justin

Bingo!
Iva also have had my fair share, no issues.

JHowell37

Many mechanics shy away from Porsches not because it's a Porsche, but because they don't want to deal with Porsche owners. Many Porsche owners make a 110% effort to live up to every stereotype regarding Porsche owners. In other words, many Porsche owners are in fact a bunch of small-dicked, whiney, nit-picking ********, and most mechanics don't want to deal with that.

pearlpower

I would say that some of what you stated would apply to anyone that is passionate about their car. Most mechanics are mediocre to incompetent-period. Where do I get this? From many, many years of dealing with mechanics and shops from the small mom and pop to the national chains from within the industry.

Granted there are a few good mechanics out there but they are far and in between which is why there are sources such as this to share our stories.

So to call passionate owners names just because they are more sensitive vs the Ford Escort owner in my opinion would be unjust. Most 928 owners here could be labeled as passionate about their car and with that could come various perceptions about the owner in itself-most of which are untrue.

If I took an Escort down and had brakes installed would I care if it stopped from 90mph when the car can only hit 85mph? But in the 928 I would question the quality of the pad,etc.... So if that comes across as a PITA so be it- it's my money.

the flyin' scotsman

Haven't met any of those in this part of the world; too bad you have.

Back on topic; I'd question the necessity of turning the rotors period. I've gone through many sets of front brake pads with the rotors left alone with no adverse effect.

morganabowen

And so, what is your point

atb

Hi Malcolm,

I'm on my third set of pads right now with these rotors and have a track day coming up in a few weeks. Not looking forward to dropping another $420 for new front rotors right at the moment (wedding anniversary tomorrow, leaving on spring break with the kids in a week, taxes due $oon), so if these discs were turnable at a lower cost then new, it is something I'd investigate. They would work fine for the track as is, but I would prefer to have new pads for the front and the condition of the rotors isn't optimal for new pad break in.

Assuming they are still within spec, I was curious if anyone had any experience turning these kinds of rotors. Sounds like some have had luck, so I will probably start checking around.

I'll report back what I find.

RyanPerrella

Adam,

What kind of brakes do you have? S4 or GTS? (I know you have an S4 car)

Something that was pointed out to me in the "For sale" section of all places was using 993 TT rotors which are compound (Aluminum hats) with GTS calipers. The 993 TT rotors are offset incorrectly for our cars but a company makes a nice billet aluminum hat for $200 a pair. The 993 TT rotors are i think $75-$100 cheaper then the 965 rotors so the upfront cost is the same but everytime you change rotors in the future the cost is much less.

Not to mention a huge side benefit of loosing 4lbs per front corner by going to the aluminum hat over the 965 iron center section. Compound rotors are quite a bit better to resist warping as well because of the aluminum hats. Its something I am definately looking into when i decide to replace rotors.

Dennis Wilson

A lot of shops won't turn rotors for the same reason they won't rebuild a master cylinder or caliper. The liability is too high especially when they can sell new parts and make more money. IIRC the WSM recommends not turning the rotors.

Dennis

atb

Ryan, I'm old school, 993TT calipers all the way around with GTS discs. The rears were machined to work with the stock 928 disc offset. They weren't quite right on the passenger side, I had to shim the caliper to bring it into spec., no issues since.

DEVEK used to market the two piece hat/rotor system. It allowed the use of the 993TT rear calipers without having to machine them because you could control the offset with the hat. I think its a great set up. If you have info go ahead and email me if its not from a Rennlist Sponsor.

RyanPerrella

Tell me more about the rear setup.

So you use 993 TT front calipers in front, Rears on the rear and GTS front rotors and GTS rear rotors? Or do you use front GTS rotors on the rear?

Doesnt the 993 TT caliper use a different mounting method so that adapters are required?

The aluminum hat is here,http://www.lindseyracing.com/mm5/mer...e=944BRAKECOMP
its from a 951S supplier but apparently the 928 S4 and 951 S have the same offsets for front brakes.

The 993 TT discs are only 320 something mm in diameter. I would really like to get into the 355mm range for the fronts if not 380mm. I dont think the difference in rotor size going from the 90 GT to the GTS is really worth the upgrade cost honestly. I believe the GTS rotors are only slightly larger then the GT rotors.

When i bought my car the Ad said it had GTS brakes, but ive never been able to confirm this. My calipers are the newer type with the Porsche stickers on the calipers as opposed to being cast in like the earlier S4 calipers. I need to measure my discs, and look at the PN on the calipers to be sure.

What is the diameter in inches of the GT rotor and the GTS rotor. I think its time i answer this question once and for all.

Jim bailey - 928 International

Grooves in the rotor do not detract from the stopping ability in fact may present more surface area once new pads are fully bedded in.

jheis

Geeze, read the whole way to the end of the thread waiting to say what Jim just said. The ridges & grooves actually increase the surface area, so why bother?

James

the flyin' scotsman

hi Adam............if it were my decision to make I'd be more concerned about pads and fluids...........I know rotors have a terminal life span but they last more than the other components.

Good luck with the track event.

atb

Hey Jim,

I guess I should clarify, I'm not concerned about the stopping power of the brakes, I think they're fine in that dept. I wanted to put new pads in since the ones in there are getting thin and I don't want the brakes to boil. I've got new pads, but because of the shape the rotors are in, I don't think they'll bed in correctly, and then my stopping power will be affected.

Malcolm, I change out the brake fluid once a year, so I'm good there.

Thanks for the commnets guys.

atb

Ryan,

I'll have to take a closer look at my discs. I just assumed that the rears were the same size as stock S4/GTS's. (I believe they are the same). I don't think that the bigger 993TT rear calipers used a bigger disc. No adapters needed to make the rear calipers work, the bolt holes all line up.

320mm sounds right for the front discs. My fronts are Porsche units (the rears are Zimmerman). I didn't think that cast hole rotors were on option on the GTS, so I assumed they were from the 993TT, but I could be wrong. Front calipers had to have the cross over tubes and bleed nipples swapped because on a 928, the caliper orientation is upside down compared to the 911.

If you can't tell by looking at the calipers if you have the big brakes (very easy if you have stock S4 to compare it to), you can definitely tell by looking at the brake pad. Pull one out and post a pic, a lot of folks will be able to tell right away.