I've got J specs brakes and always used the bog standard Toyota pads until the last set I bought which were called fast roads pads or something. I'm going to change back the standards because they squeal endlessly from the dust (thanks to 40mph limit in channel islands). The main reason I bought them is because the Supra is also the car I use on track days. But really couldn't say that fast pads felt any better than standard, this involved some very hard braking from somewhere in the region of 120mph at the end of the back straight. The thing is, they were smoking quite a bit when I pulled into the pits. Was told it was the copper something or other burning off so that might have something to do with why they didn't seem anything special.
I don't quite understand why upgraded brakes are a good thing.
If your tyres are sliding you are not going to stop any quicker even if you have tremendous brakes, surely it's all down to loosing grip on the road? So with the j-specs, you can brake hard enough that the tires start to skid and the ABS leaps into action etc. so why would you need more braking power, wouldn't wider or grippier tyres be the better solution Can anyone explain?