4 Attachment(s)
2016 Dodge Challenger R/T 5.7L Whipple with the infamous pedal surge
Hi all,
First off, I am 99.9% a Mustang tuner and do not do many Mopar or GM's but I have a good name for tuning locally so I get a lot of people wanting me to "tune" or fix their issues, that's what we have here today. So, I got a call from another shop about a year ago on this 2016 Challenger R/T 5.7L. His customer had bought a used Whipple from a 6.4L SRT and they bought all the needed parts to go from the 6.4L to the 5.7L and installed the used kit with a set of BBK LTH's and high flow cats. The car had already been to another local tuner in the area and he managed to make the car pretty much undriveable. Once I received the car and looked at the "original tune" I knew there was a lot of issues with it. I then reached out to a tuning buddy of mine and he was going to help me with it but between our schedules it just didn't work out and the customer was hounding me to get it resolved so I decided to reach out to Whipple and got a factory calibration from them for this vehicle. After a couple of revisions the car seemed pretty good so we put in on the dyno where it made 500-525 RWHP and I sent him on his way. I didn't heard anything negative from the customer and figured it was a done deal. Then around April this year (we're in MA so he had the car away for a few months for winter) the customer called me to let me know he was getting a check engine light so I told him to swing it by and it had a P0133 code so I figured we'd put 2 new front O2's and extension harnesses in it because someone had just extended one side with butt connectors. Ugh.
So, after installing the new O2's and harnesses I shipped him down the road and and not long after he was calling again, same code and a P0300 code. I then raised the O2 transport values, like a Ford and hoped that was it but to no avail it still has codes. Then from reading the forum it seems that the P0133 is common with the LTH's but I never really looked for the best way to tune it because the customer asked me drop the idle from 800 to 750 and then all I got was idle hang and "cruise control" when driving it :(. I then performed a throttle relearn and that seemed to correct the issue but the customer said it was still there so I took it back in again. Again, looking to the forum for answers I read about the throttle body small and large range along with the throttle body airflow changes that seemed like a great place to start. Whipple had only changed the TB airflow data and small range from 1.50V up so I made changes to all three tables and bam the "cruise control" effect was gone but now I feel that there is more prominent "surge" in the part and mid throttle so here I am. Any and all feedback would be greatly appreciated. I will upload the current file in the car, the last Whipple file, the stock file and a datalog with the current tune file. Sorry about writing a book but I like to be very thorough and figured I put it all down so it would limit the questions. Again, any help would be greatly appreciated. Thanks! Chris
