Hey guys i never pay attention to e85 because there was no e85 around me and now that they have few gas stations closer to me I would like to use e85 on my truck.
I was reading about e85 and I got some questions, First thing my truck comes with e85 compatible its a 2011 single cab silverado, now do I have to change something on the tune if my truck is compatible to e85 or. Just pump e85 and tune it? I was reading around that on the older styles you change the stoich A/F and the PE tables but mine comes e85 I don't need to that right? Now I have a ngk wideband and I know e85 have different readings, stoich A/F on e85 is 9.7, so my question on this is can I pump e85 and read my A/F like if it was gas (14.7) on stoich and will work? Basically can I read the A/F on e85 as I have been reading gas? Leave my cruise mode airfuel ratio around 14.7 and WOT at 11.5 on e85 and will it work?
My truck is a 2011 on 11 lbs of boost.

 

Okay so keep in mind that the main factor when running e85 is something you sort of touched on. E85 does indeed have a different stoich AF ratio. This means that significantly more fuel is required. This also means your fuel system must also be up to snuff. Hence why a flex fuel pump can support a ton of power on gas. However, when on E85 the power it can support drops dramatically. That said I would be fairly confident in saying you will need a bigger pump. Also you will need large injectors. What are you running now? I would say it needs a complete tune in order to run on e85 properly. Being boosted means a lot more work for little things like this.

 

A lot more to gain too, just figue out fueling needs and get it tuned

 

I'm using a 450 walbro fuel pump and 83 lb injectors.

 

So that pump (walbro450) will support about 530rwhp on e85 at 20psi of boost. 15psi is something like 556rwhp.

Here is where learning what lambda is will make tuning much much easier. Lambda is AFR/AFR_stoich. AFR_stoich for gasoline is 14.7 (NGK calls it 14.57 though), and E85 is 9.7. All widebands read is lambda ratio, then convert that later to AFR.

So, E85 at 9.7 AFR is lambda=1, so your wideband that is calibrated for gasoline will show 14.7 (or whatever its calibrated to). If you would shoot for 11:1 on gas thats 11/14.7=.75 lambda. On e85 0.75 lambda is .75*9.7=7.3 AFR. I generally shoot for 0.70 for boost on e85, so on your wideband you will see .7*14.57=10.2.

 

Use the wideband you have now and tune off it as you would with gas however you want to target .78 which is 11.4
I've ran 11.8 AFR on e85 and slowed down
I've ran 10.8 and slowed down

This was all done at a track rental where we went 8.6@164

With 11.8 mph dropped to 162
With 10.8 mph dropped to 160

Also another rule is tune off plugs as not all wide bands read the same.

Run a cooler plug and you'll be fine

As for fuel pump and injectors, you'll need a good size pump if you plan to make some good power
On my 2010 truck on 93 I make 540/554 on 12psi from a procharger... With a turbo at same psi you'll be higher as long as turbo isn't a POS or under sized..

I run 1000cc injectors as I had them but if I ever wanted to run e85 i have the injector

Another option for e85 is look into the fuel pump setup from a ZL1 as they are factory dual pumps. You will need to mod yours to make two work then command the fuel pcm for more pressure

 

Ok so I will tune it like I've have tune gas, target 14.7 for cruise and target 11.4 for WOT.
What are the gains on power on using e85? I've read that it's cools the intake charge, way safer, keeps injectors cleaner it's more knock resistance... How much timing can I go on 13 lb's of boost? I'm planing on spraying a wet 50 shot and I have a methanol kit that I want to use.

 

You might want to have your tuner tell you that, and not believe what you read on the internet that you should be safe with. Every setup is different.

 

I'm tuning my truck I just want ideas I have tune my cars and truck for a while since there's shops that are lazy and just give a start up tune and caring about how your car/truck runs i decide to tune it myself and I have been tuning my cars for several years already. I don't just want to go and tune e85 and not knowing what it's good or not.
My tune on gas right now it's working good I check plugs to read them and they are perfect no detonation on them not running lean at all, I always checking my A/F gauge when I go WOT and it's not that I don't trust the gauge but I like to check the plugs see how they running.
On this thread who's running or have run e85 and did you like it or not? What difference make over gas?

 

In general I have heard e85 plugs are harder to read than gas plugs, but dont hold me to that.