Switchable tune from E85 to pump gas.

Am I correct in assuming that a vehicle tuned for E85 will not work on pump gas and a tune for pump gas will not work for E85, as in the PCM will not automatically correct for the type of fuel used? Cause I would love to run E85, but don't want to be limited to just E85 just in case. And if that is the case, is there any way to run 2 tunes so that you could run E85 and pump gas without having to retune?

I know in the diesel world we have something call DSP2 and DSP5 which is a switch with either 2 or 5 positions that just wires into the PCM that changes the voltage based on the tune/position selected, so the PCM actually stores the tunes. I don't know if this would be possible with the older F-body PCM,s or not.

While I'm on the subject of E85, will stock fuel lines, dual Walbro 255lph pumps, and 60# injectors flow enough E85 to support a 700rwhp boosted 383?

While I'm on the subject of E85, will stock fuel lines, dual Walbro 255lph pumps, and 60# injectors flow enough E85 to support a 700rwhp boosted 383?

60's won't make 700, they won't do that on gas. E85 takes about 30% more than regular fuel. 83's may have a chance.

Bill

I don't think that our PCM can support different tunes. We have to reflash when we switch tunes.

I'm not 100% sure though. I wish we could swap tunes like that, but I think the ECU has to support it. (My Subaru has the ability to swap from high to low boost, and from what I heard, it was made by GM)

I don't think that our PCM can support different tunes. We have to reflash when we switch tunes.

I'm not 100% sure though. I wish we could swap tunes like that, but I think the ECU has to support it. (My Subaru has the ability to swap from high to low boost, and from what I heard, it was made by GM)

You reflash the main tune which has 4 sub-tunes into the stock PCM and you select what tune you want but turning a dial, which in turn changes the voltage the PCM see's, based on the voltage the PCM selects what tune you had set up for that voltage. So there is not need to reflash every time you want to change tunes. I don't think the F-body PCM will support it though.

60's won't make 700, they won't do that on gas. E85 takes about 30% more than regular fuel. 83's may have a chance.

Bill

http://www.camaroz28.com/forums/showthread.php?t=436206&highlight=60+motrons

I've read in numerous threads that 60# motrons will support around 700-750rwhp at 100% duty cycle at around 45psi. I figure if the duty cycle gets too high at 45psi and 700rwhp, i can up the fuel pressure with an adjustable regulator.

I'm pretty sure the 60# motrons wont keep up the E85 at that power level, that's why I asked. So would low Z injectors be the only thing that will handle a big E85 tune?

You reflash the main tune which has 4 sub-tunes into the stock PCM and you select what tune you want but turning a dial, which in turn changes the voltage the PCM see's, based on the voltage the PCM selects what tune you had set up for that voltage. So there is not need to reflash every time you want to change tunes. I don't think the F-body PCM will support it though.

So, you are agreeing with me?

My Subaru works different than that, and I know there are different ways to do it, but I never heard of it done on a stock fbody pcm.

(My Subaru need 100% TPS voltage and then a signal, which is my rear defrost button. So I can shut the car off, floor it and hit the defrost for high boost. Looks kind of stupid if you didn't know what I was doing.)

http://www.camaroz28.com/forums/showthread.php?t=436206&highlight=60+motrons

I've read in numerous threads that 60# motrons will support around 700-750rwhp at 100% duty cycle at around 45psi. I figure if the duty cycle gets too high at 45psi and 700rwhp, i can up the fuel pressure with an adjustable regulator.

I'm pretty sure the 60# motrons wont keep up the E85 at that power level, that's why I asked. So would low Z injectors be the only thing that will handle a big E85 tune?

Racetronix has some High Z 79# injectors that I am looking to get. I am also switching over to E85 after I upgrade my fuel system to teflon lined braided hose this winter. I have all the hose and fittings ready to go. I hope to max those injectors out close to 700.

Bill

I've just heard so many good things about the 60# motrons, I don't know if going up to 79# injectors and upgrading the rest of my fuel system would be worth it just to run E85.