So I have this 4b11t fully built, 2.4 liter, that makes 530whp at 23psi with a GTX3584RS on pump gas.
Spark plugs are 9 heat range gapped at 0.023", safe heat range for this kind of power on pump gas.

Now I have switched to E85 and tried a first pull at 30psi, 11.8 steady (gasoline) AFR (0.8 lambda), and had a bad misfire at 600whp and 7500rpm, with safe ignition. My first concern was for the spark plug range, maybe too cold for E85? I have a limited experience with this fuel. Can this be the cause?
I want try frst 0.02" gap because I feel safe with 9 heat range with pump gas, and swapping spark plugs every time is too long.

Ideas?

 

Gap them down to .019-.020 and raise the coil spark table slightly in the ECU.

 

I don't have a "coil spark table" on my XML, is it the dwell table?
I'm on 53050012 ID (tephra v3).

 

yes, dwell table. Try gapping your plugs down first and if that doesn’t help, do SMALL increases to the dwell table, too much can burn out your coils.

Btw, I run .018 gap on oem plugs at 30psi, e85, and small dwell table increase. It’s butter smooth.

 

Tried few hours ago, gap 0.02" no issue, short of 700whp at 30psi.
Curious to see how much igniton timing this setup will take on e85 compared to pump.

Side note, on my tephra v3 + spark cut launch the alternate revlimit doesn't work...or I completely forget how the divider works

 

what kind of timing are you running peak boost and out the top?

 

I think I reached MBT, and the knock sensor begin to show some activity : 8 degree of ignition timing at peak torque, 20 at top, 31/32 psi everywhere. About 700whp.

 

That’s a lot of timing up top. What compression ratio are you running?

 

What is the manifold your using too? Pics of the dyno curve would be great. This sounds like a beast!
That RS turbine was a Garrett fluke and I am curious how it spools up!

 

I'm using certified E85 from a racing fuel supplier, and yes, this engine has a lower compression ratio. I ended with 18 degrees up top

 

It's a custom turbo kit, I'll post the dyno later