E85 combo

[tom j]

If you are using how about a lists of your fuel system and tunning findings to get a initial R&D thread.

-10 feed (wanted to do it ounce)
-8 return
-aeromotive 1000 pump
-stock fuel rail with -10 fitting welded on
-accufab regulator
-plastic fuel cell
-83lb inj.(will support 500rwhp, but barely)

LETS HERE THEM!

[Hot Air]

The link shown below gives a fairly detailed review on E85 compatibility issues for a WRX (Subaru)
Conrad


E85 fuel FAQ - Engine Management & Tuning - NASIOC

[jdpolzin]

Ok what I'm wondering is how big of an injector I will be needing? I'm building my Stage 2 car as we speak. The set up, when done, will be this:
252ci Stage 2 block
Cat 3.625 stroke crank
DLS Cam, I believe 218/218 (not done yet so I'm still unsure, have to talk with Dan)
Champion R heads with T+D rockers
70mm TB and plenum
Champion ported stock intake
Full billet, full rollerized tranny by PTS and my best bud Jose
70 DBB turbo
FAST XFI
Other little tricks, but this gives an idea

I hate to say a HP level the motor would be at but I'm hope to get 800HP when said and done, or at least be capable. With that said, are these new 95# injectors I just recieved in the mail today going to be big enough? Is there a chart somewhere that can justify HP rating for E85?

[tom j]

I would say they wont be even close to being large enough.

E85 & tpro=500HP

[GNVYUS 1]

Here is what I have for my 69 GTO, the GN will get something similar maybe next Summer. Hopefully something over 100lbs will show in a high Z injector for us in 08.

Ricks Hot Rod Shop Stainless Sumped Tank
Magnafuel 500 with Filter
Aeromotive 13202
-12 SS Feed
-10 SS Return
-8 SS Carb Feeds
CSU 750 E85 Carb
Innovative LC-1

[cstavro]

boosting fuel pressure from 43.5 psig to 72.5 psig will give you 29% more flow. siemens 60# can work with the pressure, and flow 77#/hr. those 83# injectors will flow 107#/hr! the added benefit is better atomisation, better burn, more power, and better economy.

[tom j]

Makes sense, I wonder if I would have to play with my mainscale settings, I would probably have to bring it down. I am currently at 42psi with vacume line off. I might try that tonight.

[cstavro]

Originally Posted by tom j

Makes sense, I wonder if I would have to play with my mainscale settings, I would probably have to bring it down. I am currently at 42psi with vacume line off. I might try that tonight.

you need 32% more E-85 than gasoline...so it's very close.

the only potential problem i see is that boost referenced fuel pressure regulators could spike fuel pressure beyond the fuel injector's capability. i know 3800 delco injectors can take 100 psi...so 72.5 psi plus 20 psi (from 20 # boost) is within its safe limits.

safe modding

[Hot Air]

Dr. Booster,
Tell us more about your Ricks Hot Rod Shop SS sumped fuel tank. I don't see one on their web site! Is it a custom tank? Price? Where did you get it?
Conrad

[TurboTR]

Originally Posted by jdpolzin

Ok what I'm wondering is how big of an injector I will be needing?
...
I hate to say a HP level the motor would be at but I'm hope to get 800HP when said and done, or at least be capable. With that said, are these new 95# injectors I just recieved in the mail today going to be big enough? Is there a chart somewhere that can justify HP rating for E85?

As far as I can tell it'll probably be well under, as tom j said.

On gasoline we'd rate the injectors power capability like this:

6 x 95 = 570 lb/hr at 100% duty. Assuming a max duty cycle of 90% we get 513 lb/hr. Assuming 0.55 lb/hr/hp BSFC for turbo on gasoline we get 513 / 0.55 = 930 hp. Personally I prefer to use a more conservative 0.60. That would yield 513 / 0.60 = 855 hp. Call that the worst case number, and the 0.55 BSFC number ~ best case I guess.

Some good data I've seen suggests a ratio of BSFC's between E85 vs gasoline of ~ 1.3. So we can use 0.60 * 1.3 ~= 0.78 lb/hr/hp for an E85 BSFC as a reasonable starting point. Then our 513 lb/hr (the E85 specific gravity is about the same as gasoline) gives us only 513 / 0.78 ~= 658 hp.

In short, it looks like we can just use the BSFC ratio of 1.3 to convert from gasoline hp support to E85 hp support. That is, 855 gasoline hp / 1.3 = 658 E85 hp.

If you want to support 800 hp it looks like you'll need 800 hp * 0.78 lb/hr/hp = 624 lb/hr of E85. Again assuming that's supplied by 6 injectors and at 90% duty, then you'd need 115.5 lb/hr injectors.

Taking the 115.5 / 95, that ratio is 1.216x. The square of that is 1.478. So to get 115.5 lb/hr injectors, you could raise the base fuel pressure of the 95's from 3 bar to 3 * 1.478 = 4.434 bar. About 64-65 psi or so. Maybe still doable, assuming only of course that you have the volume and pressure capability in your fuel delivery system to support that flow at base pressure + boost pressure at full power. At 25 psi boost you'd be trying to achieve 65 + 25 = 90 psi at the rail. Even more than that at the pump(s). And the mass flow would have to be > 624 lb/hr at that 90 psi. Requires a lot of careful planning to achieve.

Hope that helps!

TurboTR

[Hot Air]

TurboTR,
Good write-up! Glad you discussed the fuel thing. As you pointed out, it will take 30% more fuel flow at any given boost. If your fuel pump is marginal on gasoline, it will be woefully inadequate with E85. We all know what happens when the engine goes lean under boost. Not pretty.
Conrad

[cstavro]

it never hurts to be conservative.

you should use the smallest injector that gets the job done...don't upgrade to the 95# until you decide to do 800 bhp.

e85 makes 5% more hp than gasoline. so his 658 hp should be 691 hp.

gas: 800 hp x 0.55 lb/hp/hr / 6 injectors / 0.80 = 92 lb/hr (552 lb/hr total)

e85: 800 hp x 0.55*1.32 lb/hp/hr / 6 injectors / 0.80 / 1.05 = 115 lb/hr (690 lb/hr total)

you can compensate by increasing fuel pressure, like turbotr said.

(58 psig / 43.5 psig )^0.5 = +15.5% fuel flow
(72.5 psig / 43.5 psig)^0.5 = +29% fuel flow

e.g. at 58 psig, your 95 lb/hr injectors flow 95*1.155 = 110 lb/hr

[Hot Air]

I agree.

However, that raises another inmportant consideration. You cannot necessarily assume that as the fuel pressure goes up that the fuel flow will go up proportionally! Youneed to make sure your fuel pump will provide the necessary fuel flow at the elevated fuel pressure. You will need to get a copy of the fuel 'flow vs pressure' curve for your fuel pump to be sure. Don't forget to add in the pressure drop from the 'pump to the engine' and 'engine to tank' and the pressure drop across the fuel filter(s).
Conrad

ps...if you haven't already done so, this might be a good time to upgrade the wiring to your fuel pump so you can get the most out of your pump.

[GNVYUS 1]

Guys, please call any fuel pump company and ask them if they would recommend pushing E85 to 90psi. The problem with your 90psi is that the pressure at the pump is higher ( mentioned by TurboTR ), especially if you are going to use stock lines. I think someone did a backpressure test and there was 3 or 4psi in the stock lines over a -8.

If you think putting the fuel pressure to 95psi at the pump is a good idea, then try it on your GN and let us know. I would take more caution putting that theory on the board for new E85 users to read and possibly use as a way to get around buying huge injectors and bigger fuel lines. Look at any fuel pump chart, they all fall off the face of the earth from 70psi on, even if you push 16 volts to them I wouldn't touch 90psi.

You can do the math to get your injector size etc, but don't take it beyond that point to then suggest to run those injectors to 90psi because then you will need to do the math for how long it takes to pull a motor and rebuild it.

[Steve]

Check out the graph listed under the specs tab on the Areomotive A1000 from the the Areomotive site. They don't even rate it above 70 psi and it falls pretty quickly as the pressure goes up.

Aeromotive Inc.

[bsdlinux]

Originally Posted by cstavro

e85 makes 5% more hp than gasoline.

LOL.... yes on a NA engine