ilv1004s

iTrader: (8)

do you guys think it's worth uprading the rear brakes to
Brembo GT kit or even F sport kit?
would the upgraded kit provide more stabel rear end stopping power?
i find it on hard braking my rear tends to move around alot

ISF4life

iTrader: (30)

Up grade to better tires to braking power. Our Brembo monoblock 6 pistons are good enouh Fsport is made by stoptech.
http://www.lexus.com/models/ISF/feat...rake_Story.pdf

Pqbrown

iTrader: (9)

Rears are 2 piston.

Murph145

Rear is a waste only about 10% of your stopping power comes from the rear

flowrider

iTrader: (9)

IMO, the stock Brembo system is a wonderfully balanced system for the F. Again, IMO, no caliper change is needed. The 6 opposed piston front caliper and the rear 2 opposed piston caliper is a great combination and well matched to our cars. As has been said above, the majority of the braking chore is handled by the front brakes. I have upgraded my front pads with Ferodo street/racing pads, and I am very extremely pleased with them:

https://www.clublexus.com/forums/is-...rake-pads.html

I believe the problem you are experiencing is when you brake hard, the weight bias shifts to the front and the rear brakes lock up causing what you describe as your rear moving around a lot. Try modulating (pumping your brakes a bit) on quick stops, that should eliminate your problem.

Lou

ISFPOWER

iTrader: (20)

+1 to what Blitz said.

lobuxracer

iTrader: (2)

Changing the rotors and calipers will make zero difference. There's too much rear brake under heavy braking, especially uphill. The only fix would be to change the brake bias, but we can't because it's electronically controlled.

avgj0F

iTrader: (2)

Upgrade to Michelin PSS tires if your existing are not.

ilv1004s

iTrader: (8)

car will be driven on slicks as its a race car
is there anyway to change the bias?

Just F Me

If you read....you'll find a great deal of info.

With that said...since you got the IS F as a race car, upgrade the brakes. Obviously have enough money to have the IS F as a toy. Who cares if it's not any better...it's cool. And with 2 piece rotors you should experience less brake fade. Maybe you can go carbon ceramic if someone makes a set.

ilv1004s

iTrader: (8)

its not for the cool factor, i asked this question due the the rear brakes being very small compared the front
will it actually help if it was bigger in the back
the question is simple
can brake bias be changed (yes i understand it is electrical but is there a switch program wat ever that can be used)

ISFpat

iTrader: (10)

On other cars that have electronically controlled brake bias, you can change the pad aggressiveness and itll alter the bias. Yes the electronics will adjust the bias back to stock as much as it can but only to a certain percentage.

ilv1004s

iTrader: (8)

thanks for that reply dude

lobuxracer

iTrader: (2)

If it's truly a racecar, ditch the whole OEM system and replace it with two master cylinders and a balance bar so you can fix the bias problem.

Larger rear brakes would only make the problem worse. You need LESS rear brake, not more.

SpeedFreaksUSA

iTrader: (1)

You can also change the brake bias by staggering your brake pads. Since you claim your rear feels unstable you could try running a more aggressive compound in the front to shift brake bias forward. Something like a Carbotech XP12 front and XP10 or XP8 rear.

-Matt