Dual Piston Front Brakes = Change in Bias on an ABS Car?

[Zazzn]

Ok back to my problem.. The breaks grab too hard! Should I get a proportional valve to make more go to the back? I only use 1/3 of the break peddle now because it locks the tires anything after... Is there a way that I can make it so it requires more foot force before locking the tires? Don't get me wrong the breaks are wonderful, but a little scary when I lock em up hauling down form 200KM because I don't have ABS working anymore for the last 2 years (and have been too lazy to check the code)



Edit by JDub: Moved from Doward's 13" brake Group Buy thread to avoid off topic chatter. Seems Zazzn needs an education.

 

[jdub]

Ok back to my problem.. The breaks grab too hard! Should I get a proportional valve to make more go to the back? I only use 1/3 of the break peddle now because it locks the tires anything after... Is there a way that I can make it so it requires more foot force before locking the tires? Don't get me wrong the breaks are wonderful, but a little scary when I lock em up hauling down form 200KM because I don't have ABS working anymore for the last 2 years (and have been too lazy to check the code)

Ummmm...excuse me for saying so, but wouldn't it be easier to fix the ABS vs installing a ghetto fix?
(after all, you've gone down that path before with other issues and the result was?)

 

[Doward]

Yep, fix the ABS!

 

[Zazzn]

Ummmm...excuse me for saying so, but wouldn't it be easier to fix the ABS vs installing a ghetto fix?
(after all, you've gone down that path before with other issues and the result was?)

Ghetto fix? There is nothing ghetto about fixing the break bias now that it's been upset by having bigger front breaks.

I want to restore the natural breaking bias so that it's no 95% front and 5%. ABS wont solve this issue it will mask it because the fronts will lock hitting abs while the backs are barely doing anything.

The ghetto fix would not be fixing the Bias, and I haven't been incline to fix the ABS because it's too sensitive in the mk3 especially for lapping days.

As for ghetto fix, If you are talking about the flywheel, I'll have you know that it's running just dandy since I cleaned it up, and machined the face, it's not ghetto it's called trying every option before being a retard and making more cost and work for your self for no reason... Just because the book says one thing doesn't mean it's the only way to achieve the same result.

 

[Doward]

Jdub hit the high notes regarding bias in an ABS system.

You need to fix that ABS, seriously - then your bias will go back to normal. The fronts are much stronger, and the only place we've seen the PBRs dominate the rears is on the Gainesville Road Course (auto-x)

That's why I'm working on 12.6" rear brakes now

 

[MRSUPRA]

Are we talking about the cobra brake upgrade?

 

[Doward]

That's part of my rear BBK project - seeing what can be done to upgrade the master cylinder. I'm thinking a slightly large bore may be in order, to displace more fluid

 

[Enraged]

So why not remove the ABS completely and then install a proportioning valve?

 

[Doward]

So why not remove the ABS completely and then install a proportioning valve?

Because the amount of meat you'd need on the ground to keep the brakes from locking up would be ridiculous.

How many pre ABS vehicles are you aware of with 13+ inch brakes?

 

[Sawbladz]

Because the amount of meat you'd need on the ground to keep the brakes from locking up would be ridiculous.

How many pre ABS vehicles are you aware of with 13+ inch brakes?

Dodge Vipers of the previous generation? It wasn't pre ABS but they didn't have it.

Sorry, I agree that the ABS should be fixed. Just playing the game. :biglaugh:

 

[Moy]

Because the amount of meat you'd need on the ground to keep the brakes from locking up would be ridiculous.

How many pre ABS vehicles are you aware of with 13+ inch brakes?

My car came from the factory without ABS, and I want to upgrade my brakes... bad idea?

 

[Jostar]

My car came from the factory without ABS, and I want to upgrade my brakes... bad idea?

But you don't have no power! :3d_frown:

 

[7Mboost]

Before it comes up, if anyone insists that they can out brake the stock ABS consistently in a mixture of conditions you ARE wrong. When I get my hands on a Performance Box I will do a serious of stops w/ and w/out ABS. A local here in Gainesville already proved these results true with his C5 Corvette (same conditions, same road, letting the brakes cool, multiple trials), I know the Corvette ABS is probably more advanced but I would still bet the late 80's early 90's Toyota ABS will conclude this.

 

[Doward]

When you stand on your brakes, one of two things happens -

1) The tires have enough grip to prevent the brakes from locking up - you stop as quickly as the brakes will allow.

2) The tires do NOT have enough grip to prevent the brakes from locking up - you stop as quickly as your skill will allow.

Have any of you ever driven a high HP non-ABS vehicle? You pump the brakes as you come to a stop - EXACTLY WHAT ABS DOES FOR YOU.

You don't want to 'ride' the brakes unless you have massive heat capacity in the rotors - as you WILL accrue a ton of heat (that energy has to go somewhere!)

Moy, you can upgrade your brakes. You'll just need to upgrade your driver mod to take advantage of them

 

[Moy]

When you stand on your brakes, one of two things happens -

1) The tires have enough grip to prevent the brakes from locking up - you stop as quickly as the brakes will allow.

2) The tires do NOT have enough grip to prevent the brakes from locking up - you stop as quickly as your skill will allow.

Have any of you ever driven a high HP non-ABS vehicle? You pump the brakes as you come to a stop - EXACTLY WHAT ABS DOES FOR YOU.

You don't want to 'ride' the brakes unless you have massive heat capacity in the rotors - as you WILL accrue a ton of heat (that energy has to go somewhere!)

Moy, you can upgrade your brakes. You'll just need to upgrade your driver mod to take advantage of them

Well anything that would force me to be a better driver :biglaugh:

Jostar: I don't have power... yet :naughty:

 

[Enraged]

what about threshold braking?

 

[thedave925]

+1 for fixing your ABS, it prevents accidents. You can't always anticipate other drivers and ABS can save your ass if you panic stomp the brakes.

Once they are fixed, pull the ABS fuse or remove/unplug the computer under the dash for your track visits.
Viable solution? I think so man, i just don't wanna see your car go down with you beating yourself up cuz this was in the back of your mind.

 

[Poodles]

Not to discount what everyone has said, but even the ABS cars run a proportioning valve stock...

Also, if you think the stock ABS steps in too quick, something is wrong as it ONLY steps in if it detects lock up, it's not like modern systems that take in force of the brake pedal, ect...

 

[Poodles]

I agree. Just wanted to clarify that it does actually have one...

There is another thing that ABS allows you to do that most people don't think about, BRAKE AND STEER. Try it yourself, but keep in mind that most modern racecars run some form of ABS...

 

[Doward]

Yep. The TCCS ABS system is the only kind of ABS I like - the one that kicks in AFTER I've let it go too far