brake advice required

[majorscooby]

Ok heres the problem and could use alittle advice please.
I have recentley fitted some black diamond drilled and grooved front discs on me wagon with (and i think this could be the prob) some blueprint brake pads from scs. "arrrggghhh why oh why i here you say". well to be honest i was quite happy with the braking performance on previous cars and thought sod it they should be fine they must be made to the same spec as the originals from the subaru dealer. But what i am experiencing is a viabration under braking from about a ton, but not hard braking gentle progresive braking and the viabration is not really through the steeering wheel more so through the pedal. its not a big harsh vibe,its asif you could imagen the grooves passing the pads as it were
im thinking could it be the fact that i now have grooved discs and brake pads with a nice slot in that are not quite bedded in yet just causing the vibe OR is something warming up and distorting i.e crap pads.
Your thoughts and knowledge would be gratfully recieved and recomendations for new pads please. (standard 4 pot calipers on a 05 wrx)
thanks richard

[Scott.T]

ADL Blueprint stuff is pretty good.
I'm running a OE Spec ADL Blueprint clutch with over 300ft/lb of torque.

What your probably feeling is the grooves passing the pads.
You will always get a level of vibration/buzz with grooved disks when braking from high speed.

But this should reduce as they bed in, and become less obvious.

Just as a word of advice. Both Scott (Silversurfer) & Tony (2 Jaffa Cake Tone) are pretty much our oracles, they can and will answer any questions.

Not to say that loads of others wil put you in the right direction (Crowman / Dukeboy / CJ / Subarman etc) as we are pretty well catered for on here

[2-jaffacake-tone]

i have all ways found groved disc's have given off more noise than vibration. when fitting the discs did you clean the hub flange to make sure the disc was sitting flat.

also ADL stuff is nomaly really good we use it alot and never have any problems.

[majorscooby]

Must admit i didnt clean the hub face but being on an 05 everything looked nice and clean, no rust or stickyness when pushing them on. I remember giving the hub a rub with the old greasy thumb as you do! i wouldnt of put them on if i wasnt 100% happy with the final fittment. You dont get the noise from everyday city driving only on the motorway from speed and since its my first pair of drilled and grooved could this be normal and ive never expierenced this before???
Ill give them a few hundered more miles or so and see if they quiet down a bit as recomended by silversurfer. cheers fellas appriciate your thoughts!

[SUBARMAN]

Great help being offered here, as usual! Well done Boys!!!

[C. J.]

Upto you but for the time it takes i'd pop them of give them a clean and put them back on .
Only saying that as i thought i had warped disc's sent them away to a local engeering shop and they said that they were true .
Cleaned the hubs up and not a bit of shudder
Also do they have a right and wrong side .? (as in the way they spiral on the disc )

[DukeBoy]

Since i fitted my grooved disc's the noise is awful when heavy braking, something you will always get from grooved disc's.

How many miles they been on there for now?
You don't want to be heavy braking on new disc's untill they are properly bedded in (200 miles or so) otherwise they can warp very easily.

[Scott.T]

Originally Posted by C. J.

Also do they have a right and wrong side .? (as in the way they spiral on the disc )

I don't think this really matters as I have seen every combinations.
The EBC dimpled/Grooved that I have at the moment run the opposite way to the Prodrive Alcons and the Comp-Brake ones I had before where not handed so the o/s and n/s went in opposite directions.

The more grooves you have the more you will notice a vibration.

My EBC done the same as you are describing when I first put them on.
they still do it now but not some much.

give em' time to bed in and the pads to face off against the disks.

[Scott.T]

Originally Posted by DukeBoy

Since i fitted my grooved disc's the noise is awful when heavy braking, something you will always get from grooved disc's.

How many miles they been on there for now?
You don't want to be heavy braking on new disc's untill they are properly bedded in (200 miles or so) otherwise they can warp very easily.

New pads on old disks, brake like a bastard to bed them in.

For new pads and new disks take it easy

[majorscooby]

Since i put the grooved discs on i have only done around 150 miles or should i say the missus has,(so no heavy breaking there then). They are new pads and new discs so i know to be gentle for around 200 and even then im a tart and dont give it large too much. like i said ive never had drilled and grooved so these little noises are new and concerning but its reasuring to hear others saying its the norm!

[doobydave]

Is it possible that it's the ABS working?