Brake bias regulating for drifting

[Maarten]

Hello,

I tried using the search function but sadly i can't find much atm.

I found the sticky about the pedal dance and I have been using it for multiple drift events. note: 95% of drifting events here are in wet conditions.
What I mostly noticed is whenever I did fuck up I still had issues with the ice mode. Meaning almost no braking force when rolling backwards. This is especially an issue when there is a tractor tire behind you.
So my solution to this was: pull the ABS fuse.
This works really wel. It's also fun to have no abs, it saved me a few times being able to lock up all four wheels and just slide straight on.

But the issue at hand is left foot braking.
It is possible, but not for a long time. I tried it allot of times and i noticed once i start left foot braking the power is almost gone.
i believe this is due tot the fact that with the abs fuse pulled, the brake bias regulation is gone causing a 50/50 brake force distribution.
Or maybe because the car is slightly lowered and the brake force distribution is regulated with that as well? I don't know if it is still active without ABS fuse.
Perhaps I just suck at left foot braking.

What would I like to do:
I would like to have a way of changing the brake bias to about 70-80% to the front, purely at the drifting event.
Is this possible? (electronically or mechanically)

Drift setup:
Front 225/35r18 federal rsr 595 2.1/30 bar/psi
Rear original wheels: 215/40r17 2.1/30 bar/psi (note that this is for wet conditions)
KW v3's and st anti roll bar
Stock power at this moment so torque dip is being a pain in my ass, but this will be solved next month.

[churchx]

I doubt a bit, for any modern car to have 50/50 bias. All cars shift weight to front when braking, so default bias should be shifted more to front. Though probably not completely to THE best bias, but to work well with electronic nannies, like stability control/traction control. Different area pistons, pad shape/area/distance from center, even stock bias is far from 50/50 split. For example charts from here or here, with ratio 1.8-(stock 2.3)-2.8 / to 1.

[alex.s]

i wonder if you could just put a couple of manual proportioning adjusters on the lines running to the rear brakes... i don't know what the electronic bias does, if it's a closed system or something like that, adding a manual adjuster might screw with that. but i bet if you just turn everything off and have inline manual adjusters it'll be just like a traditional full manual system

Wilwood 260-10922 ?

[strat61caster]

From what I can tell you'd be the first person who decided that was necessary to drift an 86. Most people don't have a problem even with relatively stock setups, sure it's not easy, but that's kind of the point, to get good at it, not to install an easy button, even if what you propose actually did make it easier to drift (I don't think that it would).

The reason ice mode engages is because you're too aggressive on the brake pedal for the conditions, especially as you describe, you panic and stand on that fucker as hard and fast as you can, but the car doesn't like that (and it won't like it when ABS is pulled either, but a full lockup stops you quicker than ice mode does).

Practice, left foot braking is fucking hard to get right, there's lots of people outside of drifting who are wicked fast and don't do it because it has real downsides, and the training time to be smooth is one of them.

This really belongs in the drifting thread if you haven't read it already
http://www.ft86club.com/forums/showthread.php?t=37205

[TylerLieberman]

Originally Posted by Maarten

So my solution to this was: pull the ABS fuse.
This works really wel. It's also fun to have no abs, it saved me a few times being able to lock up all four wheels and just slide straight on.

Pulled ABS fuse is best. We were doing this a few years back with these cars because of the same issues.

Originally Posted by Maarten

But the issue at hand is left foot braking.
It is possible, but not for a long time. I tried it allot of times and i noticed once i start left foot braking the power is almost gone.
i believe this is due tot the fact that with the abs fuse pulled, the brake bias regulation is gone causing a 50/50 brake force distribution.

The car makes 130 wheel torque. Applying the brakes is going to slow the rear wheels down, and with only 130wtq, you can't expect to hold the brakes down and keep the wheel speed up.

Originally Posted by Maarten

Or maybe because the car is slightly lowered and the brake force distribution is regulated with that as well? I don't know if it is still active without ABS fuse.
Perhaps I just suck at left foot braking.

Left foot braking should only be done very briefly. If you're holding it down for like 4-5 seconds, you did something wrong. I always like to say "pulse the brake pedal when left foot braking" with these cars when you're running stock power. Best time to use it to make fine, small adjustments to your car's position when you're chasing in tandem. Can do it when you're running solo too, but remember that even though you're still on throttle, the vehicle speed is slowing down while you're on the brake, killing momentum.

Originally Posted by Maarten

What would I like to do:
I would like to have a way of changing the brake bias to about 70-80% to the front, purely at the drifting event.
Is this possible? (electronically or mechanically)

Easiest way is change pads. Run pads up front that have strong initial bite and don't require a lot of travel in the brake pedal. Run stock on the rear.

Originally Posted by Maarten

Drift setup:
Front 225/35r18 federal rsr 595 2.1/30 bar/psi
Rear original wheels: 215/40r17 2.1/30 bar/psi (note that this is for wet conditions)
KW v3's and st anti roll bar
Stock power at this moment so torque dip is being a pain in my ass, but this will be solved next month.

Squared setup would be much more beneficial.

[Maarten]

Originally Posted by TylerLieberman

Left foot braking should only be done very briefly. If you're holding it down for like 4-5 seconds, you did something wrong. I always like to say "pulse the brake pedal when left foot braking" with these cars when you're running stock power. Best time to use it to make fine, small adjustments to your car's position when you're chasing in tandem. Can do it when you're running solo too, but remember that even though you're still on throttle, the vehicle speed is slowing down while you're on the brake, killing momentum.

The main reason for me is to reduce speed for tandems. I'm allot faster then allot of the guys around. Most of them run MX-5s and old MBWs and they go so slow that it's almost impossible for me to stay behind them.

Perhaps there is a different way of slowing down then left foot braking that I have not been taught yet?

Originally Posted by TylerLieberman

Squared setup would be much more beneficial.

The reason i have 225 up front is because my "on the road" wheels are 18" staggered setup. I don't have towing possibilities or a backup vehicle so I have to do with all the space in my car to take wheels and tires with me.
Therefor I leave the "on the road" wheels in the front and only change the rears for a drift set. I haven't really found any disadvantage over drifting with the square setup to be honest.

[churchx]

With such "opposite" to common staggered tire setups some do for looks, i guess it's worth to go for a bit less front camber vs square tire setups / their drift alignments.

[TylerLieberman]

Originally Posted by Maarten

The main reason for me is to reduce speed for tandems. I'm allot faster then allot of the guys around. Most of them run MX-5s and old MBWs and they go so slow that it's almost impossible for me to stay behind them.

Perhaps there is a different way of slowing down then left foot braking that I have not been taught yet?

Left foot braking, normal braking, and handbrake are the common ways to slow the vehicle down. Another method is throwing a lot of angle and using the slip angle to slow the vehicle down... but that's not really possible with these cars since they don't have a lot of steering angle. You can still do it, but the effect isn't as dramatic.

I'd recommend stiffening the rear or upping the rear tire pressure a good amount. You'll still be faster, though probably not as severe, and it'll be easy to keep the wheels spinning and wheel speed up should you need to left foot brake in the chase position. On the downside, the higher rear pressure will make the car take longer to slow down on its own at angle, so you'll HAVE to use the brakes if you really want to slow down quickly at angle.

If it were me, I'd up the rear tire pressure and/or find an aggressive pad for the front brakes with strong initial bite. If they're good enough, you probably won't even get enough pedal travel to really engage the rear brakes.

Originally Posted by Maarten

The reason i have 225 up front is because my "on the road" wheels are 18" staggered setup. I don't have towing possibilities or a backup vehicle so I have to do with all the space in my car to take wheels and tires with me.
Therefor I leave the "on the road" wheels in the front and only change the rears for a drift set. I haven't really found any disadvantage over drifting with the square setup to be honest.

It's mostly for clearance. If you run a lower ride height, it's easier to rub with 18s and wider tires. Also, if you decide to add extra steering lock, the larger wheels can cause clearance issues as well.

[Lynxis]

Originally Posted by strat61caster

Practice, left foot braking is fucking hard to get right, there's lots of people outside of drifting who are wicked fast and don't do it because it has real downsides, and the training time to be smooth is one of them.

This. I've tried playing around with left foot braking at my local track for certain corners where a downshift isn't needed but I find it incredibly difficult to modulate because my left foot isn't trained for it. After playing with it for a few sessions, I've realised it's going to be a significant time investment before it will have any pay off so I've decided not to bother with it for now; there is more to be gained from other things I can focus on. I'll spend more time on it later down the road when there is more to be gained from it.

[strat61caster]

Originally Posted by Lynxis

This. I've tried playing around with left foot braking at my local track for certain corners where a downshift isn't needed but I find it incredibly difficult to modulate because my left foot isn't trained for it. After playing with it for a few sessions, I've realised it's going to be a significant time investment before it will have any pay off so I've decided not to bother with it for now; there is more to be gained from other things I can focus on. I'll spend more time on it later down the road when there is more to be gained from it.

Shift into neutral and left foot brake on the street when coming to a stop, that's how I made it at least somewhat competent for autox. If you're aware of your surroundings there shouldn't be any risk to it. But now I'm going back to trying to right foot brake more often, left foot only for special scenarios where it pays off.

Brake release is important too, I get a bit of a clunk if I lift off the brake quickly, so now I'm consciously attempting to be smooth on coming off the brakes such that the pedal is silent. Cars that do nothing wrong teach you nothing right.

[churchx]

Regarding left foot braking .. i found load of articles how and where it used is good to improve lap times/speed .. big pile of videos of footwork of it properly executed .. but so little info how best to learn except generic words of lot of practice.
Points in [ame="https://www.youtube.com/watch?v=qVO8__MP1iM"]this youtube vid[/ame] makes sense for what may serve well for "learning menu" though.

[Icecreamtruk]

Some of the tracks I race in could really be considered rally, thats how bumpy they are. I have a hard time not making any sudden changes to brake pressure due to bumps and sudden movements of the car (yup, some brake zones are not very flat at all). Im gonna use that as an excuse to not learn left foot braking as of now. I've had a few instances of where my foot slips off the clutch during a downshift, the tranny did not like that at all, I dont want to find out what happens if my foot slips off brake when Im already pushing brake later and later. Besides, more than anything, its hard to control the release with left foot, which is where time is lost and gained in big amounts (a car that rotates vs a car that understeers).

[TylerLieberman]

^^ Remember he's talking about left foot braking in a drifting environment, not HPDE or anything like that.

The differences are huge

[Maarten]

I have had allot of practice with left foot braking already, also on skidpads where I could do a big doughnut.
There it's easy to just hold the throttle constant and then play with the brakes a bit with the left foot.
And even when I hardly notice any difference in angle or speed reduction, I will lose power to the rear wheels. So I tried left foot braking and at the same time increasing throttle input, but that just makes everything so unstable.

I'll try a different pad compound in the front and up the tire pressure.
Also I'll play some more with the damper settings and hope to get some results there.