I'll say it again, YOU CAN NOT USE 997TT OR 996GT2/3 FRONT CALIPERS with 380mm rotors, only 350mm. The RB kit is flawed. Look at the pictures of the front set up in the link you provided. Due to the fact that the caliper uses an offset mount and spaces out at an angle (rather than radially), as a result the caliper & pad will not line up properly with the rotor. They show a close up picture of it (show below) and even admit it in their link:

"After installing front rotors, spacers, calipers, and pads will naturally overhang the rotor top by about 2-3mm due to geometrical configuration, however this excessive lining can be easily removed with a dremel or grinder."

[url=https://flic.kr/p/D3WsNC]

First of all, there is nothing "natural" about brake pads overhanging the rotor. It's actually more like 1/4" overhang and due to the "geometric configuration" gets more exaggerated on the far end which is not visible in their picture. Look at the pad and you can see how it sits at an angle with respect to the rotor. Total BS. If they showed you a picture of the caliper mounted up with the spacers, you would see a large gap between the rotor and caliper at the top end and virtually touching at the lower end. The 350 caliper design does not lend itself to being spaced out. Period. The RB stuff is cheaply made and their lack of proper engineering should be a warning sign to stay away. Use reputable rotors make by Girodisc, Brembo, AP racing, or stick with OEM.

When running 380s in the front you will need to run 997 rear calipers. They have larger pistons and move almost 50% more fluid. The byproduct of this will be a softer pedal. As such all the 997TT/GT cars have the larger 27mm MC to firm up the pedal. You can retrofit the larger MC to the 996TT with the use of a custom brake line. The larger MC sometimes causes PSM faults however. Disconnecting PSM takes care of the issue. Hope that helps.

 

I get ya on its not normal, I figured is was due to the tips of the calipers would hit the rotor if lowered any more. It does look like the bracket is tappered. Not saying the kit is right though.
So what calipers do you need in the front to run 380mm? Is it possible to use 996 tt front calipers on 380mm? I'm guessing not because the passage in the calipers is to small for that radius. I've built and manufatored bbk kits for other platforms just have not done anything with porsche stuff and at very min will go to 350mm rotors on 996tt calipers with spacers this year

 

The bottom portion of the caliper would hit the rotor because it's at an angle. The bracket is not tapered otherwise it could not be bolted on. The bracket must be at 90º to the bolts. If they are using a tapered bracket then the bolt heads will not squarely seat against the relief in the caliper. It's simple geometry.

To run 380mm fronts, you need 997 calipers which are used with 380mm rotors. These are referred to as 997.2 calipers as all the .2GT2/3 cars came with 380 discs. They have a 225mm bolt spacing (compared to 146mm on the 996TT/GT2/3 calipers). Physically the caliper are slightly larger while using smaller pistons. They require OEM brembo adapters and different brake lines to mount up to the TT upright. All the parts are listed in the early part of this thread.

 

Ok I missed the numbers at the beginning.
On a side note from this picture it does looker higher on one side than the other but then you get to the part that the bolt isn't pulling straight down at 90 degrees which could cause the bolt to snap and then brake failure.

 

Looks like some of the yellow zircon inserts are missing on the calipers, anyone knows where to get them?

Same Problem here

https://www.6speedonline.com/forums/...ts-piston.html


Or directly go with These and no more yellow zircon inserts are needed?


http://www.racingbrake.com/Piston-Ki...9-p/bp-60p.htm

 

The only place to get the zircon inserts is in the Motorsport rebuild kit which includes them with the pistons and seals. That's why I said you need to install the Cup retainers because when they pucks fall out they crack very easily if allowed to hit the ground. I see it all the time...

 

Yes, you're right. I will maybe try the RB Pistons, no more zircon inserts are necessary with them. Looking good Quality and also 50% from the Price of the repair kit. Want to give it a try, thanks

 

To confirm, I’m looking to upgrade my stock 4pot’s also. I would like to keep the option of using my stock hollow spoke wheels for winter and 19’s for summer. So, I guess my option would be 350mm / 350mm (Probably go Giro or AP Racing). By keeping the stock rear calipers I would need to add 10mm spacer. As for the fonts, I would need to get Red 997TT / GT3 6pot? These will bolt on without the adapter bracket, correct?

I believe you mention that for 380mm, using the 997 GT3 PCCB (w/ bracket) would need the 997TT rears as well? This setup would require 997 GT3 master cylinder upgrade?I don’t want to have to upgrade the brake master, since there seems to be an issue with the PCM error.

Thanks for all your input on the brake upgrade!

 

IMO, for sake of 'simplicity', I'd sell your complete set of 996TT calipers and get a complete set of 997TT steel or 996GT2/3 PCCB calipers to get your 350mm/350mm. 997TT calipers(due to rear pistons) will give better rear bias.
But yes, 10mm spacer for rear if you want to keep those calipers(same basic design as 6GT2/3 PCCB).
Front 997tt(steel 350mm)/996gt2/3 calipers are direct bolt-up
Run 997TT discs unless frequent tracking

 

So, if you want to run a 350mm rear rotor with the stock 996TT caliper, would that be the 997TT rotor?

It a appears the 996 GT2/GT3 rear rotor was the same 330mm as the stock 996TT.

Later, Steve

 

Correct if using 997tt stock rotor. You will need to use a spacer and longer bolts with the stock 996 calipers. Adapter are available for sale or you can make your own with a piece of aluminum (11mm). I think 10mm would work also.

If you buy Girodisk 350mm rear rotor, they supply spacer and longer bolts.

 

996GT2.3 with PCCB were 350mm, 996GT3 with steel was 330mm
997 GT3 or Turbo with steel were 350mm...run these.
For a 996TT wanting to run 350mm all-round, just use 997tt parts.

 

Here is a close up picture of 977 caliper with asymmetrical legs:



And take a look of how RB spacers (adapters) are configured:


Before any of these retrofit kits are released, not only they are precisely designed, machined, and finished we also put them on the bench and explain in detail with pictures so customer can have a good understanding to make their decision.

We are proud to be able to present this type of "affordable" upgrade kits, although it may not be for everyone (eg. track use is not recommended) but we believe more choice is always good for consumer.

If you follow our posts on rennlist, you will probably find out that RB offers more brake replacement/upgrade than all the competition combined, which undoubtedly would draw some discrediting comment w/o a ground. However we still believe the intelligent consumers are our best customers.

Complete Porsche 991 GT3 PCCB Brake Option Under One Thread
http://rennlist.com/forums/991-gt3-a...ne-thread.html

Porsche Brake Offer:
http://www.racingbrake.com/SearchResults.asp?Cat=7139

Porsche Caliper Rebuild:
http://www.racingbrake.com/category-s/7185.htm

Please refer to our development forum and browse those threads to get an idea of so many exciting new brake development projects that are going on.
http://forums.racingbrake.com/forumdisplay.php?f=6

Thank you.

Warren-RB

 

Thanks

 

By using an angled spacer you are preloading the caliper attachment bolts as the bolt heads are no longer squarely seated against the caliper mounting surface but rather at a shallow angle against the caliper bolt mounting flange. This is putting the bolts in a constant state of stress. This is totally unsafe. Considering the simple fact that Porsche requires the calipers bolts to be replaced after removal, you can see how much importance they place on the integrity of the bolts. Using an angled spacer like this is a seriously flawed design. I won't even mention the added problem of the brake pads not seating properly against the brake rotor itself. The simple fact that this has been brought to your attention creates a huge liability issue when a brake failure occurs as a result of this and someone gets seriously hurt....

What do you mean by "track use is not recommended"? This is not mentioned in your ad for this kit. What you do say however is that "By purchasing this spacer kit separately from our rotor kit you assume full responsibility of your own retrofit, and agree the purchase is not returnable for whatever reason". This does not sound very reassuring. Are you admitting that brake failure would occur with this design under the higher stresses of track use? Some guys do drive these cars pretty hard on the street, not to mention those that push 200mph on the autobahn in Europe. That's a thin line to walk....

I'm not trying to be a d**k here but when I see something that is potentially dangerous, I think it needs to be brought to people's attention.