So, I am going to be using E85 at the track and trying to take advantage of its cooling properties and higher compression capabilities, so I have been digging around with different setups, info on DCR and SCR and altitude and Quench...here is what I know, and what I am curious about...

With my current cam I have a 383 stroker with the following specs:

At 6200 elevation...
SCR: 11.77:1
DCR: 7.60:1
Cranking PSI: 148.71

At 0 Elevation...
SCR: 11.77:1
DCR: 8.84:1
Cranking PSI: 180.84

Now all of the above were calculated using my current cam specs. I live in Cheyenne, Wyoming which is around 6,200' and when I plug that into the calculator of course my cylinder pressure drops, so my cranking PSI falls to 148.71. This sounds accurate to me because when we did my compression testing in Denver, I was hitting roughly 150 psi.

Now, I know with E85, because it burns cooler and has different properties, generally you can run a higher SCR/DCR with it, so I have been playing with the idea of upping my DCR slightly with my cam, and have been researching that...from what I have read, if you have a low quench it helps lower the Octane requirement of a motor, then of course the higher elevation does as well...unfortunately I will not ONLY be racing at high elevations...the LTX Shootout for example, and I would like to keep it safe for both elevations. So I wanted to see what you all think about my setup with the new DCR if I were to install the new cam, and if you think I will be safe at both this altitude, and at sea level...This is all considering it was properly tuned. I know the tuner plays a HUGE part in avoiding detonation and all, and I have a GREAT tuner who tunes on E85 and big builds weekly if not daily, so he will do a full street and dyno tune once done.

Ok, with the new cam, specs change to the following...

Specs at 6,200 elevation...
Quench: .036
SCR: 11.77:1
DCR: 8.06:1
Cranking PSI: 160.52

Specs at 0 Elevation...
Quench: .036
SCR: 11.77:1
DCR: 9.30:1
Cranking PSI: 192-202 psi

So I have a motor with very low quench, and a good cooling system, running E85 at the track, and moving between 0' and 6200' occasionally, but primarily raced at 5200'+. I also have no issues with knock with the current setup when running 91 Octane.

Thoughts, input, questions, opinions??? Ready...Set...GO!!! haha

 

E85 can handle a lot of compression.. more than you are going to throw at it. Have you degreed your cam to find IVC? I would highly suggest doing that for calculations. It is the only way to really know where the intake valve is closing. Advertised numbers on the cam card can be off.

 

IVC at 72 Degrees on my current cam, and at 66 Degrees o nthe new cam I am considering

 

11.7 is conservative for pump gas.
Stock b-body 10:1 compression motors crank a solid 190psi+ at sea level even after some miles. F-bodies will crank over 200psi stock at sea level.

I have personal experience with 245psi cranking compression at 700ft of elevation on 93 octane which is probably high as you want to go on 93,

Point being you are way off track if you think you are building a high compression high octane setup.

 

I am not trying to build a high compression motor. I went with the parts I wanted and got the compression as high as I could with these heads/pistons. I will need different heads or pistons to go higher...

My point with this thread is my DCR...making sure that I will be fine with a 9.29:1 DCR on E85...and I am curious about 91 Octane because that is all we have in Cheyenne. I am considering changing the cam to bring my DCR up some.

 

You will definitely be fine with E85, and you may get away with 91 octane. You will have to see. Put it on a dyno and find out.

I am currently making some changes to my motor for use with E85. I planned on 14:1, but my builder knocked it down to 13.5 so we can stay with a reasonable sized dome. 9.5:1 calculated DC and I race at sea level in the cooler months. This motor will have a large tuning window - where 14:1 would have needed more accuracy.

E85 has benefits even on lower compression motors that don't need the added octane. There are gains to be had.

 

I agree, and I may change my heads and pistons someday to get some more compression, but we will see...For now, a cam swap to up my DCR is cheaper, and it will give me a little more personal experience and knowledge.

 

I know your asking how much compression u can run with E85 and i apologize i dont have a good source for that let alone a DCR for E85. But since u say u want to run dual fuel and use 91 octane when needed i'll give a caution. U need a switchable engine computer for that. All those Flex Fuel vehicles have proprietary control systems that can not only switch fuel ratio for the different fuels but detect which fuel is in the tank.
Sorry no dual fuel controllers on the aftermarket. As the fuel/air ratio for E85 is something like < 10:1 where pump 91 is more like 14.5:1 air/fuel - u would have to change the fuel map to change fuel. Even worse is in the cold winter months E85 is blended more with gasoline to help engine starting and is more like E70 - another fuel map change.

What im saying is if u build for E85 your stuck with E85 mostly because of the computer not the cam.

Hope this helps more than it hurts,
cardo

 

I think this guy is funny or high^^^
I ranpump on mine and e85. Stock obd1 computer. 210 cranking psi even with the rings gapped for a 250 hit

Lots of misinformation about the fuel. It's not corrosive like w everyone thinks. It does attract moisture so Any long periods of time sitting it needs to be drained or filled to the very top. Usually in November it swings to e70

I tested 10 batches of it last summer... All of it never came close to warrant a bump In fueling.

It'll make more power then pump or a non oxygenated race gas no questions asked regardless of cylinder pressure. ..

I would suggest picking one fuel and sticking with it.

For your set up a br7efs around .032 would work best. It does love n2o as well

 

You need to search some more. Then link back for us.

A -0411 PCM (24x swap) will run a factory OE flex fuel sensor, and thats about as simple as you can get. A holley domninator system will let you have two fuel maps that you can manually toggle to and from, thats not automatic but if you wire in a flex fuel sensor you can watch your blend. The proEFI computer can do switching via fuel sensor and thats pretty easy as well. Just three popular swaps off the top of my head.

 

I have an OBD1 PCM and my own tuning software. I will have a full 91 Octane tune, and an E85 tune. Whenever I get ready to go E85 it will be because I will be racing, and I will flash in the E85 tune when I do switch.

The reason I am not going to CONSTANTLY run E85 is because it has HORRIBLE gas mileage, and I will be street driving and cruising my Camaro during the summers, so I will be on 91 octane to get slightly better fuel mileage.

I know the facts and details about E85 itself..I have helped with a few E85 LSX builds, and LTX builds. I know what I need to do regarding the fuel itself.

I just needed to know about the DCR because I am still trying to learn how that affects the engine power. I am going to tune, dyno, and race my Camaro on the current cam with E85 and see what it does...then I am going to swap the cam and do the same with the new cam and DCR and see what it does differently. I can never get a straight answer on this, so I will just do a comparison and learn that way.

 

My cranking compression was ~235 IIRC. Never had any detonation issues even in 100 degree florida heat on 93 octane.

 

Z28Camaro30Ann, good luck and post your results for us. I considered an E85 only car as E85 is here to stay and i think the higher compression ratios will allow a larger cam than gas.


I ranpump on mine and e85. Stock obd1 computer. 210 cranking psi even with the rings gapped for a 250 hit

Yeh so what? I ran a tank of E85 too and even posted a thread on it. But it ran like how u make sense. And that was this winter which would have been more like E70. Cant recommend anyone run E85 w/o a tune myself - but maybe u would - i wont. And its corrosive enough some suggest one tank a year is good for cleaning the fuel sys.




A -0411 PCM (24x swap) will run a factory OE flex fuel sensor, and thats about as simple as you can get. A holley domninator system will let you have two fuel maps that you can manually toggle to and from, thats not automatic but if you wire in a flex fuel sensor you can watch your blend. The proEFI computer can do switching via fuel sensor and thats pretty easy as well. Just three popular swaps off the top of my head.

Ok i did a search. So your saying here u need to run a -0411 PCM for the flex sensor and holley dominator for the dual fuel maps? So u have to piggy back PCMs? Good luck.
ProEFI does advertize E85 on fly. But $3k-$4k and no 4th gen applications listed - good luck. So do u know of anyone actually using an E85 on the fly on a 4th gen? Or are u just fantasizing again. I thought u had some good info at first - just more verbiage.

cardo

 

Lay down the crack pipe.
Post up some pictures of your ride, time slips or the basement you live in at your mom's house.
You are ignorant. No where did I tell him to run it with out a tune. I'm stating that I ram 2 different fuels with 2 different tunes on a stock computer. You don't need a flex fuel sensor out of your mom's prius to get it to run right.

So you stuck e85 in your car and I'm Assuming didn't tune for it? Keep doing it and post the results.. Throw some of that Las Vegas sand in your gas tank probably will help a bit

 

No, you run a 24x system with a flex fuel sensor and tune. Automatic like OEM switching based off of percent ethanol.

Holley just has the stored tune ability, which is nice if you know you run down the tank of E85 and can't find ethanol so fill with gas, or vice versa.

You are complaining about a lack of perfect plug and play? Come on. This is not the bubble perfect land you live in here, a car from 95 will need mods for things to work. Instead of just copy and pasting BS from stuff you read cardoo, why not take a look in the forced induction section of LS1tech? Running dual fuel tunes, or hell, even 16 injectors, two tanks etc is done.

Open your brain yo.

 

I ranpump on mine and e85. Stock obd1 computer.
Dont read nothing bout a tune there. Now u say 2 tunes. U must be from the looney tunes yourself.
And u want more profile when yours is empty? Oh yea cowards dont post profiles because they actually are driving ricers and living in San Francisco telling everyone they are from Motor City. BIG10 = 0 credibility.



Instead of just copy and pasting BS from stuff you read cardoo, why not take a look in the forced induction section of LS1tech?

So its look at what someone else has done - again. Not what u have done. U are a big help here. Keep dream'n SNO - u wont like reality.

 

Come on guys get off of it! Reminding me why I quit posting on LS1Tech...**** gets completely off topic and people start getting into pissing matches, then the original topic gets forgotten. Either shut up and get back on point, or find another thread...If another comment is made off topic between you two in this thread, I will just delete the damned thing.

 

Put it on e85... you won't regret it... you stated that you plan on switching back to gas because of the mpg issue, I think personally your spinning your wheels there. Let us know what you do. .. quick fuel makes a cheap tester that I've been testing my batches with... It's all been spot on from April to usually mid November. That is when it goes to e70 and will need a fueling correction

That means you're going to have to flush the system completely and have 2 tunes for the car... my car never saw a mpg drop drastic enough to warrant switching tunes and fuel. ..
Usually burned about a half a gallon per run. For the measly dollar difference I think it would be quite a hassle for you imo.

There is a great thread on yellow bullet under the fuel section labled e85 facts and myths. .. It has some great info and feed back on the fuel and will see real world results over there. ..

I love the stuff personally... Makes great power, and is cheap.

I've been on it for 3 years and my fuel system looks absolutely spotless. .

Sorry I rant. Cardo is feeding you some pathetic information to say the least and I don't like seeing people waste there time and money on someone that copies and paste info from Wikipedia. . Like I said go to yellow bullet and check it out.... hundreds of guys will simply confirm everything I've told you. .. The fuel likes to be fat and run it with a hot plug. I'm running a 62.5lb Siemens deka.

 

The need for the E85 is only for the track, but the switch to 91 Octane is for cruising from Cheyenne to Denver, around Denver, then back to Cheyenne which could total over 250-300 miles. E85 at the track may not be a whole lot different than 91 in consumption during 1/4 runs, but take it 200-300 miles and see what the difference in consumption is.

When I cruise the Camaro I drive it. When I go to Denver to race, I will be trailering it so that if it breaks I can get it home...so what I will do is get it down to 1/8 of a tank on 91. Trailer it to the nearest E85 station in Denver. Put my E85 in, and in the time it takes me to put the fuel in my tank I can bust out my laptop and flash in my E85 tune. The tune finishes loading, I finish fueling, I crank the motor and put it back on the trailer and go to the track. I can then race all I want, trailer it back to Cheyenne, run it down to an 1/8 of a tank and then while I am filling the tank on 91 Octane, I bust out the laptop and flash in my 91 Octane tune...it finishes, I finish fueling and press on with a summer DD. It is not that difficult, and on a longer drive, yes, E85 has TERRIBLE mileage.

 

If you put in e85 with a 1/8 tank of gas and you have it tuned for e85 you are going to run that thing rich and foul plugs guranteed... your talking 2 or so gallons in the tank and another half in the lines and rails...


You plan on switching plugs to while your filling it up?

Like I said go to the bullet and read... In a lot of cases the mpg ain't gonna change unless you have your foot in it every stop light. The 2 or 3 mpg difference is gonna be offset by fuel cost and again just my opinion