jfryjfry
jfryjfry UltraDork
12/28/23 8:58 a.m.

In my line of work I almost always am left-foot braking. At least until the last few years as cars increasingly make it more difficult.  Many if not most will kill power abruptly and it's getting more difficult to defeat. 
 

I imagine that many autocrossers deal with this and I was wondering how they deal with it?

 

JG Pasterjak
JG Pasterjak Production/Art Director
12/28/23 10:38 a.m.

Most of the cars that you see at an autocross will defeat (or at least reduce) the amount of power cut under braking when the traction/stability control is switched off. So I think the key here is to suggest to your directors that all chases be shot with A91 Supras.

But if you're using something with less aggressive intent it definitely might be a tricky fix. Short of a reflash, you might be looking at hydraulic bypasses like you do for your drift brake installs. Although then it's still going to depend of where the power cut is getting the signal to cut power from. If it's simply from brake pedal or line pressure, that should be easy to bypass hydraulically. But if it's taking wheelspeed data and using that to make decisions about power delivery, that's going to be tricky to defeat.

Or just Blackbird everything :)

 

accordionfolder
accordionfolder UltraDork
12/28/23 11:17 a.m.

What, precisely, is your line of work? 

The make/model of the cars you're looking to defeat is somewhat important - it varies quite a bit. 

Jesse Ransom
Jesse Ransom GRM+ Memberand UltimaDork
12/28/23 11:26 a.m.
accordionfolder said:

What, precisely, is your line of work?

I should really let him have the fun of answering for himself, but it's too good to pass up.

https://grassrootsmotorsports.com/articles/inside-life-stunt-driver/

jfryjfry
jfryjfry UltraDork
12/28/23 11:48 a.m.

Haha yeah, I wish I could narrow it down. Or even know before I get to set!

we used to be able to unplug a wheel speed sensor but increasingly that just causes other issues. 
 

before that it was just pull the brake light fuse.  But that doesn't work much any more. 
 

sometimes unplugging the brake switch works now. 
 

but I am surprised that this isn't a bigger deal in autocrossing.   

Andy Hollis
Andy Hollis
12/28/23 12:17 p.m.
jfryjfry said:

but I am surprised that this isn't a bigger deal in autocrossing.   

Is is a bigger deal in autocross...for those of us that LFB religiously.  It's why I don't own a Civic Type R.  :(

But younger folks that have grown up around these newer cars have never learned LFB because it doesn't work on their vehicles of choice.

accordionfolder
accordionfolder UltraDork
12/28/23 2:41 p.m.

In reply to Jesse Ransom :

I was thinking that's who it was but couldn't remember for sure, ha!

Tom1200
Tom1200 PowerDork
12/28/23 7:15 p.m.

Man I am going to be a great crumudgeon; I read these now and it reaffirms my love of old cars.

L5wolvesf
L5wolvesf Dork
12/28/23 7:19 p.m.
Tom1200 said:

Man I am going to be a great crumudgeon; I read these now and it reaffirms my love of old cars.

I right with you on that smiley 

GameboyRMH
GameboyRMH GRM+ Memberand MegaDork
12/28/23 8:23 p.m.

It's baked into the ECU programming so short of a reflash, you'll have to unplug the brake switch to fully defeat it, which could cause problems starting on an automatic, so you'd then need a dummy brake switch to flip on for startup. And then the brake lights won't work, but for most movies that shouldn't be any more of a problem than a 27-speed gearbox cheeky

Cars were allowing a couple seconds of brake/gas overlap before they cut power until recently at least.

JG Pasterjak
JG Pasterjak Production/Art Director
12/28/23 8:52 p.m.

Build it into the script. 

I'd totally watch two hours of like grizzled old Jeff Bridges sitting in prison arguing with Glen Powell that they only got caught because the kid picked a FL5 Civic Type R as a getaway car and it started throwing stability codes and went into safe mode when they were about to outrun the cops.

Brett_Murphy (Agent of Chaos)
Brett_Murphy (Agent of Chaos) GRM+ Memberand MegaDork
12/28/23 11:49 p.m.

In reply to JG Pasterjak :

The cops are using modern cars as well. Pity that they have radios and spike strips.

Tom1200
Tom1200 PowerDork
12/29/23 12:58 a.m.
Brett_Murphy (Agent of Chaos) said:

In reply to JG Pasterjak :

The cops are using modern cars as well. Pity that they have radios and spike strips.

I now have this vision of a 15 mph limp mode car chase.

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