Quote:
Originally Posted by Votlon
I got some tomei uel headers and i've been running e90-80 from a local gas station for the last 5k miles. Never had a problem and love e85 
I decided I should put some 91 with some detergents in the tank for the hope of cleaning a little, so I ran the tank down to e45 with 91 from shell and was just driving around a little and the car seriously sounds different!
I normally pull from any gear around 3k rpm to get around cars but at e45 I need to pull from 3.8k-ish to hit the powerband. My guess is since the headers are uel and the powerband is different, the air is colliding at different intervals in the headers making a really different exhaust note.
Just a theory but I'm gonna get a good mic and test it to find out! :p |
As the flex fuel sensor detects lower content of ethanol it signals the ecu. The ecu then adjusts the fueling and ignition timing for the new ethanol content. The difference in ignition timing from petrol to E85 can be up to 10 degrees or so. This is likely to change the exhaist note as well as the power and torque charasteristics of the engine. some tunes may also adjust the intake and exhaiust cam timing as well and boost levels on turbos