Brakes not up to it?

[Ian C]

All, and by that I mean Chris Wilson :D ,

While testing my nice new working-ignition single turbo I wound the car up to 170lph and braked as hard as I could. While the retardation was immense, I couldn't get the ABS to cut in no matter how hard I pressed and I'm sure I got the pedal down to the floor at one point. I can't believe my worn Pirelli's are that good, so what's going on there then? The brakes were fine afterwards, in fact the pedal felt a bit better :confused:

I've got:
All round UK spec calipers
Stock UK spec discs
CW fast road pads
Motul brake fluid (er, rbf600 or is that a motorbike? Well, it's the stuff Chris Wilson likes anyway)

This behaviour only seems to manifest when I'm braking from daft speeds down to 'normal' ones (170 down to 80 sorta thing)

I don't think the fluid is boiling, it got new fluid and a flush less than a year ago, it brakes in a straight line... Do I need the track pads? I can't believe the UK spec system isn't up to the job, please no daft suggestions of £2500 brake upgrades :p

-Ian

[Alex]

Maybe it's worth finding more abrasive and probably shorter life pads with a higher Mu (friction not the company) rating? They will cause more brake dust though.

Or maybe it's caused my gas build up not allowing you to press the pads onto the disc hard enough.

I would try either, new short life Hi Mu pads or slotted discs to dissipate gasses better....or both :)

[Ian C]

Gas buildup is my working theory...

Slotted discs. Hmmm. I'll wait for more replies before taking a stance on those :)

-Ian

[Alex]

Paul Laing reckons 3G 20 groove discs are great :) ;)

In all seriousness they make discs for Brembo I believe so maybe a good bet :)

[RICHARDA]

Ian, I have exactly the same brake spec as you and have been very pleased with the performance. Although not braking from the mega speeds you mention I too have performed a couple of brake tests in the dry running F1's from about 60ish and have managed to activate the ABS.

HTH
Rich

[matt]

10 year old hoses??
Unless, of course, you've changed them...

[Mad Ad]

Whenever I'm braking hard, I like to take my foot off the pedal for a split second then start braking again. Seems to work quite well for my car. Suppose it gives them a quick rest before working again.:thumbs:

[Ian C]

And Goodridge braided hoses :) Thanks Matt :)

Maybe it's just THAT much harder to stop a wheel dead when it's turning at 170mph than at say 40mph...?

-Ian

[Gordon F]

Originally posted by Ian C
Maybe it's just THAT much harder to stop a wheel dead when it's turning at 170mph than at say 40mph...?
-Ian
There's certainly a lot more heat involved. Probably a bit of fade after pulling 1500kgs down from 170 to 0 :)

[dandan]

You crazy SOB, imagine if they did lock at that speed !

[Ian C]

Originally posted by dandan
You crazy SOB, imagine if they did lock at that speed !

This is why I don't drive cars without ABS :thumbs:

What I mean is, I can't feel the ABS kicking in... Not that the wheels lock up per se.

-Ian

[Sharpie]

I have the exact same set up as you Ian, bar the rubber so, I'll give it a try if it's dry tomorrow, it won't be 170 though :eek:

(I have new pads, discs, fluid & F1's only in the last few months)