How do you like your aftermarket brakes?

Better brakes = safer car! I'm currently saving pennies for a brake upgrade. While my brakes are good, they are not great. I've updated quite a bit on my GT4, brakes are next.

JIM

 

Jim, this brake system will go nicely with your GT4.
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It is a tricky upgrade. I track my car a great deal and have had the Brembos on for 5 years. It is difficult to balance with the rear. I haven't played with a bias valve but I can tell you that if you put Carbotecs on the front and Porterfields on the rear, your gonna be locking the front up more than you want. More on the street in a panic stop when they are colder. Ask me how I know.

Mike C has a pretty good set up paired together but I forget the details.

 

The stock brakes are plenty for normal street/sport use. If the pedal feels a little soft to you then you can switch out the rubber brake lines for ss covered teflon lines - that'll firm up the pedal a bit. From a pure performance standpoint the brembo type big brake upgrades are really only necessary where you're going beyond nomal sporting street use - track days are an example. The thermal capacity of the stock brakes is insufficient for a track day if you're really getting your foot into it. You'll start to have some brake fade and a soft pedal (that's your fluid boiling) after 5-10 hard laps.

The big brake kits are great for increasing the thermal capacity of the system and also increasing the swept area. The increased thermal capacity will lessen any brake fade, and the increased swept area makes the pedal easier to modulate more precisely (so you can stop quicker). Definitely worth the money for any kind of serious performance driving.

ps. I'd highly recommend adding a bias control when installing a big brake kit (either a balance bar on a dual master, or an adjustable bias valve) as you'll likely find that one end is locking up a little prematurely.

 

can you point me in the direction to a suitable adjustable bias valve

 

The stock proportioning/bias valve is not adjustable, so yes, putting one in is the only way to adjust the bias other than working the pad combination. I came up with my pad combination with the help of the folks at Girodisc. I use Porterfield R4S pads up front on the Brembos, and EBC Greenstuff pads in the stock rear calipers. It keeps the aproximately 60-40 stock bias.

The Brembo set out of the box shifts the static brake balance to the front by 9%, (69.7%f, 30.3%r) over the stock balance split. This is not ideal, but it is not dangerous in most circumstances. If you put in a very high performance rear pad, (ferodo ds2500 or 3000, Pagid 4-2-1, SBS Pro Track, or similar) you can put the balance closer to a 5% front balance increase, which is far more acceptable, but you may not want to put such a high friction track pad onto your stock rotors, which is why I went with "Green Stuff". Then if you also put the R4-S pads on the front, you're getting very near to the stock bias (the 308 Brembo GT kit comes with Ferodo DS1100 pads in Ferrari 360 shape).

Ferodo DS1100: friction number .45
Ferodo DS2500: friction number .48 to .5
Ferodo DS3000: friction number .62
Carbotech Panther Plus: number .55
Carbotech XP8: friction number .58 to .6
Carbotech XP9: friction number .6+
Porterfield R4S: .4
Porterfield R4: .5
EBC Greenstuff: .46
Hawk HPS: .4-

 

I had always heard that if you can lock your tires up you have "enough" brake. Bigger brakes etc are for heat dissapation for racing. I agree with the comment that a stainless rubber line will firm up the pedal, but do you need more than that? If so, maybe you want stickier tires that will grab the pavement better??

 

I agree with the above, for most of us SS lines & a good pad is enough, after all, Enzo wouldn't give us a poor braking car. My question is which pad? I tend to squirt around in traffic & need a pad that grabs HARD hot or cold whenever Joe oblivious pulls out in front of me and tries to give me a heart attack. So Which Pad?????

 

You aren't going to feel a night and day difference with SS lines. The Brembo kit comes with them.

 

Hi Tommy,

Tilton Enginering makes a great stepped proportioning valve. When i did the big brake upgrade, I found that the stock proportioning wasn't correct for the added F/R braking torque.

I will get a photo or two of the installation. It can be done up in the front by the master cylinder.

The major trick is removeing the stock unit and bypassing it. It lives down by the drivers feet and is bolted to the frame. The brake line fittings are of different pitch on the inlet and outlet. so a bit of fitting is needed.


company arrived, gotta go. Will get back to you,

chris

 

Thanks! I can't wait to see the setup

 

Here is some info lifted from the current tilton brake catalogue.
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I have large Wilwood calipers and Coleman rotors on my 77 GTB. (and SS lines). MUCH MORE POWERFUL BRAKES THAN STOCK! I don't care what anyone says, the stock 308 brakes are weak. I drive an E46 M3 as a daily driver, so moving to the 308 with stock brakes was markedly uninspiring. In fact, it felt unsafe. So, I did the upgrade. Larger rotors + strong calipers = a longer stronger lever.

Yes I lost my parking brake, still looking for a solution to replace it somehow. It's been about 4 years without, so I'm getting used to not having it!

My .02

Greg

 

The brakes on my 328 are excellent for any street use that I have managed and I did a practice "panic" stop from well over 100MPH when driving the car out in AZ desert. I agree with all the comments re track use but for the street I don't see how they could function any better than they do. I don't know what pads are installed and they may be be something more aggressive than stock; they appear to have way too much pad remaining to be original ones at 29k miles.

 

I can see how one can get used to not having a parking brake (unless you live in San Francisco...). It's that of one tenth of one percent of the time that the parking brake is referred to as an emergency brake that not having it bothers me... :-|

 

I don't understand why 308s e-brake doesn't work as good as they should but mine seems to work just fine, maybe because I use it all the time and it's being exercised.

 

Hi Mike,

How did you work out the proportioning issue with the new bigger calipers and rotors??

What did you do for a master cylinder???

In looking at the parking brake set up on the stock 308, I think the biggest problem is not enough leverage. I had the identical calipers on my 914-4 Porsche, (they were an upgrade from the stock calipers because they had, I believe a 2 mm bigger piston. The 308 and the 914-6 Share the same rear caliper, (except for a different spacer between the caliper halves to permit a vented rotor for the 308).
I installed the 914-6, (308) rear calipers and they worked fine on the 914, principally because the cable actuating system had more leverage than the 308. I could park on any hill and the parking brake would work fine.

The 914-4 and 6 all shared the same adjustment difficulties and seizing problems as the 308.

Here are a few photos of how i used a 360 Brembo parking brake caliper, in the rear,(stock) caliper location.

Basically, i had the front upright ears machined flat, drilled and helicoiled, in the same plane as the standard rear ears. Then, i installed a Girodisc, custom radial mount adaptor to install the Brembo "lotus", (Brembo Big Brake 308 front caliper) on the front of the upright.

I had a cnc machinist machine a bracket to mount the 360 parking brake caliper on the rear upright in the stock caliper location.

The cable mounts to the 360 caliper in a nearly identical location as the stock caliper, so you just need to lengthen the stock cable.

Having done all of this i am pleased to report that the 360 caliper works just as "well" as the stock parking brake. The fix, which i have not yet done, is to lengthen the actuating arm on the pulley assembly by about 50-70%. I feel that this will give the caliper the leverage it needs to pull strongly enough to actually hold the car on a real hill.

Don't hold your breath, but i will test this out.

The P brake brackets are a real work of art. If you have a 13 inch rotor mounted clos to the stock centerline, i think the brackets could be remanufacturered fairly reasonably.

Pulling the uprights, spot facing the front ears, drilling and helicoiling will take a bit more time, (Rizzo, didn't you do this on your red beauty???).

This is a maximum brake upgrade, as Rifledriver pointed out, the Brembo Big Brake upgrade for the 360 Is the F-50 front brake and is only really usefull in endurance racing.

Can you have too much horsepower or too much brakes ??? Yes, you probably can. If i went to a lighter, thinner front rotor, it would probably make the car a tiny bit faster due to less rotating and unsprung weight.

But back to the OP's question, yes, i think the 308 could benefit from a bigger, more capable and more controllable brake set up. The bigger diameter discs and larger caliper pistons were an effort to aid controllability as well as greater durability and fade resistance.

The biggest bang for the buck is better pads, fluid and stainless hoses. After that, better tires, and after that, the Girodisc set up is an improvement on the Brembo set up because, it addresses not only the balance issue but also lighter rear discs and more even heat dissipation, so as things get they do so in a better f/r.

Moving up from there, the smallest brembo caliper is 36/40, I used them for the rear and found a used set of 40-44 F-50 for the front with 355-32 front rotors. Then custom hats and caliper mounting brackets had to be made, along with about 1000 in fabrication costs to adapt a bigger Wilwood 1-1/16th tandem master cylinder. Cost about $7000, with used calipers & parts.

So, the Girodisc set up is looking like the way to go if you need to move beyond the stock discs and calipers.

How well do the Bigga brakes work??? Totally LINEAR, better controllability and absolutely zero fade under the hardest tracking i could do. I really enjoyed doing this upgrade.

hth,
chris
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Hi Tommy, here's the Tilton cockpit adjustable bias valve I have in my car:

http://www.tiltonracing.com/content.php?page=list2&id=38&m=b

Works very well. One very large advantage of a cockpit adjustable bias valve, if you're doing track work that is, is that you can adjust the bias depending on the conditions of the day at the track. For example, more rear bias is typically used on a wet track day as there's less weight transfer to the front on a wet day. So, you can really tailor the f/r bias to maximum effect, all on the fly - very helpful and a meaningful advantage over competitors with static bias.

I much prefer the screw type adjustable valve (such as above) over the twin master balance bar set up - it's kind of hard to get your head down in the foot well to make an adjustment when you're doing 130+ on the main straight and trying to overtake your competition!

A lot of folks like to bias such that the rears lock up prior to the fronts. Me personally, I like f and r to lock up at the same time, but that's just me.

My $.02.

 

Very interesting, I used to run the DS3000's on my daily driver which I used to do club sprints in. It had 6 Piston AP Racing brakes as standard. I like agressive pads.

You seem to be up to speed on brakes. I was planning to use DS3000's on my 308 for track days. Do you see any problems with that? I know they are very agressive on rotors but I don't mind replacinig rotors a couple of times a year, they are very cheap at only around $200 each. My daily drivers rotors were $1200 each (383mm in diameter).

 

This thread seems to have split into street brakes vs track brakes.

After tooling around with the EVO's monster Brembos, the 328 doesn't feel like a "quick" braking car. But the stock brakes will stop the stock size tires from turning, so the rest is thermal control and brake "feel".

I asked the dealer about the steel brake lines last autumn, but they gave me a labor quote for more hours that it'd take me to install them myself. I may try an indie shop.

On the EVO, I've noticed that cold pads *will* grab. That's something I don't like -- they don't seem very "linear".

They're okay for panic stops. It's gently slowing that they have trouble with.
(This isn't as obvious on the 328, as lifting off the throttle on a high compression engine will give you some slowing that you have to do with brakes on a mill with its compression out in the turbo (like the EVO).)

I just bought a set of Porterfield R4S pads for the EVO to replace the stock pads.
(The stock pads only had trouble in mid-winter in MA, but in DC they chill sitting at traffic lights.)
I'll have to report back after installing them (probably in spring, when I swap back to summer tires).

 

I'm presuming that your horsepower is stock, and your brakes are also in their stock configuration. No, I don't see any problem with that as long as you understand that rotors may become "consumables" and you keep fresh very high temp brake fluid in the system (I use Motul RBF 600).

 

Since the Tilton proportioning valve can be used to reduce brake line pressure, but will
not increase it, I presume you put it inline with the front system, letting full flow go to the rears?

I'd definitely like to see the installation photos...