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Xenonk

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Posts posted by Xenonk

  1. blah, you dont have to.. but it is the cost effective way to get at least the rotors and not worry about anything else as you are paying for a quality rotor (lasted me plenty of miles on the track before I had to toss them away).

     

    the Polishing? I think you are thinking of "turning" or "resurfacing" the face of the rotor to get rid of the vibrations or imprints of the pad material on the surface. Typically I brake a little harder in a smooth fashion to resurface them.. if the vibration is too much, a couple of things could have happened:

     

    1) they warped

    2) they are worn too thin to the point where resurfacing them is a waste of money

    3) lug nuts are loose

     

    I would check your brake pads.. some pads have a beveled edge to them, which helps slightly of removing the water when it's the initial contact of the pad to the rotor.. but that just goes away.. I never had "water" issues at all.. you would have to be driving in some really deep waters for actual water to hinder your braking.

  2. hi,

    after 53000km i'm planning to upgrade my front brake discs to cross-drilled zimmerman sport.but wondered if it's ok to replace the front stock brake disks and leave the rear stock discs?

     

    it's ok, but if you are street driving, you dont need the cross-drilled or even slotted brakes.. you are better off just driving around with full blanks as they dont eat up your pads as quickly.

     

    either case, you should just check your rotor thicknesses regardless, if you need to get rear ones because they are getting too thin, then you should get them replaced anyways.

  3. Keefe!! NOOOO!! You gotta come! I got a few questions I wanted to axe you, brah! Ahh well, next time.

     

    Ken, I would love to go another round of billiards. I had a BLAST last time and it was a ton of fun. You truly are the lord of the table. But if you will be with your daughter, it is no biggie. I will tease her about Michaela a bit. :p She still thinks I don't know her cousin. :lol:

     

    As far as Tyson's BooF-eh, yes they are CASH only, unless you want to get charged another $5.50 if you are paying below $15. Taipei Tokyo is not only Sushi. It is a Chinese restaurant with very excellent food. Look at Ken's link for the restaurant. I have been there a ton of times and love their food a lot.

     

    And next time, I want to recommend a Hibachi grill over at Rio, called Ziki's Japanese Steakhouse. They have VERY good food there. The taste there is orgasmic. The service sucks and the chefs are not Japanese (don't bother trying some Japanese with them). But man is the food AWESOME!!!

     

    So when is we all meeting? This Friday? Or next Friday?

     

     

    that's because you dont know the servers and the people that work at Ziki's well enough ;) The bartenders all got me lit up last time.

  4. Keep seeing you on 198 guy. You should come out. Friday at Fridays

     

    yea, it's my way to work of course.. cant stand driving on that parking lot called I-495.

     

     

    I'll try to make it, it's one of the few Fridays taht I dont have much to do. Wife gets off from work around 6pm from the metro, I can probably just pick her up from Twinbrook Metro and meet you guys at Fridays.

     

    Hope to see you guys there.

  5. 05 and 07 Legacy factory manuals quote opposite sequences...

     

    I do RF, LR, LF, RR.

     

     

    I think the order really doesnt matter too much as long as you get all the old fluid out.

     

    The only time I have seen it matter is when you have fixed piston calipers where you have 2 bleeder screws on each side of the caliper, normally I bleed the outside as much as i can and then bleed the inside one last. That way, you end up forcing as much of the bubbles out, and any of the remaining bubbles are caught up in the in-board nipple/bleeder.

     

     

    I've always done all my cars furtherest corner from the ABS unit if the car has one, and if it doesn't I go by the furthest from Master cylinder.

  6. make sure you bed the pads properly. My stock rotors lasted over 40,000 miles with a number of autox and probably 8 lapping days total. I upgraded to some DBA 4000 rotors and they have held up well. I could do without the slots, but no big deal having them. I am still on stock calipers and they are fine unless you really want to improve the brake feel with wilwoods or a BBK. I've been stage 2 for the last 15k miles or so and did an event last fall on Carbotech XP8 with the DBA's and they were great. I would recommend XP8 or Hawk HP+ for track use at the least

     

    i would go higher since I drive faster :lol::p

     

    just kidding buddy.

  7. Keefe, I am taking your recommendation and getting some Toyo R1R's in 225/40/18 to put on my 18" spec.b stockers. Before I get back out to the track I also need to get my brake situation taken care of.

     

    On my previous hpde event, after about the second lap of each session, the car would start to shake violently when braking. There was no pulsating in the pedal, it was mostly felt in the steering wheel, but it shook the car enough for the instructor to be concerned. We checked for flat spots in the tires, checked air pressure, checked the lug nut torque, and everything looked fine. When I came back from lunch, he had someone check over my car and said that it is cause by a soft spot in the rotor and it not heating up uniformly. I took the car to the dealer to have the rotor replaced but they only resurfaced it (there was some very slight warping) and said SOA will not allow them to replace the rotor. They told me the rotors are not designed to withhold track conditions and even if they replaced it, the problem would return (I know this is total bs).

     

    Since the problem is not fixed, I am looking at what I should do. I know I need lines, pads and fluid at the least, and I probably want some slotted front rotors, but they need to clear the stockers. I am also considering the wilwood kit with 4-pot front calipers, slotted front and rear rotors, front and rear lines and hp+ pads all around, but I would rather not spend that much if it isn't necessary.

     

    My current pads have about 75% life remaining after 8500 miles and 1 track day, and the tires have enough life left in them for probably another 2 track days. With my bad rotor I was letting off the throttle around 120 and coasting down the rest of the straight getting on the brakes early and braking early and light on all the other turns because it was tough fighting the vibrations. This really took a lot of the fun out of things. Any recommendations? I will need to order brakes and tires very shortly, my next track day is 3 weeks from today. I've also gone stage 2 since my last day out which means I will have even more speed to shrub off.

     

     

    Stock rotors are fine.. if anything, you got a "hot spot" (not exactly a soft spot) where you burned and overheated the pads onto the rotor and caused a significant difference in thickness of the rotor. Usually that's a sign of the rotors overheating and that initial slam of the brake pedal eventually wore it to where you got a lot of melted pad material or that you ended up smacking that exact same location of the rotor at every brake entry zone. Either case, that's an indication to work on your braking input as a driver as well. Overall, stock rotors hold up just fine for track days. It's the pads that you need to worry about that you are not glazing them and melting them onto the rotors and causing a hot spot or a pad imprint on them. Spotty pad material will do that to a rotor and that's probably why the shop re-surfaced them.

     

    You could look around for some slotted rotors but that still won't solve your problem if you overheat the rotors again. The slots could prevent the pads from burning onto the rotor, but the slots WILL eat up your pads quicker, it's something for you to consider. I used to track the blanks all the time and they did well, they just got really hot so I had to use higher temp pads and looked at changing up my driving habits and also looked into brake ducts.

     

    The biggest thing you need is to get new fluid, some new stock/oem-sized rotors and higher temp brake pads as there are enough out there to choose from. I AM NOT DOING A PRODUCT PLACEMENT NOR DOING ANY ADVERTISEMENT OF PARTICULAR VENDORS/SPONSORS by saying this: Brakeswap or Racecomp Engineering probably has a better solution of what you may need to run with your R1Rs and your situation since they have slotted, blanks, and other rotors that would fit your budget than what I would recommend (Magnetic1 has a M3 E36 that he races often at the track, so he knows exactly what you need and Racecomp Engineering have a long history in racing and instructing HDPE as well.. we all came from the same background starting as HPDE students like yourself, so you can learn from our experiences). Call them up to see what pads that will work for you. I would lean towards something along the lines of at least getting new front rotors and front pair of track pads something like Carbotech XP12 or higher (since you have stage 2) and Carbotech XP8 or higher [or match them all aroundif you want] and you are also running on R1Rs and you wont have the response from an r-compound tire, so your braking zones will be longer than an r-compound tire which means you will be on the brakes longer which in turns feeds out more heat. Get some new fluid in the lines (as Im pretty sureu if you glazed your pads from the last time, you probably boiled your old brake fluid too). The SS lines are not neccessary, but just a nice thing to have if you want better pedal feel, but it's not going to make you a better in braking exercises.

     

    swap out your stock pads before your track day and swap them back in after your track weekend is over. Stock pads were never meant to do track days.. heck they aren't even good enough for even autocross events. They are only good for the joe shmoe that's trying to get to work at the speed limit with only him driving on the road on a cold weather rainy day while driving grandma home (to keep things quiet).

  8. since we are doing fairly the same commute, I dont see myself using the brakes all that much even in stop and go traffic (since I'm not hard on the accelerator to speed up fast just to hit the brakes in another 5 seconds). I'm usually light on the brakes on stop and go traffic.

     

    I run around town on all sorts of pads, from ceramics to track pads between weekends at the track (too lazy to change them out again for the following weekend if I know I'll be out on track soon). Overall, any street performance pad will do, but if you see yourself driving like i do and do hard late threshold braking going into the decel lanes of the off/on-ramps, then I suggest using a little bit higher bite and a bit higher temperature range (probably something that is along the lines of Carbotech Bobcats or higher). Most of the time in the DC area, we dont drive around much in the hills either. The only thing with going with a higher temperature range is that you may need to change out the pads to something colder when winter comes around (unless you are comfortable with warming up your brakes with a few good drags before you head out as you pull out of your driveway on the cold winter days).

     

    In terms of suspension, it depends on your set up and how much weigh transfer and suspension travel you are dealing with. On the grand scheme of things, head dive is probably the least of your concerns if you are doing an emergency brake stop because someone brake-checked you or that you came up on heavy 495 traffic, you have other things to worry about at that point.

     

    It would be safer to say that the stiffer (this is a very gray area actually because there's a difference between the term "stiff" and the term "compliant" or "controlled" shocks depends on the roads than your tires) can lead to a larger emphasis of what your tires can do, but not always the case. Take for example if you had stiff shocks on a smooth surface, your tires will be in contact of the road all the time. This is assuming that your front shocks and springs are stiff enough to prevent head-dive which allows the rear tires of the car to help slow you down. It is correct that 90% of cars built have the front brakes to be the brute of the force (unless you drive a Porsche 911 or some other Rear Engine Rear Drive car). If your car's suspension was going to do an endo or a stoppie like a motorcycle would, then it's obvious that your rear tires will have little or no effect in helping you slow down, overall, you are only using 70~80% of the braking potential of your car. Even in Motorcycle Safety Classes the instructors spend time teaching the students to use front and rear brakes together to get maximum stopping distance. So backing up, if the road is not smooth, then this causes some problems. As I mentioned before, shocks play a big role in how well the car can stop and non-compliant shocks will make braking distances longer because they are spending too much time in the air or off the ground from the previous bounce or bump and not enough time pushing back down onto the ground to keep the tires back on the pavement. Sure, you can have stiff shocks, but you also need for them to be compliant or matched with the road surface. A fast reacting shock will help (think rebound, or the force of which the shocks pushes back down to extend the shock back to touch the ground) keep the tire down on the ground. What makes a suspension "stiff" is actually how the bound or compression portion of the shock reacts.. and there are two functions of the compression: fast speed and slow speed (rate of which the shock compresses). Fast would be considered how quick the suspension reacts to hitting a pot hole or how quick it can absorb a bump like a 2x4 on the road while a slow speed compression would be the rolling action of the car through a turn or how you are slowly adding the pressure on as you crest over a hill or hitting up a banked turn. So if the car's fast speed compression and fast speed rebound are lousy, then it's going to be obvious that whatever contact that you can make with the tire on the road will determine how well you are going to stop based on how much contact time you have with the road and the tire's grip levels. The "stiffness" really comes from the slow speed bound and rebound actions of the shocks. Hope that all makes sense.

     

    Back to the basics, so long as the tires are on the ground and that you are using threshold braking, the tires will do their job to slow you down. If the car is so stiff [and suspension is not compliant] that the tires are leaving off the ground, then it's obvious that you dont need brakes, rather you need air brakes or some kind of parachute to slow you down.

     

    I actually reside not too far from Andrewtech in Gaithersburg area, but I drive everywhere north of DC.

     

     

     

     

    Hey Keefe, lots of great info here. However, I do a lot of spirited driving going to work. I am opposite to traffic both ways (to and fro work). I also drive in Washington DC a lot where breaks are heavily involved. What category would I fall into, based on your chart?

     

    BTW, I saw your car on Georgia Avenue last week, heading towards Olney! Is that where you reside? I also saw your car parked at the Advanced Auto Parts off of 355. I took several pictures of your car, if that is OK with you! :)

     

    Also, one more question, how about suspension? How would that affect things in terms of braking distance? Would it be safe to say that the stiffer your car/suspension is, the more you travel in braking distance due to lesser tire grip? I remember having this conversation a long time ago while I was active at Summit Point Raceway. But I forgot what the verdict was and have lost a lot of my knowledge due to a rusty brain! :lol: Any insight?

  9. I ended up going into a brake shop and having them check out the pads and rotors. I feel confident in changing them but not in evaluating them... so they said the rotors and pads are shot. I guess this makes sense because I've had the rotors resurfaced before. I don't know how the previous owner drove the car but considering what I've had to have done to it (new strut, bent rim, etc) I don't think he was a mellow driver. Anyhow, I think I'm going to go ahead and have the rotors replaced with something of equal to or greater quality to the OEM rotors and then put some upgraded pads on, like the Hawk HPS pads. The guy at the brake shop was pretty adamant that the OEM brake setup on the LGT is more than sufficient which seems to jive with what I've seen in this thread.

     

    aside from the stock pads, the rotors are plenty good as they are.. the way I see it, the only way you would want better rotors is if you do a lot of braking that overheats the pads, at that point, you might as well get better pads if you use the brakes that much.

  10. I'm just waiting for some Alcon calipers that Eric at Brakeswap may come out with.. You don't neccessarily need more pistons, but it's about size of the piston and how much clamping force you are trying to put on the pads and also how big/"strong" your master cylinder is to push that kind of piston to make it effective.
  11. Keefe

    what would you recommend for a good setup on a lowered outback XT for spirited street driving and maybe track in the future (but i doubt it)?

     

    My outback has megan coilovers lowered 1.5 inches, pilot sport a/s tires on stock 17" wheels and soon to be stage 3 with 325 whp.

     

    Its time to replace the brakes and I want to do an upgrade front and rear.

     

     

    I hope you'll upgrade the tires as well, you'll probably overheat the tires too as well. If you are running on the stock wheels, you could do a GT conversion or get a 2-piece rotor OEM sized kit to expell the heat a little bit faster. Get some high-temp brake pads like Carbotech XP8s for street use and Carbotech XP16s if you plan to do track.. the rotor size is pretty good for what they are and considering the weight of the car if you dont want to upgrade the rims. But your tires are really lacking in braking power as well, so you may want to look into better tires for street summer ues and also for track use since you are putting down 125 whp more than me (which is a lot more speed and acceleration). Tires play a huge roll. While you can have the world's best brakes, it's pointless if you are still sliding to a stop due to the lack of grip in the tires. A good and ideal brake setup is the one that can be used aggressively without any fade in performance while locking up the wheels as fast and as best as possible. One thing that is overlooked is that suspension and wheels and tires play a part of the braking potential.

     

    You may want to consider readjusting your suspension so that your rear end can do some braking (as we all know that weight transfer happens when you hit the brakes, sending the rear end going up in the air and rendering the rear brakes and tires useless for stopping), so if you want, you can change your suspension settings to give you more braking abilities and also stablize the car more so during braking transitions. Suspension isnt just about lateral movements ;)

     

    A tip to driving a car like that on the track is that you have to transitition smoother from accelerating down the straight, ease off the gas so the car doesnt accelerate anymore, allow the car to coast for half a second or 1 second and then apply the brakes progressively.. if you go straight from gas to brakes, your car not only has to deal with the normal braking g forces, but it has to fight the positve gs that you still have. This will make your brakes last longer during a track day. So until you have money for bigger brakes and bigger wheels and wider tires, I would suggest to change your driving style to fit the car's potential and capabilities as well.

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