The Fixer

Great thread and wrenching Andrew, -Matt

jeff spahn

Problem with this idea is if you drive cross country you might not always be able to get E85 and then what do you do?

AO

I can get my hands on a set of 951 pistons quite cheaply if needed. But that might be too low. Need to do some calculations once I get the heads done and cc'd.

Yes, but...

Ding, ding, ding... This is the issue in my opinion. It's just not worth going down the e85 path for me because of this issue.

Thanks Matt. I keep showing my son and daughter your thread and say, "See! That's what I want to do next time!"

69gaugeman

You want a round hole and a round shaft with just the "right" clearance. The bearings "should" be the same thickness all along them to give a round hole after being installed into the bore.

I once had a discussion with a Bosch engineer about their brake rotor drawing and the equipment they chose to machine the rotors with. The bores were coming out, out of round by .010. In real world size this is quite small, but the tolerance of the hole was +/- .012. They basically halved the tolerance . The Bosch engineer said " I drew the bore round, the tolerance is correct" We lol'd for a while over that one.

Measuring is not as black and white as it seems. I can tell you of hundreds of instances where the part was "right" but wouldn't work. Some is engineering fault, some is manufacturing fault. some is temperature, surface finish, material surface strength... lots of variables.

jetrainor

Following the thread out of interest.....i SC'd my 87 last year....Murf Stage One.....but havent had a chance to shark tune yet so am experiencing knocking at higher rpms...also a hesitation from start that disappears at higher rpm's.......anyway im curious about Hilton's comment earlier about using 87 pistons....i have an 88 engine in my car following TBF on the 87 however i still have the old engine with about 80,000 miles on it and heads etc are still like new.....not the crank obviously.....

BC

Where I go (which is here to the Mississippi) I can always find e85. Especially from here up to Cali, and through the western states.

I can map my way to texas and up through OK.

I just don't see a problem.

And if he is not changing his engine hard parts, it just gives him extra room for no knock (there WILL BE no knock that I can see in studies except in stupid tuning tricks)

IF he really needs to, he can go to petrol in a pinch.

BC

Then you haven't experienced what it can do for power. Or you aren't the power junky you make yourself out to be.

Tony

Oooooooooooooooooooooooooooooooooooooooooooooooo

BC

Oh no he di-ehn.

69gaugeman

You clearly don't know Andrew.

All junkies eventually run out of money to get their "fix".... even Andrew.

AO

Nice try to bait me... so I'll play along.

Switching to an aftermarket ECU is out of the question for me at this time. I just don't have the budget for it. But let's say there was a way to accommodate an e85 tune on the car. And let's say there is also a way to accommodate a parallel tune with 93 so that if one were stuck without e85, you could switch over. And let's say there's even a way to have a tune in between such that you could have a "transition tune."

I actually have a way to do it! (I think)

Mike V (KillaV) hooked me up at OCIC with a switch that goes into the coding plug port that allows one to switch between one of three tunes. You can even switch between the tunes real time. SO the question becomes what would I need to use e85?

My guess is that if I wanted to use e85, I should stay with the current compression ratio. I probably would have to go to a larger injector, something like a 55 to 60 lb injector. Not sure if I would need to run high fuel pressure or not, but that can be done pretty easily as I have an adjustable FPR.

Hmmm... so the more I think about it... the more it seems possible. Am I missing anything?

Oh, BTW, I started taking the SCer apart last night. Couldn't quite get thing separated. That goo is strong stuff. Also here's a bunch of bolts that are all cleaned up. I just like the picture.

AO

To continue the thought...

The advantage of e85 is that I could run much more advance and make the same or more power with less propensity for knock. I don't think I could run more boost as I'm spinning the SCer near max as it is, but I could try.

Oh... e85 is cheaper, but also gives you less range because I think you end up using 20-30% more fuel.

hacker-pschorr

GM fuel sensor, measures the resistance of the fuel going into the motor. Gasoline does not conduct electricity, ethanol does.
Every possible combination will have a different resistance.

This is crucial when running e85 since you never now what percentage of ethanol you will be getting from an e85 pump. "e85" simply means a maximum ethanol content of 85%. You could fill up one day and get 50/50.
When Todd pre-starts the twin turbo he has a gauge that tells him what percentage of ethanol is being sent up by the fuel pump. He keeps a close eye on this.

That is where the fun part comes in with e85 that is not for the novice tuner, having your map(s) setup for e85 / 91 octane and everything in between.

Then you have cold start maps, which is a real bear, especially when it gets cold out..... (never does that in Michigan, does it??)

The first car Luke converted to e85 ran so cool he had a hard time getting the engine hot enough to use the full warm up boost map, which is a real pain when the light goes green at the drag strip.

BC likes to royally oversimplify jumping to e85 which I guess is easy to do since he hasn't actually done it himself. In reality, unless you want to spend all year fine tuning the car, having random temp swings causing the car to run horrible (and possibly not start) etc.... you would be better off to drop it off at a place like Beyond Redline to do it for you.
I have no idea what that would cost but a stand alone ECU would definitely be needed. I don't think the SharkTuner with the LH can add enough fuel to the maps for e85, that is assuming you could get it to work with the fuel sensor in the first place.

Not to mention a supercharged GT engine is probably the last setup I would use as my own personal "test mule" for running e85. Personally, I plan to use my replica Cobra since 302 Fords are a dime a dozen.

BC

Erik, I don't appreciate that. I have run two separate 928s on ethanol 100% of the time since 2009. I don't speak about these things without having done it myself. The only area of the entire process I am not completly up on is the cold start. That's just because I made a better decision geographically than you guys 'der.
I probably have more miles on e85 than anyone in this forum excluding some 951 guys.

I am not royally oversimplifying. People who have no experience with e85 royally OVER complicate the entire situation. Its just not that big of a deal.

AO

Ok... so what's all involved? Assuming stock ECU's...