brauer

Tried asking this in the general forum and didn't get much response. Thought I'd try here, too.

Looking to get some big brakes to fill out some 20" wheels, and increase braking ability (hope to do some track days soon).

Which combo would you prefer, and any other comments about any of them? (It'd be ~ $2500 either way)

(Personally, I like the big SSBC calipers front and the Baer 14" 2-piece rotors rear. But do you think it'd look weird for slotted-only fronts and cross-drilled rears? )

SSBC Force 10 V8 front, w/ Steeda 13" slotted rotors rear




OR



Wilwood 6 piston drilled front, w/ Baer 14" 2-piece drilled rotors rear

brauer

Test picture

SoundGuyDave

If you're serious about tracking the car on an HPDE day, then avoid the 20" wheels like the plague. The increased unsprung weight and rotating mass will kill you on accel and decel, and the rubber-band wound around the rims won't have enough sidewall compliance to let the tire really grip the pavement. In other words, you'll be braking early, be too slow through the corner, and slow tracking-out. Your car will most likely exhibit a tight-in, loose-out behaviour, and your cornering will be so slow, that you'll be getting eaten alive by 350Zs, Civics, and Miatas in the corners. You'll still be able to leg away from them on the straights (sheer power), but even there you'll be losing "grunt" due to the wheel/tire weight.

If you're going for looks, on the other hand, and just want to try tracking your car, hold off on the brakes until you do a day or two (DO replace the pads with something "race" oriented, flush the fluid and use fresh STOCK rotors). If you wind up loving it as much as I do, you'll never think about 20's again. If, however, after your first few sessions, you think "ehh, whatever," then by all means go big, with whatever looks good to you.

brauer

Thanks Dave for the info.

Wow, 20s are that bad??

The ones I've got coming are the same weight as stock, though I know the MOI is increased just from the diameter increase, although the tires are actually a bit lighter than the equal width 18s (at least per Tire Rack's tables).

So what you're saying is if I'm gonna go ahead and get the bigger brakes (which I probably will, though maybe the smaller Baer 6P just introduced last month), I should actually get some light weight (how light?) 18" wheels that'll fit them as well, and then track the car with those alone. 20s for show, 18s for go, eh?

Out of curiosity, what are the more serious track boys doing for brake upgrades on the S197s? I know they've been a weak link from the start.

Thanks again, Dave.

--Josh

SoundGuyDave

Yeah, 20's are just about that bad... You won't see a single serious contender running 20's, and most of the S197s that I've seen on-track (competition cars) are running 17 or 18" wheels. Another factor is tire choice. Toyo R888 are not available in 20" sizes, nor are Hoosier DOT radials, Nitto NT-01, Goodrich G-Force R1, or any of the Goodyear Eagle variants that I could find. Street tires, at least the "ultra-high-performance" models, are OK to marginal under track conditions, but to REALLY carve through the corners, race rubber (DOT Radials or slicks) is critical. The fast-lapping time trialers and the competition cars are all running race rubber, and it's not hard to see why.

At Road America, which has three REALLY long straights (135+MPH in my Mustang) is a perfect example. I started one session right ahead of another S197, which was very similar to mine in terms of general setup. We had chatted in the pits and compared cars, and the differentials made this an interesting matchup. We had similar amounts of track time, I had taller gears and more power, he had bigger brakes and race rubber. On the track for the first lap and a half (4-mile, 14 turn track) I could pull slightly on him on the straights, and then he clawed back up to me in the corners. After he passed me, I tried to stick to him, but every corner left him pulling a little bit further away. Yes, I made up some space in the straights, we were about even in the braking zones, but he could pull on me every single corner. I tried to stick with him, but couldn't match his speeds at turn-in, and he was able to go flat to the floor through the apex of most corners, where I would have to roll in. That's how critical tires are, and you won't find any "real" rubber in the 20" format.

As far as brakes go, I kind of disagree that the brakes are the weak point on our cars. Mine weights 3719 with a full load of fuel and driver, and I have no problem with brakes, based on the stock setup. I'm running factory calipers and rotors front and rear, but I did upgrade the pads (Carbotech XP12/XP10 or XP10/XP8, track dependant), pull the dust shields, add ducts up front (Quantum Motorsports with Steeda inlets), and go to braided lines (Steeda) and DOT4 race fluid (Motul RBF600). The most common brake upgrade package that I see on the S197 is the GT500 front kit, with stock rears. That will force you to go to an 18" wheel, and I personally want to run 17" for the weight and cost savings. Given that thus far I'm not burning up the brakes any faster than my fellow drivers, I'm pretty satisfied with what I've got.

I will just reiterate: Sign up for a lapping day or two (Nasaproracing.com), and THEN evaluate what you have issues with, and work from there. Brakes are the first thing to change, but just do fluids and pads to start off with. Then you can make decisions on a rational basis, and avoid spending lots of money needlessly.

Glenn

is there an advantage to two piece rotors or is that the only way to make them that big?

SoundGuyDave

First, and the biggest by far, is the lower unsprung weight and reduced rotating mass that comes from having an aluminum hat, or center section. The second is that if the diameter of the brake package is increased, the weight saving is amplified. I can't say this for sure, but it wouldn't surprise me to find that a two-piece for the GT500 weighs less than a stock GT or V6 rotor, despite being an extra inch in diameter. Initial acquisition cost is, of course, huge. Last time I looked, two-piece rotors for the S197 run between $500-900 each...

StillenMustang07

2 Piece Rotors - Front - Mustang GT - Slotted - $940.87/pair. Cross-Drilled/Slotted - $980.18/pair

Hope this helps some

Page

MontrealStang

We are on the same wave length ! Stock rotors ($40 for take-offs !), RBF600, stainless steel braided lines (EARL's), 17" mags and race pads ...

Still looking for the right front pads ... see my post: http://forums.bradbarnett.net/showthread.php?t=471509

Are the Carbotech corrosive for the wheel ? Meaning that if you put water in the mix, do they detroy the mags ?

I had bad experience with Gransport GS3 & Cobalt Friction XR2; I used oven cleaner & even sand paper to remove the deposit

SoundGuyDave

The Carbotech pads are not corrosive at all, from my experience. I got caught in the rain twice with them, and wound up having to wait over a week to wash the car both times, and the dust came right off.

PayDay99

I'm running almost the exact same setup (AP5.1 for the Motul).

Also, RE 20s, there were two GTRs at the track last weekend running the crap out of their 20s.

tkogt

Stock set up here,with backing plate removes and hawk hps pads, and works good, not great. A little common sence goes a long way tword keeping the stock brakes alive.

If I push really hard I can overheat the brakes in about 3 laps the fluid boils and things turn to mush. If I lift 100 feet sooner the brakes will go 10 laps before they poop out. If I lift another 50 feet sooner they will go all day. The difference in lap times is about 10 seconds between full out and all day. That on a 1:50 or so lap. If you feel compelled to do a brake kit the wilwood 6 piston kit can be ordered with a 13 inch rotor and will fit under MOST 18 wheels. I think thats the way I'm going to go if and when I upgrade my Stang.

As far as the tires go I run Toyo 888's in a 275/40/18 all the way around and they rock and roll. I like them so much that I run them as my daily tires!!!

Import-Slaya

Tko, what brake fluid are you using? I used Valvoline in the past until I boiled it during an event and have been on Motul 600 (~590 deg F dry b.p.) ever since with great success. The only negative is that it is $20 per 500 ml bottle locally. I'm toying with a switch to ATE gold (~535 deg F dry b.p.), since it is $10 per 1000 ml container locally.

tkogt

I use the Valvoline Synpower. I called Ford motorsports and asked about the Motul/ Wilwood/ ect hi temp fluid and was told that it would eat the seals in the abs unit. Because of this I havent tried it. Was I misinformed buy the tech at Ford racing??

SoundGuyDave

Granted, it's not that long for a categorical statement, but I've had RBF600 in my system for almost a year now, and the ABS is working just fine...

Import-Slaya

I've at the 600 in my system for a little over a year and now problems, either. I know a few others running it for longer. The only brake fluid that will eat seals is a silicon based fluid, which the DOT5.1's are not. Maybe the tech at FRPP was confusing it with a DOT5 fluid?

By the way, the new Valvoline has an even lower dry BP than the previous formulation (the gold plastic bottle with a black label). It used to be ~500 deg. F (which I boiled), but it is now 480 deg F (white bottle with blue label).