ECUflash E85 tuning

[HadesOmega]

So I've just barely starting to get the hang of tuning with ecuflash with gasoline. I recently converted to E85 and was wondering if I have to change my target afrs. Ive been doing a lot of reading about tuning e85 on the forum and would like to confirm my findings.

First here is my basic setup:
Pte 1000 injectors
Boost @18psi e316g
Aem uego mounted in o2 housing used to simulate narrowband signal to ecu
Target afr 10.5
Gasoline injector flow setting=940

So with a 960 injector scaling I was getting about the 10.5 afr with no knock at wot. I thought ok the tune is ok so went e85. I used the conversion formula 960cc * 0.67 = 643.2cc and input this for injector scaling to compensate. So now the car runs much smoother but im thinking because it is runing much richer. Anyway im confused on the target wot afr I read that I should be aiming for 11.5+ afrs. Right now it like 10 so its definately rich. Im still using the 10.5afr from the gas tune so I should change my last 4columns on the fuelmap to 11.5 and then do pulls and adjust my injector scale to match the 11.5 target afr?

SOrry im still a noob at this also all my afr numbers are still using the gasoline scale for my afr gauge. Im just concern I am running too rich at wot. Also my cruising and idle afrs are pretty much the same still 14.7-15.5, this should still be good?

 

[clipto]

I have had a tune where my idleish reading's where like 14.7 but also while running e85 also tune where my idle wouldn't even register on my widebad be like 16.7.-17.0 or leaner. On e85 I have always noticed even my friends we would be in the 12.0 under wide open throttle. I don't wanna say to much as it will depend on your logs how far you can take it.

 

[HadesOmega]

Ok sounds good ill have to watch what my idle is to double check. Yeah I have read about people going from 11.5 to as lean as 13.5. Its wierd u need to be leaner at wot than with gas though, is it because it is so much higher octane than gas?

 

[WES_393]

You want to shoot for around 11.5-12 on the gasoline scale. There's not much point in running any leaner than that. I'm actually surprised your not seeing knock from running that rich.

I believe one reason we run E85 at leaner AFR's than gasoline is because it's more oxygenated, but I'm not sure if that's the main/only reason. I'm now equally curious though.

 

[snowborder714]

When I started tuning on E85, I targeted 11.5 AFR and 16° of timing. I've since pushed it further and my current tune targets 12 AFR and 19° of timing. I could probably push both of those further, but I haven't had enough time to test whether that would actually help or not.

You really don't want to run anything richer than 11.5 or so on E85.

Idle and cruise will still be 14.7.

I can post my current maps, even though their for link, if you'd like to see.

 

[Hal]

Timing effects E85 power output more than the air fuel ratio.

A while back I spent some time testing the effects of afr changes on my car.

No other changes (boost, timing, etc) on my 8.5:1 2.3 @ 35 psi

____

Low of 708/568 and a high of 752/622

Low power afr was 11.5, high power was 13:1

No timing changes, but I think 13:1 is tad leaner than I like even on
E85.

So I settled on 12.5 netting 743/619

All numbers are corrected (SAE)

________

Hal

 

[HooKnBooK]

I can post my current maps, even though their for link, if you'd like to see.

Please do!

 

[snowborder714]

These are the maps that I ran my 12.5 @ 110. I hadn't touched them much before I ran that, so they could still use some tweaking. I remember reading about Hal's tests a while back and haven't had a chance to replicate it on my car yet.

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[HadesOmega]

Thanks for the replies. I have gone with a 12:1 AFR, it still a little rich so I gotta adjust the injector scaling a bit. It ran much better I haven't logged any runs yet but it will pull but sometimes it will studder bad like it knocking but the CEL knock doesn't go on. Have to figure out why but its driveable. I'll try dropping the spark plug gap to 0.025, might help some. Also from a cold start it has a hard time staying running until it has been running for a little bit. It will kinda just stall. But once its warmed up runs fine.

I filled up after a 130 miles mostly freeway and was able to get 28MPG still, I hope its setup right, I was guessing my mileage would be down a lot.

 

[phunny]

When I started tuning on E85, I targeted 11.5 AFR and 16° of timing. I've since pushed it further and my current tune targets 12 AFR and 19° of timing. I could probably push both of those further, but I haven't had enough time to test whether that would actually help or not.

You really don't want to run anything richer than 11.5 or so on E85.

Idle and cruise will still be 14.7.

I can post my current maps, even though their for link, if you'd like to see.

After 11.5 we saw 0 gains from leaning out the car. This is on e85 me 20* peak timing.

 

[eclipsegsx1736]

Timing effects E85 power output more than the air fuel ratio.

A while back I spent some time testing the effects of afr changes on my car.

No other changes (boost, timing, etc) on my 8.5:1 2.3 @ 35 psi

____

Low of 708/568 and a high of 752/622

Low power afr was 11.5, high power was 13:1

No timing changes, but I think 13:1 is tad leaner than I like even on
E85.

So I settled on 12.5 netting 743/619

All numbers are corrected (SAE)

________

Hal

Wow, that's a pretty significant gain in power (6% HP, 10% torque) from just AFR! More than I've seen. I wonder if the timing was a decently below MBT. As I'm sure you know, the more fuel you have the more timing you tend to need, so if the timing value was well suited to the 13:1 pull but a little low for the 11.5:1 pull, this would explain the signicant difference between the two. I'll find out soon on my car when I throw it on the dyno and tune for just below MBT at a wide variety of AFRs.

Beau