2013 Ford Mustang GT
LT Headers, cat delete, Roush CAI, FRP 47Lb injectors, upgraded fuel pump, on pump E85. In our area I have measured the E for years at 68-70% Alcohol. Everything else stock.
I am having an issue that has me completely baffled. I am not an expert tuner on these Mustang, but I have done several and not seen this behavior.
I logged on the dyno look at pedal % vs TB CMD vs Actual. It stays in sync until about 30* throttle and 30% pedal. Then the pedal keeps increase, but the TB CMD stays constant until later in the run then the TB jumps up suddenly. I have tried a dozen different things in the tune. I should not be having this issue on a stock TB.
On the street it shows up as a surging. I did not log pedal, but you can see the saw tooth pattern in all the other parameters. I put a new TB and MAF and it still does it.
Also, the guy cam in with a BAMA E85 tune. When I put that tune on it at around 30% pedal the TB jumps straight to WOT. On the BAMA tune it is very twitchy. HPTuners will not read the BAMA tune so I can not compare.
The guys is not happy with his BAMA tune, says it starts hard. I am tuning it for nitrous, but I am trying to get the E85 part of my tune dialed in before I put the nitrous on it.
Throttle Pic.PNG
surge while driving.hpl
8-15-2020 Rev2.hpt
Sudden jump to 80 THROTTLe.hpl
BAMA Tune Log.hpl