M52 + ferodo ds2500's, pagid discs = cracks. Any suggestions

[Supafly]

Hi,

After a bit of recent quick driving I've found that my recently renewed braking set up has caused my front discs to have lots of small cracks in the swept area of the pad. My brakes sound like they're metal to metal at the moment.

My current set up is DS2500 pads front and rear, new pagid discs front and rear and ate super blue fluid. Tyres are Michelin Pilot Sport PE2's which provide a lot of grip.

I haven't experienced any fade although initial bite is poor (esp from cold, can't lock wheels up) from the pads until they warm up slightly.

I've read up on lots of threads and although the WMS kit is tempting I can't stretch to the circa £500 cost.

So are there any other options for improving my set up. Should I switch to brembo or other manufacturers discs? Improve cooling to front discs?

I'm considering changing my pads for ebc yellows. Does anyone have any experience of them and their initial bite especially in comparison to ds2500's?

Thanks in advance

[bimanut]

If your on a budget you could try these,
http://www.ebay.co.uk/itm/BMW-3-E30-325 ... 19c9e7f6a0

[Supafly]

Thanks for the reply.
I see that these are drilled and grooved, I honestly don't think that these are needed even though I've managed to put lots of small cracks into my discs!

My budget isn't too tight but I can't justify the cost of a BBK when this set up has lasted nearly two years. I don't mind spending a reasonable amount, I just want to make sure I'm spending money on decent hardware.

On closer inspection it looks like my front pads have worn down. Looks like I'll be needing new front discs and pads.

I'm thinking of stickng to new pagid discs and yellowstuff pads. Unless the cracks in the disc have been the cause of excessive pad wear????

Does anyone know who the oem brake discs are made by and if they're available at discounted rates anywhere?

[DanThe]

GSF supply Brembo at reasonable prices, try Matt (meatballs) on here with the zone ECP discounted account

[Supafly]

Thanks for the heads up Dan. Think I'll try the brembo discs with yellowstuff pads up front. The rears are still at about 70%. Think the ds2500's may not be the best bet for the rears as I don't think they get enough heat into them.

I'll pm you soon regarding a remap, I wanna squeeze what I can out of this lump ;)

[zaust]

The yellow stuff is good I'm using them with no complaints. I use tar-ox discs or red dot depending on availability. Should both be good with the ds2500's up front.

[Jimbob]

I have brembo discs with yellow stuff pads on my M52, only had normal road driving on them so far but initial bite seems quite good for what is considered an aggressive pad.

[Supafly]

Thanks for the replies everyone. Looks like I'll be going with yellowstuff pads and brembo discs.
Where is eveyone getting their pads from?
Could do with getting these fitted quickly as I miss driving it already

After looking into the cracking situation it seems as though I've put a lot of heat into the discs, I'm fairly hard on the brakes but this has also got me wondering if my rear brakes are pulling their own weight so to speak. I have an LSD so have never allowed it on the rollers at MOT time.

Is there any way I can check the rear braking effort? After reading up on this I found a thread where someone had the rear in the air and tried to stall the engine is this a good enough check?

[keri-WMS]

For what it's worth, we hear better feedback for DS2500 in terms of bite than for EBC Yellows (that may be when warmed up though)...and if you've already got surface heat crazing on the discs I would stay away from grooved and/or drilled discs as they tend to crack more than plain ones.

Sorry to muddy the water!!!

[Supafly]

Not muddied at all, all the better for some real feedback ;)
Thank you for the input.

Real feedback is what is needed. Although driving habits vary wildly, I can only go by how I drive and so far I've generated enough heat through the ds2500's on roads to have surface heat crazing. This could be due to ineffective rears, although at slow speeds I can feel the rear pull down So I'm assuming there is some rear effort.

For anyone reading this thinking of upgrading their pads then I can definately recommend the DS2500's, but only if you do brake late and regularly drive the car quickly. When cold they aren't as immediate as a normal road pad, they need at least one 60mph + slow down in order to get them behaving like normal pads. With heat they get better and better and then stay very consistent.

If your driving style doesn't require frequent repeated braking or regular braking from speed then I honestly think a good oem pad would be better as it will have time to cool and be better from cold.

As for me, I've already ordered a set of yellowstuff and will see how I get on with these after a fluid change and full check of the braking system. If I'm not happy with these then I'll be saving for an upgrade to the whole system.

[Demlotcrew]

Not a fan of DS2500's, a highly metallic compound which destroys disks.

Have EBC made an Orange compound for stock E30 callipers yet?

[bss325i]

Ive had and still have a set of DS2500's on my Sport since 2009 which was used for a 12 lap ring trip and have stayed on there since for road use only!

I would say they have done about 11000 miles road use since and the discs are still fine.

Sqeeky as fook when cold but quieten down with heat in them and the bite certainly improves as well.

Obviously road use doesn't compare to track use but the brakes often get a nice work out when i give the car some shit which is most of the time i drive it!

[Demlotcrew]

DS2500's after a track day and then no use for a few months.



They destroyed very expensive AP disks.

[bss325i]

Bummer about the discs! Dont those ones of yours have like 1mm wear range or something silly?

[keri-WMS]

Some compounds will revert from "pad material vs pad material" (most performance pads "smear" themselves onto the discs) to a basic abrasive friction mode if they are not driven hard every now and then (or regularly) to maintain the transfer layer on the disc.

They can then start eating the discs at low temperatures, even though they DON'T when being worked hard and run at higher temperatures.

I suppose if DS2500's are hard on discs.....that's less of an issue if you are running inexpensive discs! That said it's the first time I've heard that about them.

As for EBC's range and the new EBC Orange:

Green ("fast road"), not had good results with these.
Red ("fast road/200bhp+/trackday") good all rounder.
Yellow (VERY fast road/trackday/race) this is the most similar to DS2500
Blue (RACE ONLY, endurance)
Orange (RACE ONLY, apparently even harder than the Blues)

As far as I am aware, EBC blue, orange (and Ferodo DS3000) are all 100% race only and shouldn't ever be used on the road.

[harry_p]

DS2500's after a track day and then no use for a few months.



They destroyed very expensive AP disks.

use the car more often then

ive had 2500s on a few cars and really like them, i've yet to find anything else thats as good all round for a mixed use vehicle. everything else i've tried has been good from cold, but melted or crumbled when pushed, or dead until you get some heat into them.

or crap from cold, work for 10 seconds then crap when hot (greenstuff, i'm looking at you... )

2500s are the only pads i've found which work well on an everyday car, are happy with moderate track use, and have a decent life span.

[Supafly]

Just fitted the yellowstuff to the car with new discs.

I was surprised to find how much the discs had been worn. Not worn through but I wouldn't run another set of ds2500's on them with that wear rate, even though thats academic now because I had plenty of surface cracking (only on the outside which surprises me).

Lets see how these yellows fare. I'm not keen on the 200 mile bedding in, I'd much rather use my regular several slow downs from speed and then know it was over and done...

[Demlotcrew]

Im glad im not the only one that wont use DS2500's again for their seriously bad wear rates.

Im now using RS29's front and rear as these have the lowest disk wear rate of any pad on the market, they are very good at high temperates too.

A few weeks ago, I bought some EBC Orange pads for the turd E36 M3 and this what was on the seal sticker.



They actually don't feel that bad on the road, yes the temps outside are still moderate but ill be honest they feel just as good as any fast road performance pad when cold.

Lets see what they are like on the track.

[keri-WMS]

If the Oranges really are a full-race-happy pad that works from cold that would be really handy...price depending!

EBC have been talking about them for a very long time now, the hype has died down a bit and they are still not properly available which is a bit daft.

[Demlotcrew]

Well I got these for less than £80 delivered, which I thought was pretty good, took about a week before they were ready.



Andrew

[Supafly]

I considered moving to the pagid pads but the price put me off. They made me consider a brake upgrade instead!

When pads start to get close to £200 per axle then upraded brake kits become a bargain. I'll see how these yellow stuff pads go and if they're not as good as the ferodo's then it's BBK time for me

[rix313]

Certain 'race' pads will be more aggressive on discs than others but don't be surprised when they do shag the discs faster than a more road based set of pads do. We run Pagid RS29's on the Astons with Brembo floating discs (at £300+ each per time) on the front and we will do 3 races and a test tops before pulling them off and changing them.

You will also find that generally performance pads for aftermarket calipers such as the WMS, Wilwood etc are cheaper than standard fitment pads. I recently bought some PF01 compound pads for my Wilwood calipers and they were 1/3 cheaper than standard fitment PF06 compound pads for the rear

[Demlotcrew]

After three races and a few tests they will be hardly worn at all

All the 24hr cars run RS29's as I'm sure you know

[Supafly]

Bit of an update..

New front discs, yellowstuff pads new ate super blue fluid. All sliders cleaned and checked.

Haven't driven the car much with all the salt on the roads but have managed to do the couple hundred miles and bed them in a little. The break in coating is very grabby and I quite like it

I've put some heat into them a few times and thought they were bed in, but the last time I took the car out and put the brakes to the test I nearly shat myself as I got pad fade.

The pads feel quite wooden and require a LOT of pedal effort for the equivalent braking I got from the ds2500's. They've left me feeling very unsure as to whether they'll be there when I need them. When I get a chance I will go through my normal bedding in procedure with repeated slow downs from speed til I cook them and keep moving without stopping until they are fully cooled.

Then I'll see how they compare to the ds2500's and report back in case anyone else has the same issue as me.

The rears with ds2500's are doing their thing and when warm under hard braking they can lock the rears.

I will be checking all the hard lines, renewing all the flexi's for braided, re-furbing all the calipers (seals and sliders) and re-newing the master cylinder. This may effect my braking as I think I may be getting swelling on the front lines...

[Supafly]

Fixed the gear linkage on my friends car tonight which meant taking mine out of the garage.

So I took it for a drive and did a load of decel's from high to low speed and managed to get some green fade. Then I got almost 5 miles of 50mph driving before I touched the brakes again and didn't once come to a stop until I got home 15 miles later. So they were definately cooled fully.
It was getting late and I didn't have time to go and do another round of heat cycling although I will probably go out again today if it is dry. Drove very gently home and will report again when I have cycled them once more as per ebc's instructions.

I've been thinking about the rears locking when warm, this never happened when running ds2500's all round, although I had michelin pe2's all round then and now there's a temporary set of falkens ze912's all round. All the tyres are the same just the bias difference of yellowstuff (unbedded?) front and ds2500's on the rear....????

I'm not ruling out any weakness in the front brake system just yet as that may also be the cause, new braided lines have been ordered and I'm about to order new refurb kits for the calipers...
it's late and I'm waffling. More later.

[Demlotcrew]

The friction coefficient of the differing compounds are no doubt causing you issues with the bias.

I would ask both manufacturers for dynamometer plots, that will show if they are both compatible with your car and driving style.

[Supafly]

Ive found that the average coefficient of friction for the ds2500 is 0.42 from 20-500 degrees Celsius.
http://www.ferodoracing.com/it/car_racing/ds_2500.htm

However, I'm struggling to find definitive data on the yellowstuff. Ebc have got their own way of showing how 'good' their brakes are, but it is difficult to compare apples to apples. Although I remember reading that they were around 0.5 cf but I can't find it again. Email will be on its way to them now.

I'm going to heat cycle them again then go over my entire braking system renewing or rebuilding as necessary, if that still leaves me with an issue I'll be contacting ebc. I want to be as fair as possible and if its down to my set up being at fault I wouldn't like to point fingers. If however I eliminate all other possibilities then I will be in a position to.

[Demlotcrew]

Sadly looking at the DS2500 plot it looks like a very advanced racing pad with a steeply rising friction plot. Not so good for the rear brakes!

I prefer a high initial bite and as the pad surface heats up in the braking zone grip slowly fades away (as the weight transfers to the front).

Possibly having a harder pad on the front and a softer one on the back is the way to go.

[keri-WMS]

Sadly looking at the DS2500 plot it looks like a very advanced racing pad with a steeply rising friction plot. Not so good for the rear brakes!

I prefer a high initial bite and as the pad surface heats up in the braking zone grip slowly fades away (as the weight transfers to the front).

Possibly having a harder pad on the front and a softer one on the back is the way to go.

The steeply rising line on the DS2500 is temperature, the multiple blue lines are the "stop events" and show the torque rising during each stop to start with and then dropping during each stop as they get too hot?

Based on the blue lines that looks like a pretty easy pad to live with (which ties in with what I've had in terms of feedback, that "DS2500 works better than EBC Yellow both hot and stone cold").

In any case I would either put Yellows on the rear or DS2500's on the front depending on your budget / preference - but get a full set. Remember that while the rears DO do less work than the front, they are also a smaller pad and a lighter disc so will heat up faster than the fronts for the same energy input - they should be a pretty good match with identical pads.

[Demlotcrew]

Exactly Kerry, if you notice the pad has a sweet spot at 300º-350º where its pretty much flat and then as the temperatures rise the friction coefficient reverses.

The DS2500 have a 'low' friction rate at 0º-100º and that delta decreases as the pad heats up to 300º where it flattens and then as the temps rise it has high initial bite and then drops off (which is what you want on the rear).

Sadly I very much doubt those temperatures will be seen or even sustained on the back, thus as you rightly point out DS2500 (Hard Compound) needs to be on the front and EBC Yellow (soft compound) needs to be on the back as 'climbing' friction rates during braking are the hardest to control (not good on a light tail happy E30).

[Demlotcrew]

Just so that we are both talking about the same plots.

"Climbing Friction Rate"



The blue dot is the mean, and not something Im concerned about.

[keri-WMS]

I'd maintain that the DS2500 is actually pretty civilised. Here's a nice comparison:

http://www.ferodoracing.com/it/car_racing/DS_3000.htm

It rises slightly then pretty steadily drops away. The other (true full race) pads are all over the shop in comprison!!!

It's Keri, not Kerry

EDIT - Nearly all pads will warm up and increase friction in stages on the way up (hotter) then fade in stages too as they overheat, you can't get away from that!

[Demlotcrew]

Sorry Keri

My opinion of the DS2500, at best a performance road pad, those graphs on the ferodo site are slightly misleading (they are all Mean values). I hate the fact that the manufacturers don't show dynamometer plots for all their compounds especially those for track use. My money would go on the 4003 as a better match on the rear for a track car and the DS3000 on the front.

For a road car, some stock Pagid pads are best, I found DS2500 slow to react, especially when on the motorway and long periods between application.

[keri-WMS]

All I can do is go by the feedback I get from customers, and nobody I can remember has ever gone back to EBC Yellow after trying DS2500 (fast road / trackday use).

Pads are a nightmare as everyone has strong and normally conflicting opinions and I normally say "use the pads you like, they all fit the WMS caliper" or something similarly vague to keep my nose out, but this one is very clear cut, especially as EBC's prices keep creeping up.

I'd like to see a massive dyno comparison run between all the pads from all the manufacturers - but even then there are so many other factors like noise, dust, disc life, pad life, price and so on...

[Supafly]

I'm in the situation of having had a full set of ds2500 all round which were good but when the front were worn I decided to give the yellowstuff a try primarily for cost reasons.

It's a nightmare trying to find hard data on different pads. I keep reading that people say this and that and then there's the flavour of the month... Performance friction, carbone lorraine etc... When you try and get data to compare and make an educated choice it all becomes very vague and subjective.

Hence me going through the effort of noting carefully how my set up is behaving in order to help someone else who may stumble into the same situation.

I've only found "nominal coefficient of friction" for yellowstuff which is 0.5 and 0.6 depending on the source, so pretty much useless.

I found one comparison but it's in italian with different pads tested, interestingly they rated the redstuff better than the ds2500. I've got it on pdf but don't know how to post it up. I'll see if I can figure it out.