replacing brake discs

[Simon J]

Adam,

Can you give any 'guesstimate' as to the impact of using DS2500 pads on the life of the 280mm discs. The improved stopping power as a result of the more abrasive pads must come at a cost - no free lunches, etc., etc. I realise that this will depend on the way the car is driven (or more properly the way it is stopped!) but some sort of comparison would be interesting.

For example, I got about 45/50K miles from the standard 302mm discs using standard pads on my previous T5 (the Black Diamond and Redstuff were fitted at around 100K just before I sold it so I have no idea how long they lasted), and around 30K on the 320mm ones on my current T5 using the Volvo pads. Simon (sholtby) on the basis of his figures above (80% worn at 13K) seems to be heading for, say, 16/17K on his AP discs (assuming he stays within the manufacturer's tolerances) with DS2500.

So from your experience, what do you think would be the impact on disc life of using DS2500 in place of standard pads? Any idea?

Simon J

P.S. Would you ever chase Hamish up about the availability of DS2500 for my Volvo setup? As they aren't listed by Ferodo under 'Volvo' I sent him a drawing of the outline of the pads ages ago to help identify them. Ta.

[sholtby]

I've just checked my brake disc thickness again with a micrometer and they are 26.4 mm thick! From this thread

http://www.volvoclub.org.uk/dc/dcboa...ng_type=search

I must have fitted them in January. Mileage will be about 12k miles at the most.
I'm surprised AP says they should be replaced when they are 27mm thick as this would mean a lip on each side of the disc of 0.5 mm which is nothing. A hard track day would most likely wear them that much! I usually replace discs when the lip is about 2mm on each side, possibly more, so I'm probably looking at a life of about 30k miles.
The pads dont look that worn and I think will outlast the discs.
I dont believe the material AP discs are made from is significantly harder than standard discs (they are all cast steel) so due to the combination of harder pads, drilled holes in the disc and the fact that larger discs are passing between the pads at a greater velocity all these factors mean that discs on a big brake kit will wear out faster than say stock 280mm discs with soft pads.
I've tried all the braking combinations on my car and am of the opinion that 280mm discs with stock pads are just adequate on a standard T5. 302mm discs give an increased 'bite' of about 10 to 20%. Fade on these discs/pads is acceptable for faster than average driving. Fitting hard performance pads will reduce the 'bite' of the brakes during normal driving but also reduce fade if for example you had to stop quickly from 90 mph.
Driving at normal speeds and around town AP brakes dont feel that much different to standard brakes but they are significantly better when stopping quickly from very high speeds (80 mph+) or when doing repeated braking on twisty roads or track days.
You really need to think about how you drive your car as to what brake setup is best. If you drive at normal speeds you will be making your brakes worse by fitting hard pads hence the reason car manufacturers chose to fit the pads they do.
If you are fitting ds2500 pads on a car with standard discs I wouldnt worry about the disc wear as they are only about £60 a pair from Eurocarparts.
Anyone know of a cheap source for AP discs or if any other brands will fit when the time comes to replace them?

Simonh

[don kalmar union]

Good place to check Ferodo's own take on their various racing compounds is www.federal-mogul.com/ferodoracing.

Their part numbers and UK retail prices for the pads discussed here are:

for standard 850,S/V/C70 280 & 302mm discs FCP 1285H DS2500 £114.56 plus VAT

For AP kit FRP 216H DS2500 £82.85 plus VAT

For the DS 3000 race only compound change the sufix from H to R and the prices are £92.85 and £89.18

All available from stock.

Will post up best AP replacement disc prices Monday.




Don.Norchi.

PS. Simon, will try to get a bit of a deal on the discs as I have a few to order.

www.kalmar-union.com

TME software for serious Volvo Tuning.

[don kalmar union]

Mind you, as an afterthought...none of us should buy a Federal Mogul product as they have left one hell of a lot of employees in the UK with no pension as they had robbed the pension pot and liquidated some of their companies here.


Don.Norchi.

www.kalmar-union.com

TME software for serious Volvo Tuning.

[sholtby]

Hi Don,

I'm pleased to read that the Ferodo pads are cheaper for the AP kit than for standard calipers!
I was reading sometime ago about a guy with a TVR which I think came as standard with AP brakes and he replaced the discs with Brembos. The cost was possibly about £100 per disc. I think it could be in my interest and possibly yours to do some research to see if any other disc manufacturers produce discs that will fit the AP bells.
With the cost of fuel these days replacement parts prices are becoming less significant even for the more expensive items. £50 in fuel doesnt seem to last long!

Simon

[Andy]

Hi

Just dug out my invoice from July '03 for replacement AP discs from Circuit Supplies.

These are the 'cheaper' (lol) grooved not drilled 325mm discs and they are £177 + VAT each. To add to that is the disc to bell mounting kit at £12.30 + VAT for each side.

Invoice total is £456.41 of which £10 is postage and thats 2003 prices!

I bought the whole kit for £360 second hand back in 2001!

Makes me laugh as I can't afford to put fuel in it any more...

[Simon J]

So the current price of £180 + VAT a side (down £100 on two years ago) for the Volvo ones isn't bad. Perhaps I should start buying one every few months just to build up a stock against the day that they don't make 'em any more!

[Al115]

>Conversely, I know of another T5 owner who runs Police
>Spec brakes and is still consistently setting his brakes on
>fire!

That'd be me, then. I'm running Police-spec 302s and they are (frankly) dire if you do any serious driving. For everyday road use, no problems, they'll stop you from 90 to zero without fuss, but once they get warm you are wasting your time with them. You know you've got problems when people start trying to flag you down because of all the smoke! :-)

Moderate my driving style? I've had to - until I can afford some bigger brakes. I have a man on the case!



Alastair
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http://www.volvoclub.org.uk/photopos...357v70-sig.jpg

[Ross9]

outstandingly pedantic thread on brakes lol.

if they fade, put better fluid in, make the brakes bigger, choose pads closer to race spec.

don't use redstuff, they are #### and eat your brake discs.

fast heavy cars fit yellowstuff, I have a very fast light car, and use them, they come with skulls and crossbones on and say for trakc use only.

From stone cold at 1am (average time I leave the Co-Op yard at after the backshift) they work like normal brakes, get them het up and yo think the car is going to stand on its nose.

282mm EBC flat discs, no grooves, no dimplies or drilling, keeps the temp up for the pads.

Works a treat, no complicated physics, standard brakes were pish, fit bigger ones, the wheels need spaced out t fit them under the standard 15" ones, with better discs and better pads and voila
full conversion was around £200 in parts
paying over £1000 for a brake upgrade, anyone doing so is quite frankly off their head.

Ross

[sholtby]

Andy,

Can you measure the thickness of your discs and how many miles you have done with them please?

Thanks
Simon