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On my car those naca ducts were missing along with the control arm scoops. Who knows why.... I added them back.
When you remove the belly pan the nada ducts will separate from the pan. I can easily see them getting lost in the shop or mechanics just forgetting to put them back.
I run the complete 7GT2 380/350 PCCB brake system with steel rotors on my car. For cooling I have the front large 6GT3cup brake ducts and rear .2RS ducts pictured below. The .2 ducts lowered the rear rotor temps about 40F compared to running the smaller 6GT2 ducts. I only have ABS on my car without any nannies. With this set up my rotor / caliper temps have been virtually identical front to rear, all within 10-20F running PFC 08/11. Recently I replaced the stock ABS with a PMNA 6GT3 Cup ABS. While braking performance is phenomenal now, my rear rotors are now running about 50F hotter than the fronts even after switching to 08s in the rear. Every 7GT3 I have seen smokes the rear calipers when the nannies are left on. Once you turn them off, rear brakes run much much cooler.
You have to trim the stock backing plate to fit the .2 ducts..
thanks for the info, i'm going to take another look when i have my wheels off. btw, how do you like the PFCs? i want to give them a try with my stoptech trophy setup
The 997 GT3 is heavily balanced towards the rear. At Daytona and Sebring for the endurance races, we see equal or more pad / disc wear in the rear of the car. We are talking 997.2 Cup without ABS or TC using OE calipers and motorsport AP, Brembo or PFC rotors.
We always keep an eye on rear rotor and cal temps.
Pad wear rate for me with steels on .2 is 2x front pads for about every 1x rear, but I am not very hard on brakes.
However, that said, I have had more dragging issues with rear calipers, in fact I found what looked like a stuck piston that wore down the inside pad nearly to the backing plate, while the outside pad was at 50%.
Pad wear rate for me with steels on .2 is 2x front pads for about every 1x rear, but I am not very hard on brakes.
However, that said, I have had more dragging issues with rear calipers, in fact I found what looked like a stuck piston that wore down the inside pad nearly to the backing plate, while the outside pad was at 50%.
Pad wear is the same for me as well in the GT2 using the stock front ducts and the larger rears on PCCB with OE pads. Nannies are turned off, but I think with them turned on the rears would get smoked pretty quick. I'm not hard on brakes compared to many other people.
Uneven pad wear tapering is normal to me. I have rarely seen brake pads that don't taper with higher wear on the leading edge on virtually any vehicle.
The 997 GT3 is heavily balanced towards the rear. At Daytona and Sebring for the endurance races, we see equal or more pad / disc wear in the rear of the car. We are talking 997.2 Cup without ABS or TC using OE calipers and motorsport AP, Brembo or PFC rotors.
We always keep an eye on rear rotor and cal temps.
There must be something more at play here... brake bias differing from street cars or pad compounds f/r? I've not experienced this with my car. I run RE10 pads f/r and type5 rotors f/r.
Originally Posted by ShakeNBake
Pad wear rate for me with steels on .2 is 2x front pads for about every 1x rear, but I am not very hard on brakes.
i get even wear in front and rear, left/right, inner/outer pads, but rears last about 1.5-2x longer than fronts.
My calipers have been rebuild not too long ago and I have new front calipers on the car now. (Time to turn them to brownbos)
There must be something more at play here... brake bias differing from street cars or pad compounds f/r? I've not experienced this with my car. I run RE10 pads f/r and type5 rotors f/r.
The ABS system has a lot to do with it. All else equal, in my case simply changing from the street ABS to the Cup ABS caused the rear brakes to work a lot harder which resulted in higher rear temps and greater rear rotor wear. I ended up changing to a less aggressive rear pad compound to offset it to a degree but the difference is still quite noticeable.
From our experience on the 997s, it had more to do with the brake balance combined with a lack of effective rear brake cooling. On certain hard braking tracks (like sebring) where we saw a lot of rear brake temperature which tended to result in higher pad wear in the rear. A few years ago, a good team ran out of brake pads at the 12 hour at Sebring but it was the rears which went down not the fronts.
Some people paid more attention to the rear cooling & managing the brake temperatures front to rear leading to a more balanced pad wear F to R and those were the better teams.
On the 997 Cups with the Porsche red calipers, we always overhauled the calipers and serviced the brakes every few races to get the best out of them. But once they turned dark maroon to reddish black, we tossed them and got new calipers as they stop working well at a point. Funky pad wear in general was never an issue on the Grand-Am versions of the cups with the actual Brembo race calipers.
All I am saying is normally, the fronts work more than rears. But in some cases, its’ not uncommon on these cars to have the rear brakes working more than the front and we just pay attention to it on the track as needed.
Rebuild your calipers with RB's HT Blue Boots and Stainless Steel Pistons to reduce the temperature inside your calipers and extend the caliper life.
High temperature dust boots
Our high temperature dust (blue on right) boots protect your pistons from dust and shield heat for a lower brake fluid temperature brake system.
For regular tracking - Use black boots on left (good up to 300F)
For heavy tracking - Use blue boots on right (good up to 450F)
Stainless Steel Pistons
SS pistons transfer only about 10% heat of OE (aluminum) piston. One piece solid construction vs. several pieces OE combination also make your replacement and maintenance job easier.
09-08-2015, 11:48 PM
