AWD -> RWD launching very finicky

[propel]

So I have a 2018 AWD GT2 and my local shop that I go to a lot has a RWD dyno. I looked into other dynos nearby and there aren’t any AWD within less than 1.5hrs driving distance.

I did some research and found that there is a 20amp fuse labeled “AWD” in the engine bay that somehow deactivates the front wheels from getting power, not entirely sure but my guess is something to do with the transfer case or front differential.

Anyways so I pulled the fuse and started her up and you can immediately tell a difference, especially in cold weather with hard tires. It’s crazy how much she will spin and lose traction if you push the gas a little more than you should. Back to the main point of the thread, launches.

Of course I had to do some launches in RWD mode, turned off traction and stability control and used launch control. Wheels spun like crazy getting ZERO grip (partly due to cold weather and wet road) and the car would redline much faster than before and the engine would just stop while I have my foot all the way down on the gas. Then after 1 second it would try again and just spin and move a little bit, then back into limp mode. Not sure why this happens with all the safety systems disengaged, if anyone can think of cause or solution it would be nice to know

 

[Luc343]

Does the awd have an lsd for the rear wheels?

If not, that might explain it...

 

[propel]

Does the awd have an LSD (Limited Slip Differential) for the rear wheels?

If not, that might explain it...

I don’t believe it does, which is a very good point. That would make sense.

 

[MerlintheMad]

Also, red line triggers "limp mode". It's a safety device. That 100K miles warranty is protected. I had the same thing happen when I tried AWD launch control, but forgot that I had engaged manual gate: punched it and it red lined and upshifted - you're doing this WRONG!, is what my car said to me; I figured that was reasonable: and at the time I was grateful that Kia included a stupidity escape valve, as it were: I didn't know till later that even if you could red line and hold it there, probably nothing inimical would occur; this engine is close to bullet proof.

 

[vipeboy2000]

I don’t believe it does, which is a very good point. That would make sense.

Yep. Only the gts and indigo trims with d-awd have the lsd along with awd. Even with the lsd it is still easy to burn up those rear tires when in rwd drift mode .

 

[propel]

Also, red line triggers "limp mode". It's a safety device. That 100K miles warranty is protected. I had the same thing happen when I tried AWD launch control, but forgot that I had engaged manual gate: punched it and it red lined and upshifted - you're doing this WRONG!, is what my car said to me; I figured that was reasonable: and at the time I was grateful that Kia included a stupidity escape valve, as it were: I didn't know till later that even if you could red line and hold it there, probably nothing inimical would occur; this engine is close to bullet proof.

Yeah, that redline limp mode is weird, I got scared the first time it happened to me lol. But this is something else, it completely kills the engine for a whole second, RPMs drop to very low while the petal is all the way down, then it tries again and redlines tries screeching. Very fun, just not good for acceleration lol.

 

[MerlintheMad]

Yeah, that redline limp mode is weird, I got scared the first time it happened to me lol. But this is something else, it completely kills the engine for a whole second, RPMs drop to very low while the petal is all the way down, then it tries again and redlines tries screeching. Very fun, just not good for acceleration lol.

What you describe has to be the result of poor traction in the mix.

 

[runner1]

I wonder if the fuse out driving eventually cause any issues or damage?