JB4/ECU tune review

[jfowler85]

Right off the bat - this is NOT a post to bash anyone or start any arguments. These are just my results/first hand experiences with using my JB4 and Lap 3 ECU tune.

2018 Stinger GT RWD

To start, I’ve used my JB4 since I bought the car in 2020. Added the BMS wmi kit a short time later. Using the JB4/WMI, I was able to make 490whp/530wtq on the dyno, and run 11.4 @ 117-118 in the 1/4. Never had any issues, and was happy with it. But ultimately a 10 second 1/4 is my goal, so I decided to go with an ECU tune - Lap3 2.5

I had every intention to keep the JB4 for logging and WMI control, but kept running into issues with timing being pulled and where I could not get my fuel trims down. I had seen that issue before with a few other people, and was told that others experienced issues where having the JB4 hooked up with an ECU tune caused interference and ultimately higher trims. It was suggested to switch to the Lap3 S4 controller to see if it changed anything.

I went ahead and purchased the S4 contoller, and immediately saw my trims down where they should be, and timing looked perfect. Every car seems to be different, but for me, I had to switch controllers to make my setup work.

Like I said, I never had any issues with my JB4, and a lot of people still run it with CPI or WMI and an ECU tune, but for me unfortunately it didn’t work out.

Was able to Dyno my new setup today and made 521whp/582wtq. Can’t wait to get it to the track soon!

 

[ChaneRZ]

Great job! Me too, I just bought the Lap3 ecu tune but 1.5
Going to use JB4 for logging. Map0 and disconnect fuel wires just in case.

 

[Terry@BMS]

Just to clear up some misinformation in your post...

On fuel trims remember the JB4 logging has different scaling. 25 = 0% on the JB4. The fuel trims look roughly equivalent in your two logs. In the JB4 app we don't like to chart negative numbers so we set trims such that 25 = 0%. and 50 = +34%, and 0 = -34%.

As for the timing corrections they look more or less equivalent also, towards the floor there. Also keep in mind Lap3 only samples at around 1 data point per second vs 6-10 data points per second with the JB4. So you'll simply see more movement in JB4 logs on certain parameters due to the superior logging speed.

Also keep in mind the lap3 WMI controller can't monitor meth flow or run any useful safety systems for you.