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ECU pulling power when applying brake+throttle

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Old Apr 12, 2007 | 01:49 PM
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Default ECU pulling power when applying brake+throttle

I know a lot of people pull the brake fuse in order to do a standstill burnout, but WHY does the ecu pull power when on the brake and the throttle at the same time?

The reason I am asking is because I talked to UpRev about the issue and want to be able to do a burnout without having to pull the fuse all the time. I am going to take my car there to see if they can make the ecu not pull the power when the brake and throttle are both engaged.

So, why does the ecu do this? Is it due to the electronic throttle control or something else? I need some direction to give to them because they have never been asked this question, insofacto, they have never tuned or flashed for this before. Thanks for any insight they you guys might have. I think it would be pretty cool if they could figure it out.
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Old Apr 12, 2007 | 01:53 PM
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i just said f*ck it and installed a line lock...lol
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Old Apr 12, 2007 | 03:23 PM
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It does it because not many people under normal circumstances will be applying the brake and throttle at the same time, and just in case yo uscrew up it is trying to save your ***. If you want it that bad do line locks as suggested.
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Old Apr 12, 2007 | 05:44 PM
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Originally Posted by eltness350
i just said f*ck it and installed a line lock...lol
do you wanna write up a DIY on a line-lock install? that would cool.... maybe some pics,too?
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Old Apr 13, 2007 | 02:11 AM
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ECU does it so in case of emergency when you slam on the brake and so happens to hit the gas at the same time, it cuts down engine power so it'll save your ***.

Pretty useless in our cars considering the pedal designs. But damn, definitely need this function in the 06 VW Jetta, the pedals are just Ghey! Hit brake and gas with the same foot all the time and nearly rear ended someone too because of that.
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Old Apr 17, 2007 | 03:49 PM
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Check this out:

https://my350z.com/forum/showthread.php?p=3617302

Have they got ECU reflashing down to the point they can actually change the way the ECU operates?
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Old Apr 17, 2007 | 07:46 PM
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If you brake, there is a bias towards the front wheels in terms of clamping force. If you were able to gas it at the same time, then you would lock the front wheels while spinning the rear wheels, which would cause you to fishtail or spin out on, say, the highway...
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Old Apr 17, 2007 | 08:00 PM
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someone on the boards makes a simple switch that you can turn off (essentially 'pulls' the brake fuse)...I made one and have the switch where the seat heater buttons would have been - easy way to do burn outs (and also provides stealth mode at night )

-Peter
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Old May 1, 2007 | 06:05 PM
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is the brake fuse near the battery or my left foot?
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Old May 1, 2007 | 06:18 PM
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I did some test with a m35 rental and the best way to do a standing burn out it just pull the main conector off the ABS. This is under the Brake cover in the engine bay. The abs is seeing that you have the brake on and the rear wheels are spining. It "thinks" you have locked up the front and are sliding. SO it puts more flow to the rear brakes and clamps harder on the rear rotors and then no spin. But once you disco the brain on the ABS it does not know that your rears are spining and you can burn them until they blow if you wanted. This is because the normal braking you can over power with the throttle due to the front bias.
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Old May 2, 2007 | 12:00 PM
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Originally Posted by KPierson
Have they got ECU reflashing down to the point they can actually change the way the ECU operates?
depends on what u want to change.

i know they have full control of over the TB, but as far as brake operation and gas same time? that i dont know.

are you thinking about something like the Hondata two stage drag setup?
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Old May 2, 2007 | 12:14 PM
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Originally Posted by Chebosto
depends on what u want to change.

i know they have full control of over the TB, but as far as brake operation and gas same time? that i dont know.

are you thinking about something like the Hondata two stage drag setup?
I didn't have anything in mind, I just just knew that they could change tables, not actual operating conditions.

It would be nice to be able to completely rewrite the software!
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Old May 8, 2007 | 04:41 PM
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The yaw sensor is located under your elbow beneath the center console. The orange wire is 12v. Install a switch inline to that wire. Mount the switch.

Done

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Old May 8, 2007 | 04:51 PM
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Will you get dash lights doing that?

Can you add throttle this way while pressing the gas? I was under the impression that this will only disable the VDC system?
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Old May 8, 2007 | 04:53 PM
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Originally Posted by first350
someone on the boards makes a simple switch that you can turn off (essentially 'pulls' the brake fuse)...I made one and have the switch where the seat heater buttons would have been - easy way to do burn outs (and also provides stealth mode at night )

-Peter
https://my350z.com/forum/inventor-classifieds/144005-cmods-brake-torque-kit-illuminated-or-non-illuminated.html
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Old May 8, 2007 | 05:57 PM
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Originally Posted by SmokyTyrz
The yaw sensor is located under your elbow beneath the center console. The orange wire is 12v. Install a switch inline to that wire. Mount the switch.

Done

and waht would that do?
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Old May 8, 2007 | 07:24 PM
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Originally Posted by Chebosto
depends on what u want to change.

i know they have full control of over the TB, but as far as brake operation and gas same time? that i dont know.

are you thinking about something like the Hondata two stage drag setup?

CAN THEY DO THAT?????????????
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Old May 9, 2007 | 06:20 AM
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Originally Posted by KPierson
Will you get dash lights doing that?
Yes. You will get the VDC OFF and SLIP lights. But everything else works as normal. Use these lights to determine when you are in "Yaw Sensor Off" mode.

Originally Posted by KPierson
Can you add throttle this way while pressing the gas? I was under the impression that this will only disable the VDC system?
I assume you mean brake and throttle, and yes you can now trail brake/brake boost without worry of the VDC or traction control "backup system" kicking in.


I have this switch installed in my custom cubby, along with a few others...


Works great! Simple install, and you avoid all the fuss of fuse pulling, tail-light disabling, etc.

Originally Posted by nicholasm617

and waht would that do?
Wiring a switch inline on this orange wire will allow you to turn power on and off to the Yaw sensor. The Z's Yaw sensor acts as a "hub" of sorts, for the portion of the traction control system which manages the VDC and the "backup VDC" that "stays on even when you push the 'VDC OFF' switch". When you disable power to the yaw sensor, you also cut communication from the part of the traction control system that interferes when you try to use brake and throttle simulatenously.

The end result is that the traction control system is completely disabled, while the ABS function is retained. Two indicator lights (mentioned above) are the only visual evidence.

PS: This isn't my invention. There are tons of threads about this on my350z
Cheers
-Smoky
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Old May 9, 2007 | 08:54 AM
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Great setup Smoky and thanks for the heads up.

Found this for anyone else trying to look up this mod: https://my350z.com/forum/2003-2009-nissan-350z/138480-how-do-you-disable-vdc-completly.html

And this has a diagram and a good explanation: https://my350z.com/forum/showpost.ph...1&postcount=12

Last edited by rcdash; May 9, 2007 at 09:31 AM.
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Old May 10, 2007 | 02:00 PM
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how many amps go through this orange wire? my switch is rated at 20 amps.
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