E85 On Na+T Tune Safety. Experienced Input Please

[25GTV]

Hey guys. I know what I am doing when it comes to cars but I dont know everything. So any input is a great help

The car is a 180sx running a s15 NA (non autech) sr20 with all the original s13 turbo gear. Loom ecu, inj, maf, etc etc.

Basically ive been stuffing around with the factory maf etc to get the tune to run safe on e85.

Standard compression and 6psi of boost from a r33 gtst turbo.

I run a 2:1 ratio of E85 and 98. This is why its difficult to work out correct afr. I guess it runs about E50 and that means it should need about 10-15% extra fuel than normal 98. Also the afr will read different as its calibrated for petrol.

On a PETROL calibrated wideband O2 I get the following readings and it drives 100%.

WOT above 4k (on boost): 10.2 - 11.4

WOT between 2k and 3.5k : 12.5 - 13.1

Accelerating half throttle (max 1 psi boost) : 13.2 - 14

Cruising 5% : 14 - 15.3

Where is it dangerous? Is it bad to run rich on E85? Some say it can cause knocking...

Any info is much appreciated!

[NYTSKY]

So you are just tuning fuel % by the wideband?

Just tune it the same as you would petrol. Real gains are to be had with ignition timing.

[25GTV]

Im mainly after safety and thought the lower EGT would definitely help with this high comp turbo setup. As long as rich is ok/safe I am happy and I guess if its lean when off boost im not to fussed as na sr20s dont seem to blow up from cruisng around a bit lean...

[scotty nm35]

Most ecu's will add up to 10-15% based on the stock o2 reading, I have seen up to 50% ethanol run fine in a factory car. If the afr's on your wideband look good you should be fine, as long as the injectors aren't at 100%...

[25GTV]

Yeah well it all looks good to me and the difference in engine bay heat after a thrash is a lot lower. Getting a slight rattle at 1500-1950rpm on 30% throttle but ti should eb too bad with no boost