praedet
-
Posts
3,382 -
Joined
Content Type
Profiles
Forums
Gallery
Posts posted by praedet
-
-
That link is awesome because it gives the actual effective radius from the FSM. The problem is that we don't have that for the BBKs. I am going to assume that the effective diameter for BBKs is the rotor diameter - largest piston diameter*5/4
That is what the front and rear of the STi Brembos are. With that in place I have redone the numbers, and included the XT brakes based on 02-05 WRX brakes...
Ted
-
That would be great. Measure the XT stock set-up also!
Main things I need, rotor diameters and piston diameters...
Ted
-
Yep! Hopefully you won't have to do that. Did you upgrade your rear pads when you did the front brakes?
Ted
-
Excellent, I ask him for the:
4-pot front piston sizes, I know the rotor is 330 mm
6-pot front piston sizes and rotor diameter
4-pot rear piston sizes and rotor diameter
4-pot rear piston sizes and rotor diameter
Thanks,
Ted
-
Get me the XT stuff and I will run the numbers...
-
Dan,
The mu values for the Endless and Carbotech offereings are on their sites, and has been posted here. I don't know for those two though. I would do a search on nasioc, or e-mail the vendors.
Ted
Does this deserve a sticky?
-
Yeah, but most people are wondering whether or not to just do pads, lines, and fluid, or step up to a BBK. For biasing, I thought keeping the pads the same would be best.
Ted
-
I pm'ed Street Image to try and get the info I need for that. I will post it when I get it Allen.
Interestingly, if you were to use SS-Ms in the front (mu = ~0.4) and Bobcats in the rear (mu = ~0.5) you would get 68.7%/31.3% F/R bias...
-
Ok folks, I have been trying to check the biasing of the many brake systems that are out there.
I am going to try and keep an updated list. If you have a BBK system you want to check, or for that matter, if you want to understand what changing brake pads does, post the size of the rotor, the type of caliper (fixed/floating), how many pistons it has, and what diameter they are. If you are asking about simply a brake pad change, post the mu of the pad you will be using…
Now, to explain how I did this. I keep everything the same in the brake system up to the caliper. I assume that the coefficient of friction (brake pad mu) is the same from the stock system to the BBK unless otherwise specified. Taking out the inefficiencies and difference due to fixed and floating, and the stiffness of the caliper itself (this does make a difference, but it is small enough that we can simplify for these nonlinearities), the torque generated by the brake set-up is a function of piston size, # of pistons, and effective radius. With the stock front set-up you have 2 42.8 mm pistons that act like 4. With the BBK set-up you have 4 X mm pistons, or 2 X mm pistons and 2 Y mm pistons. I have pulled the effective radius for the Subaru set-ups from another site that got them from FSMs. The BBK effective radius is based on the STi Brembo set-up, with effective diameter = rotor diamter - largest piston size*5/4. With this, I calculated the difference between the torque generated by the stock set-up, and the torque generated by the BBK set-ups. I did not calculate the system’s ability to tolerate heat. This is looking at braking once with the system in a fixed temperature regime. I then calculate the rear set-up the same way. With no proportion valve interaction, the Front bias is Front Torque/(F Torque + Rear Torque) and the Rear bias is R Torque/(F Torque + R Torque). I can calculate this for both the stock system and the upgraded system. I can also compare the F+R torque of the upgraded system to the Stock system. This gives an idea of the pedal force vs. stock. Remember that the pedal force vs. stock does not take into account the “give” of a floating caliper vs. the stiffer fixed caliper.
Here is the resource I used to calculate this stuff.
Remember, all brake pads are equal in this. Simply upgrading the pad mu from 0.3 to 0.4 increases brake torque by 1/3. If you do a BBK front w/ a mu higher than 0.35, but leave the rear stock (0.35), your bias will drastically shift to the front...
Also, I added the Racing Brake rear kit which moves the stock caliper out and uses a 316x18 mm rotor. I have put a calculation in on all BBKs and the LGT/OXT stock set-ups with this kit since it is an easy/cheap upgrade...
Now, the list.
Front Brakes
05 LGT 05 OBXT iON4pt330 iON4pt310 RB4pt322 RB6pt355 Rot4pt330 Rot6pt330 Rot6pt355 STI4pt326 #pot 2 2 4 4 4 6 4 6 6 4 Caliper float float fix fix fix fix fix fix fix fix float/fix Pist 1 42.8 42.8 41.3 38.1 38.0 40.0 42.9 40.5 40.5 46.0 mm Pist 2 42.8 42.8 38.1 38.1 38.0 38.0 38.2 34.9 34.9 40.0 mm Pist 3 0.0 0.0 0.0 0.0 0.0 27.0 0.0 30.2 30.2 0.0 mm Rotor 316 294 330 310 322 355 330 330 355 326 mm Eff Rot 261 247 278 262 275 305 276 279 304 268 mm mu 0.35 0.35 0.50 0.50 0.45 0.45 0.40 0.40 0.40 0.40
Rear Brakes
05 LGT 05 OBXT iON2pt310 Rot2pt290 Rot4pt330 STI2pt316 RB316Stoc #pot 1 1 4 2 4 2 1 Caliper float float fix fix fix fix float float/fix Pist 1 32.0 32.0 38.1 40.5 30.2 36.0 32.0 mm Pist 2 0.0 0.0 0.0 0.0 30.2 0.0 0.0 mm Rotor 290 266 310 290 330 316 316 mm Eff Rot 254 230 262 239 292 268 280 mm mu 0.35 0.35 0.50 0.40 0.40 0.40 0.35
Brake Bias
[b][color="Red"]05-07 LGT Brakes[/color][/b] [color="RoyalBlue"][i]Stock LGT Front RB 316mm[/i][/color] Front Rear Front Rear Tbrake 10349 2815lb*in Tbrake 10349 3103lb*in % 78.6% 21.4% % 76.9% 23.1% Ttotal brakes 2194lb*ft Ttotal brakes 2242lb*ft F/R 3.68 %Stock Force 2.2% F/R 3.34 [color="red"][b]05 OUTBACK XT[/b][/color] [color="red"][color="RoyalBlue"][i]05 OXT Stock OXT Stock Front RB 316mm[/i][/color][/color] Front Rear Front Rear Tbrake 9794 2549lb*in Tbrake 10778 3103lb*in % 79.3% 20.7% % 77.6% 22.4% Ttotal brakes 2057lb*ft Ttotal brakes 2313lb*ft %Stock Force -6.2% %Stock Force 5.5% F/R 3.84 F/R 3.47 [color="Red"][b]iON[/b][/color] [color="royalblue"][i]APR 310mm 4-pot Stock Rear APR 330mm 4-pot Stock Rear[/i][/color] Front Rear Front Rear Tbrake 8244 2815lb*in Tbrake 9512 2815lb*in % 74.5% 25.5% % 77.2% 22.8% Ttotal brakes 1843lb*ft Ttotal brakes 2055lb*ft %Stock Force -16.0% %Stock Force -6.4% F/R 2.93 F/R 3.38 [color="royalblue"][i]APR 310mm 4-pot RB 316mm APR 330mm 4-pot RB 316mm[/i][/color] Front Rear Front Rear Tbrake 8244 3103lb*in Tbrake 9512 3103lb*in % 72.7% 27.3% % 75.4% 24.6% Ttotal brakes 1891lb*ft Ttotal brakes 2103lb*ft %Stock Force -13.8% %Stock Force -4.2% F/R 2.66 F/R 3.07 [color="royalblue"][i]APR 310mm 4-pot 2-pot Rear APR 330mm 4-pot 2-pot Rear[/i][/color] Front Rear Front Rear Tbrake 8244 4122lb*in Tbrake 9512 4122lb*in % 66.7% 33.3% % 69.8% 30.2% Ttotal brakes 2061lb*ft Ttotal brakes 2272lb*ft %Stock Force -6.1% %Stock Force 3.6% F/R 2.00 F/R 2.31 [color="Red"][b]RACING BRAKE[/b][/color] [color="royalblue"][i]RB 316mm 4-pot Stock Rear RB 322mm 4-pot Stock Rear[/i][/color] Front Rear Front Rear Tbrake 8392 2815lb*in Tbrake 8580 2815lb*in % 74.9% 25.1% % 75.3% 24.7% Ttotal brakes 1868lb*ft Ttotal brakes 1899lb*ft %Stock Force -14.9% %Stock Force -13.4% F/R 2.98 F/R 3.05 [color="royalblue"][i]RB 355mm 6-pot Stock Rear RB 316mm 4-pot RB 316mm[/i][/color] Front Rear Front Rear Tbrake 12454 2815lb*in Tbrake 8392 3103lb*in % 81.6% 18.4% % 73.0% 27.0% Ttotal brakes 2545lb*ft Ttotal brakes 1916lb*ft %Stock Force 16.0% %Stock Force -12.7% F/R 4.42 F/R 2.70 [color="royalblue"][i]RB 322mm 4-pot RB 316mm RB 355mm 6-pot RB 316mm[/i][/color] Front Rear Front Rear Tbrake 8580 3103lb*in Tbrake 12454 3103lb*in % 73.4% 26.6% % 80.1% 19.9% Ttotal brakes 1947lb*ft Ttotal brakes 2593lb*ft %Stock Force -11.3% %Stock Force 18.2% F/R 2.76 F/R 4.01 [color="Red"][b]ROTORA[/b][/color] [i][color="RoyalBlue"]Rotora 330mm 4-po Stock Rear Rotora 330mm 6-po Stock Rear[/color][/i] Front Rear Front Rear Tbrake 9854 2815lb*in Tbrake 11402 2815lb*in % 77.8% 22.2% % 80.2% 19.8% Ttotal brakes 2112lb*ft Ttotal brakes 2369lb*ft %Stock Force -3.8% %Stock Force 8.0% F/R 3.50 F/R 4.05 [color="RoyalBlue"][i]Rotora 355mm 6-po Stock Rear Rotora 330mm 4-po RB 316mm[/i][/color] Front Rear Front Rear Tbrake 12422 2815lb*in Tbrake 9854 3103lb*in % 81.5% 18.5% % 76.1% 23.9% Ttotal brakes 2539lb*ft Ttotal brakes 2160lb*ft %Stock Force 15.7% %Stock Force -1.6% F/R 4.41 F/R 3.18 [i][color="RoyalBlue"]Rotora 330mm 6-po RB 316mm Rotora 355mm 6-po RB 316mm[/color][/i] Front Rear Front Rear Tbrake 11402 3103lb*in Tbrake 12422 3103lb*in % 78.6% 21.4% % 80.0% 20.0% Ttotal brakes 2417lb*ft Ttotal brakes 2587lb*ft %Stock Force 10.2% %Stock Force 17.9% F/R 3.67 F/R 4.00 [i][color="RoyalBlue"]Rotora 330mm 4-po 2-pot Rear Rotora 330mm 6-po 2-pot Rear[/color][/i] Front Rear Front Rear Tbrake 9854 4240lb*in Tbrake 11402 4240lb*in % 69.9% 30.1% % 72.9% 27.1% Ttotal brakes 2349lb*ft Ttotal brakes 2607lb*ft %Stock Force 7.1% %Stock Force 18.8% F/R 2.32 F/R 2.69 [i][color="RoyalBlue"]Rotora 355mm 6-po 2-pot Rear Rotora 330mm 4-po 4-pot Rear[/color][/i] Front Rear Front Rear Tbrake 12422 4240lb*in Tbrake 9854 5780lb*in % 74.6% 25.4% % 63.0% 37.0% Ttotal brakes 2777lb*ft Ttotal brakes 2606lb*ft %Stock Force 26.6% %Stock Force 18.8% F/R 2.93 F/R 1.70 [color="RoyalBlue"][i]Rotora 330mm 6-po 4-pot Rear Rotora 355mm 6-po 4-pot Rear[/i][/color] Front Rear Front Rear Tbrake 11402 5780lb*in Tbrake 12422 5780lb*in % 66.4% 33.6% % 68.2% 31.8% Ttotal brakes 2864lb*ft Ttotal brakes 3034lb*ft %Stock Force 30.5% %Stock Force 38.3% F/R 1.97 F/R 2.15 [color="Red"][b]STI BREMBO[/b][/color] [color="RoyalBlue"][i]STI 326mm 4-pot Stock Rear STI 326mm 4-pot 2-pot Rear[/i][/color] Front Rear Front Rear Tbrake 10778 2815lb*in Tbrake 10778 3759lb*in % 79.3% 20.7% % 74.1% 25.9% Ttotal brakes 2265lb*ft Ttotal brakes 2423lb*ft %Stock Force 3.3% %Stock Force 10.4% F/R 3.83 F/R 2.87 [color="royalblue"][i]STI 326mm 4-pot RB 316mm[/i][/color] Front Rear Tbrake 10778 3103lb*in % 77.6% 22.4% Ttotal brakes 2313lb*ft %Stock Force 5.5% F/R 3.47 [b][color="Red"]STOPTECH[/color][/b] [i][color="RoyalBlue"]ST 332mm 4-pot Stock Rear ST 332mm 4-pot RB 316mm[/color][/i] Front Rear Front Rear Tbrake 10133 2815lb*in Tbrake 10133 3103lb*in % 78.3% 21.7% % 76.6% 23.4% Ttotal brakes 2158lb*ft Ttotal brakes 2206lb*ft %Stock Force -1.6% %Stock Force 0.5% F/R 3.60 F/R 3.27 [color="royalblue"][i]ST 328mm 4-pot Stock Rear ST 328mm 4-pot RB 316mm[/i][/color] Front Rear Front Rear Tbrake 7106 2815lb*in Tbrake 7106 3103lb*in % 71.6% 28.4% % 69.6% 30.4% Ttotal brakes 1653lb*ft Ttotal brakes 1701lb*ft %Stock Force -24.6% %Stock Force -22.4% F/R 2.52 F/R 2.29Brake Pads
Man. Type Type min T max T min mu max mu Rating Endless Vita Nuv non-asbesots 32 570 0.30 0.35 Street Endless SS-Y ceramic 32 716 0.38 0.48 A. Street Endless SS-S ceramic 32 932 0.35 0.43 Auto-X Endless SS-M ceramic 32 986 0.30 0.40 L. Track Endless CC-X semi-metalic 120 1300 0.38 0.50 Track Endless CC-R semi-metalic 300 1500 0.35 0.42 H. Track Carbotech Bobcat ceramic 40 900 0.45 0.45 Auto-X Carbotech XP9 ??? ??? 1400 ??? ??? L. Track Carbotech XP10 ??? ??? 1600 0.60 0.60 Track Carbotech XP11 ??? ??? ??? 0.65 0.65 H. Track Ferrodo DS 2500 ??? ??? ??? 0.50 0.50 ???
Pad Levels from Low to High: Stock, Street, Agressive (A) Street, Auto-X, Light (L) Track, Track, Heavy (H) Track
-
Keefe,
I propose annotating the top with stages like this...
Stg 1
Pads, fluid
Stg 1.5
Stg 1 + lines, fluid
Stg 2
Stg 1 + F+R Rotors
Stg 2.5
Stg 2 w/ 2-piece F Rotors
Stg 3
Stg 2 + Calipers
Stg 3.5
Stg 2.5 + Calipers
Stg 4
Stg 1 or 2 + front BBK
Stg 5
F & R BBK
-
Has anyone checked into ordering the canadian aero bars for their wagon?
-
So, where did you get the material...
How hard was it to pull up the carpet?
I want to do my doors, floor, and definitely the floor of the wagon bed, but I have never done this at all, and I am a little scard of doing it...
Ted
-
Jazzy,
So, for those of us who have been lazy and haven't installed yet, but already have the board(I think I had one of the first 10 or so...). How much is just the "Pro" part. I would prefer the gold connectors etc.
Ted
-
see_obxt, Where can I get the aero bar you show above for my LGT wagon?
Ted
-
What is the word on the next-gen model Jazzy?
Ted
-
-
Man, i would be up for something like this, and I would be willing to put in a deposit to help defray development costs. Would $50 help?
Ted
-
So is that on the Thurs-Fri (13-14), or Fri-Sat(14-15)? I would like to get up there to at least see that!
Ted
-
Keefe,
Which endless pads did you go with? Are you still enjoying them? I remember that it was the pad with the lower coeff. of friction. (relative to the other pad, not stock) I am planning to gradually assemble my braking suplies over the winter and I wanted to try something beside Bobcats. (though I liked those a lot for the street)
Ted
-
I got mine yesterday, but it will be a while before I can install it. I think the 2nd Gen would go over very well, and I would definitely get one!
Ted
-
I will be up for following you mccory, but since I still don't have my LGT, I can't promise I will keep up. (I will hold my own though...) I am cool with whatever hotel. Since I will be on my own, I am good with sharing a room for better costs...
-
I can't go on the 18th, but I also think that meeting people is part of the fun. If the majority can go on the 18th, but not on the 4th, then I think you all should do the 18th...
Ted
It would be great if everyone could do the 4th though
-
I'm there the 4th...
-
Sadly, I can't go on the 18th, so I will hope for a miracle...
(I'll be snowboarding in CO, so I guess I shouldn't complain...)
BBK Brake Bias List
in Suspension/Brakes
Posted
The iON AP Racing kit is the best combination of heat management/perfect biasing I have seen so far. They did their homework. 70/30 is ideal in my mind. Obviously, that is as long as you put DS2500s on the rear too...
RB is starting to go towards the unsafe side of things, and either STi swap has a worse bias vs. stock. If you add in the brake dive present in the stock LGT, a too rear biased system will lock up the rears very quickly...
Ted