Technical Brake fade issue

[Mytheroo]

Hi, I have a 1.6 with 257mm front disks. When I got the car it was listed as having EBC Dimpled Disks and Green Stuff pads, but actually had Apec (I think) pads. Stopping power was ok and I noticed no fade. I live in Milton Keynes so I get to "track day" it regularly (fast straights with a chicane every 1/2 mile or so).
When MOT time came around I replaced the disks with the grooved and dimpled EBC, and also got the Green stuff pads. Stopping power was higher but after 5 or 6 roundabouts I started getting massive fade - Pedal wasn't spongey, was kinda hard but the noise changed and stopping power dropped to say 10%. 10 minutes later all was back to normal.
Recently I changed to Torax pads (some kind of fast road compound iirc) but the issue remained. I've changed to Motul 660 (?) brake fluid but the issue remained.
I'm wondering if the 257mm disk just doesn't have the meat or the cooling to deal with these higher performance pads?
Am I likely to get rid of the issue with a 284mm disk/caliper setup (or the other bigger size), or do I need to create some active cooling ducting?

 

[Alfettaman]

The standard brake set-up on the Stilo is actually pretty good, and copes with a couple of very hard stops in quick succession - but are not suited to a track day - perhaps not even your 'Milton Keynes' one!

EBC Greenstuff have very good initial bite when cold but the coefficient of friction starts to decline as soon as they begin to warm up. Track pads are designed to do the exact opposite of that - generating higher friction/more stopping power as they heat up. See attached graph.

The bigger, heavier and faster the car, the less successful Greenstuff will be. EBC themselves suggest that they are suitable for "...lighter model Asian and European sports compacts". Greenstuff pads are fine for everyday driving and they do inspire confidence when cold - but I'd never use them on anything that's driven briskly, or where the brakes need to be at their best when hot. The Greenstuff compound is also pretty soft, so won't last as long as some others.

I fitted Tarox G88 discs...
http://www.tarox.co.uk/performance-brake-discs/g88-brake-discs/
...and Tarox Strada pads...
http://www.tarox.co.uk/performance-brake-pads/strada-brake-pads/

...to my Stilo Abarth and they were a real transformation. Not cheap, but totally bomb-proof and utterly dependable. I run this same set-up on my Alfa Romeo Alfetta saloon, and have never suffered brake fade.

 

[Ralf S.]

As above really.

The fade you get is more likely related to pads than the discs, so try new (different brand) pads. I've never rated EBC any Stuff and I don't understand how they have so many fans... but there you go. Personal preference I suppose. Ferodo DS2500 is my recommendation since they don't have lag when cold and hang on well when they're hot. They're a fast road pad rather than a regular or extreme compound. They'll do well for you, I think.

You only need to change the brake fluid if it's boiling, which yours isn't. If you notice a spongey pedal when really hot, then that's the fluid. It's more important to just change it every so often, especially if it also feeds the clutch.


Ralf S.

 

[Mytheroo]

i meant to say I'd fitted Tarox pads not Torax. And typically, that's the one purchase I seem to have not kept an email for, but looking at prices I believe it was the Strada pads I have.
Had a quick look for DS2500 pads and saw DS3000 pads for sale on DemonTweeks outlet shop on ebay...at £33.48!
So, I'm going to try them with proper warm up and see if I can avoid the fade issue, which should clarify that the pads are indeed the issue if no fade, and then I'll look for the DS2500s or something that is a bit safer cold.

 

[Mytheroo]

well, the DS3000 weren't horrible cold and unbedded. I've kinda did the right bedding in (20 fast to slowish braking events) but not even sure if they got up to the temperature they were designed for.
Tomorrow morning will be a test, as will in the rain.
I cleaned and double waxed the wheels, and they are quite dirty again after 10 miles or so . I'll see if I can get them to activate the anti-lock system on good tarmac, I think that's a good test. I noticed no fade but haven't done a full test for that yet as I'll need to build up to the confidence level.
But, so far so good. And only £33 for a set of pads!

 

[Yorkshire007]

The DS3000 need you to ride the brake pedal for a few miles to warm them up. After which you will boil the brake fluid before you get anywhere near to getting a fade from them ...... Try a motorway slip road and silly miles per hour to really enjoy the power.

 

[Mytheroo]

have you used them? I'm finding they can set off the antilock system from cold, not really noticing any degradation from cold. Lots of dust though. Maybe slightly grabby when in a queue and edging forward while warm.

edit: just went out on a vigorous drive, once hot there's a lessening of the initial bite of say 10% brake that I was doing just before full braking. This was a bit disconcerting, however with full pressure after this they do indeed work magnificently. So it's just getting used to that 10% pedal feeling (or bypassing it). But zero fade of the type I was getting after 1/4 of the time with the EBC greenstuff.

 

[Ralf S.]

On the other hand.... if you're constantly hooning around and activating the ABS even in the dry, you made me worry that sooner or later you're going to have a very big shunt.

Apart from "you don't live anywhere near South Wales, do you, I hope..? slow down a bit and enjoy the ride. Driving is a lot cheaper and a lot less stress when you back it off 20% (maybe 80% in your case)...

Ralf S.

 

[Mytheroo]

i was just making the point that from stone cold, the pads are grippy enough (with pilot sport 4s) to use all the grip of the tyres, so I'm not concerned about stopping power when these pads are cold, contrary to most advice I see. I also read that the reason they don't get official road rating is because the hot stopping power is too much of a percentage higher than cold stopping power, even though the cold stopping power starts off as good or even in some cases greater than other officially rated for road pads. I'm inclined to agree with that assessment.

 

[jimboy]

On the other hand.... if you're constantly hooning around and activating the ABS even in the dry, you made me worry that sooner or later you're going to have a very big shunt.

Apart from "you don't live anywhere near South Wales, do you, I hope..? slow down a bit and enjoy the ride. Driving is a lot cheaper and a lot less stress when you back it off 20% (maybe 80% in your case)...

Ralf S.

Totally agree here, your style of driving that you describe in your first post is by far the problem here. Like it or not you may find yourself looking for more than new discs & pads if you carry on like this. Just saying.

 

[Mytheroo]

seeing as you come from a place where A roads are single-tracks with passing places I'll let you off the judgemental attitude. Having driven my local roads for almost 3 decades now, and putting my not inconsiderable brainpower towards paying attention to all aspects of the road and other road users, i'm fully happy about where my and my cars limits are, and how far under them I drive.
Just saying....;-)

 

[jimboy]

seeing as you come from a place where A roads are single-tracks with passing places I'll let you off the judgemental attitude. Having driven my local roads for almost 3 decades now, and putting my not inconsiderable brainpower towards paying attention to all aspects of the road and other road users, i'm fully happy about where my and my cars limits are, and how far under them I drive.
Just saying....;-)

Erm! No single track roads in my area fella.

 

[Ralf S.]

Aye okay... Just take it easy. I'm worried you'll hurt yourself. We can't afford to lose any Stiloists, otherwise this particular forum would become a ghost town.


Ralf S.