Guest Posted June 30, 2008 Share Posted June 30, 2008 I just installed rear Brembos yesterday. The difference is obvious, the car is less front biased with full Brembo set than stock. Link to comment Share on other sites More sharing options...
spiralsmurf Posted June 30, 2008 Share Posted June 30, 2008 so you're running a full brembo setup with the original master cylinder? Link to comment Share on other sites More sharing options...
Guest Posted June 30, 2008 Share Posted June 30, 2008 so you're running a full brembo setup with the original master cylinder? Yup. Link to comment Share on other sites More sharing options...
fweasel Posted June 30, 2008 Share Posted June 30, 2008 Sprial - you're not looking at it right. By running both front AND rear calipers from another car, the bias shift is a function of how those calipers were designed to work with one another and the size of the master cylinder used with them will then only affect pedal travel , feel, and mechanical leverage. When you run only a different front caliper from another system, you're now changing multiple variables at once. You cannot apply the logic that if the STi Brembo calipers work on the Legacy, then the front WRX Stoptech kit should as well. While it is true your kit is 332 and not the smaller 328, I would suspect the shift rearwards would be more dramatic than the Brembo upgrade, but I have not done the math to prove this. Stoptech HIGHLY advises not running WRX based BBK's on the Legacy. ignore him, he'll go away. Link to comment Share on other sites More sharing options...
spiralsmurf Posted July 1, 2008 Share Posted July 1, 2008 I wasn't suggesting anything, merely asking. I'm going to measure the wrx piston size and compare it to a legacy kit tomorrow. maybe if the legacy kit has larger pistons, the wrx caliper can be machined to fit. Replacement pistons can be ordered from stoptech without any issue. Link to comment Share on other sites More sharing options...
spiralsmurf Posted July 1, 2008 Share Posted July 1, 2008 ST 332mm 4-pot RB 316mm 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 is the stoptech 332 kit mentioned here the legacy kit or wrx? if so, seems like it could be balanced out with the Racing brake rear kit. Link to comment Share on other sites More sharing options...
praedet Posted July 1, 2008 Author Share Posted July 1, 2008 The 332 kit is the Stoptech Legacy specific kit... Link to comment Share on other sites More sharing options...
spiralsmurf Posted July 4, 2008 Share Posted July 4, 2008 (edited) I'm going to install the WRX 332mm kit next week and will post any impressions from normal street driving. Despite what Stoptech says about installing the WRX kit on the Legacy, the numbers suggest that it would only shift bias about 8% rearward. The 06 wrx with 4/2pot brakes has a 67/33 factory balance and that is how they came in the rest of the world for years. I think using the 328mm wrx kit would be a pretty aggressive shift to the rear because the piston sizes are the same but the rotor size is smaller. I'm hopefully this will actually help keep the car more planted under braking and reduce dive. For anyone who wants to run the numbers, the LGT kit has 3*/4*mm pistons vs the WRX 3*/4*mm. Have a great Holiday! Edited July 4, 2008 by praedet Removed numbers at Stoptech's request Link to comment Share on other sites More sharing options...
praedet Posted July 4, 2008 Author Share Posted July 4, 2008 I edited the above because Stoptech has specifically requested we do not post their piston sizes... Link to comment Share on other sites More sharing options...
LittleBlueGT Posted July 4, 2008 Share Posted July 4, 2008 I edited the above because Stoptech has specifically requested we do not post their piston sizes... So if someone buys their kit they cannot measure and discuss piston sizes? Full tune of 68HTA, KSTech 73 MAF, Racer X FMIC and ID1000s................by the DataLog Mafia!!! Link to comment Share on other sites More sharing options...
fweasel Posted July 4, 2008 Share Posted July 4, 2008 So if someone buys their kit they cannot measure and discuss piston sizes?They can, and have been via PM's. ignore him, he'll go away. Link to comment Share on other sites More sharing options...
LittleBlueGT Posted July 4, 2008 Share Posted July 4, 2008 They can, and have been via PM's. I know. I still think it is crap. Full tune of 68HTA, KSTech 73 MAF, Racer X FMIC and ID1000s................by the DataLog Mafia!!! Link to comment Share on other sites More sharing options...
fweasel Posted July 4, 2008 Share Posted July 4, 2008 I know. I still think it is crap. Why? They provided both Ted, and myself with the numbers we were looking for and asked that we not post them on a public forum. I was happy to oblige. ignore him, he'll go away. Link to comment Share on other sites More sharing options...
LittleBlueGT Posted July 4, 2008 Share Posted July 4, 2008 Why? They provided both Ted, and myself with the numbers we were looking for and asked that we not post them on a public forum. I was happy to oblige. If you ask them for some numbers and they give them to you, but ask not to post in a public forum, just fine. If someone owns their kit, and then they take measurements of them, I think they should be able to post up the measurements. What is next, I will have to take down the weights of all the products I bought that I posted? Full tune of 68HTA, KSTech 73 MAF, Racer X FMIC and ID1000s................by the DataLog Mafia!!! Link to comment Share on other sites More sharing options...
fweasel Posted July 4, 2008 Share Posted July 4, 2008 If you ask them for some numbers and they give them to you, but ask not to post in a public forum, just fine. If someone owns their kit, and then they take measurements of them, I think they should be able to post up the measurements. What is next, I will have to take down the weights of all the products I bought that I posted?What's the big deal, they asked, we agreed. If the manufacturer of another product I owned asked me not to discuss a particular specification on a public forum, I'd probably go along with that as well. You know the measurements, have at it, post away. ignore him, he'll go away. Link to comment Share on other sites More sharing options...
spiralsmurf Posted July 4, 2008 Share Posted July 4, 2008 Not a big deal but I got the info by calling a distributor and asking what seals need to be ordered for a specific kit. the info is out there for the public so it doesnt really matter. what matters is how the kit will work on the legacy. Link to comment Share on other sites More sharing options...
praedet Posted July 5, 2008 Author Share Posted July 5, 2008 The torque numbers for both kits are in the calcs. If someone wants to do something on their own, they can pm me. This is a sticky on a large forum. I am respecting stoptech's wishes on this one... Link to comment Share on other sites More sharing options...
Drew888 Posted July 24, 2008 Share Posted July 24, 2008 I've read through all 5 pages and eager for more. This has been a very good read. So, where have we all left off? Another thread? [URL="http://legacygt.com/forums/vbpicgallery.php?do=view&g=1586"VbGallery/URL] Link to comment Share on other sites More sharing options...
KartRacerBoy Posted November 25, 2008 Share Posted November 25, 2008 Praedet, I been meaning to ask but at my forgetful age I often lose my train of thought, but your bias numbers are only relevant to stock suspension, correct? I understand you are calculating front/rear torque, but how these bias numbers will affect braking distance will also be affected by suspension mods since such mods will affect front vs rear weight distribution during braking. A stiffer and lowered suspension will mean less forward weight bias under braking compared to stock, no? Link to comment Share on other sites More sharing options...
whitetiger Posted November 25, 2008 Share Posted November 25, 2008 ^this only afffect brakring when taking tires in to account. Im assuming these bias #'s are only relevant when traction is taken out of the equation. A stiff suspension wil crap tires will brake worse than a car that allows some weight transfer on the same crap tires. a stiff suspension will make the rear brakes work more as long as the tires up front are not overwhelmed. Link to comment Share on other sites More sharing options...
praedet Posted November 26, 2008 Author Share Posted November 26, 2008 This is simply the bias of the rotor and caliper set-up. There are WAY too many variables to go beyond that for suspension changes too. I eventook out the differences in biasing due to different pads and assumed folks would match them front to rear. May be I will do a write-up on how to calculate biasing including suspension, with an example using my car, so folks can do it on their own... Link to comment Share on other sites More sharing options...
KartRacerBoy Posted November 26, 2008 Share Posted November 26, 2008 Thanks praedet. I figured as much. I imagine that's why stock brake calipers usually outdo big brakes in stopping distance, at least on a one or two stop basis. But DOOOOOOOOOOOOOOOOOO it! What's a little less time with your family or sleeP???? Link to comment Share on other sites More sharing options...
PhilT Posted June 2, 2009 Share Posted June 2, 2009 Read through the whole thread, very interesting information indeed. Now that I have completed the Brembo F&R install, I was wondering about the bias, and how to actually measure it rather than calculate it. Braking generates heat; would it be too simplistic to measure the difference in temperature of the rotors after a long hard braking and use that as a way of seeing what the bias is ? Double Award Winning Legacy GT Wagon Link to comment Share on other sites More sharing options...
KartRacerBoy Posted June 2, 2009 Share Posted June 2, 2009 We need a political brake bias thread. Do Brembos make you pull to the right or left? What about Stop Tech and APs? The PA wants to know. Do your stuff Praedet. Link to comment Share on other sites More sharing options...
MGV101 Posted September 8, 2009 Share Posted September 8, 2009 Was trying to do my own calculations for the endless BBK that I am about to purchase and produced this spreadsheet. Just enter your Piston diameter, rotor diameter and pad mu and it should be able to calculate you brake bias. Please note that the effective diameter/radius is estimated using the forumula suggested by praedet (effective diameter = Rotor diameter - Piston size x 5/4) and therefore some the bias calculated using this spread sheet for certain calipers may be slightly different to the bias posted here where the actual effective radius were used. Please rename the file extension to .xls if it does not work.Brake bias.csv Link to comment Share on other sites More sharing options...
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