Thinking Brake Upgrade

[kent olsen]

And that's a 6 lb increase in unsprung weight, a 12% increase.

[VFR750]

Only 3lbs for me, only doing the front rotors

[Superman]

I am interested in this thread because I am planning to swap out my failing brake booster (I have a hopefully-good used unit in a box) and replacing the MC with new. I might as well blow out the lines and rebuild the calipers. I believe I have a set of SC calipers and a set of Carrera ones....at least for the front. I will know for sure when I get things removed and measured.

It sounds like we are not in consensus about whether this is an upgrade, due to the extra unsprung weight. We see a 1.5 lb difference per rotor. I think the Carrera calipers are also slightly heavier. Total weight increase for the front axle then becomes about 4-5 lbs. Hmmm...

Question: The pistons and rubber rebuild kits are the same for SC and Carrera calipers, correct?

[VFR750]

The piston and seal kits are identical for the SC front and Carrera front calipers.

The rears are different.

The added weight of the front Carrera rotors increases the thermal capacity and the wider cooling slots increase the ability to shed heat.

Net improvement in energy absorption and dissipation. Small weight increase for better stopping.

I just need to lose 4 lbs for a weight wash. 😉

[Bill Verburg]

Originally Posted by Superman

I am interested in this thread because I am planning to swap out my failing brake booster (I have a hopefully-good used unit in a box) and replacing the MC with new. I might as well blow out the lines and rebuild the calipers. I believe I have a set of SC calipers and a set of Carrera ones....at least for the front. I will know for sure when I get things removed and measured.

It sounds like we are not in consensus about whether this is an upgrade, due to the extra unsprung weight. We see a 1.5 lb difference per rotor. I think the Carrera calipers are also slightly heavier. Total weight increase for the front axle then becomes about 4-5 lbs. Hmmm...

Question: The pistons and rubber rebuild kits are the same for SC and Carrera calipers, correct?

A few #s of extra unsprung weight makes little to no noticeable difference in ride or handling or acceleration of these cars.

even going from SC to 930 rotors makes little difference in feel or performance.

The big things are first and foremost tire OD and secondarily tire weight

[911 Rod]

Originally Posted by Bill Verburg

A few #s of extra unsprung weight makes little to no noticeable difference in ride or handling or acceleration of these cars.

even going from SC to 930 rotors makes little difference in feel or performance.

The big things are first and foremost tire OD and secondarily tire weight

Question for you Bill.
Would running stock 16" 6&7" be better or worse than 8&9" on the track?

[Bill Verburg]

Originally Posted by 911 Rod

Question for you Bill.
Would running stock 16" 6&7" be better or worse than 8&9" on the track?

i'd need more info to be specific

but in general for track use 8 & 9 would be better,

again speaking in generalities and w/ the same tire compounds
w/ 6 & 7 X16 you will run 205/55 & 225/50 tires(these tires are a semi sloppy fit on these wheels(meaning that the tires really want a 1' to 1.5" wider wheel for best performance), w/ 8 & 9 x16 you would run 225/50 & 245/45 tire, these are a tight fit on those wheels meaning they are at max recommended width.