Two Stage Brake Rewiring

[Jumbosock]

I just read our cars have Two Stage Brake Force Display meaning the rear lights up brighter if you brake harder. In the E46M3 it's common to rewire the brakes so that it always lights up the brightest (all lights). It's a simple wire tap. Has anyone looked into this for our cars? I have to see how it lights up differently under heavy braking to figure it out. I'd prefer the rear to always light up the brightest!

See post 4 in this link:
http://www.m3forum.net/m3forum/showthread.php?t=179858

[psygnosis]

I remember reading about someone doing this to a pre-facelift model because we just have an ugly half circle that lights up first. Don't remember where I saw it though :/

[Jumbosock]

Does anyone have a picture of the two braking stages?

[StickMon]

I had this same idea, and being an Electrical Engineer, I think I can sort it in short order.
What made me hold back was the fear that it will set off the bulb warning indicator.
I'm not sure if it senses overload as well as under-load.
I'll get around to trying it in the next few weeks and post the results in this thread.

[Jumbosock]

Thanks! If I get time I will also try to sort it out. In the M3 there was no bulb warning indicator after the mod. Of course that's a different car but a decent indicator that we might be successful without setting anything off. I think success depends on what actually changes with the lights. If they simply get brighter that will be harder to mimick and possibly not worth it. However if there are additional bulbs that illuminate then that will be a simple cut and solder.

[StickMon]

It's an additional bulb that lights an additional section.

[ZStig]

What exactly would this mod accomplish? A reduced chance of getting rear ended while braking lightly?

[Beedub]

Originally Posted by Roffle Waffle

What exactly would this mod accomplish? A reduced chance of getting rear ended while braking lightly?

cant lie... i think this is modding for the sake of modding....

[-c-]

wife did it the other night braking hard for a light, and activated the feature while I was following her in the MINI.

here is what the additional light looks like when activated.

sorry quick Photoshop.

also note the activated light stays on for about 10 or so seconds then turns off so its a timed activation.

[Incompatible]

Originally Posted by Beedub

cant lie... i think this is modding for the sake of modding....

To a degree.
I'm of the school that the brighter the better, brighter = more attention (hopefully). For the same reasoning, I don't like smoked tail/brake lights on cars driven on roadways. This is a mod that I would be interested in doing.

[Beedub]

Originally Posted by Incompatible

To a degree.
I'm of the school that the brighter the better, brighter = more attention (hopefully). For the same reasoning, I don't like smoked tail/brake lights on cars driven on roadways. This is a mod that I would be interested in doing.

fair enough... i think the 2 stage thing is a great idea....

[Beedub]

ive never seen mine work!!! EVER!! even on track day video clips!!

[-c-]

Originally Posted by Beedub

ive never seen mine work!!! EVER!! even on track day video clips!!

lol i know, when i saw it happen i was like "what the hell" at first i thought thats where the euro fog light feature was and when i saw them light up i was going to call her and ask her where on earth did she find the button i never knew exsisted...... then after thinking about it i realized it was the panic stop funtion and after it turned off after 10 seconds it made sence.

the light apears visiably brighter to warn drivers who may not be paying attention that "Hey wake up and hit the brakes"

other than that cool little feature.

[Shipkiller]

I did this mod to the 03 several years ago, but not to the ///M.

While the two stage brake lights might seem like a good idea, it is ONLY a good idea if ALL drivers know about this. 99% don't. Although -c- has a good point that it might wake some knucklehead up who is not paying attention.

[Jumbosock]

I think all brake lights should always go on when the brakes are pressed. The two times I have been rear ended were not under extreme braking conditions. I don't think the two stage brake force concept makes any sense in the real world.

Since an additional bulb goes on (and nothing more complicated) this should be a fairly straight forward wire tap. Worse case scenario a couple diodes per side will be needed. Thanks for the info -c-! I'll work on this soon.

[ZStig]

here is where I think 2 stage braking HELPS:

u're in traffic, going up to 10mph, and slowing down to a compete stop every few seconds. stop and go traffic. The guy behind you gets used to how your brake lights look.

then there is suddenly a clearing, and you speed up to 80mph, the same guy following behind. all of a sudden, you see that there is another jam up ahead and everyone is stopped. you jump hard on your brakes, stage 2 lights activate, and the same guy who's been following behind the whole time says to himself "wow, his brake lights are ALL lit up, he must be braking hard"

(not sure if serious)

[inTgr8r]

Originally Posted by Jumbosock

I think all brake lights should always go on when the brakes are pressed. The two times I have been rear ended were not under extreme braking conditions. I don't think the two stage brake force concept makes any sense in the real world.

Since an additional bulb goes on (and nothing more complicated) this should be a fairly straight forward wire tap. Worse case scenario a couple diodes per side will be needed. Thanks for the info -c-! I'll work on this soon.

^this

[Jumbosock]

Originally Posted by Beedub

cant lie... i think this is modding for the sake of modding....

It's definitely not just for the sake of modding. I think it's increased safety and will prob look better too.

[StickMon]

Here's the right side. Jumper pin 3 to pin 6.
Left side is pin 4 (Normal) to pin 1 (Panic).

[StickMon]

Pulled out pins 3 and 6.
Soldered jumper across.
Put pins back in.

[Jumbosock]

Did it work? Take pic!

[StickMon]

Update: Bulb warning comes on and turn signals go to fast flash after you hold the brake for about 15 seconds. Goes out again when you lift.
I'm going to leave it like this for a week and see how annoying that gets.