*BOOM* Zero Boost on 2018 GT2 3.3T

[propel]

Hello all,

Backstory
I've had my 2018 KIA Stinger GT2 since June of 2019, got it with 8000 miles and now have 23k miles.

I have a custom Catback exhaust straight pipe and the JB4 tuner as my only mods (and spark plug swap) and have had many problems in the past with boost, not making enough.
My JB4 makes no difference to my boost pressure, I have tested this at a dyno where my car only made 280 WHP stock and 280WHP on map 3 JB4 tune, getting 5.8 - 6 second 0-60 times stock and tuned.

What Happened
Today, I was racing a Stage 1 VW Golf GTI down the highway and got gapped, also my car caps out at 148MPH. Everything was fine, met up at the gas station after met the guy, was very nice.
Then, when leaving I floored it out of the gas station, and after a gear shift I let off the throttle quickly and heard a very loud boom which I thought was a backfire but then my car made no boost.

You can still hear the turbos winding but there is no boost. I have no idea what happened, maybe a vacuum / exhaust leak. Let me know what you think!

Video (all full throttle pulls)

 

[LordStark]

Maybe the Bov? If you don't have smoke I think youre turbos are okay but could be a torn diaphragm on the bov.

 

[Mr. Tech]

I've heard of people blowing clamps/couplers off on some turbo cars (not the Stinger specifically). But it sounds like you may just have a boost leak somewhere. Also, check your logs and see what's happening under load. You'll be able to see how much boost you're actually making.

The JB4 also has a fail safe where, if it encounters a bad condition for the car, it puts it into limp mode to protect the car. If you're running Map 3 on 93 octane or less with no additive or WMI, you maybe have put the car into one of those fault conditions and the JB4 is just protecting the car.

It's also worth checking you logs to make sure your ignition timing looks good. Especially if you're using Map 3.

 

[DevLF]

Check hoses, clamps, and intercooler/charge piping. Sounds like a hose or pipe came off from your description.

 

[propel]

I've heard of people blowing clamps/couplers off on some turbo cars (not the Stinger specifically). But it sounds like you may just have a boost leak somewhere. Also, check your logs and see what's happening under load. You'll be able to see how much boost you're actually making.

The JB4 also has a fail safe where, if it encounters a bad condition for the car, it puts it into limp mode to protect the car. If you're running Map 3 on 93 octane or less with no additive or WMI, you maybe have put the car into one of those fault conditions and the JB4 is just protecting the car.

It's also worth checking you logs to make sure your ignition timing looks good. Especially if you're using Map 3.

So what fuel should I be running for Map 3 and above? Can the JB4 really detect the fuel mixture and knows when to go to limp mode or not? Also i didn’t think WMI made that much of a difference. You recommend a brand?

 

[AJG]

This same exact thing happened to me last week. After a restart I had boost again and no further issues. I dont have a good explanation for it. I was also in map3 and am assuming bad gas or I messed up the mix of 93/85. Added some octane booster, dropped to map2 and gonna wait for a couple fillups to make sure all the 85 is out before trying map3 again.