IW STi Forum banner

1 - 3 of 3 Posts

·
Registered
Joined
·
2 Posts
Discussion Starter #1 (Edited)
So for starters I have an early 2014 WRX STi Hatchback. I think i'm in the right place but i'm not sure, lmk if there's another community i'm supposed to be in, i'm new in this forum.

As far as modding goals I'm mostly interested making a rally-cross-able street car: capable in dirt (for messing around at OHV parks and maybe SCCA rallycross) while remaining, or being easily switchable to a practical daily driver. I only intend to disable OEM safety systems for off-highway recreational or race driving. To be honest I mostly just go out to low traffic winding country roads and push myself a little, but i'd like to have the option to practice rally technique when the opportunity arises.

I'm interested in disabling ABS and the Brake Booster so i can practice loose surface techniques, and have been looking around for answers, but have come up with a lot of differing opinions. (I plan on also disabling TCS and installing protective/safety equipment among other things, just putting these together cuz i'm confused on the topic and they're both about brakes). Any and all advice is welcome, but firsthand knowledge is preferred.

ABS
For clarification on why i'd want to disable ABS theres a youtube video by Team O'Neill Rally School titled "The Best Car Modification Ever" that helped convince me to want to do this.
I've seen a few posts by people who are happy to pull the fuse, but I've also seen some horror stories about pulling the fuse disabling the DCCD and EBD, resulting in rear torque and brake bias. I'm fairly confident in saying that the ABS fuse affects the DCCD and EBD, but i can't cut through the conflicting information on the topic. I am aware of the thread titled Disableing ABS but it didn't seem like they came to any hard conclusions, and the conclusions i did read from them seemed to contradict my past reading on the subject.

1.) Does pulling the ABS fuse fully disable DCCD, or just the automatic settings on the DCCD?
1.a.) If pulling ABS disables DCCD, what is the failure mode? (I've heard full lock, fully open, and rear bias)
2.) What affect does pulling ABS have on EBD? (I've heard that it disables EBD, but have heard conflicting reports on the resulting brake bias, some say 50-50, some say it's tuned by orifices (speaking as an engineer, it seems like orifices would only affect dynamic pressure distribution, in steady state the pressure would be even throughout the system))
3.) Some people recommend avoiding the problem altogether by using an aftermarket DCCD controller. It seems like if Brake bias is significantly thrown off I'd also need to adjust my brake bias somehow. Does anyone have experience or thoughts on this approach?

Brake Booster
The reason I'd like to disable the brake booster is because I want to be able to use left foot braking while on the throttle without the booster going haywire from vacuum pressure.
1.) Does anyone have practice left foot braking in a 3rd Gen STi? Is the brake booster really that influenced by the throttle/rpm?
2.) What's the best approach to a disable (some people say u can just cap the vaccum tube feeding the booster, some delete the part entirely, and some insist that you do a full brake system swap with an unboosted system)? I guess if capping the tube works I'd prefer that so i could just put a valve in line.
3.) I think i might eventually switch to Group N brakes, and having a set of rally wheels/tires. Should i just wait until then to mess around with any of this?
1.) With deletes and disables, some people recommend redrilling the brake pedal to give more leverage, does anyone have experience with this? how necessary is that?

Any and all help on these questions is appreciated.
 

·
Registered
Joined
·
279 Posts
the current systems add the extra pressure as not having it causes SIGNIFICANT amounts more effort to apply the brakes...the ABS I can agree makes the car more predictable...for the DCCD, as everything is in a circuit you should probably look at the aftermarket controllers...good luck, will be fun to see how you do!
 
1 - 3 of 3 Posts
Top