I'm looking to upgrade my front and rear brakes. Preferably to brembo 380mm 6 piston front and 4 piston rear. However, I'm running 18 inch Forgeline's and want to make sure they'd fit. Would love to hear some feedback on the following options:
1. rotor size
2. caliper pistons
3. wheel size you're running
4. how do you use the car (track days, daily driver, weekend warrior, etc)
5. how the braking feels before and after
6. pictures

Thank you!

 

what master cylinder do you intend to run and will you be modifying your ABS?

 

I have the gt2 upgrade, and don't plan on modifying abs unless recommended.

 

Call Race Technologies in Orange County- LA.
They are the number one wholesale company for Brembo. I needed a set of 993 Turbo Big Red brakes for my 914 and they fab a complete set for me.

 

Plus one for RT. They have all the specs and they know the wheels. I believe we've done a car with that set up before using the new calipers. Let me know if I can help in any way.

 

I am currently undergoing changing mine over to 997 cup car brakes. using cup car calipers and girodisc rotors. changing my master cylinder as well. you need adapter brackets for the calipers to for the tt front uprights but they are a porsche oem part if using tt hat offsets. they are a 380/350 setup. I will have about 3k into the change but I got used calipers and rotors.

as for the 18 inch wheels, I wonder the same thing. I'd like to get a set of forgestar f14 for track use and am wonder the inside barrel diameter.

 

There is a guy semi-local to me in Karlsruhe (an hours drive) who has a Porsche repair shop and also sells parts including brake upgrade packages (and he runs a 996tt in club events and track days). He has tried varying combinations of brake and wheel packages with customers. Turbo twists def do not fit. Two 18" wheel types that work with 380mm brakes are BBS E88 and OZ Alleggeritas.

There are numerous threads on the board of you search, but they can be a bit confusing and require a bit of reading. Maybe we should do a complete brake upgrade thread as a sticky...

Some quick pointers to hopefully help clear up some confusion from the outset (I am at about the same stage as flewis with many of the same parts except that I will be swapping to GT3 spindles so I will not need offset adapters. But my knowledge is less from personal experience with brake mods than research on this and other forums. I defer to people like Pwdrhound, Kaizu, Pete95zhn(?) who have experimented themselves):

- Rotors- the turbo rotors have a different offset than the GT3s. You can run GT3 rotors, but you will need to shorten the inner pad locating pins in the caliper by a mm or 2. Pads can be an issue (thickness). Or you can pm flewis and see if he'll make you a set of offset adapters. You will need adapters anyway, so this solution seems perfect. BTW, there are a lot of people who rag on the use of GT3 rotors on turbo spindles, but I just recently found out that one of the companies doing this is none other than Manthey Racing, which is part owned by Porsche. Flewis has a thread on this topic going here somewhere...

- Calipers- you will need the 6 piston Porsche calipers with 225mm spacing. The earlier 6 piston, 350mm calipers look the same except for the lower mounting lug which sticks out. These calipers will not work with the 380mm rotors. You will also need adapters - either oem Porsche (997.2 turbo with 380s) or aftermarket. Blkmgk has a google spreadsheet with pn's and I believe he has the adapter pn's.

- Rear- 350mm rotors from many sources and for all GT3/turbo/etc fitment. You can use your old calipers and space them out 11mm or go to 997 rears. If you stick with the 996s, you'll have a heavier front bias. If you're serious about braking performance, the 997s are the better choice. Search for posts by Pwdrhound on this topic - very informative.

- Mastercylinder- you are shifting more brake fluid with the new calipers, so if you stick with the OEM turbo MC, you will have a long, soft pedal. Swapping to a GT3 MC gives a firm pedal but can cause PSM faults and requires a custom brake line or adapter. Again, search for Pwdrhound's threads on this topic.

- Brake ducts - there are many different versions ranging from inexpensive to outrageous. Check Blkmgk's spreadsheet and Pwdr's posts.

I'm not quite sure what Blkmgk meant with "modifying the ABS". Generally, the stock ABS is good with these upgrades - though the stock ABS can suffer from "ice mode" (search). And swapping to Cup ABS will yield better performance, but IIRC this involves both the ABS block and ECU. Quite involved and expensive.

 

Last spring I went to 997.1 GT-3 brake calipers with 997 turbo rotors, OE rear and Sebro front w/RS29 pads. Use car whenever it's dry and hit the track for lunch hour most weeks in the summer and get in a few other half days too.

Compared to stock, the pedal feel is a little less grabby/responsive, partially due to performance pads and not swapping to the GT3 MC. Way more powerful braking when pushing it with less fade at the track and much quicker slowing when doing something like 130>60mph. Using a pair of front 996 GT2 ducts on the LCA's.

Stock hollow twists, 18' Allegrita & Forgestar F14 all fit fine but I ditched them all for some Finspeed 18" because I'm swapping to the 380 setup below.
Leaving the stock turbo MC in place for now to see how the feel is and because some have mentioned less ABS issues. Have the GT3 part on the shelf in case I don't like the feel and ABS issues vs feel is worth the swap.

 

The OEM Brembo GT/Cup 380 stuff is proven and good (I would not recommend the 380TT versions). With the full 380 system I don't even bleed brakes anymore, once a year or maybe every 25 track days or so... Definitelly do the matching rear calipers too. That's a must.. Keep in mind the stock 330/330 system has plenty of power to lock up the wheels and engage ABS so you're not buying anything with the 380 set up except far superior heat dissipation and consistent pedal feel under prolonged hard use. With the right cooling/fluid/pads the stock 330/330 is very formidable at the track. When running Rcompound and slicks at the track, a motorsport ABS, along with other benefits, will substantially improve braking as it is programmed with a higher engagement threshold for the higher grip tires.

There is a lot of ancillary stuff you can upgrade depending on your end use, cars/coffee, full on track, or anything in between. Cooling ducts, fluid, pads, 997GT3 MC, 997GT2 vacuum pump, Motorsport ABS, etc... I personally found the 997GT2 vacuum pump to be a huge improvement to brake feel but that may by due to my altitude, I'm a huge fan of the vacuum pump mod. I've run just about every permutation of the Porsche brake system you can imagine. Upgrading all of the above is straight forward bolt on except for the Motorsport ABS swap which is not for the faint of heart but so well worth it for heavy track use. The Motorsport ABS swap is about $10K in and of itself at a minimum.

The stock ABS is fine on the street and the track if you respect it's limitations. If running split tire diameters you can always install a front tension bolt with less teeth to keep the ABS in it's happy zone. 1 less tooth will account for 1/2" of tire diameter difference.

I have no idea how any of the brake upgrades would affect PSM. Many guys have reported issues after adding the larger MC. I have no first hand experience with PSM.

Only a hand full of 18s will fit the OEM 380s. 18x9x12 Finspeed and BBS E88 fit. Forgeline momoblocks should all fit. You will generally need a 9" front to fit. 8.5" won't. I don't believe Forgestars or Alegerittas will clear. I run Finspeed 18x10x13 and have tons of room

[url=https://flic.kr/p/Bz8R86]

 

Unless you're a hardcore track addict
-350mm discs all around are more than adequate
--GT3 discs are not direct fit to turbo's front hubs and 7turbo's discs are cheap
-4 piston front calipers with spacers are again more than adequate, 6 piston ones look better at cars and coffee...pads are more expensive too. If you really want to change to 6 pistons, search for the latest ones with smaller pistons.
-7turbo's (or 7RS's even better) rear calipers are the best choice, although OEMs with spacers work well with 350mm discs

With those two 997 caliper choices (F&R) you will move brake bias to rear, as the factory did with 7RS.

IMO installing 380mm front discs without adding rear braking/bias will not improve braking performance. Neither does the braking performance improve with any 8 piston calipers with larger-than-life -discs / one-size-fits-all-cars -tuning sets... 911 is quite unique concept and can use much more rear braking than any other car.

6GT3 MC is OK for mostly street driven cars, no PSM issues. With 7GT3 a definitive PSM off switch must be installed in order to keep ABS working at track.

Always take care brake cooling, use only track proven fluid and pads.
Again, if your car feels restless in braking, first check your rear wheel alignment before hardware changes.

EDIT: Keep your rotational and unsprung masses low for better handling. Start adding huge front brakes after your'e added serious rubber to front for increased grip. Your 330mm discs / 4 piston calipers can lock your OEM size front tires before rears easily. Just add cooling for repeated use...if you do not believe, pull your ABS circuit breaker and test.

 

I have no idea with regard to Forgestar - 18" OZ Alleggeritas fit over OEM 380 components according to first hand reports.

So this thread turned out to be quite informative.

 

Good to know. I can do a trial fit of the 18x8.5 alegeritas to confirm as I have access to them

 

Looking forward to what people have to say here

Completly coincidence, but I was watching this video when I came across this thread. Seems to be a good primer on brakes

 

I asked about the ABS because of issues that have been noted on track with ice mode and the PSM, likewise I knew the master cylinder would probably need to be addressed. Since I'm no authority on it I simply asked to urge research rather than try to inform

Here's a link to the spreadsheet I've put together. I'd be careful taking it as gospel and doublecheck PN's just in case. The ducting in particular I'd research since some of the higher end pieces really look like the cheaper pieces with added length pop-riveted on!
https://docs.google.com/spreadsheets...A02I/htmlview# if errors are found please let me know! I'd happily take additions too, the suspension section needs work

I'm personally interested in moving to 350mm rotors from the 997 with stock calipers. I'm also curious if say 14inch Coleman with an appropriate custom hat might be worth considering. I've got 18s so space is a concern.

 

stock 350/350mm 6GT2 brakes with steel discs with stock cooling and proper pads and fluid are completely competent at track on HOT summer days..I personally don't see the need to go 380mm as 350mm works very well and wear items are very cheap
To optimise, the system needs more rear bias and rear cooling, front has too much bias and the fluid oxides faster in rear vs front for me
6GT2/3 utilize different ABS system vs TT, don't think I've had an ICE moment yet despite some very extreme circumstances...I've ICE'd just about every other car I've driven, on street even...that said, Motorsports ABS would be nice to set the slip allowance....