PhilT3 (PT3)

who has done them? Any experiences / impressions? Firmer pedal?

And for those who haven't done them....

What are your thoughts... is it worth it to upgrade the lines on the 991 RS?

Thanks!

orthofrancis

I just switched out my lines on a 2007 GT3 for braided. No difference. The factory lines do have a braided core, surrounded by rubber outerlayer.

I just swapped mine because I do some HPDE and was worried about safety issues with 10 year old rubber lines in the arid L.A. atmosphere. There were no cracks or anything in any of the lines - I probably could have left them alone.

badabing

there are many threads debating this. basically comes down to the factory race teams use the standard lines in all races so if its good enough for them... vs the steel braids supposedly offer some protection from outside damage of the lines.

I brought a set of steel braids to my local porsche specialist race shop and they declined to install them. They will only install the oem. So I returned them and bought oem. only changed them for preventative maintenance on track since my lines were presumably 7 - 8 years old.

Bill Lehman

I switched to braided on my track prepped Cayman S. I noticed no difference in brake feel or performance. Leaving my GT4 stock.

gmgracing

This is my personal experience with this. My qualifications come from supporting well over 100 vintage bmw dedicated track cars (2002's, big-fendered E9's, E30's, E36's) over the course of several years, having designed a half-dozen brake kits, and personally making pre-bent hardline replacement kits for a number of vintage cars. Not to mention talking with the race-techs here at GMG....

The 991 cup cars, GT4 Clubsports, and GT3R race cars all run stainless braided lines with a thin black cover. Other than helping to resist abrasion, I have seen legitimate data showing that the braided helps fight expansion as the lines heat up (prevalent during enduros, and/or with those that have a heavy braking foot). This is what is meant by those claiming a firmer pedal feel (at least if they are legitimate).

For track days, the abrasion protection is a nice touch. I have seen where on-track debre has sliced through a rubber line while resisted by a stainless line. In regards to swelling due to hot fluid, it's not that likely for track-day Porsches.

The caveat here is that regardless of rubber or braided you want to use a brand you trust completely. There are a lot of "made-in-the-usa" and fully legitimate DOT-legal stainless lines (from ebay to some prominent brake manufacturers) that use fittings not fit for consumer use. Using OEM Porsche (not oem-equivalent) for rubber, and Speigler/Brembo/PFC for stainless braided lines is a safe bet.

Bottom line for track-day or canyon carver guys is that there is no right answer. OEM and quality stainless lines will both get the job done. If you want a little protection from errant track debris, go stainless.

-Andrew Adams

Raucky

Brian C in Az

Factory teams change their hoses a couple times a season; not really an apples to apples comparison.
Stainless can be better, stainless can be worse.
Some brands say "Not for street use" Translated that means they don't meet DOT requirements. STAY AWAY from those brands!
Some brands are DOT and TUV certified and compliant. Buy those brands only. Goodrich is one such brand. They cost less than oem rubber hoses and are more durable.

Last, rubber deteriorates even when sitting unused. Change your hoses every 3 or 4 years if you track your car. More often if you race your car.
If you have to ask why, you shouldn't be on the track at all.

amurph182

Something I've seen a few times here and on other forums is "the most common failures I see on track are <insert thing being discussed in thread> and stainless brake lines" and obviously in this thread there's the caution to only use lines from specific trusted brands. While the braking system is obviously not a place to try and save a few bucks by going cheap, is there something inherent in stainless lines that makes them more prone to failure or especially difficult to construct? Or is it just a case of better brands using superior quality components and fabrication methods?

yokevlee

having tracked my 981 with and without ss lines, the difference is quite noticeable. with all else equal, pedal is firmer for longer. since then, i've had ss lines on all my sports cars. the downside of ss lines is that u can't visually inspect wear, so be aware of when u should replace them.

Otto Mechanic

Braided stainless lines will separate at the connectors after being flexed over and over. They need to be inspected regularly because of that. Rubber lines last longer and you don't need to pay as much attention to them but they don't perform as well. It isn't a myth that rubber lines get soft and make for spongy brakes on the track; they do and that's the reason people use braided stainless. even though they're sort of a pain in the butt and don't last as long as rubber.

I use braided stainless on both my cars but only because I used the 928 for HPDEs a couple of seasons. I may switch it back to rubber now I'm not tracking it anymore, I've never overheated my brakes on the street but I've literally melted brakes on the track, it's not that hard to do. I use Goodridge on both the 928 and 944, far superior performance as compared with rubber OEM lines, but you need to watch them carefully and change them at the faintest sign of wear.