333pg333

I just thought I'd check in here as I've been on a bit of a quest to find some slotted rotors for the track. (I don't consider the OEM vented GTS or 965t X drilled rotors an option anymore).

I became interested in a 2 piece setup for a couple of reasons. Firstly the reduction in unsprung weight. Don't have the figures but it will be lighter. Secondly the design and material of the more modern slotted rotors is superior to OEM and they're also cheaper to replace....once you get some hats made up. So then this brought me to finding these components. I have found a rotor that is actually made down here in Australia however there is actually plenty of stock in the US according to the tech guy I spoke to today. So then it's a matter of having some custom hats made. If anyone has been involved with custom parts that are designed, drawn, and CNC'd it can be expensive, especially for one off parts. So I'm in the process of checking out what a couple of guys can do as far as numbers and costs. At this stage I was only getting the fronts done but I would entertain all 4 if there was enough interest?

This idea may prove fruitless if you guys have already found a solution. I just see the question asked in many of the forums about where they can obtain some slotted rotors for their 951/928/964 (and 993, though different offset). Essentially anyone using the Big Red/Black calipers.

So if you are interested let me know and I'll continue this quest. I am speaking to the CNC guys in the next few days.

Oh and for those of you who have a line on some hats, it would be extremely fortunate if they fitted other rotors. I've already asked.

stuartph

Patrick

I had an AP racing set up made for me and i can say the bigger disc's i have are the same weight as the old GT disc's, so if you kept the same size they sure would be alot lighter.

mark kibort

do you really think that reducing the unsprung weight will be worth the effort. what are you trying to gain? I think the GTS rotors over the S4 rotors were about 1-2 lbs heavier , so what does that mean (going from 12 " to near 13" rotors) . I did it for heat, and more rotor surface area and better leverage in braking. All seemed to have a positive effect. unsprung weight was not a concern because of it being such a small factor in handling and in net power loss or gain.
If I could find some slotted rotors for the GTS type set up I have now, I would jump on it. hole'ed rotors crack at the track, and the flat rotors seem to work well, but they dont look as cool. Lap times have proved no difference, as well as not really any difference in feel, however, I do sense a little less "bite" with the flat rotors vs hole'ed, but that could just be in my mind.

Mk

mark kibort

I have found someone that has made these hats. I would be interested, but they are expensive. I think it would be something like $800 to have them made, maybe less if we did a run of them. in the end, you could use the coleman rotors that bolt on for about $200 a set, very close to the price you can get a good deal on GTS rotors for. (or 965T rotors)

333pg333

Mark, there is apparently a kit out there already. I haven't looked into these closely yet. From what I can tell the rotor is a flat one with 3 straight routes across the whole rotor at angles that make it look like a triangle of sorts. I don't know the quality of the rotor, design of the vanes, or if it's been cryo or heat treated.

There will be some sort of reduction in unsprung weight which is a nice bonus but I'm doing it for the same reason as you. I don't want OEM GTS rotors due to gas build up, nor do I want to replace cracking X drilled rotors every 1-2 meetings.

I shall let you know my findings.

odurandina

Carl Fausett has the exact rotors you're looking for i'll get a photo up in a minute. i have the GTS big blacks on my 968 but i decided to go with the oem rotors for their longevity. are these the rotors you're lookin for ?



.

Lizard928

If you were to make the hats so that one could run 380mm rotors I would be keen.

mark kibort

those rotors dont even look like they have through holes, and we dont want through holes. plus, the vents look terrible, as if there is no left and right side. that would not be good for a performance application. street, probably fine.

blau928

I am in the process of designing hats for 380mm rotors. (I already have started files in CAD, and have rears specced for use as well retaining the parking brake function).. I think I can get 355mm in back with a bit of squeezing with the 380mm in front. I know I can fit 370mm/F and 330mm/R with no issues and may do this..

However, there are issues depending on the calipers and rims you will use. One of the very few 18" rims that you can stuff 380mm rotors and decent calipers under is the BBS E28/E88 cup car rims, and they cost a king's ransom.. They may also clear CCW's, but I don't know as I haven't measured the spacing..

370mm fit better under most 18" rims... The rotors are easy, as many make them. However, the hat depends on the caliper to be used as well as the rotor and the the number of mount holes, as well as if it will be a floating or solid mount to the hat.. There is also a difference in bobbins and possibly screws between some of the manufacturers...

Just my $0.02

The 2pc GTS setup has been done years ago by DEVEK. Maybe one should ask Marc T if he will sell you a set even if DEVEK is no longer around. I know the stuff can be made easily, and know who made the stuff for DEVEK. However, anyone interested needs to ask Marc T.

Colin if you wish to discuss 380mm fitment further, let me know..

Lizard928

Richard,

I have 18" Kodiak racing wheels for the track. So the 380mm should be no issue.

And I would prefer a floating design.
I was going to go with stock S4 hat and rotor in the rear and modify a hub to house a secondary smaller caliper for the e-brake (hydraulic). Seeing as how it is a track car really

blau928

Ok, but with which caliper, and what rotor thickness...? Lots to choose from, and offsets are going to be the issue depending on caliper bolt spacing and offset.... Maybe you've already resolved this in your blueprint spec..

Cheers,

Vilhuer

http://www.lindseyracing.com/mm5/mer...28BRAKEKIT8791
http://www.lindseyracing.com/LR/Pors...789-BBHAT.html

Ducman82

i just did this today. GTS big blacks and 993 2 piece rotors.

mark kibort

so there you go, about $600 for the hats so that you can use the $420 per set of 993TT 2 piece rotor, rotors.

I think Ill stay with my flat GTS solid 1 piece rotors for $300 for the set (or less)

mk

mark kibort

the offset is all wrong. how did you do it? did you use the adapters on an 928S?

mk