ITT: We discuss adding ABS to a car that didn't come with it..
 

I am probably adding ABS to the autocross car over the winter. It is a 92 chassis if that matters and did not come with abs. Hopefully someone who has btdt can offer some information and advise.

Is it worth the effort?

Which year donor Miata has the most effective ABS?

Is there an aftermarket alternative that provides value?

This thread. It's relevant to my interests.

I have done a tiny bit of light research regarding this. From what I can gather, using all Mazda parts, it would cost in the thousands from Mazda specialists for all used parts. I know off the top of my head that there are ABS specific axels. But that's about it.

The cheapest way is almost certainly to find a donor car and swap the bits over. I've pondered this myself, and I think you need:

- Front hubs with ABS rings
- Rear axles with ABS rings
- ABS sensors and wires
- ABS hydraulic unit (the big cube thingey)
- various hydraulic lines
- somewhere to remount the washer bottle (NB hydraulic unit goes where washer bottle sits in non-ABS cars)
- ABS computer (I think this is separate?)
- wiring harnesses
- ABS prop valve

I could see all that being a couple grand from Mazdacomp, but I doubt it's that much from a junkyard.

--Ian

The ABS computer is separate and only shares a few wires with the main ECU.

Here's what I posted on the pointy board a couple years ago.
http://forum.miata.net/vb/showthread.php?t=279977

Ideally, you use the 2001+ three channel ABS. That's what I've (mostly) swapped into my '90 XP car. Some of those things above aren't needed in an SM/XP build.

Things you absolutely will need.

1999+ ABS spindles (to mount the sensor to)
ABS front hubs
ABS axles
ABS rear uprights (to mount the sensor to)
Four ABS sensors
2001+ integrated ABS pump and ECU. There is no separate ECU for this system.
2001+ wiring harness plug to the Pump/ECU

That's all. You'll have to plumb and wire the system. If you can't find the schematics, I'll dig one up and send it to you. The plumbing is easy too. There are only two ports from the master cylinder to the pump, one front and one rear. From the pump there are three lines, front left, front right, and rear. The rear line feeds both rear tires. FWIW, I'm using it with dual master cylinders, no booster and a bias bar. Keith Tanner has a good post on M.net on different master cylinders, boosters and pedal effort.

http://forum.miata.net/vb/showthread.php?t=363284

Also, I was able to buy all the parts I needed above plus two more 2001+ pumps, a 2001+ ABS master cylinder and booster, the front hard lines, pump cradle mount, and spare front arms for around $200. There's no need to buy and part out a whole car for this stuff. The SpecMiata part suppliers have it sitting around because the race series can't use ABS.

You can also easily disable ABS so it will work with launch control.

Did anything ever come of this? Has anyone actually completed the 2001+ ABS swap on a NA chasis that came without ABS and actually had it work? Sorry to resurrect a year and a 1/4 old thread but this is VERY interesting to me and it seems was just left hanging.

Doing a swap right now, putting 01 ABS in a 99 non-ABS car. It's a prepared class autocross car so it won't necessarily be done in a stock-like manner :).

NA->NB shouldn't make any material difference; just don't try to mix-and-match the knuckles and (front) upper a-arms; the ball joints have different tapers (say people more knowledgable than I....)

-- Glenn

What about adding 2001+ 3 channel ABS to an NA chassis that already has ABS installed:
- What is shared in ABS hardware between the 3-channel and earlier models?
- Is it worthwhile to make the swap or is the gain negligible?

I like having a flat spot fail safe in place to protect my wallet, but don't enjoy the way ABS cuts is during rainy trackdays.

Different number of channels means different hard parts (lines); also (I'm told, will know for certain from my own experience in a week or so) the ABS pump & computer are integrated in the 01+ so you'd certainly have different wiring to sort out. Several other brake components vary between 01+ and earlier cars (master cylinde, booster, prop valve) but depending upon your needs you may or may not want to bother swapping all of that.

Everything at the wheels would be the same.

And Boose Joose: I don't need ABS in the hope it will shorten braking distances; I can already threshold brake quite well. I'm trying to manage flatspotting, and larger & stickier tires makes flatspotting *worse*, not better. 1.6 vs 1.8 brakes is irrelevant; that just changes heat dissipation (which isn't a problem for autox, which is what I do), with 1.6 having worse heat dissipation. The size of the rotors or pad sweep area doesn't really affect flatspotting behavior, presuming you have taken steps to maintain appropriate front-to-rear brake bias (which I have).

The car in question already has 275 width A6s & 1.6L brakes. It stops... it just squares off a $200 tire (inside front one, often) every time that braking isn't in a straight line.

-- Glenn

ew abs

Well last night I picked up a 1996 ABS pump and ECU already paired with a RACE LOGIC traction control unit. So it looks like I'll be adding ABS to the car with the older parts. This was previously installed on a 400rwhp Track only that had been completely rewired and was removed as a unit. I'm in the market for some abs hubs, axles and NA Wheel speed sensors now.

Nice pick up. I am assuming you got it from Jeremy Schuster. I love shopping his spare parts bins too.

at the track i find ABS horrible, that being said what do you see as the advantage of going through the work to add this to your track car?

We have already had to ask mods to clean this thread up once because a newb questioned the rational...so I'm going to say this once.

1) This isn't for a road race car this is for an AutoCross car

2) You can find the perfect braking points on the track because you get to drive the same turn on the same track the same way 3 million times over 30 years...in Autocross we get to drive the course 3 times...and that's it. ABS will help overcome that.

3) 275/35/15 Hoosier A6's cost $1,200 a set and last 60-80 runs depending on the surface...one lock up of the brakes from taking a turn too hot and they could be a junked $1,200 set of tires

4) Traction control uses the ABS wheel speed sensors.

I haven't finished my XP build, but I have been party to updating E36 BMWs. There are standalone 3-channel and 4-channel ABS units before BMW integrated traction control into their ABS. We've had very good success with these units in E36s and Z3s. I'm expecting my Miata swap to go as well. I even thought about using the BMW 4-channel in my Miata.

And the 2001+ units do not have a separate ECU. The brain is built into the pump.

FWIW I am currently considering this for a track car after flat spotting a few expensive race tires over the last year. All it takes is a bumpy corner entry (the common factor from track to track IME) and the tire can easily be toasted.

OK so Modernbeat, you are talking about retrofitting a BMW ABS system from an E36 to a Miata? Interesting... go on please. Is the BMW ABS a superior system? Could it use the Miata ABS sensors and hub rings, or at least the hub rings? 4-channel might be cool, though all my flatspots have been on the front so a 3-channel would probably be fine. I assume the 4-channel would require installing another brake line to the rear.

I find the ABS in my 2000 Miata less susceptible to ice mode than my 97 M3.

Ice mode?

Give up because nothings going to help mode?

When you get on the brakes very hard and very quickly and a tire hits a bump (and skitters) it thinks you're on ice and so it applies the brakes very gently -- very weak stopping. You need to lift and brake again. Google "ABS ice mode".

Strange because Germans being the way they are, I'd expect that the BMW ABS computer would be more difficult to get into ice mode if it sees the external ambient temp sensor shows 70°F.