Open Source ABS

Anyone have a line on any sort of open source or at least programmable ABS that doesnt cost 10 grand like the bosch motorsports one? I know there's a BMW motorsports one but it doesnt sound programmable except by the dealers. Basically I'm sick and tired of cording right front hoosiers on my miata and I'd love to get setup with something better than the 01+ miata 3 channel ABS. I know some people have had success with it in my class but its still going to cost me like $400 for one of the controllers and I feel like 275 hoosiers are pushing it a little bit out of its design envelope.

I've so far come up empty on anything. We have opensource ecu's and data loggers now we need an abs controller.

Do you know the cording is caused by the ABS?

Might be worth disabling the ABS and see if that makes any difference?

I have zero abs present and want to add abs.

Im curious to hear how ABS is causing excessive and uneven tire wear...

ABS isnt causing uneven wear. I want to add abs so that I can stop harder and also lockup less and destroy less $300 hoosiers. Lack of ABS is allowing brake lockup and cording tires.

Brake without locking up the tires?

Cornerweight the car and add adjustable proportioning is the easy answer.

Next easiest is retrofit the factory stuff. If you don't want three channel, then get four channel from another similar car (such as an NC), get the basic brake proportioning right, and go with it.

I've never heard of an open-source implementation.

I would love an aftermarket abs on my miata fir the same reason to save tires. I know you can in theory brake faster without abs, but a good system saves tires and will only add a little to the stopping distance over perfect threshold braking which is difficult to achieve on autox especially when turnig and braking since sometimes there isn't room to brake then turn. If you find something post it up.

+1 for what Keith said...never heard of open-source ABS either. You could also try depowering the brake system to get finer control.

About ABS on the track, consider this: If one side loses grip in an oil spill or marbles or something, the other side won't get more braking force than is safe for the low-traction side. You couldn't even spin/slide under braking towards the grippy side if you wanted to.

GameboyRMH wrote: +1 for what Keith said...never heard of open-source ABS either. You could also try depowering the brake system to get finer control. About ABS on the track, consider this: If one side loses grip in an oil spill or marbles or something, the other side won't get more braking force than is safe for the low-traction side. You couldn't even spin/slide under braking towards the grippy side if you wanted to.

Not really true on a multi channel system. The ABS monitors each wheel. Your scenario would be true only for the rear two wheels of a three channel system.

Keith Tanner wrote: Cornerweight the car and add adjustable proportioning is the easy answer. Next easiest is retrofit the factory stuff. If you don't want three channel, then get four channel from another similar car (such as an NC), get the basic brake proportioning right, and go with it. I've never heard of an open-source implementation.

Car is corner weighted, prop valve I bought from you guys is fully rearward, aggressive pads in the rear cheap pads in the front. The brake balance is excellent except when it randomly decides to lock the right front like most auto-x miatas. ABS that doesnt have an ice mode and understands how much grip hoosiers can actually make will without a doubt make the car faster.

The hard part about just picking up and off the shelf abs unit is that it needs to be from a similar size and weight car and must have almost the exact same brake fluid volume in the calipers.

I don't like power assist because I can't modulate the braking as well as with manual. Before going all ABS I'd suggest look into that. Basically it's removing the booster then installing a master cylinder sized appropriately.

Something else, too: the right front could be locking up due to insufficient suspension droop. The Jensenator lifts the inside front in hard turns, for instance. If that's what is happening, maybe look into controlling body roll or adding droop?

I'm not really a fan of manual brakes I modulate better with distance than pressure. And you've got to basically come completely off the brakes to unlock the wheel when this happens. Its not like a normal brake lock when you just ease up and it starts spinning again. Its a pretty typical issue and adding ABS fixes it and makes cars faster.

So what is everyone else using? Stock 3-channel?

I'm thinking that with the legal climate in this country no way is anyone going to offer open source or 'universal' ABS systems. At some point I betcha AngryCorvair's gonna chime in with a good idea.

Just as a point of interest, there used to be these things called 'Safety Brakers' way back when. Basically it was like a small reservoir which went in the lines for the end of the car that was prone to lock. Inside there was a moveable piston, a rubber seal and a stupid strong spring. The idea was at low brake pressures the piston stayed put, as brake pressures increased the spring would allow the piston to move thus cutting pressure at the caliper/wheel cylinder. Yeah, it was probably about as safe as it sounds.

Motorcycle version:

No, I could never bring myself to try one.

I'll chime in that people do use the E46 and E92 M3 units with some sort of custom progamming on Tilton manual brakes. Apex Speed in CA seems to be pretty knowledgeable on these. The MK60 units in E46 M3s are not as sophisticated or expensive and may be the huckleberry you are looking for if you can pinch one from a pick n pull.

My race car uses the Tilton manual setup with bias bar, prop valve and so on... and there are times when I'm 2 or 3 wide going into a corner where I get beat... and really wish I had a good ABS system. Not because I don't have enough brake or enough modulation but because I'm keeping 3 to 4 targets in a 360 mental picture inches from another car and damn if I don't want to lock a wheel and take the three of us out. So I leave a little on the table.

It is a "confidence while juggling chainsaws" problem. I don't have enough bandwidth to safely shave my balls with them so I don't try it because the consequences are dire.

Giant Purple Snorklewacker wrote: It is a "confidence while juggling chainsaws" problem. I don't have enough bandwidth to safely shave my balls with them so I don't try it because the consequences are dire.

Since you are running cheap pads on the front, you may consider biasing the brakes even further to the rear by chamfering your brake pads so that the surface area touching the rotor is less. AFAIK that is the cheapest brake tuning there is, but you DO have to do it over and over again and finding your sweet spot might be tedious.

Just my useless .02.

Keith Tanner wrote: So what is everyone else using? Stock 3-channel?

Yeah stock 3 channel.

I think I heard of the bmw unit that can be re-programmed but only by turner but not of the apex speed one. Looking at apex speed tech's website, they look like the kind of shop where the price is, "if you have to ask you cant afford it".

Another option I was thinking of. These ABS pumps are just a solenoid block more or less. Making a controller that takes in 4 pulsed wheel speed sensors, a variable voltage (for the ABS strength dial on the dash), does some math and comes out with a control schema to a few high amperage low side drivers probably wouldn't be terribly hard. I would spend forever and a day coming up with the control scheme, but I could probably come up with the controller hardware in a month or two.

I fail to see how ABS is going to reduce tire wear without setting it sensitive enough that it will reduce performance.

Vigo wrote: Since you are running cheap pads on the front, you may consider biasing the brakes even further to the rear by chamfering your brake pads so that the surface area touching the rotor is less. AFAIK that is the cheapest brake tuning there is, but you DO have to do it over and over again and finding your sweet spot might be tedious. Just my useless .02.

I'd rather try to make the rears work better instead. Bigger pistons in the calipers, bigger pad area, bigger rotors, something like that. Leafy, what's your whole setup?

Kenny_McCormic wrote: I fail to see how ABS is going to reduce tire wear without setting it sensitive enough that it will reduce performance.

ABS certainly reduces the likelihood of flatspotting and ruining expensive race tires.

That was my front right going into turn 11 at Laguna earlier this year, it's corded on the inside edge.

I'm putting an 2003 ABS system in my 99 (build thread on miataturbo.net), which is supposed to include EBD electronic proportioning. I'm not sure how that compares with the Wilwood prop valve, though.

Nathan JansenvanDoorn wrote:

GameboyRMH wrote: +1 for what Keith said...never heard of open-source ABS either. You could also try depowering the brake system to get finer control. About ABS on the track, consider this: If one side loses grip in an oil spill or marbles or something, the other side won't get more braking force than is safe for the low-traction side. You couldn't even spin/slide under braking towards the grippy side if you wanted to.

Not really true on a multi channel system. The ABS monitors each wheel. Your scenario would be true only for the rear two wheels of a three channel system.

That depends on whether the system has split-mu detection - most newer systems, including all of those where the ABS is integrated with the traction control, do have it. These systems will reduce braking force to the side with better traction to prevent a huge spin from happening just because you hit the brakes - even if at the cost of plowing into something.

My ABS system sends the entire car into glide mode if the inside driver's side wheel leaves the ground. I discovered this in a fast, decreasing radius left hander. It was very exciting. As a consequence, my ABS system is not currently operational.

Yeah, ive run into this situation a couple times after putting a space saver spare on and driving down a very steep hill. Luckily nothing bad happened before i learned to anticipate it.