fccs

iTrader: (26)

I have a 98 trans am, have turbo kit coming in, etc etc. Only question I have left is for fuel system. There is no e85 around me much but in case I wanted to get it sometime, can I or whats the best way? I want a fuel setup that runs pump gas normally, but if I went to track or somewhere that had e85, can I still run that?

HCI2000SS

iTrader: (2)

You have to tune for it. Can't just throw it in and run

JoeNova

Pump gas and water/meth are more than enough for most setups. Most tracks sell race gas, you could throw that in without a tune and still run pretty well, but either E85 or race gas would be pointless without a separate tune.

Detoxx03

iTrader: (14)

Can the f body ecu's do a flex fuel setup? That's what I run on my. Works great. Pump/meth for most days and pump some e85 in for more power.

lmt0705

iTrader: (7)

just build your system to handle the e85 (teflon lines, bigger injectors, bigger pumps and lines) and have a gas tune and a e85 tune. if you have hp tuners its just a simple reflash to go back and forth. and draining your tank i guess

fccs

iTrader: (26)

This is for a 700rwhp build. Just the point that it's safer to run e85 and make more power than pump for my setup anyways. I am getting new fuel lines and whole setup, the point is I don't want to be forced to run e85 24/7 only and never pump gas. I want to be able to run pump normally, but if I get e85, or some race gas, throw it in whenever also.

JoeNova

That's how much power I make on a stock 5.3 with a small cam and single turbo. Pump gas and meth, driven almost every day. The problem with a dual system using E85 is that you'll have to drain your tank to make the switch and the reflash your ECU.

For me, all I have to do is go to the track, toss some race gas in the tank, twist the boost controller a couple of times, and add 4 degrees of timing to the bottom line of the timing table in HPT. I can even do it in real time tuning so I don't actually have to reflash or shut the car off.

If it was E85, it would be much more of a hassle. Race gas might burn a little hotter and dirtier than E85, but it requires less fuel, is more compatible with my current fuel system, has more octane, and doesn't require the tank to be drained to get the ethanol % accurate.

If you're running pump gas on the street and need another fuel for 'track only' situations, race gas is a clear winner here. If I was ever going to run E85, it would be 100% of the time.

Forcefed86

iTrader: (4)

If you buy an MS3x or other flex fuel capable ecu you can easily do what you are wanting. It reads the percentage of ethanol and adjusts on the fly. No retuning/flashing or draining tanks necessary.

Also e50 has the same octane properties as e85. You don't need to run 85% ethanol. You could run 50% and make the power you are wanting easily. Making the demand on the fuel system much less.

fccs

iTrader: (26)

This sounds much easier and more of what I am looking for. So basically do the normal pump gas setup, for track, throw race gas in and adjust boost controller and timing. ? That's basically it?

JoeNova

That's how I do it. Pull up to the pump, throw a few gallons in, load up HPT and throw a few degrees of timing in it, and then turn the boost controller up a bit. I leave everything below 14 PSI completely untouched.

Pull timing when you leave the track, fill up with pump gas on way home.

E85 is great and all, but unless you have something like MS3x and a flex sensor that can adjust the tune on the fly based on ethanol %, it's just easier to either run E85 full time or throw a few gallons of race gas in at the track and run it.

etijsma

With all this said and its still on topic, I was planning on running flex fuel with the stock ecu on a flex fuel program. As long as its tune correctly there should be no issues performance wise on either fuel, correct?

Forcefed86

iTrader: (4)

E85 has it’s downsides as well. Huge expensive fuel system, ethanol “goo” build up on the injectors etc… I’m not saying it’s the best option.

What I don’t like about the race gas idea is the “throw a few gallons in” idea. Unless you know exactly how much fuel is in the tank and add the same amount of race fuel and mix it perfectly before running it’s always a crapshoot on octane. IMO having a sensor that calculates exactly what percentage of ethanol you are running in the system is a more consistent way to tune.

If you don’t want to build the mega fuel system E85 requires (or mix your own E50) I think 2 tanks with a drainable surge tank is one way to go. You pull up at the track on pump, drain the surge tank back into the main pump gas tank. Then block off the drain back and fill the surge tank from a separate race gas tank. When you go home drain the race gas back in the tank and switch to pump gas.

Or setup a dead head system like this to switch fuels easily on the fly from in the cab

JoeNova

I always put in enough to give me at least a 50/50 mix of 93 and 118. Puts me around 105 octane (Similar to E85), more If I add more race gas than I have pump in the tank. My tunes are usually setup to operate on about 100 octane + water/meth so I have a decent safety window.

Once you start working on a dual feed system with 2 separate types of fuels, you just complicate matters and increase the cost, space, and weight of your fuel system.

E85 all of the time, or pump gas topped off with race gas at the track. 1 fuel system, very little tuning effort, and you get the octane you need.

I dabbled with a dual feed system a few times in the past. As with what 90% of the people here seem to think has to be done to make power, it was an overcomplicate system that's purpose was to uncomplicate the race gas delima.

Detoxx03

iTrader: (14)

Flex fuel is the way to go. I can fill up with ethanol or pump and have any mixture in between and the ECU adjust timing. No hassle and no draining etc.

stevieturbo

For only 700hp, if E85 isnt readily available, it really isnt worth the effort and money it will take to run it.

Pump fuel can do that with ease

Monte4ever

iTrader: (2)

^^^^^^^^^^What he said^^^^^^^^^

gols1go

iTrader: (4)

Interesting! I have been watching your latest build and the power output is nice! I am assuming that you are still on the stock ecu? So how did your tuner do it? Did he have to tune it for both, E85 and pump? Or did he tune it for one and the pcm automatically makes the calculations for timing and injector pulse width and/or duty cycle, once on the other type of fuel is dropped in? I do understand that now, you can fill up on either and the ethanol sensor prompts the pcm to switch timing on the fly.

But I was wondering how it was done in the tuning process. I know that some Tahoe pcm's have the capability to use a flex fuel sensor from factory. Would this be a viable option for us 24x crank wheel guys? I am also going E85, but it would be nice to have the option to run pump if I needed to for instances like driving cross state lines to events and going thru places that do not have E85 readily available. To the op, thanks for posting this question, and no disrespect, not trying to hijack your thread.

stevieturbo

In order to achieve optimum results on both fuels, it must be tuned correctly on both fuels.

Doing anything else is just making guesses or assumptions unless you err heavily on the side of caution.

JoeNova

mS3x can tune on the fly for ethanol % with a flex fuel sensor.

Detoxx03

iTrader: (14)

It's tuned on pump first then tuned for e85. Once the tank was full of e85 and that tune was done he started filling pump gas back in to tune the blend and make sure the sensor was accurate. Turned out well adds anywhere from 1-3* depending on ethanol %.