ABS on an S12

[30psi]

Use a Z32 one, it's the biggest master cylinder of them all. I wouldn't worry about using this over the S13 one unless you're using Z32 calipers.

The wheels sensors are nothing more than a hall sensor on a toothed wheel. so you could make up new toothed wheels on the back of the front hubs and also on the prop.

There is an issue that you need to check on however, and thats whether the different diff ratio will cause an issue with the ABS, because the rear will be turning at a slightly wrong speed compared to the front.

Unless you use an S13 back of course, but this has difficulties in itself.

[JackieFan]

The only reason I was thinking that the S13 MC would be best is because it'll match the ABS pump.

Not sure how the S13 is set up for ABS at the rear but if it only runs 1 sensor on the prop then you might be in luck. As far as I can work out the ABS controller only looks for unusual deceleration, so slight differences in wheel speed front to rear shouldn't effect it.

[old-and-rusty]

Dan,
The rear sensor can be found once the prop is removed. It`s just behind the flange that connects the prop to the diff (so just one bolt to remove the flange) .

I wonder if you could rig up the set up that a lot of kit cars use for the speedo sensor on the front hubs, do you think that would work Martin?

I know that TVR`s use this type of idea.

Regards,
Ian.

[sideways danny]

for the love of god why??? s13 ABS is positively dangerous, the worst ABS system known to man. Best mod you' can do to any s13 is remove the
ABS

[JackieFan]

What makes it so bad? Is it one of those systems that jumps in and doesn't let you have the pedal back until the car is wearing with either a tree, wall or innocent bystander?

[old-and-rusty]

I`ve only driven a couple of s13`s and TBH I didn`t have a problem with the ABS systems. Both of them worked perfectly (in the wet).

I`ve checked the 2 servos side by side, the s12 servo is slightly larger in diameter, but the s13 one is deeper. The s13 servo fits into the bulkhead perfectly, but the s13 MC is a bit closer to the suspension turret than the silvia one. Plus the rod (that connects to the brake pedal) is a bit shorter on the s13. But I guess this can be altered on the adjuster to take up the difference.

I`ve not checked to see if the s13 MC will fit onto the s12 servo. But if anyone is thinking of this mod, it`s probably best to use the complete s13 servo and MC complete .

Regards,
Ian.

[30psi]

Don't see the need to use the servo.

Just use the master cylinder, it bolts on

[sideways danny]

Originally Posted by JackieFan

What makes it so bad? Is it one of those systems that jumps in and doesn't let you have the pedal back until the car is wearing with either a tree, wall or innocent bystander?

pedal sinks to the floor and doesn't recover easily if ABS engages. ABS ecu gets confused if you spin (on track for example) and gives you zero braking going backwards, and most of all it totally kills the pedal feel. The best thing I've ever done to s13 brakes is remove the ABS. I'd do it before changing calipers now.