7gt3 brake bias
Discussion
Just wondering if anyone has ever run different pads front and rear on a 7gt3 and managed to shift the brake bias to the front without any major issues? More specifically I'm looking to run a slightly higher friction front pad vs the rear (probably RS29s front vs RS19s rear) as I'm not too keen on the tendency of the car to shift it's braking to the rear. Plus I've killed my rear pads after 4-ish fairly sedately driven trackdays (Esc off as well) with plenty of front pad left which imo should never happen on a reasonably heavy road car and even the Mclaren 12c I've tracked a lot has more or less worn it's pads evenly despite using rear brakes as a diff. Usually I'm told not to mix pads but that's a trait of the car I would really like to iron out if possible and ideally without having to install a motorsport ABS unit!
Something to note is the car is obviously rear weight biased, about 62% on the back, so it will use its rear brakes more from a bias perspective for that reason alone. Mac will be about 56% weight on the back.
Second thing is have you got additional brake cooling on the rear by fitting the 997 GT2 ducts that go on the lower arms? High temps can accelerate the wear on the rear axle.
Third is are you talking 997.1 or .2? Front disc sizes in the steels makes a difference with 997.2 being larger.
Fourth have you adjusted up the rear wing for track work? Adds stability in braking zones in my experience, I have mine at the max 8deg now having tried the 0, 4 and 8 positions.
Last one is the diffs have a reputation for wearing out clutches early with track work so if the rear axle moves around in braking and if lifting off mid corner it could point to a worn clutch pack, but that shouldn't accelerate brake pad wear.
I run Performance Friction PFC08 compound all round (because they squeal less than Pagid RS29, but still squeal) with 997.2 steel disc sizes. Pad life great and you can brake super late and hard every time.
Second thing is have you got additional brake cooling on the rear by fitting the 997 GT2 ducts that go on the lower arms? High temps can accelerate the wear on the rear axle.
Third is are you talking 997.1 or .2? Front disc sizes in the steels makes a difference with 997.2 being larger.
Fourth have you adjusted up the rear wing for track work? Adds stability in braking zones in my experience, I have mine at the max 8deg now having tried the 0, 4 and 8 positions.
Last one is the diffs have a reputation for wearing out clutches early with track work so if the rear axle moves around in braking and if lifting off mid corner it could point to a worn clutch pack, but that shouldn't accelerate brake pad wear.
I run Performance Friction PFC08 compound all round (because they squeal less than Pagid RS29, but still squeal) with 997.2 steel disc sizes. Pad life great and you can brake super late and hard every time.
Pookster, it's a 7.2RS. Good point re weight distribution, I had forgotten about that. It's more the feel of the car being more heavily braked at the rear than the pad wear I'd like to change if possible though. I think the diff is still fine for now though, the car is still solid under brakes.
Have the GT gears diff as per Steve planned to be fit into the car when the diff wears out as I assume after a couple more trackdays the standard diff will be buggered soon enough!
Have the GT gears diff as per Steve planned to be fit into the car when the diff wears out as I assume after a couple more trackdays the standard diff will be buggered soon enough!
Last week..
HokumPokum said:
I know of another that has racked up plenty of track miles on their 4.0
Let me know what other setup trinkets you go with.
At the moment just the DSC suspension module. have some side muffler delete pipes somewhat as that's supposed to save a decent chunk of weight I haven't got around installing yet. Let me know what other setup trinkets you go with.
Future plans would be the GT gears diff as mentioned and some proper grooved rotors with endless pads once the existing oem stuff runs out of puff.
It's the centre silencer that mainly affects the volume iirc as the side mufflers are bypassed after a certain rpm. Or i think so anyway! was looking for something that lost some weight and aboslutely not something to make it louder tbh. Someone i know has the side pipes and seems not to have had any issues at Spa or Silverstone which are 2 of the 3 tracks i usually go to so think I'm ok 
Pookster said:
Only other suggestion I have then is to try putting in a pressure differential or raising the rear a touch to 2.5. Michelin advised me to run the fronts lower than the rears because of the weight difference, front can be as low as 2.1bar hot as there's so little weight.
K thanks, will give that a try next trackday then.Porsche911R said:
I would just ditch the PASM and fit some proper 3 way shocks.
That would fix most issues imo and make the car so so nice, not only to drive to your style you can just adjust the hell out of it.
that's why we have the DSC sport controller and its ability to use more of the sensors' output than the original OEM version. It rides better on the road as well. win win really.That would fix most issues imo and make the car so so nice, not only to drive to your style you can just adjust the hell out of it.
HokumPokum said:
that's why we have the DSC sport controller and its ability to use more of the sensors' output than the original OEM version. It rides better on the road as well. win win really.
Been thinking about one of these for my GT4, I must get around to finding out more about them. I gather they can be DIY fitted?jcosh said:
HokumPokum said:
that's why we have the DSC sport controller and its ability to use more of the sensors' output than the original OEM version. It rides better on the road as well. win win really.
Been thinking about one of these for my GT4, I must get around to finding out more about them. I gather they can be DIY fitted?Gassing Station | Porsche General | Top of Page | What's New | My Stuff