How to launch on boost

[WildBill]

@Tonkabob Are you saying that your car cuts throttle with the brake pedal unplugged? Reading in between the lines, it doesn't appear that you've tried that yet. They are saying that the dash lights up like 4th of July fireworks with the pedal unplugged and it disables a bunch of additional nanny systems entirely.
My apologies if you have, just looking for clarification.

 

[Tonkabob]

@Tonkabob Are you saying that your car cuts throttle with the brake pedal unplugged? Reading in between the lines, it doesn't appear that you've tried that yet. They are saying that the dash lights up like 4th of July fireworks with the pedal unplugged and it disables a bunch of additional nanny systems entirely.
My apologies if you have, just looking for clarification.

No i havent tried the brake switch yet. Well i just unplugged it but didnt test yet. Raining. I'm talking about rwd burnouts not using the brake. If i pull the fuse to go rwd the tires only spin briefly before the throttle cuts.

 

[Kinvara8017]

No i havent tried the brake switch yet. Well i just unplugged it but didnt test yet. Raining. I'm talking about rwd burnouts not using the brake. If i pull the fuse to go rwd the tires only spin briefly before the throttle cuts.

Im a Gt2 AWD, I cant spin the tires unless the pedal is unplugged..

 

[Tonkabob]

Im a Gt2 AWD, I cant spin the tires unless the pedal is unplugged..

Meaning it won't spin at all or when it starts to spin it will cut out? I'm spinning the tires with out using the brake so don't think unplugging it would change anything.

 

[WildBill]

Meaning it won't spin at all or when it starts to spin it will cut out? I'm spinning the tires with out using the brake so don't think unplugging it would change anything.

Judging from the video it looks like It might if it disables even more nanny systems. I understand he's using the brakes to get the fire lit but I would think if there were a latent nanny system hanging around it would put an end to that fun in a hurry. I would think it is less about how you get the tires rolling than about the car stopping you from keeping the smoke going.

So are you saying you are able to do what he did in the video if you use the brakes to start?

 

[Tonkabob]

Judging from the video it looks like It might if it disables even more nanny systems. I understand he's using the brakes to get the fire lit but I would think if there were a latent nanny system hanging around it would put an end to that fun in a hurry. I would think it is less about how you get the tires rolling than about the car stopping you from keeping the smoke going.

So are you saying you are able to do what he did in the video if you use the brakes to start?

No I can't spin with out the throttle cut no matter what I do so far. I've seen a different video of a Stinger doing big smoky burn outs on a GT and they did not unplug the brake. Not a big deal, I don't need to do one but interesting to understand how this all works.

 

[stargtsi]

Awd gt2 here. I tried unplugging brake tonight. Did brake boost rear tires spun then car went into limp mode. Had to replug and restart to clear

 

[Tonkabob]

Awd gt2 here. I tried unplugging brake tonight. Did brake boost rear tires spun then car went into limp mode. Had to replug and restart to clear

Not good. How long did you power brake for?

 

[WildBill]

Awd gt2 here. I tried unplugging brake tonight. Did brake boost rear tires spun then car went into limp mode. Had to replug and restart to clear

Was the AWD fuse pulled or were you trying a brake stand in an AWD car?

 

[stargtsi]

Was the AWD fuse pulled or were you trying a brake stand in an AWD car?

I did it with the Awd fuse in. Rear tires still spun for a moment hardly tried. I think it's the jb4 causing the limp mode

 

[WildBill]

I don't know, I wouldn't try to hold the brake and try to get an AWD car to spin, it is going to put a heck of a lot of abnormal loading on the driveline.

An AWD in sport mode runs 80% torque to the back and 20% to the front.
Traditional folklore says that 60% of braking force is routed to the front brakes.
With that knowledge 60% of your total braking force is going to totally dominate 20% of your torque especially when coming from a stop.

I'm honestly not surprised that it went into limp, your center differential was crying for mercy. It couldn't drive the front wheels like it was supposed to do because the brakes were binding it up.

If you pull the AWD fuse so you are effectively RWD then there would be no real problem. I doubt you hurt anything but I would not try it again.

 

[Tonkabob]

I defeated the brake sensor with out unplugging the entire clip. I am able to launch at up to 2800 RPM and 6.5 PSI. However its still slower! After that awesome launch the throttle takes its sweet time opening completely, not fully open until 20 MPH. (Despite the fake new spread previously, less than full throttle is slow). On LC my throttle opens much faster, by 10 or 12 MPH, and has better 60 foot and 0-60 times. Bummer.

 

[brancky3]

I defeated the brake sensor with out unplugging the entire clip. I am able to launch at up to 2800 RPM and 6.5 PSI. However its still slower! After that awesome launch the throttle takes its sweet time opening completely, not fully open until 20 MPH. (Despite the fake new spread previously, less than full throttle is slow). On LC my throttle opens much faster, by 10 or 12 MPH, and has better 60 foot and 0-60 times. Bummer.

How do you think you defeated it without unplugging? Maybe there was something else that needed to be done to allow throttle to open immediately

 

[Tonkabob]

The switch is magnetic. You can slide your dragy mounting plate over the switch and use the sticky side to hold it. Or add a magnet to hold the plate. Works well as far as boost and RPM. Only the traction control light comes on but goes out once the plate is removed and the car restarted.
Get the plate close but not covering the switch, go to drive with E brake on, reach down and push the plate up. If you open the door to push the plate up GT2s automatically go into Park.
I've seen some Jb4 logs where they don't get full throttle until 20 MPH. Not sure what kind of launch they did.

 

[brancky3]

The switch is magnetic. You can slide your dragy mounting plate over the switch and use the sticky side to hold it. Or add a magnet to hold the plate. Works well as far as boost and RPM. Only the traction control light comes on but goes out once the plate is removed and the car restarted.
Get the plate close but not covering the switch, go to drive with E brake on, reach down and push the plate up. If you open the door to push the plate up GT2s automatically go into Park.
I've seen some Jb4 logs where they don't get full throttle until 20 MPH. Not sure what kind of launch they did.

Did you also get the same result actually unplugging it? This damn throttle on this damn car is a total boner killer

 

[Tonkabob]

Did you also get the same result actually unplugging it? This damn throttle on this damn car is a total boner killer

I didn't try the full unplug as its not a very drag strippable option. I taped a zip tie to the dragy plate so I can pull it out with my foot or hand if I need to go to reverse. Its inevitable at the track someone breaks and you have to back up. It would be a bit embarrassing to open the door wedge yourself under the dash and plug the connector back in so you can back the car up. Seems the plate would be less intrusive as the car thinks the break is off but isn't as confused as having the plug un done. But someone can test.

 

[Whiteybird]

The switch is magnetic. You can slide your dragy mounting plate over the switch and use the sticky side to hold it. Or add a magnet to hold the plate. Works well as far as boost and RPM. Only the traction control light comes on but goes out once the plate is removed and the car restarted.
Get the plate close but not covering the switch, go to drive with E brake on, reach down and push the plate up. If you open the door to push the plate up GT2s automatically go into Park.
I've seen some Jb4 logs where they don't get full throttle until 20 MPH. Not sure what kind of launch they did.

I'm trying to figure out in my head what you're doing. You mind posting pics?

 

[Revvdmedia]

The car must be detecting SOMETHING. My old Sportage SX was terrible about pulling throttle if you brake boosted it (there was no launch control). A launch off the line lagged until about 3000rpm. Brake boosting caused it to pull back boost by about 5 or so LBS all the way through first gear. Slamming the throttle if only going about 5mph already and it was a rocket compared to coming off the line from a stop.

I called it Kia throttle lag tune lol. Proprietary tuning of Kia.

 

[Tonkabob]

I'm trying to figure out in my head what you're doing. You mind posting pics?

If you look under your dash you can see where the brake switch touches the brake arm. The brake arm has a little soft plastic tab on it to keep it quiet I guess. Just slide metal between the switch and that plastic tab on the brake arm (has to be metal since its a magnetic switch). No more brakes detected. You need to be in D and ready to go before you do this or you cant shift into D.

 

[Kazz]

Some bright, engineering type needs to design some kind of switch that you can install and remove but leaves the driver with an easily reachable button/switch.