This past weekend I drove 200 miles west to Abilene TX to get a guy to tune for E85. He has tuned a GS for my son before and did a great job and it just so happened there was a TX Musclecar Challenge race close to where he lives so I could kill 2 birds with one stone.if you will.
He had some issues reading the wideband through the EGR at first and was getting some crazy numbers that the car was running real lean 13.0 so he kept adding fuel, well the car ran worse each time. He figured out the wideband but the car was still running bad and lean.
He set it where he thought it should be and the car would not run just spit and sputter. He spent more than several hours on the car.
The AFR would jump all over the place. The car had NKG Iridium plugs gapped at 050.
We changed the plugs to Autolite 104's and gapped tham at 040 with the AFR at 11.6 the car ran pretty good. Very smooth felt real strong. No ET's to report yet but planning to racing again next weekend.
I'm sure the Iridium is a great plug for pump fuel but not for E85 at least not this car.
The ET on a 3.4 pulley, Iridium plugs and 93 pump 1/8 mile was 8.41 @83 mph.
Now on a 3.25 pulley with E85 anyone care to guess where it will run now?