Jump to content
SAU Community

Brake Cut Off Mod - How To Guide?

jackbh241

By jackbh241,
in Four Door Family & Wagoneers

 Share

Recommended Posts

jackbh241 Collaborator

jackbh241

Posted
Posted

Hi all,

I know this has been posted a million times but I was just wondering if anyone has written a succinct how to guide for the brake cut off mod on the m35? Can only find 100 page discussions and no actual how to.

Any help would be greatly appreciated and sorry about the noob-ness.

  • Like 1
Link to comment
https://www.sau.com.au/forums/topic/436771-brake-cut-off-mod-how-to-guide/
Share on other sites
Commsman Veteran

Commsman

Posted
Posted (edited)

All info you need is here: http://www.skylinesaustralia.com/forums/topic/397960-m35-stagea-brake-cut-off-mod/page-1, but read all the way thru to get all the tips.

There's no fully detailed DIY 'how to' as such, mainly because it's really easy.

Find wire on ECU.

Cut wire.

Run to switch or some other 12V source to allow ECU to 'reset' CEL.

Edited by Commsman
scotty nm35 Grand Master

scotty nm35

Posted
Posted

Don't worry about running it to a 12V source. I have had to replace an ecu which blew from fiddling around with 12V to pin 55.

Just cut the wire and put a switch over the cut. Run it to wherever you need to mount the switch.

Commsman Veteran

Commsman

Posted
Posted (edited)

Don't worry about running it to a 12V source. I have had to replace an ecu which blew from fiddling around with 12V to pin 55.

Just cut the wire and put a switch over the cut. Run it to wherever you need to mount the switch.

Sounds like someone did something wrong then. 12V is 12V. How does the ECU know if you've got your foot on the brake or the wire is connected to the reverse lights (for example)?

Then again its a wagon. Not a gtr

True, but why does anyone do mods at all? This is about the easiest mod & best bang-for-buck of any available for a M35 imo. Even if you never drag it ('cause it's a wagon, not a GTR :)), being able to give it more than 30% throttle immediately after you've braked for a corner is worth the few minutes spent doing it.

Edited by Commsman
Brick Mentor

Brick

Posted
Posted

did it take you long to do the mod?

Not really. The wires going into the ecu don't have much play so it was fiddly , but other then that it's prob a 30 min jon by the time you pull the kick panels off etc.

joshm35 Veteran

joshm35

Posted
Posted

[quote name="Commsman" post="7154590" timestamp="1388140065"

True, but why does anyone do mods at all? This is about the easiest mod & best bang-for-buck of any available for a M35 imo. Even if you never drag it ('cause it's a wagon, not a GTR :)), being able to give it more than 30% throttle immediately after you've braked for a corner is worth the few minutes spent doing it.

My reason for not doing is 'Not' because its a wagon, its that im color blind and cant figure out what wire to cut....

scotty nm35 Grand Master

scotty nm35

Posted
Posted

Pin 55, not hard to find mate, you don't need the color... Just makes it easier.

Perhaps you can get someone color capable to tell you if you have the correct wire? :P

ECU_PINOUTS 13_12_10.PDF

Rudi_ARX-TURBO Rising Star

Rudi_ARX-TURBO

Posted
Posted

Not really. The wires going into the ecu don't have much play so it was fiddly , but other then that it's prob a 30 min jon by the time you pull the kick panels off etc.

did you have to connect to 12v power josh? eg cigaret socket

Brick Mentor

Brick

Posted
Posted

did you have to connect to 12v power josh? eg cigaret socket

No just throw a switch across the cut wire. Then when the car throws the code. Just flick the switch on and hit the brakes a few times

joshm35 Veteran

joshm35

Posted
Posted

did you have to connect to 12v power josh? eg cigaret socket

the main 12v power source used is the reverse light circuit which can be found in boots top panel where compliance putsvthe baby seat holding points. All you will need is a test light to find the wire once the reverse gear is selected. Hope that makes sence
Rudi_ARX-TURBO Rising Star

Rudi_ARX-TURBO

Posted
Posted

the main 12v power source used is the reverse light circuit which can be found in boots top panel where compliance putsvthe baby seat holding points. All you will need is a test light to find the wire once the reverse gear is selected. Hope that makes sence

would you do this on the ecu wirring for reverse?

scotty nm35 Grand Master

scotty nm35

Posted
Posted

No just throw a switch across the cut wire. Then when the car throws the code. Just flick the switch on and hit the brakes a few times

This. ^^

As there are many other people who are going to read this, just crimp some spade terminals onto the wires and run it to a switch, that way you can easily reset the code every month or two.

Leon seems to think everyone is an electronics guru, but there is absolutely no need to automate such a simple signal. All the ecu needs is a 5 second burst of power which is easily automated but I have seen so many wiring faults caused by DIY brake cut fiddling after owners reading threads like this... Now I just recommend the simple wire cut. (unless you feel very confident).

  • Like 1

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • MBS206
      What brakes on R34 GTT(Europe)

      By MBS206 · Posted

      For DBA, check out their guide table here. https://dba.com.au/wp-content/uploads/2023/01/Direct_Replacement-Guide-2021.2.pdf   Additionally they have some other guides and info on how to make sure you choose the right pad.
    • GTSBoy
      What brakes on R34 GTT(Europe)

      By GTSBoy · Posted

      Sorry, just assumed that talk of coloured pads meant EBC red/green/yellow/shit stuff. I don't know the DBA pads, but it's a reasonable bet that they will be OK. DBA make good stuff generally. Those 4000 series rotors I linked to are very good. I may well replace the RDA rotors I have with those when required.
    • joshuaho96
      Unpeeling the Orange

      By joshuaho96 · Posted

      The average previous owner for these cars were basically S-chassis owners in the US. Teenagers or teenager-adjacent. I often tell people that neglect is easier to fix than something that was actively "repaired" by previous owners.
    • MBS206
      Mistakes were made, my R34 Story

      By MBS206 · Posted

      All I hear is ROADTRIP!
    • sunsetR33
      Unpeeling the Orange

      By sunsetR33 · Posted

      Update 3: Hi all It's been a while. Quite a lot of things happened in the meantime, among other things the car is (almost) back together and ready to be started again. Things that I fixed or changed: Full turbo removal, fitting back the OEM turbo oil hardlines. Had to do quite a bit of research and parts shopping to get every last piece that I need and make it work with the GT2860 turbos, but it does work and is not hard to do. Proves that the previous owner(s) just did not want to. While I was there I set the preload for the wastegates to 0,9bar to hopefully make it easier for the tuner to hit the 370hp I need for the legal inspections that will follow later on. Boost can always go up if necessary. Fitted a AN10 line from the catch can to the intake hose to make the catchcan and hopefully the cam covers a slight vacuum to have less restrictive oil returns from the head and not have mud build up as harshly in the lines and catch can. Removed the entire front interior just shy of the dashboard itself to clean up some of the absolutely horrendous wiring, (hopefully) fix the bumpy tacho and put in LED bulbs while I was there. Also put in bulbs where there was none before, like the airbag one. I also used that chance to remove the LED rpm gauge on the steering column, which was also wired in absolute horror show fashion. Moved the 4in1 Prosport gauge from sitting in front of the OEM oil pressure gauge to the center console vents, I used a 3D printed vent piece to hold that gauge there. The HKB steering wheel boss was likely on incorrectly as I sometimes noticed the indicator reset being uneven for left vs. right. In the meantime also installed an airbag delete resistor, as one should. Installed Cube Speed premium short shifter. Feels pretty nice, hope it'll work great too when I actually get to drive. Also put on a fancy Dragon Ball shift knob, cause why not. My buddy was kind enough to weld the rust hole in the back, it was basically rusted through in the lowermost corner of the passenger side trunk area where the wheel arch, trunk panel and rear quarter all meet. Obviously there is still a lot of crustiness in various areas but as long as it's not rusted out I'll just treat and isolate the corrosion and pretend it's not there. Also had to put down a new ground wire for the rear subframe as the original one was BARELY there. Probably a bit controversial depending on who you ask about this... but I ended up just covering the crack in the side of the engine block, the one above the oil feed, with JB Weld. I used a generous amount and roughed up the whole area with a Dremel before, so I hope this will hold the coolant where it should be for the foreseeable future. Did a cam cover gasket job as the half moons were a bit leaky, and there too one could see the people who worked on this car before me were absolute tools. The same half moons were probably used like 3 times without even cleaning the old RTV off. Dremeled out the inside of the flange where the turbine housing mates onto the exhaust manifolds so the diameter matches, as the OEM exhaust manifolds are even narrower than the turbine housings as we all know. Even if this doesn't do much, I had them out anyways, so can't harm. Ideally one would port-match both the turbo and the manifold to the gasket size but I really didn't feel up to disassembling the turbine housings. Wrapped turbo outlet dumps in heat wrap band. Will do the frontpipe again as well as now the oil leak which promted me to tear apart half the engine in the first place is hopefully fixed. Fitted an ATI super damper to get rid of the worn old harmonic balancer. Surely one of the easiest and most worth to do mods. But torquing that ARP bolt to spec was a bitch without being able to lock the flywheel. Did some minor adjustments in the ECU tables to change some things I didn't like, like the launch control that was ALWAYS active. Treated rusty spots and surface corrosion on places I could get to and on many spots under the car, not pretty or ideal but good enough for now. Removed the N1 rear spats and the carbon surrounding for the tailpipe to put them back on with new adhesive as the old one was lifting in many spots, not pretty. Took out the passenger rear lamp housing... what do you know. Amateur work screwed me again here as they were glued in hard and removing it took a lot of force, so I broke one of the housing bolts off. And when removing the adhesive from the chassis the paint came right off too. Thankfully all the damaged area won't be visible later, but whoever did the very limited bodywork on this car needs to have their limbs chopped off piece by piece.   Quite a list if I do say so myself, but a lot of time was spent just discovering new shit that is wrong with the car and finding a solution or parts to fix it. My last problem that I now have the headache of dealing with is that the exhaust studs on the turbo outlets are M10x1.25 threaded, but the previous owner already put on regular M10 nuts so the threads are... weird. I only found this out the hard way. So now I will just try if I can in any way fit the front pipe regardless, if not I'll have to redo the studs with the turbos installed. Lesson learned for the future: Redo ALL studs you put your hands on, especially if they are old and the previous owners were inept maniacs. Thanks for reading if you did, will update when the engine runs again. Hope nothing breaks or leaks and I can do a test drive.
×
×
  • Create New...