stoptech for the is350 is now available!
#31
Lexus Champion
Originally Posted by lobuxracer
Last but not least, the OEM ADVICS calipers are some of the very best made. They're a monoblock design with all four cylinders bored from the back, and plugs installed to complete the cylinders on the rear of the caliper. There is no separate mount for it, attachment is directly to the suspension upright with threads in the caliper and holes in the uprights. You will be VERY hard pressed to improve on this caliper from a pure performance perspective. Sure you can bling it up all you want, but this is one stout design with relatively light weight. I will not be investigating any BBK. I seriously doubt it will provide any improvement over stock, even on a track day if the right pads are in them, and especially if the necessary ducts are in place as well.
If someone offered a two piece rotor in the same diameter but had better venting and more mass/heat capacity, I would definitely go that route as it would be much cheaper, and the rotors themselves would be lighter (the aluminum hats reduce a lot of unsprung rotational weight).
Stoptech doesn't plan on offering their aerorotors for the IS. Project mu might but I'm not willing to wait for something that I don't know will happen or not.
#32
Lexus Champion
iTrader: (1)
Originally Posted by rys
Maybe our terminology is different, but when I think knuckle I think steering knuckle? Hub is the piece where the studs go through? I thought I gave a pretty accurate description of removal, no "knuckle" needs to come off.
In any case, you seem to know what you are doing without needing the instructions so why ask? Basically, start taking pieces off until the piece with the studs comes off, replace studs, then put it back on the vehicle.
I did this to my last vehicle using a mallet and a vise.
-Brian
In any case, you seem to know what you are doing without needing the instructions so why ask? Basically, start taking pieces off until the piece with the studs comes off, replace studs, then put it back on the vehicle.
I did this to my last vehicle using a mallet and a vise.
-Brian
#33
Tech Info Resource
iTrader: (2)
Originally Posted by al503
Your points are well-taken, bux. However, your focus is on the wrong component, at least IMO. The main concern in brake fade is not the caliper design (as long as it's relatively well designed). It's the heat capacity of the rotors. The aftermarket BBK's have larger diameter rotors, they have better venting vanes, and there is more rotor mass, which will simply absorb more heat. The M5 and M6 have single piston calipers but large rotors.
If someone offered a two piece rotor in the same diameter but had better venting and more mass/heat capacity, I would definitely go that route as it would be much cheaper, and the rotors themselves would be lighter (the aluminum hats reduce a lot of unsprung rotational weight).
Stoptech doesn't plan on offering their aerorotors for the IS. Project mu might but I'm not willing to wait for something that I don't know will happen or not.
If someone offered a two piece rotor in the same diameter but had better venting and more mass/heat capacity, I would definitely go that route as it would be much cheaper, and the rotors themselves would be lighter (the aluminum hats reduce a lot of unsprung rotational weight).
Stoptech doesn't plan on offering their aerorotors for the IS. Project mu might but I'm not willing to wait for something that I don't know will happen or not.
The rotor has one job - convert kinetic energy to heat. If I am not applying more heat than the rotor can dissipate to maintain the preferred pad temperature range, then all is good. More mass != better in all cases.
I completely concur with lower unsprung weight, but again, a heavier disc is not only unsprung weight, but possesses greater rotational inertia in the worst place - far from the center of rotation. It's all about balance. Having worked with both asphalt and dirt racing, I can tell you there are times when you'll want the tiniest rotor you can get, and other times you'll need so much mass and airflow that you'll be putting a pump and heat exchanger on the brake fluid to keep it from boiling in the calipers (a la NASCAR short track).
#34
Lexus Champion
Originally Posted by lobuxracer
I disagree about the heat capacity. I'm not going to run a disc any heavier than I need with the cooling methodology I have in place. All I care about is the disc not fragging and the brakes not fading. If I can blow air through them, the fin design will be inconsequential. I've been through the calculations with curved vane and straight vane discs and the difference is pretty much academic if you just ensure good airflow through the vanes.
The rotor has one job - convert kinetic energy to heat. If I am not applying more heat than the rotor can dissipate to maintain the preferred pad temperature range, then all is good. More mass != better in all cases.
I completely concur with lower unsprung weight, but again, a heavier disc is not only unsprung weight, but possesses greater rotational inertia in the worst place - far from the center of rotation. It's all about balance. Having worked with both asphalt and dirt racing, I can tell you there are times when you'll want the tiniest rotor you can get, and other times you'll need so much mass and airflow that you'll be putting a pump and heat exchanger on the brake fluid to keep it from boiling in the calipers (a la NASCAR short track).
The rotor has one job - convert kinetic energy to heat. If I am not applying more heat than the rotor can dissipate to maintain the preferred pad temperature range, then all is good. More mass != better in all cases.
I completely concur with lower unsprung weight, but again, a heavier disc is not only unsprung weight, but possesses greater rotational inertia in the worst place - far from the center of rotation. It's all about balance. Having worked with both asphalt and dirt racing, I can tell you there are times when you'll want the tiniest rotor you can get, and other times you'll need so much mass and airflow that you'll be putting a pump and heat exchanger on the brake fluid to keep it from boiling in the calipers (a la NASCAR short track).
As to your other points, can't disagree with them. I don't plan on ducts unless someone comes out with a bulletproof, solid kit. You don't want that thing coming loose at speed and I've seen 'homemade' ducts get scraped off at places where the suspension is fully compressed. I also don't know how feasible this will be for the IS in that will be as there is really no room (unless you're going in a straight line) to work with between the tire and fender liner. You would have to have the tubing go underneath the body of the car where you only have about 5-6" at most between the car and the ground at rest. I plan on lowering the car at least an inch (2" if I get coilovers and I'm at the track) and when you add that to the compression from the turns, you have maybe an inch or two to work with.
#35
Tech Info Resource
iTrader: (2)
I wonder how many people would be seriously interested in a ducting kit. I'd want to do a CF backing plate with a solid connection for the tube, then I'd need to figure out how to route the tube. Yes, clearance and damage to the ducting are always big problems. Even worse is the guy who wants to run these on the street because it's a racecar part.
I'll have to think about this for a minute.
I'll have to think about this for a minute.
#36
I guess any type of brake upgrade is a good thing, safety factor and all, but spending 6k on brakes for a lexus, you must be a.) racing the living ****e out of the car or b.) wanting to bling bling around the city with your dubs. There is absolutely no point in gettin a such a brake system, I would think powerslot rotors and hawk pads would work great as an upgrade. But to each his own.
#37
Tech Info Resource
iTrader: (2)
I just noticed in the New Car Features that our OEM front rotors (on the 350) have curved vanes for improved airflow. So they did go the extra mile to add the last percent and a half or so. I wonder if they're as cheap as Supra discs (~$70).
#38
How do this StopTech's compare vis-a-vis the Endless systems that were posted on this board a while back?
I notice this thread is staying on topic a lot better than the bash-A-thon the Endless thread turned into.
I notice this thread is staying on topic a lot better than the bash-A-thon the Endless thread turned into.
#39
Lexus Champion
The biggest difference is Stoptech takes brake bias (front to rear) into consideration and their front kit can be used with the stock rear brakes. Endless recommends using both their front and rear kits for best results. You can get just the fronts in the Endless as cars with EBFD do apportion bias front to rear depending on grip.
#40
Lexus Champion
iTrader: (1)
Endless is considered to be Japans best and people compare them to brembo and alcons (with alcon arguably considered the best anywhere.) Stoptech is still probably considered 2nd tier compared to the above, but they have a very good presence in the motorsports and they're popularity is catching on.
The biggest difference is Stoptech takes brake bias (front to rear) into consideration and their front kit can be used with the stock rear brakes. Endless recommends using both their front and rear kits for best results. You can get just the fronts in the Endless as cars with EBFD do apportion bias front to rear depending on grip.
The biggest difference is Stoptech takes brake bias (front to rear) into consideration and their front kit can be used with the stock rear brakes. Endless recommends using both their front and rear kits for best results. You can get just the fronts in the Endless as cars with EBFD do apportion bias front to rear depending on grip.
#41
Tech Info Resource
iTrader: (2)
The bias is controlled by a computer, not the typical proportioning valve. The computer balances the brakes on every stop, so they don't feel consistent. I've experienced the same thing with my Scion, and I can't say I like it after having mechanically proportioned brakes for 25 years or so. I'm not convinced EBFD is a mature technology at all.
#42
DANG! $6K. They'll look awesome!!!! but the stock brakes work GREAT for me on the road... stops just as fast as a BMW. hahahaha so i'm good. I already out brake like 99% of the cars on the road I dont need better brakes so they can ram my rear.
#43
Lexus Champion
They can get the bias by varying the pad shape, piston size, etc. Stoptech just could have offered both their st-40 (smaller pad, 4 piston caliper with less piston area) along with the st-60 that they are offering but they won't because the st-60 has similar braking ability/bias as the stockers.
#44
Lexus Champion
The bias is controlled by a computer, not the typical proportioning valve. The computer balances the brakes on every stop, so they don't feel consistent. I've experienced the same thing with my Scion, and I can't say I like it after having mechanically proportioned brakes for 25 years or so. I'm not convinced EBFD is a mature technology at all.
A g35 coupe with EBFD did the same in 112 and 199 ft, which is about what the 911 Turbo can do. Both of the other cars have much better front/rear weight bias, lower center of gravity, etc. EBFD (at least Nissan/Infiniti's) can work wonders.
I haven't slammed on the brakes in my IS yet but I'm hoping to get the same kind of performance.