[glenB]

Originally Posted by PolynesianPowerhouse

The rotor size is also smaller. 13.6.

The 5th gen rotor is a 14 in front and 14.4 in the rear.

The pistons are prob smaller, to go along with the rotors and also the lighter weight of the car.

Well, rotor diameter is all about leverage. So in the case of the SS, you have smaller rotors and pistons so therefore, you have less leverage and less pressure.

Curb weight on a '15 is 3908. The '16 is 3746 w/auto. So even at 200 lbs. all that means is 1 slightly large adult. Do you notice much difference in the braking when you have a passenger?

Yeah, me neither. Even at 200 lbs. lighter we're still under braked at the track.

[PolynesianPowerhouse]

Originally Posted by glenB

Well, rotor diameter is all about leverage. So in the case of the SS, you have smaller rotors and pistons so therefore, you have less leverage and less pressure.

Curb weight on a '15 is 3908. The '16 is 3746 w/auto. So even at 200 lbs. all that means is 1 slightly large adult. Do you notice much difference in the braking when you have a passenger?

Yeah, me neither. Even at 200 lbs. lighter we're still under braked at the track.

I TOTALLY agree with rotor diameter being about leverage , but we are ONLY talking about 5.08mm, which I don't think would affect it much, but maybe a small difference.

Old 5th gen = 14.0 inch

Current 6th gen = 13.6

.4 inch difference on the overall diameter, .2 on the radius... we'd be looking at the radius since the pad only touches one side at a time.


In terms of caliper piston size, its one of the two things that generate clamping force.

2) Clamping force can only be increased either by increasing the line pressure or by increasing the diameter of the caliper piston(s). Increasing the size of the pads will not increase clamping force. Any increase in caliper piston area alone will be accompanied by an increase in pedal travel. The effectiveness of a caliper is also affected by the stiffness of the caliper body and its mountings. It is therefore possible to reduce piston size while increasing caliper stiffness and realize a net increase in clamping force applied. This would typically improve pedal feel.

3) Only increasing the effective radius of the disc, the caliper piston area, the line pressure, or the coefficient of friction can increase brake torque. Increasing the pad area will decrease pad wear and improve the fade characteristics of the pads but it will not increase the brake torque.

http://stoptech.com/technical-suppor...rade-selection

Pressure in intial use, is generated by the master cylinder piston. but to increase that, you would also prob have to increase pedal travel. I think GM did a better job this time around especially on all models since I don't have to do a MC upgrade on the V6 to run a larger brake caliper setup, efficiently. remember the 5th gen, the SS brakes and ZL1 setups were sold with a Master cylinder upgrade. for those that had the SS you were good. but with the current master cylinder we got guys running everything from single piston to 8 piston calipers on this platform. no issues there

Some things to look at is a stiffer caliper can use smaller pistons and create an over greater clamping force. Which is prob the case here (remember, GM and most on the forum have touted, everything is "lighter and stiffer" on the 6th gen).

See the triangulated Ribs of the current caliper near the top vs a 5th gen caliper with nothing at the top...

6th Gen


5h Gen




To further the clamping force issue, the pads which are responsible are the coefficient of friction. and for many, I think that's the issue, or not really an issue, but the focus/complaint.

if you look at the track guys in this post along, many state the brakes are good. they are consistent, and there. might not have the initial bite that some are used to on other cars, but they come on and modulate pretty well for a solid braking experience, when pushed.

the lack of initial bite...that would be an issue of the pad composition. and with the amount of "i hate brake dust, lemme switch to a lower dust pad"...for some it will exacerbate the issue.

a decent vid on that to explain what people are getting/feeling or not feeling (START AT 2:35) :




As far as noticing a difference. Im gonna err on the side of, it depends on who you ask. I mean as this post goes alone, some people have said, the brakes are phenomenal. some have said they are weak. same calipers, rotors and pads lines when stock.

but as for myself noticing a difference. i'm willing to bet I prob could, or the time slips would..

when I first took the car to a track last year, I ran 14.1-14.3 in the 1/4 mile. the next time out, I removed 2-300lbs of weight from the car (its in the 1/4 mile forum), along with the exhaust upgrade....ran 13.5's all day long.

each 100lbs is good for a 1/10th on 1/4 mile times, the temps were almost exact as well as the DA. and the exhaust was the only performance upgrade. given the weight removal and the rule of thumb about that, I should have been at 13.9-14.0

but either way, I def noticed not having the extra 200 or 300lbs of weight in the car.




underbraked at the track....maybe in stock form, but there are many guys in the road and track forum, that are having GREAT success against other cars in similar platform levels (mustang, challenger, BMW) with simple small pad and fluid upgrades. that we cant overlook. and many are running the 4 piston brembos. just make sure you make good use of the brake duct deflectors and such.

[Sub]

Wow, Thanks for the info! As I read more, Im guessing I might just need to get some air out.

[ny tdi]

My experience is that there's very little "initial bite" when driving around town. I almost always feel like im going to rear-end other cars at stop lights.

HOWEVER, the brakes feel very well calibrated at the track and on mountain roads. The long pedal travel really allows you to dial in just the right amount of braking power at high speeds. It seems that chevy engineers felt that they could only do 2 out of three: yes on the great track feel and flexibility of brake upgrades, but a big fat no on initial bite when driving around town.

Bummer, but I get why they did it.

[Norm Peterson]

Originally Posted by Sub

Has anyone else been a little surprised by the braking capability of this car? The brakes on my c7 are fantastic, so I guess thats what I'm comparing them to. I havent tried a bleed yet, but just curious if others think they are a bit weak too.

Comparing against a C7 is going to put most other OE cars at a disadvantage at least with respect to initial bite. Especially if you have some experience with the C7 on the track, probably more so if it's a Z51.

I drove a Z51 for one lap and was just utterly amazed at the brakes from the first braking zone. To go the other way (from lots of C7 driving) would have been a disappointment.


Norm

[Norm Peterson]

Originally Posted by Sub

Anyone happy with the carbotech street pad for bite?

I have these pads on the Maxima in my sig . . . and the jury is still out, though I don't think it's a pad issue.

I'm looking at AX6 in CT or R6 in G-loc for the Subaru some time this summer and expect better things.

For the avatar car, any of the lower three XP pad numbers are the street pads .


Norm

[Norm Peterson]

All you have to do is get pads that have a more 'aggressive' initial bite and at least bleed all four calipers. You may have to live with a bit more dust and occasional noise.

Pads and fluid is all I've done so far with the brakes on the car in my sig, and even with front rotors that have to be smaller than yours (mine are only 12.4"), that's been enough for over 20 minutes of track driving at a time without taking any 'easy' laps to cool brakes and tires down.


Norm

[YaBoyJordy]

I've heard good things about the new hawk hps 5.0 brake pads. I'm planning on changing out the pads soon and will probably install news rotors and fluid as well. Hopefully that helps with the initial bite the car seems to be lacking.

[PolynesianPowerhouse]

Originally Posted by Paulbates455

The brakes on this car are horrible. To the point it make me nervous sometimes. And $2250 to $3000 for the cheapest big brake upgrade? C'mon man. There is no initial bite and the pedal is very squishy. And it gets worse with hard use on a hot day. Much worse. I've seen and read reviews on these cars where they said they were disappointed with the brakes. And the front rotors look like they came off of an old Honda Civic. Don't understand why you increase the hp and torque, but decrease the brake rotor size. How is that a good idea?

Upgrade to dot 4 fluid, and go to a brake pad with more initial bite. Bigger brakes gove you better heat dissipation. But pad bite and brake feel is mostly fluid and pads. And no whwre near 2000-3000$
The video i posted above touches on that a good amount. I can post one for ya that goves a better explanation on pad choice if itll help. Just lemme know.