Options: Stock Gt Brakes or BBK?

[Xenonk]

I always wanted to ask...is the stock LGT caliper a one piece (like the FHI 4pots? From the pics I've seen, it looks like they don't have a separate bracket and dustboot; caliper bolts directly to the hub...

 

the stock GT is a floating caliper, not like a fixed caliper like the FHI/Subaru 4-pots. The stock GT does have dust seals and the calipers bolt onto a carrier that is the bracket that has slider pins that acts like a 4-pot where both side of the caliper puts pressure on the rotor.

[rougeben83]

Cool, thanks for clearing that up. Now, anyone selling their front LGT brakes? :D

[TSiWRX]

it's calipers that are not sealed that you need to be careful of rebuilding (typically even calipers with dust seals need some rebuilding if you overheat the calipers and the rubber boots start to tear apart and possibly the caliper starts to leak the brake fluid or the caliper sucks in air).

 

Wilwood is one of the companies that sell cheaper calipers with no dust seals that probably need a rebuild after every 20,000 miles or so. Im not sure if Wilwood has started to make calipers with dust seals, but you can ask to find out.

 

+1 on all counts.

 

sutter2k, in so far as I know - via direct contact with Rotora's tech-line and through verification with authorized dealers - our 4-pots are sealed. So unless something goes wrong, bruddah, we're OK, and won't need rebuilds for quite a while.

 

I believe, brother Keefe, that there are indeed Wilwood kits out now which are sealed. I'm not sure of their exact application nor parts numbers, though, but pricing seems to be a good non-quantitative way to at least get a "first-glance" approximation as to whether or not the sets are sealed (of course, the sealed sets are much more expensive).

[Xenonk]

At one point I was looking at the Endless BBK kit (calipers are made by ALCON ) (14+" rotors up front with their racing 6-pot kit and the 14" rotors in the rear with their racing 4-pot), but that was a $7,000+ setup. I would have probably needed to run a set of 18" at the minimum as well as run dual master cylinders to move enough fluid through the system....

 

but the more and more I track the GT, the way I have it now is good enough for the speed I am going at.. if anything, I just need wider tires and some brake ducts..(and spend more time later in the future of gutting out the "luxury" out of the car if I decide to get more out of the car, but I dont see that happening anytime soon as I have a 1989 BMW 325is as a track car to race with soon). I think the way I have my GT sorted out I can probably get about stage 2 protune worth of power and it will still be managable. It's going to be the tricky part for the driver to adjust the off-acceleration-onto-brakes transition that they will have to learn and give themselves that split second of time for the car to level back to zero g-forces, of the brakes just have that much more to do and the tires will take a toll on the hard braking. Remember, F=MA and we sure dont want the "A" to be still positive when we hit the brakes, that's just more work for the brakes to work against.

[LittleBlueGT]

One of the main reasons why I am going BBK is that it can handle more heat on a street application.

 

So, if I have say Ferrodo 2500 pads for the street, I will be able to drive them that much harder before I get fade then good street pads in the stock calipers.

 

I think it is almost common knowledge that with the right pads you can track your car aggressively on the stock braking system.

 

I DO get pad fade with my Bobcats right now, but I have to drive pretty aggressive to feel it.

 

Also, real good calipers (like AP Racing) will give a better pedal feel, all things being equal.

[Xenonk]

One of the main reasons why I am going BBK is that it can handle more heat on a street application.

 

So, if I have say Ferrodo 2500 pads for the street, I will be able to drive them that much harder before I get fade then good street pads in the stock calipers.

 

I think it is almost common knowledge that with the right pads you can track your car aggressively on the stock braking system.

 

I DO get pad fade with my Bobcats right now, but I have to drive pretty aggressive to feel it.

 

Also, real good calipers (like AP Racing) will give a better pedal feel, all things being equal.

 

 

You mean to tell me you drive well beyond 900F (or +1200F for that matter) for brake rotor temps??? I do track driving for a solid 20+ minutes in 90F ambient temps with another passenger in the car and I barely get up to 1200F.

 

What kind of crazy driving that you are doing on the street that would require you to run up your brakes so high in temps?? Not to mention that I run on r-compounds to even get up to those temps. Granted that you can overheat a set of Bobcats (supposedly rated around 750F for operating temps), but that's some really aggressive driving and possibly your style of aggressive driving may need some improvement in throttle-to-braking transition to keep the brakes from over heating so much. You also drive a Non-Limited, so you should be definitely lighter by a good 100 lbs, so that should be less mass for you to deal with and you shouldn't be hitting those kinds of marks.

 

If that's how you drive on the street, what or how do you drive on the track????

 

 

Btw, the melting point of iron is ~2700F, if anything, you are just glazing your pads to hell with your hard driving, hence your brake fade. Raising the heat capacity of the rotor isnt going to help you any at all, it's only in due time that the rotors will overheat the pads and glaze them again. What you need are some track pads for street use if you are going to be driving THAT hard (which I dont see the point of even doing as that is some incredibly aggressive driving). And I have yet to see anyone out there making a "street pad" that can handle the range of 32F to 1200F. Track pads are already 300F to 1500F in operating temps. Endless SSMs max out from 32F to 900F.

 

And another thing, aluminum's melting point is 1220F, so if you are using some aluminum calipers and using a two-piece rotor with an aluminum hat, you will end up warping those parts in the process if you dont have some kind of brake ducting to keep them cool between braking zones (sure aluminum can dissipate heat faster than iron, but when the intervals of the braking zones are shorter, there's no time for the aluminum to get rid of the heat, especially without a brake duct kit)... BBK aint gonna help you there if you are driving that hard, your pads will still be the weakest link..

 

but never mind that, your fluid will be the weakest link next to your pads. You better be running some Castrol SRF..

[rougeben83]

Are you sure you weren't just feeling it like a placebo effect? (i.e. do you think you brakes are bad because you felt the fade, or you thought your brakes were bad to begin with and you felt the fade)

 

Regardless, like I said before, be honest with yourself on why you want the bigger brakes - looks, absolute performance, best bang for the buck, etc?

 

A few people are already said that the stock LGT brakes, with the right pads and fluid can more than handle a casual track day or two. As for the feel, there's cheaper solutions to get a more linear feel (ss brake lines).

 

It looks as if you want us to convince you that LGT brakes are the best way when you seem to already be leaning towards the rotora BBK.

 

Well...it's your money and your car, so spend on my friend! :D

[LittleBlueGT]

You mean to tell me you drive well beyond 900F (or +1200F for that matter) for brake rotor temps??? I do track driving for a solid 20+ minutes in 90F ambient temps with another passenger in the car and I barely get up to 1200F.

 

What kind of crazy driving that you are doing on the street that would require you to run up your brakes so high in temps?? Not to mention that I run on r-compounds to even get up to those temps. Granted that you can overheat a set of Bobcats (supposedly rated around 750F for operating temps), but that's some really aggressive driving and possibly your style of aggressive driving may need some improvement in throttle-to-braking transition to keep the brakes from over heating so much. You also drive a Non-Limited, so you should be definitely lighter by a good 100 lbs, so that should be less mass for you to deal with and you shouldn't be hitting those kinds of marks.

 

If that's how you drive on the street, what or how do you drive on the track????

 

 

Btw, the melting point of iron is ~2700F, if anything, you are just glazing your pads to hell with your hard driving, hence your brake fade. What you need are some track pads for street use if you are going to be driving THAT hard. And I have yet to see anyone out there making a "street pad" that can handle over 1000F. Track pads are already 300F to 1500F in operating temps.

 

And another thing, aluminum's melting point is 1220F, so if you are using some aluminum calipers and using a two-piece rotor with an aluminum hat, you will end up warping those parts in the process... BBK aint gonna help you there if you are driving that hard, your pads will still be the weakest link..

 

but never mind that, your fluid will be the weakest link next to your pads. You better be running some Castrol SRF..

 

Just too funny reading this post.

 

I can't use track pads for everyday use, you know that, besides I live in Canada, it gets cold up here!

 

My Bobcats can go to close to 800F, and they are very good, but I can definitely fade them on the street. BTW I happen to live right on a highway and my everyday commute is devoid of any cars and has some turns, so I take advantage of that!

 

I don't need a BBK, I don't need a new turbo either. I am just saying that I am buying it for its performance not bling.

 

I can get good street pads (very very similiar to the Ferrodo2500s) that can get fairly close to 950F, so that would be an improvement. But not a huge one.

 

If I can get my street set-up to 950F then I should be able to get a BBK that will do the same kind of braking and only hit 700 or so.

 

Bigger rotors, better venting, better calipers should all make a noticeble improvement. Just depends on how "good" of a kit I get.

 

The center of the rotor does not get as hot as the face BTW (I know you know that, just saying). I will not be wrecking my aluminum mounting hats.

 

 

When I do track my car (building a track 2 mins from my house!!!!!) then if I get a good BBK I should be able to go about 20-30% harder on it then on my stock brakes and Bobcats w/o changing pads. This will be nice when I want to go for a couple of quick runs just before I go to work.

 

As an example if you drive a Maclaren F1 or F40 or something exotic like that they have huge brakes that are able to take some pretty serious abuse on a track with street pads! That is what I would like, I will have to see how close I get!

 

One other thing. A good BBK just has better feel then our brakes. Maybe it is just how I see it, but many others agree with me. I amwilling to pay a bit for better feel. Already have pads, lines, fluid, and that got me 50% of the way there, but I want better feel still. Stiffer calipers, rotors that expand evenly when hot (vs 1 piece rotors) all contribute to that.

 

A local guy is getting iONs BBK front and rear and I am anxiously awaiting see it, and how it works.

 

On his kit he loses around 14 lbs of weight on each front brake, and 17 lbs on each rear brake. I imagine that has got to make a pretty noticeable improvement in acceleration, braking and suspension response (especially when considering our frost heaves that we get in the spring!)

 

Bling really is not much of a factor for me, I have spent next to nothing so far on my car for bling!

 

I really do like to be able to just nail the brakes as hard as I like whenever I like, especially when I am hitting redline on the highway in 5th and I see a car that could be a cop!

 

More power is addictive, you like to use it all the time! Better braking is also addictive. Now I could just get my GT to accelerate as good as it brakes!

 

I doubt that this set-up will be as good as stock brakes with race pads on extended track use, but I hope it will get close.

[Xenonk]

Just replace the master cylinder with a LARGER one, that's best way to get the best feel out of them.. the more fluid you can pump in one press, the quicker the response and less modulation or "soft" play you get. The typical caliper "feel" you are referring to is the amount of fluid is a lot less to move the pistons.. that would explain the "stiffer" feel as it doesnt require as much fluid to be pumped to push the pistons. Preadet (Ted) also has a huge sticky about piston sizing which shifts the brake bias.. and generally speaking, the stock GT pistons in the stock calipers are pretty big as they are, that's why they require a lot of brake fluid movement to push the pistons in. The other way to solve the fluid movement (and probably a hell of a lot cheaper than getting all these upgraded calipers) is getting a large 1" bore master cylinder.

 

I only have stock power, I dont even have a stage 1 setup on my car. My brakes match the power I make already. And of all the track driving I do from as low as 23F to 99F temperatures, I see no real point of making the car THAT sensitive with the brakes as there wont be any room left for modulation for threshold braking.. 1/4" or 1/2" pedal travel is going to be hard to deal with when you want to be able to modulate the brakes. Too sensitive of brakes will overpower the tires you run anyways. I think what you are really missing is running a good set of tires, (even if you are in Canada, you just have to live with the fact that you have to run some kind of ultra high performance all-season tire) and that is already a big trade-off.. you can have the world's best brake setup, but you know and I know that it's not going to live up to its potential simply that you dont have the tires to transmit the negative sharp acceleration curve.. if you had to compare between stopping power of the brakes vs acceleration power from your motor, you will see that the brakes and tires can stop possibly faster than you can go, but again, it's all limited at your tires.

 

I think what you are looking for in the brake set up is too broad of a range, especially pouncing on a set of street pads (as I stated before about increasing the heat capacity wont help with a limited temperature range of the pads). Besides, as you look further and further up the brake pad temperature range, you will see that there's quite a few pads that can retain the higher end of coeff. of friction.. you will eventually have to trade off on that already.

 

I dont recall the ION kits losing 14 lbs in each front corner and 17 lbs in each rear corner.. that's really hard to swallow as the calipers and rotors in stock form are around 15 lbs and 25 lbs for the front.. that's shaving off about 50% of weight.. I can give the benefit of the caliper made as aluminum, but it's hard to swallow the notion of shaving that much off from the rotor.. Racing Brake Rotors are already 5 lbs lighter than the stock rotors, and that's already barely track-usable for a session or two.

 

That's a lot of wishful thinking that's very border line to fictional to get what you want out of your brakes for the use that you are looking at. I dont think you will actually get to the 70% of your target because there's just too many trade-offs, and living in Canada is a big factor in your case.

[LittleBlueGT]

Just replace the master cylinder with a LARGER one, that's best way to get the best feel out of them.. the more fluid you can pump in one press, the quicker the response and less modulation or "soft" play you get. The typical caliper "feel" you are referring to is the amount of fluid is a lot less to move the pistons.. that would explain the "stiffer" feel as it doesnt require as much fluid to be pumped to push the pistons. Preadet (Ted) also has a huge sticky about piston sizing which shifts the brake bias.. and generally speaking, the stock GT pistons in the stock calipers are pretty big as they are, that's why they require a lot of brake fluid movement to push the pistons in. The other way to solve the fluid movement (and probably a hell of a lot cheaper than getting all these upgraded calipers) is getting a large 1" bore master cylinder.

 

Nobody I know of here has changed their master cylinder. It is not the amount of pedal travel I wish to change. A BBK with less flex has a different feel to it, not necessarily less travel.

 

I only have stock power, I dont even have a stage 1 setup on my car. My brakes match the power I make already. And of all the track driving I do from as low as 23F to 99F temperatures, I see no real point of making the car THAT sensitive with the brakes as there wont be any room left for modulation for threshold braking.. 1/4" or 1/2" pedal travel is going to be hard to deal with when you want to be able to modulate the brakes. Too sensitive of brakes will overpower the tires you run anyways. I think what you are really missing is running a good set of tires, (even if you are in Canada, you just have to live with the fact that you have to run some kind of ultra high performance all-season tire) and that is already a big trade-off.. you can have the world's best brake setup, but you know and I know that it's not going to live up to its potential simply that you dont have the tires to transmit the negative sharp acceleration curve.. if you had to compare between stopping power of the brakes vs acceleration power from your motor, you will see that the brakes and tires can stop possibly faster than you can go, but again, it's all limited at your tires.

 

Already run Toyo max performance tires (have seperate winters), but really want some more aggressive summer tires, and I will get some when these are done.

 

I don't want the brakes any more sensitive. In fact with a 38 mm piston & a 41 (or maybe 42)mm piston it will change bias to the rear a bit and actually increase slightly the amount of travel the pedal must make, actually decreasing sensitivity. More rear bias will also help a lot as right now with my ABS defeat switch the fronts lock a good deal sooner then the rears. I will have to re-evaluate once I get different tires.

 

I think what you are looking for in the brake set up is too broad of a range, especially pouncing on a set of street pads (as I stated before about increasing the heat capacity wont help with a limited temperature range of the pads). Besides, as you look further and further up the brake pad temperature range, you will see that there's quite a few pads that can retain the higher end of coeff. of friction.. you will eventually have to trade off on that already.

 

I dont recall the ION kits losing 14 lbs in each front corner and 17 lbs in each rear corner.. that's really hard to swallow as the calipers and rotors in stock form are around 15 lbs and 25 lbs for the front.. that's shaving off about 50% of weight.. I can give the benefit of the caliper made as aluminum, but it's hard to swallow the notion of shaving that much off from the rotor.. Racing Brake Rotors are already 5 lbs lighter than the stock rotors, and that's already barely track-usable for a session or two.

 

For the LGT the BBK is 26 lbs lighter 13.5 lbs per corner at the front. The fronts are similiar in construction to the RB units (although track tested over and over) except they are 2 piece units. The rears are 3 piece units with a liner in the E-brake drum. Look at this thread:

 

http://www.legacygt.com/forums/showthread.php?t=40956&page=2&highlight=ion+rotors

 

BTW the suby that is getting the above brakes is not a LGT, and he is getting a kit that uses slightly smaller rotors.

 

 

That's a lot of wishful thinking that's very border line to fictional to get what you want out of your brakes for the use that you are looking at. I dont think you will actually get to the 70% of your target because there's just too many trade-offs, and living in Canada is a big factor in your case.

 

Living in Canada is a bit of a factor, but all I need is the proper tires and pads that I can run with on the street. I don't know if I wil get 70% of the way there or not, but I know the kit I want to get will get me a lot closer then I am right now.

 

Porsche, Ferrari, and other manufacturers seem to be able to achieve what I want, why can't I do it on my LGT?

[Xenonk]

^ different suspension design will be your next factor.. if you increase the spring rates in the front to prevent less weight transfer, that would solve 50% of your problems right there (that's what I did). It doesnt matter how much rear bias you can transfer if the rear end keeps lifting off the ground under braking, you are simply not getting any good grip from the rear to help you slow down and overloading your front tires (hence you have plenty of lock-up, but you are still carrying a lot of speed), hope that makes sense. With a 60/40 front/rear weight distribution, it's obvious that the front has a lot more mass to deal with.

 

As for all the higher end cars, they sure run A LOT wider tire and a lot better suspension set up to use those brakes effectively.

 

Dont always look at brakes as an individual unit, tires are part of the suspension, so you will have to nip this one in the bud and get your suspension setup to be better to be able to keep all 4 tires on the ground.. remember, braking is nothing more than a g-force that is applied to the car, you can also slow the car down using lateral g-forces as well. It's all about understanding the traction circle and knowing how to use all 4 tires to stop rather than depending on them as pairs (2 front or 2 rear).

[LittleBlueGT]

^ different suspension design will be your next factor.. if you increase the spring rates in the front to prevent less weight transfer, that would solve 50% of your problems right there (that's what I did). It doesnt matter how much rear bias you can transfer if the rear end keeps lifting off the ground under braking, you are simply not getting any good grip from the rear to help you slow down and overloading your front tires (hence you have plenty of lock-up, but you are still carrying a lot of speed), hope that makes sense. With a 60/40 front/rear weight distribution, it's obvious that the front has a lot more mass to deal with.

 

As for all the higher end cars, they sure run A LOT wider tire and a lot better suspension set up to use those brakes effectively.

 

Dont always look at brakes as an individual unit, tires are part of the suspension, so you will have to nip this one in the bud and get your suspension setup to be better to be able to keep all 4 tires on the ground.. remember, braking is nothing more than a g-force that is applied to the car, you can also slow the car down using lateral g-forces as well. It's all about understanding the traction circle and knowing how to use all 4 tires to stop rather than depending on them as pairs (2 front or 2 rear).

 

 

Of course what you are saying is true, but not what I want for my daily driver. Any more front stiffness will hurt my cars ability to rotate, and make the ride rougher. I already have variable rate front springs (iONs Bilstein specific ones that are atiffer then iONs normal front springs). I can compensate by changing my alingment a bit, but that hurts tire wear.

 

I DO NOT AT ALL think of just brakes as an individual unit.

 

What I am saying is that a BBK can help me acheive my goal of better braking while still using street/autoX pads. They will be able to withstand more abuse then stock brakes on similiar pads. As a side benefit they will weigh significantly less, and give better bias.

 

Do you need a BBK to track your car? NO! If you have 350+ whp and really good track tires then maybe, depends on a lot of things.

 

Can a BBK help even a street car? It can, I know it can. It depend on what your goals are.

 

I am just highlighting my thinking process in my decision to get a BBK. I have researched this for well over 2 years for my LGT. And I am almost ready to buy (should have been saving for two years).

[Fabius]

so who can help me out by buying brand new calipers, brakets, and whatever else i need?

[LittleBlueGT]

so who can help me out by buying brand new calipers, brakets, and whatever else i need?

 

Do you have a thread in the WTB forum?

[magnetic1]

 

Can a BBK help even a street car? It can, I know it can. It depend on what your goals are.

 

I am just highlighting my thinking process in my decision to get a BBK. I have researched this for well over 2 years for my LGT. And I am almost ready to buy (should have been saving for two years).

 

hrm... how did I miss a HUGE brake thread

 

Im inclined to think something is not right if youre fading on the street, especially with Bobcats. Check to make sure the pad surface is not glazed.

 

BBKs in theory should not help on the street. The LGT rotors are plenty big enough to absorb heat and dissipate that heat.

 

What you can do is, buy some brake temperature paint. Slab some on your rotors and see if it gets above the set temperature. Then you will know for sure.

 

As far as BBK goes... we are currently developing a kit for the LGT that will be priced VERY well using super high quality parts. Large 4 piston calipers from a well known builder, high quality rotors that wont crack in one track session and your choice of pads (Hawk, Carbotech). Look for an announcement soon!

[LittleBlueGT]

hrm... how did I miss a HUGE brake thread

 

Im inclined to think something is not right if youre fading on the street, especially with Bobcats. Check to make sure the pad surface is not glazed.

 

BBKs in theory should not help on the street. The LGT rotors are plenty big enough to absorb heat and dissipate that heat.

 

What you can do is, buy some brake temperature paint. Slab some on your rotors and see if it gets above the set temperature. Then you will know for sure.

 

As far as BBK goes... we are currently developing a kit for the LGT that will be priced VERY well using super high quality parts. Large 4 piston calipers from a well known builder, high quality rotors that wont crack in one track session and your choice of pads (Hawk, Carbotech). Look for an announcement soon!

 

Nice to hear from you.

 

Yes I have glazed my Bobcats, but I resurfaced the pads and all is well. I do not normally fade them on the street, but I can! There is noting wrong with them, they do what they are suppose to do, 3 times better then OEM pads (which I pretty much destroyed in 1 week).

 

I want a BBK that has better feel, but I want to be able to push the braking limits much more while keeping in the street pads. A BBK (not all of them, but some) should help me do that.

 

Looking forward to your next kit!

[PhilT]

Hi Eric,

 

I went to the track today and was hugely impressed by the XP110 / XP8 set up that I bought from you. With SS lines and the GS610 fluid, pedal feel is very good, and it was easy to activate the ABS when I wanted to, previously, no matter how hard I pushed it would never kick in.

 

I measured temps around 850F on the front discs immediately after coming into the pits, so possibly 950 to 1,000F while in operation ?

[Th3Franz]

Hi Eric,

 

I went to the track today and was hugely impressed by the XP110 / XP8 set up that I bought from you. With SS lines and the GS610 fluid, pedal feel is very good, and it was easy to activate the ABS when I wanted to, previously, no matter how hard I pushed it would never kick in.

 

I measured temps around 850F on the front discs immediately after coming into the pits, so possibly 950 to 1,000F while in operation ?

 

What speeds were you seeing? I'll be running my Endless SS-S at Gingerman and on the front straight I might be able to do 100+. I don't have time to bed the XP8's I just got.

[PhilT]

What speeds were you seeing? I'll be running my Endless SS-S at Gingerman and on the front straight I might be able to do 100+. I don't have time to bed the XP8's I just got.

 

About the same, 100 mph on the straight, braking down to 30 for turn 1.

 

http://legacygt.com/forums/showthread.php?t=36858

 

When are you going to Gingerman ?, a few of the STi guys from Windsor, On. frequent that track.

[magnetic1]

What speeds were you seeing? I'll be running my Endless SS-S at Gingerman and on the front straight I might be able to do 100+. I don't have time to bed the XP8's I just got.

 

When are you going? Temperatures may have cooled off a bit now and you could be ok w/ the SSS....

 

Id see if you could still bed in the XP8s at the track... maybe ask if your instructor can take your car out in another session just to maybe show you around the track at 5/10ths and to bed in the pads at the same time

 

PhilT: Glad you liked them. It's really an amazing feeling going from "street" pads to track pads. Now we just get some more track time under your belt, throw on some RA1s and you'll REALLY be movin!