E-85 solved??

I hear conflicting information on this but I've heard that the energy content of E85 is about 70% of gasoline. Most injectors are sized so that maximum flow occurs at 80% duty cycle (with gasoline).

I suppose you could run bigger injectors and have them running at 50% duty cycle for gas?
 
I did a quick search- Gas has about 18000 BTU per gallon and alcohol has about 9000 per gallon. Explains why the guys racing on alcohol use jets that are 3-4 times bigger than the guys running gas. Bigger fuel lines too.
I saw a thing about methanol- if you run that, you have to flush the system with gasoline before you put it away. Seems the Methanol draws water so fast things will corrode.

One of the race engine builders has one that is designed for E-85. Decent HP numbers with it too. (Shafiroff?) I don't remember which one for sure.
 
BBShark said:
I hear conflicting information on this but I've heard that the energy content of E85 is about 70% of gasoline. Most injectors are sized so that maximum flow occurs at 80% duty cycle (with gasoline).

I suppose you could run bigger injectors and have them running at 50% duty cycle for gas?
Click to expand...

Or just increase the fuel pump pressure with a simple regulator adjustment.
 
turtlevette said:
Or just increase the fuel pump pressure with a simple regulator adjustment.
Click to expand...

It's not simple to adjust a non-adjustable fuel pressure regulator (95% + of all cars). It IS easy for the computer to adjust the pulse width.
 
BBShark said:
turtlevette said:
Or just increase the fuel pump pressure with a simple regulator adjustment.
Click to expand...

It's not simple to adjust a non-adjustable fuel pressure regulator (95% + of all cars). It IS easy for the computer to adjust the pulse width.
Click to expand...

More pressure provides more flow. Pulse width is shorter on gas and there is room to increase it for E85.

Yea, the regulator may be non-adjustable but just put an adjustable one in or one set at a higher pressure. As long as the pump can output the higher pressure, you're all set.

They used to do this to the 3.8 turbo Buicks to get more HP with a bigger turbo.
 
TimAT said:
I did a quick search- Gas has about 18000 BTU per gallon and alcohol has about 9000 per gallon. Explains why the guys racing on alcohol use jets that are 3-4 times bigger than the guys running gas. Bigger fuel lines too.
I saw a thing about methanol- if you run that, you have to flush the system with gasoline before you put it away. Seems the Methanol draws water so fast things will corrode.

One of the race engine builders has one that is designed for E-85. Decent HP numbers with it too. (Shafiroff?) I don't remember which one for sure.
Click to expand...

HUMMM.....or condense water with it in the tank bottom???

that damn water got in there SOME how.....:bonkers:
 
AFAIK to maximize performance from E85 you need to:
- increase the amount of fuel
- advance the spark
- increase the compression ratio

EFI computers can do the first two electronically. If your car is super / turbo charged, then the compression ratio can be increased too. If it's normally aspirated, then your engine will be adjusted to run as best as possible with the compression that you have.

It sounds like their kit provides a fuel sensor which provides the actual percentage of ethanol in the fuel and the computer does the rest.
 
Gotta go larger injectors, the hysteresis of the things have limits on how high you can bump the fuel pressures, and they no longer act correctly, the widening of the pulse width also is a problem as at some point in the upper RPM ranges, the duty cycle approaches 100%, which is not sustainable...

as a rough guess, I think increasing the flow rate of the injectors would be on the order of 50%....???

I dunno how the O2 sensors would react either.....I suspect ok....then there is that comp ratio....wonder if advancing the cam by say 6-8* would help...???

:thumbs:
 
mrvette said:
Gotta go larger injectors, the hysteresis of the things have limits on how high you can bump the fuel pressures, and they no longer act correctly, the widening of the pulse width also is a problem as at some point in the upper RPM ranges, the duty cycle approaches 100%, which is not sustainable...

as a rough guess, I think increasing the flow rate of the injectors would be on the order of 50%....???

I dunno how the O2 sensors would react either.....I suspect ok....then there is that comp ratio....wonder if advancing the cam by say 6-8* would help...???

:thumbs:
Click to expand...

No, you don't HAVE to use larger injectors. Fuel pressure bump is done all the time.

hysteresis? I wanna hear you explain that one.

You don't want to exceed 80% duty cycle so you have margin, not because the injector can't sustain it. That's a misconception. If its not hot at 80% increasing the last 20% is not enough to fail the injector.
 
Some injectors will shut off at increased pressure. GM Multec's will shut off at about 55 or 60psi. This is because the coils are not strong enough to open the valve against the pressure. Also flow does not increase with more pressure and then shut off, most injectors will decrease flow (at higher pressures) before shutting off.

Increasing the pressure also overworks the injectors and will cause thermal breakdown of the coil.
 
BBShark said:
Some injectors will shut off at increased pressure. GM Multec's will shut off at about 55 or 60psi. This is because the coils are not strong enough to open the valve against the pressure. Also flow does not increase with more pressure and then shut off, most injectors will decrease flow (at higher pressures) before shutting off.

Increasing the pressure also overworks the injectors and will cause thermal breakdown of the coil.
Click to expand...


Bull, You better go around to hundreds of websites and set everybody straight then.

Do you claim to have an engineering degree?
 
Why are you such an ass?

Here is what I could find quickly, Multecs from a Corvette shut off at 60psi. Watch it and learn instead of blindly posting contradiction.

[ame]http://www.youtube.com/watch?v=7oTirEZNRw8[/ame]
 
turtlevette said:
BBShark said:
Some injectors will shut off at increased pressure. GM Multec's will shut off at about 55 or 60psi. This is because the coils are not strong enough to open the valve against the pressure. Also flow does not increase with more pressure and then shut off, most injectors will decrease flow (at higher pressures) before shutting off.

Increasing the pressure also overworks the injectors and will cause thermal breakdown of the coil.
Click to expand...


Bull, You better go around to hundreds of websites and set everybody straight then.
Click to expand...

:footmouth:
 
Looks to me like the tan color injectors had a better atomization at every pressure in the video. The 2 in the center had decent flow, but looked more like they were spitting a stream rather than a mist.
 
TimAT said:
Looks to me like the tan color injectors had a better atomization at every pressure in the video. The 2 in the center had decent flow, but looked more like they were spitting a stream rather than a mist.
Click to expand...

That is the sort of vid/tests I was thinking of....

and by Hysteresis I mean the changing ON/OFF slope of the injector, it does not remain constant when pressure is varied....maybe the term is slightly misapplied....

:flash:

and BBshark's comment is of course correct too.....

Some injectors will shut off at increased pressure. GM Multec's will shut off at about 55 or 60psi. This is because the coils are not strong enough to open the valve against the pressure. Also flow does not increase with more pressure and then shut off, most injectors will decrease flow (at higher pressures) before shutting off.

Increasing the pressure also overworks the injectors and will cause thermal breakdown of the coil.
 
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TimAT said:
Looks to me like the tan color injectors had a better atomization at every pressure in the video. The 2 in the center had decent flow, but looked more like they were spitting a stream rather than a mist.
Click to expand...

Now here is what's interesting....I had a set of light blue injectors in my car, they supplied by 5 oh motorsports....some years ago....they proved to be fine in a Dodge 318 van engine....but ran like shit in my vette....seemed ok at speeds about ~1500 rpm, but idled like crap.....before/during/after finding/fixing that water in tank problem....I put in a set of Jsup's injectors....and it was a huge improvement...I THINK he said they were Bosch....at any rate they looked like the tan ones on there, same body shape anyway.....so about 2 weeks ago I finally replaced the fuel lines with steel reinforced aeroquip fuel line hose and with a tad of driving, I hardly feel the engine at idle anymore....

so the old fuel hose I could feel pulsing when engine was running, which is why I decided to replace it, found a good source for the hose in town here....the new AQ hose does not flex/pulse with the injectors firing....

so what I was fighting was a additive problem, first the water, then the injectors firing when the hose was doing GOD knows what to the pressures, and Jsup's injectors were better at dispersion and handling the pressure variations....then on top of it, replacing the hose.....

SO FAR, it seems 'normal' now for the last couple of weeks....

:shocking::beer:
 
You know, that 74 Ferrari I worked on had an accumulator in the fuel system to smooth out the fuel pump pulse. I wonder if that would help? It was a Bosch unit also used by VW.
 
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