, the owner of PMR the makers of MAP-ECU came to the US to visit with me. During this time we went out and tuned a truck together. It was a Taco with an STS system on it.

He told me to jack in some timing. I told him it will not do anything in boost. So, to show him, we did a power run and monitored the ignition advance on the scan tool. It was say 18* at WOT and full RPM. I jacked in 5* of advance and did another run. Now the timing on the scan tool dropped back to 13* of advance. The engine was at the knock threshold, something we cannot change and the ECU took out what we put in. The end result was no power change and we reduced the ECUs control authority to retard timing if needed to protect the engine.

This is all explained in the version of the U-Tune Guide I wrote for the AIC units.

The best approach here is to do a lot of data collection on your engine before you go strapping a turbo or supercharger to it. One of the many things you will want to know is what the ignition advance is at WOT and full RPM. Normally this is somewhere around 18-20* depending on engine and conditions.

Now you bolt up your forced induction system. After you get your fuel dialed in and you think your tune is straight, do a power run at WOT and see what the ignition advance is at full RPM. Lets say the boost has knocked your knock threshold down to 13*. The ECU has used up 5 degrees of its retard capability. How much authority does it have to retard timing? That is like asking how many licks does it take to get to the center of a tootsie pop. Know one really knows on most of these Toyota ECUs.

What if it can only retard 6* and you have used up 5 of it? Get the engine a little hot on a hot day and maybe the gas you got is not the greatest and the knock threshold drops. The ECU now needs 8* of retard to protect the engine. It needs 2 more than it has the ability to. Now you are driving around with knock and the internal engine parts are superheating because of all that energy that is going into the internal parts. You will quickly get things hot enough to start detonation and you just popped your engine.

So, what I like to do is to restore much of that retard authority as practical so the ECU can retard timing as needed. I will add retard in boost until I see the ignition advance move forward to where it was on the stock engine. In this example I have added 5* of retard and the scan tool is reporting the same 18* advance as it had stock and you have restored the ECU's control authority to retard timing in response to knock to protect the engine.

It is also important that you do not add to much retard. If you drop it to far you will loose power and send a lot of heat down the exhaust and over heat the cats. You can also induce knock with to much retard, but that is a more advanced lesson...

Yes, on some engines, the ECU programming is overly conservative. You maybe able to add some advance in vacuum where the ECU is not advancing enough to get to the knock threshold, but be very careful.

The MAP-ECU2 does retard and advance ignition timing. You just have to understand more of what is going on. You also have to never forget that ignition timing is dynamic and always self adjusting in an effort to get it to and keep it at the knock threshold.

Gadget
___________

 

[FancyPantsMcGee]

interesting bit of info, I think I've read it before.

"How much authority does it have to retard timing? That is like asking how many licks does it take to get to the center of a tootsie pop. Know one really knows on most of these Toyota ECUs."
"The ECU is not calibrated for a forced induction engine."

This is all I was saying. If you fill up on e85, you will increase the knock threshold I agree. But that doesn't mean the engine/ecu is capable of putting it all to the ground smoothly.
E85 is a hot topic right now, someone needs to try it out and post up!

 

[98OzarksRunner]

This is all I was saying. If you fill up on e85, you will increase the knock threshold I agree. But that doesn't mean the engine/ecu is capable of putting it all to the ground smoothly.
E85 is a hot topic right now, someone needs to try it out and post up!

If you fill up with e85 (without new injectors and tune) you will definitely have knock (if it runs at all) since it will be way too lean (i.e. don't do it!) The ecu will have a maximum timing value based on the type of gas recommended (though it may push it to 93 octane settings then backoff if knock is detected, but I doubt it). It won't just increase until it detects knock and back off. Detonation is considered an abnormal condition, not a normal input parameter used to set timing.

To use e85, and get any benefit from it, you have to up the fuel system capacity by at least 50% and retune the ecm, including the timing and fuel tables. As I noted earlier, e85 tuning is tricky and you need an a/f gauge (wideband O2 sensor) and a dyno (to get the most out of it) and learn a lot about efi theory or take it to a tuner who knows e85.

 

[JayRolla]

If you fill up with e85 (without new injectors and tune) you will definitely have knock (if it runs at all) since it will be way too lean (i.e. don't do it!) The ecu will have a maximum timing value based on the type of gas recommended (though it may push it to 93 octane settings then backoff if knock is detected, but I doubt it). It won't just increase until it detects knock and back off. Detonation is considered an abnormal condition, not a normal input parameter used to set timing.

To use e85, and get any benefit from it, you have to up the fuel system capacity by at least 50% and retune the ecm, including the timing and fuel tables. As I noted earlier, e85 tuning is tricky and you need an a/f gauge (wideband O2 sensor) and a dyno (to get the most out of it) and learn a lot about efi theory or take it to a tuner who knows e85.

E85 tuning is not tricky, its just like tuning any other fuel. True you would need an wideband o2 too tune but thats true on any fuel. I have tuned e85 cars for many years and its easy since it never wants too knock even when running really lean!!

 

[98OzarksRunner]

E85 tuning is not tricky, its just like tuning any other fuel. True you would need an wideband o2 too tune but thats true on any fuel. I have tuned e85 cars for many years and its easy since it never wants too knock even when running really lean!!

I agree it's not rocket science, and getting the A/F right is the easy part. But getting the timing right really requires a dyno. The problem is not detonation, since it almost never detonates (though I wouldn't want to run it lean with boost) but that you can get too much timing and lose power (and still not get detonation), thinking 'if a little is good, more must be better' (an attitude not uncommon among the inexperienced).

 

[Robb235]

Gonna bring this discussion back to the top.

I just picked up some green top 315cc Supra injectors in preparation for a turbo. Since stock injectors are 240cc, these green ones are 31% bigger, which is about how much more fuel flow you need when switching to E85. I see E85 stations all over Atlanta, so I'm kind of tempted to throw these larger injectors on and fill up with E85 and see how it turns out. I don't think I would get much benefit being N/A, but I think it would be cool to try out. I'd have to stick with E85 until I switched back to the smaller injectors, but that's ok since I use my wife's Civic for long road trips.