Grinding down disc rotors?

[TooF]

yes but as you notice this is a smaller secondary slot. this aids in the deglazing of the outer edge of the pad as you will notice that slot dosent continue all the way with the rest of the other slot.



also are you planning on using this serisouly at the track ? if not the 4000/5000 might be overkill. reasn being is they are not only slotted differently bjut also the steel itself has been heat treated and processed differently to the standard (slotted and drilled) so if it is just going to be street use i wouldnt stress over 4000 rotors.

get the aw11 rotor and redrill it as i can confrim even in unslotted (standard) they work bloody well out in the hills with the twin piston calipers on them.

[Joshstix]

the ST18x came with both 278 and 25xmm rotors, both in 5x100 PCD. Why not just use the smaller rotor? Although I think the smaller one may be a bit thinner as well, not sure I only paid attention because I knew the smaller one was what I was avoiding.

Actually come to think of it the small ST18x rotors are 25xmm diameter and 22mm thick. The big ones are 278 x 27.

Do you have calipers that are designed for 22mm or 27mm thick rotors?

[Aust162]

yes but as you notice this is a smaller secondary slot. this aids in the deglazing of the outer edge of the pad as you will notice that slot dosent continue all the way with the rest of the other slot.



also are you planning on using this serisouly at the track ? if not the 4000/5000 might be overkill. reasn being is they are not only slotted differently bjut also the steel itself has been heat treated and processed differently to the standard (slotted and drilled) so if it is just going to be street use i wouldnt stress over 4000 rotors.

get the aw11 rotor and redrill it as i can confrim even in unslotted (standard) they work bloody well out in the hills with the twin piston calipers on them.

I'm only looking at the standard slotted series. (eg.DBA***SL), not the 4000 series. The car wont be track raced, street driven daily but i want good stopping power.

And again, whats the point of the getting aw11 rotors and redrilling them? The original st162 rotors (dba739) are the same size/thickness (both originally 22mm)and they will bolt straight on for me!

I was having a closer look at the slotted rotors (standard series)and the slots go right-out to the outer edge. they dont go to right to the inner edge though..

[Aust162]

the ST18x came with both 278 and 25xmm rotors, both in 5x100 PCD. Why not just use the smaller rotor? Although I think the smaller one may be a bit thinner as well, not sure I only paid attention because I knew the smaller one was what I was avoiding.

Actually come to think of it the small ST18x rotors are 25xmm diameter and 22mm thick. The big ones are 278 x 27.

Do you have calipers that are designed for 22mm or 27mm thick rotors?

I wish i could just use the smaller rotor, then there would be no problems at all. But DBA dont have a listing for the smaller rotor.

The 278mm are 25mm thick,with a minimum of 23mm. So are the smaller 255mm ones i'm quite sure. (all i can confirm is that i have stamped "23mm min" on my originals)

I am using the twinspot st165/early st185 calipers which are designed for a 25mm rotor.

[dynomatt]

I had to grind down my ST205 front discs from their original size (315mm) to 290mm...so it's possible.

They are on a rally car and are subjected to pretty extreme conditions and I've not had any dramas with cracking etc. They replaced a similar set that had done goodness knows how many rallies before that.

Cooling is possibly a little less effective, but mine don't get hot.

Matt

[TooF]

are you *sure* on that slotting nopt going all the way to the edge.... every dba slottled disc vie seen is slotted to about 2-3 mm before the edge.

i say this from being though the dba factory where they have specifically noted it as a feature....

[takai]

Yep, my GT4 disc was slotted all the way to the edge.

[Joshstix]

OK well DBA list standard disks for the ST 162 as being 258 x 22mm. This is the exact same rotor as the twin piston ST 185's used. The St165 and ST185 twin piston caliper is designed for a 22mm rotor.

Your original question is not at all clear. Is your aim simply to have new slotted rotors? If so just buy new rotors DBA 739 and have them slotted by a brake shop. On the other hand the DBA catalog does list slotted rotors for the ST162 SX part numbers 739SL and 739SR.

[Aust162]

OK well DBA list standard disks for the ST 162 as being 258 x 22mm. This is the exact same rotor as the twin piston ST 185's used. The St165 and ST185 twin piston caliper is designed for a 22mm rotor.

Your original question is not at all clear. Is your aim simply to have new slotted rotors? If so just buy new rotors DBA 739 and have them slotted by a brake shop. On the other hand the DBA catalog does list slotted rotors for the ST162 SX part numbers 739SL and 739SR.

Well this is the 2nd thread i've started about my brakes. i want to change my front discs that i have fitted to the car atm. the ones on the car are 2nd hand from the wreckers. They are on their 23mm limit and one has developed a groove.
I want to replace the disc's and hopefully get slotted ones to improve the braking.

I know dba list the 739's in slotted. but i wanted to replace the disc's with something the same as i was taking off. (the 739's are thinner than what i currently have on)

So here is my new question i guess: what are these disc's off?
measurements: 255mm diameter, minimum thickness of 23mm, total height of 46mm (approx), hat height is about 16-16.5mm.
I cant find a listing.

[Youngy]

Hi,

I have posted up plenty of non WRX questions on this forum:

http://www.mrtrally.com.au/forums/forum.asp?FORUM_ID=17

with great results as one of the guys on there (who is quite active) is from DBA.

Cheers

[MWP]

I have posted up plenty of non WRX questions on this forum:
http://www.mrtrally.com.au/forums/forum.asp?FORUM_ID=17

Thanks for pointing out that forum!
Rep points for you.

Itll be a good resource for those of us running the Pug604 & Hilux caliper combo as WRX pads fit.