Launch control qustion

[Schauer2018]

I have a 2018 RWD GT2 and used launch control for the first time yesterday. I don't know if I did something wrong, but I just ended up doing about a 20 feet burn out and almost lost my tail end and had to let off the gas to recover. All the videos I have seen on YouTube of people using launch control there is very little loss of traction, so I am wondering if I did something wrong or if that's normal.

What I did
1) turned off traction control and stability control (held the button for ~5 seconds)
2) put the car in sport mode
3) depressed the break fully
4) depressed the gas fully
5) saw an indicator that launch was ready
6) let off the break and held down the gas

I got up to about 30 MPH or so and still had no traction and let off the gas or I felt like I would have been sideways.

I bought the car used it does have non-stock rims and tires and am wondering if that is the issue!

Any advice would be great.

Thanks in advance everyone!

 

[Stock_stinger]

being rwd you can easily spin. usually stock isnt as much an issue but being the tires are aftermarket, they probably didnt put sticky tires like stock had. when doing launch control, traction and stability off makes the responsibility of traction land on you.

any tune?

 

[ChaneRZ]

Probably it has some crappy tires.

 

[87and66]

yeah the tires are probably cheap and don't give you much grip or they're the wrong type of tire for the season. Like summer performance tires when its 30 degrees out. Or they just have no tread left and need replaced.

 

[MerlintheMad]

"They" have already said it: gription, i.e. tires. Do you have Michelin PS4(S)? If not, likely you are not going to get good launch on an unprepared surface (aka open roads). You did everything right, except use less go pedal.

(Welcome to the forum, by the way.)

 

[Crisis]

Sounds like fun to me - I wish I could do that. Yeah, I know I'm a child.

 

[Schauer2018]

Thanks everyone if it helps the tires on it are Nitto NT555 G2. Also doing a bit more of googling about the rear rims are also not the stock size. I'm thinking once the tires need replacement just going back to stock Kia Rims and some Michelin PS4(S) as Merlin suggested.

The dealer did not tell me it was tuned so I am unsure, I would assume that is not something I can check easily.
Thanks for the assist its my first fun car I have had since my 1996 Mustang GT when I was a younger lad, so I have a lot to learn!

Side note it was fun and yes I am also a man child.

Have a good weekend everyone!

 

[turboAWD]

Seems like a pretty high performance tire, in general. What size are the wheels / tires? Lots of people have fitted non-stock sizes (myself included) and it's just fine. I'm running 245/285..

 

[MerlintheMad]

Nitto NT555 G2

My "winter" setup uses Nitto Motivo A/S UHP; and they grip really well for an A/S. But yours are "summer" tires, although rated "W" not "Y". NT555 G2 | Nitto Tire One of the comments says, "They do not do well on track with high horsepower cars. Will break traction on dry pavement. Good for cruising the highway not for straight line dragging." This seems to back up your experience. You save c. $100 per tire on the Nitto compared to Michelin PS4S. But maybe that means that you have to ease up a bit on the gas when launching: learn to get the most out of your tire, instead of just bury the pedal.

 

[legbuh]

I thought launch control was supposed to not allow spinning...

 

[turboAWD]

I thought launch control was supposed to not allow spinning...

Isn't that traction control? Which has to be disabled to enable launch mode?

 

[oddball]

The ECU pretty obviously uses a lookup table on engine output to determine what power level to request - and more or less ignores wheel speed sensors. To a lesser degree when traction and stability control are on, but it's not like an old Lincoln. So the ECU assumes your tires are perfect, they're hot, you're on clean, sticky pavement, and nothing has changed on the car (no exhaust, intake, piggyback, etc etc).
Change anything and the ECU tables are now worthless, and you'll spin. And they coded it to allow you to spin, rather than have the safety algorithms override.
So it's back to your brain and your right foot to get a good launch.

I also have the 555 g2's. Love 'em, but yes, they're not drag radials. I like them more in general than the PS4/s, but that's just me.