Drilled/Slotted Rotors
 

How important is it to have drilled and slotted rotors on the SVX? Are the OEM rotors like that, or are they normal? Whiel it's nice to have additional cooling on the breaks, if they're not necessary, i'm not a race car driver, and an extra 200+$ for them doesn't seem worth it. Thanks.

It isn't, and the people who buy them are not, for the most part, race car drivers either. :) I mean no disrespect towards the people on this site, but the vast majority buy slotted and drilled rotors because they look cool, not because they've been proven to actually work better on the car.

Do they work 'better?' The best any of us could honestly say is maybe. As far as I know, nobody's actually tested how slots and/or holes affect stopping distance, brake temperature and longevity.

I intend to buy new brakes for my SVX very shortly. I will either have them slotted or leave them solid. Honestly, I'm waiting on my own unscientific study to decide. My friend and I put slotted rotors on his car, which we will both be autocrossing this year, and I'm waiting to see how that affects the car. :)

I put the eBay drilled/slotted rotors on my car, since because with the Axxis pads and s/s lines, they were still cheaper than AutoZone cheapies, and also because they were cad plated, so they wouldn't rust, etc.
(Just type "SVX" into an eBay search, they're all over the first page currently).

Drilled and slotted rotors do help expel gasses from building up between the pad and rotor, and help keep the pads from aquaplaning on the rotors (a problem in some cars). Honestly on the street the better braking I notice is simply from having newer equipment and better pads, I don't attribute any of it to the rotors themselves in my case.

Now, but actual "big" brake kits, etc, when used on the track, drilling and/or slotting will make a difference in heat dissipation, which will aid in braking distances as well as brake longevity.

One last note: Drilled rotors crack, and slotted rotors are very tough on pads. There are a handfull of rotors out there where the holes are cast in, instead of drilled in after the fact, and this helps, but they're very expensive. Porsche OE rotors and Slot*It are the only ones I'm aware of. I don't know whether rotors which are "dimpled" instead of drilled are as effective at dissipating heat or water, or at crack resistance.

Good luck!

I'll let you make up your own mind. Here is the URL of the technical data page from a company called Power Stop Extreme Performance http://www.autospecialty.com/html/co...to_thrive.html

They would certainly want to try and sell you some drilled and slotted rotors, wouldn't they?;)

Lets take a look at the temperature graph
http://www.autospecialty.com/images/graph4.gif

Even though this graph doesn't show you how hard the brakes were applied, from what speed, or what the time interval was between each brake application was, one thing is immediately apparent, on the first stop, drilled rotors make no difference at all.

Subsequent stops show a small but growing temperature difference, we know that there must be some shortish time difference between the two stops, as a longer time interval would have allowed the solid rotors to have cooled down. By the time we get to the 15th stop there is a 200 degree temperature difference. How significant is that?

Well lets look at the next graph
http://www.autospecialty.com/images/graph5.gif

The graph shows that there is a reduction in coefficient of friction of about 20% or so, whatever pads you have fitted, so there is some minor 'fade' but not enough to have you running out of leg muscle.

The other graphs are of little interest, and tell you little worth knowing - one of them even has the axes mislabelled.

Bearing in mind that the SVX already has ventilated discs at the front, and at the rear too, outside the USA, how much benefit do you think you are going to get from aftermarket rotors.

Make up your own mind.

Thanks for the input. I know the general principal about them, but short of auto-x or something similar, i can't see them being a big deal. I saw the package on ebay about the rotors, pads, and lines. it's 160 for 4 new rotors and all new pads, which i think will be good for the time being. Want to get some other stuff done on hte car before i do that. Anyone have any experience with larger than calipers on the car? For the mx-6/probe you could put 3000gt calipars and rotors on if you boared out the screw holes and just used other bolts, and there was a huge difference in stopping distance and over-all performance. Thanks though for the input. I think i'll put drilled/slotted on the back burner for the time being.

Larger calipers will make a big difference, as will more aggressive pads.

I've been considering having a local race shop (ALMS supplier) develop a 4-piston kit using the OE rotor size.

For my 2 pennies, The SS lines have better response. That would be the best for in response.

I put ART (Applied Rotor Technology) Cryogenic treated slotted rotors on quite a while ago along with metallic pads. They were less than OEM and have lasted a lot longer than OEM. They used to offer a discount to the group. Pretty sure they still do. The Cryogenic treatment is a whole story unto itself, but I feel it's worth while.. Pics in my locker.
http://www.subaru-svx.net/photos/fil...BABY/4388.html

The brakes on my teal SVX have required no attention in 40,000+ miles of routine work, with lots of very curvy roads and a few panic stops thrown in. You really don't need any sort of "performance" brake components for anything but sustained aggressive driving.

dcb

If you want to improve your braking performance, the one thing that I would do without question is put a set of SS brake lines on. That did more for my brakes than anyother thing I have done. :D :D