Tanus

Ok so planning my build and wanted to know what would be the better route, FI too.
Which has a greater margin for tunning errors as it will be my first go at that?
Which has greater power potential?
Or is it worth it to run both? E85 and meth.
Also it'll be a2w if that matters

Wicked69

If you type that in and "search" there are tons of recent topics on this. The consensus was if E85 is readily available then use it. A lot depends on your compression, intended use, etc...

Search, "pump & Meth or E85" and a ton of threads will come up and probably answer your question though.

fotoboy

iTrader: (1)

I run e85 and meth. Most say meth is not needed in a e85 app but I disagree.

Unreal

If you want to deal with the downsides then run both. I know several friends that did that for awhile then went to just 91+meth because they made the same power without the downsides.

I made 1047rwhp on 91+meth on a really soft tune. I have no urge to use e85.

Forcefed86

iTrader: (4)

True, either will work. But meth inj has just as many (if not more) pitfalls as E85.

1.) If your relying on meth inj to control detonation and something happens to the alky kit/pump you'll blow the motor in a hurry.

2.) if your fuel pump drops and the meth keeps spraying... Also blows the motor.

3.)Depending on how much of your total WOT fuel your replacing with meth you also need to worry about even cylinder distribution. Another thing you don’t worry about with E85. There is a reason fuel injection systems don't use one huge injector pre throttlebody.

Friend of mine blew a pretty expensive motor pushing it on pump and alky inj. The fuel pump went out mid pass, ran just lean enough to detonate the crap out of the motor. It was a total loss, even took the block out.

If he had be running e85 and the fuel pump dropped off the motor would have just died.

Several things to consider.... I've ran both. Less chance of failure in an E85 system IMO.

Unreal

Put the correct controls in and it can be safe either way. If someone didn't notice fuel pressure going down that much I don't know what to say besides they should have had a fuel pressure gauge. Same thing could happen on e85 if you are running a multiple pump setup. My fuel pressure is monitored and if it drops below where it should be a big red light comes on.

My meth is setup on different maps so if meth isn't spraying then car runs accordingly. Adjust timing and fuel based on meth on or off.

cajundragger

iTrader: (2)

seems like a hobbs in the fuel line and in the meth line hooked to an idoit light will work for an indicator? no?

Unreal

That is one easy way to do it. You could even tie that into a LPE timing box or something to pull timing if one fails. Or tie it into the ecu to do the same if your ecu supports dual maps.

Forcefed86

iTrader: (4)

I don’t know about you, but when racing, my eyes are in front of me. I don’t stare at gauges. (at 150+ it's all I can do to keep the car straight) Shouldn’t do that on the street either IMO. I try occasionally, but mostly rely on data logs. I run one pump and E85. If my pump dies my engine dies.

Sure, fail-safes are great, but also add more parts that can fail. It’s common sense. The more variables you add to a system the more likely one will fail. Multiple pumps, alky kits, progressive controllers, pressure switches, etc… I ran ALKY INJ for many years in my turbo buick days, Pretty awesome stuff, just making the OP aware is has draw backs as well. IMO more than e85.

Seems that would only protect you if your meth pump quit?

Say your half way into a ¼ mile pass. Your METH is spraying so your ECU is being told to run the meth tune. Then a fuel pump(s) drops out. The ECU still sees the METH is spraying so your still on the METH tune. What happens?

Also depends how much you rely on the meth. in your tune. Fuel/timing changes alone couldn't have saved my engine at the boost levels I ran. I would have needed something to add fuel and drop boost/timing at the same time. (more $ and added variables)

Again I’m not saying meth isn’t great, it is. Or that things will always go wrong. IMO, why risk i? I’ve got E85 a mile from my house and a mile from the race track. Cheap and easy. If I didn’t have E85 I’d be running meth inj, too.

All kinds of ways. Fuel press hobbs switch idea wouldn't work to well. FP varies too much with boost. Then you would have to stare at idiot lights while driving. I like buzzer alarms instead of lights. Some of the new WB02 setups have a switch that will activate if the AFR’s drop below a certain amount while in boost as well. All kinds of fail-safes, most of the kits I see on the street and at the track don’t use them though.

LS6427

iTrader: (2)

So.....if I use E85 (and no meth) there is no possible way to hurt the engine.....?

I mean what can fail during a hard run where the engine can get damaged? Seems if the fuel pump(s) quit the engine just dies down and /or quits.....no?

.

Forcefed86

iTrader: (4)

What does that wonderful post accomplish? I didn’t say any of the things your hinting at, and it doesn’t help anyone. Pretty pointless…no?

Unreal

I agree with what you are saying. If e85 is commonly available and it is a track car/etc then keep it as simple as possible. I put 10k+ miles on my car, take it on multi state trips/etc so e85 doesn't work well for me. I chose the pump+meth with as many fail safes as I could do with my current ecu. If I had something like a haltech/proefi/Aem you could have it kill the motor/etc if fp drops or whatever you want. A lot of the newer stand alones have a feature to try to save a motor if FP drops/etc by ramping up the injectors/etc. AEM does that for sure.

The biggest risk I have is probably running a dual fuel pump setup instead of a big single. If one dies then it will lean out. Car flashes all sorts of warnings. No need to star at gauges. HUD is programmed so if boost >2 and AFR >11.5 to freak out. I can program the dash/hud/speakers in the car to do whatever based on any PID/analog input. I still have to be smart enough to let off and hope that was quick enough.

As far as nothing can go wrong with just e85, uhh no. Making power and racing, something can always go wrong. Fuel filter can clog, pump may start dieing but not enough to kill car, injectors may clog up, etc.

LS6427

iTrader: (2)

Who the hell said you said anything........it seems the consensus throughout the thread is that running E85 is plain safe, where going meth and other electronic safety stuff CAN cause you to lose an engine if something fails during a hard run......

You didn't get that out of my post.....? Did you see me quote anyone in particular?



I'm planning to run full time E85 on my boost set up and this thread is exactly a subject I'm interested in. Some people say to run meth with it and some say its not needed.

.

Unreal

Meth failing and hurting can only happen if you are depending on the meth for octane/fuel. On a lower HP car you can easily tune off meth, then just run it for cooling/iat advantage and if it fails nothing bad happens, just means you are running without meth and may lose some power. Without knowing what the OP is going for he may not even need safety devices. My car doesn't go lean off meth, it runs fine without it, but it does pull 6-7 degrees of timing without it which kills power.

Forcefed86

iTrader: (4)

Nowhere in the whole thread does anyone claim if "I use E85 (and no meth) there is no possible way to hurt the engine" Makes no difference who it was directed at. The comment had no purpose. It came across as a sarcastic statement that you knew was false. That helps no one.

If it was an honest question I'm sorry I took it the wrong way.

The answer would be no, many things can fail. But taking out additional systems that CAN fail lowers your risk factor.

True. But this was a comparison of E85 VS Meth Inj. and which had the greatest margin of error for tuning. If your not using a ton of meth. There would be no comparison. E85 would win by a landslide.

LS1x2

iTrader: (11)

1) LOL
2) LOL
3) The problem is overstated here. Run it a little fatter. Same reason we aren't running lean and mean at 12.8:1 with FI. Leave a little room for error.

A friend of mine ran e85. He blew his motor. It wouldn't happen with meth+pump. I know a guy!

Forcefed86

iTrader: (4)

LOL all you want at 1&2 those are very real scenarios and have ruined alot of engines.

I know I’ll regret asking, but what the heck are you talking about with #3? Run what a little fatter? How does that have anything to do with even distribution of the Aux inj.?

You need to run A LOT of meth inj. if you are going to get the same octane/detonation threshold as E85. Even distribution to the cyls is very important at high volumes. That’s why they have direct injection kits, direct injection nitrous, and fuel injection in general.

Arguing the fact that a dual fuel system (meth+pump) is not more prone to error than a single fuel system (e85) is asinine. Which performs better is disputable.

Sorry to hear about your buddy's E85 experience. I'd guess he doesn't have a clue how to tune and it wasn't the fuels fault. But again I wasn't arguing whether meth+pump worked, I know it works. I said it was not as reliable as E85 alone.

LS1x2

iTrader: (11)

My meth pump failed a few weeks ago. I saw it leaking. New one is in. Regardless the tune is pulling out so much timing in the event of a failure the car will fall dead on it's face anyway. Might see a fouled plug. Proper tuning goes a long way with the stock ecm. Aftermarket, forget it. Your point is just null and void.

If the fuel pump drops pressure and you DON'T have meth you blow the motor too. It takes 4x as much meth vs gas to sustain combustion. Your gonna need the pump running at a pretty constant 50% duty cycle while spraying a metric **** ton of meth to see your scenario play out. What would actually happen is the motor would cut out.

Everybody knows the # on these motors are most prone to detonation. If the WB says 11.8:1 you can assume #7 is less happy than the other cyclinders. I would fatten it up to 11.5:1 just to be cautious about that. With heavy meth injection OR wet nitrous I'm gonna go a little fatter to account for possible distribution issues.

Meth/pump is not as knock resistant as e85. No doubt. Your dual/triple pump setup has the same pitfalls as a meth pump though. So does your gigantic single pump running off a stock charging system and stock ecm. Little voltage drop leans it out. 1 of 3 pump fails, and you don't know it.

You are spreading bad information

Forcefed86

iTrader: (4)

What point of mine is null from this comment exactly?


No, if my pump quits, my engine quits. Just like fuel cut on OEM ECU. If the fuel shuts off quickly there is *usually* no damage as there is not enough fuel for combustion to occur. Damage is caused if there is just enough fuel to run dangerously lean. Luckily my fuel pumps that have failed basically just shut off. They did not slowly peter out. I also dont' run a check valve in my fuel system for this reason. when the pump shuts off pressure instantly drops and the eng dies. No run-on etc.

Last I checked stoich on gas is 14.7 and 6.4 for meth. Thats 2.3x as much fuel for the same AF ratio. Peak power meth is 5.0 5.5 and peak power on gas is 12.5-13.0.

DC of the pump is totally irrelevant why did you even bring that up? 50% DC with 1 30gph nozzles and 50% DC with 2 30gph nozzles will produce totally different results.

As far as the **** ton goes I don't know how to argue that. Can you put a number in there or something?

I replaced 30% of my WOT fuel with meth inj on my pump gas 3.8 turbo motor. Making roughly 620whp or so. As long as you spray 100% METH and not a water/meth mixture I had no ign issues. (OEM ign)

So your assuming that it's the AFR being lean thats causing the detonation. I could see your point there. I'm sayin it's the octane of the pump gas that is the ultimate limiting factor. Even if the AFR is perfect it will still detonate.

Lets pretend its a perfect world and all your cyls have a perfect 12.5 AFR. At X amount of boost your going to run into detonation no matter what the AFR is because you've reached the limit of yout fuels octane.

In comes meth injection. It's the percentage of meth that makes it into each cylinder that essentially raises your octane. But if your spraying it all in the throttle body your not going to get even amounts of meth into the cylinders. So some will run at less octane than others. This isn't a problem at low levels, but as you raise the boost each cyl needs more meth. Eventually one will one cyl will detonate. Alot depends in the intake manifold design as well. Some will act worse than others.


I never claimed a 3 fuel pump system was any more reliable.

I run one pump. On an OEM charging system with OEM alternator(ls1). It does not lean out and my voltage doesn't drop. I have logs with a steady 13.4x across the board.

My pump is a magnafuel 750 protuner. Draws 14a at 45 psi. I have one 35a relay powering it.

What bad information am I spreading exactly?

I drive my car to and from the track and all over, pump doesnt over heat and I never even think about it. It's just a great pump.

LS1x2

iTrader: (11)

Tldr

Surely you are right. What would I know about meth injection. Lol