77 308 -- Will new discs alone improve my brakes, or do I need better calipers also?

Contact qv London. They make a 355 kit for the 308. Reasonably priced.
Philip

 

to grig318; the webb addresss is http://www.hamletcg.co.uk/qv/email.htm, P.S. (gettaliffe)

 

Before you start spending a lot of money, you should think about what you're asking. First, are you racing? Race cars need huge brakes to help control overheating. Big rotors, big calipers, good venting. Talk to racers for some expert advice there.

Are your brakes okay now? No air etc. and firm pedal pressure? Correct F/R brake bias?

Normally, you should be able to lock your wheels if you try (no ABS of course). Bigger rotors/calipers will not stop you any better than the stock brakes if you can lock them, because the point of course is to NOT lock them but be just on the verge.

Bigger brakes means less pedal pressure to do this; is that what you want? You may find you have too much brake and you can't modulate them as well. In the end, it comes down to driver skill and tires to have great brakes on any given car. Unless overheating is a problem for you, I don't see the point in changing correctly functioning brakes.

Anyone have a different opinion?

Ken

 

Drilled or slotted rotors dissipate heat better than solid rotors - thus reducing brake fade that is caused by heat build up under hard use. There should be no real difference in stopping distances and feel under normal driving conditions.

Before I would replace the calipers I would make sure everything is working properly - bled etc. Replace any questionable brake lines and experiment with different braks pad compounds. Any of these could drastically improve your braking without going the full caliper route.

 

Hello Greg,

We have installed a brembo brake kit in a customer's 308, he just can't believe the change.
We have this kit in stock for $2335 including free shipping.
let me know if you are interested
thanks

Victor
www.polepositionusa.com

 

Greg, i can recommend the Brembo fronts for sure BUT they really grab and my rears now seem a bit weak. PERHAPS the Gyro guy (Eric Dahl) can chime in as i am waiting as they will have front AND rear solutions. http://www.************

Check the archives as there is A LOT of data there about my experience. Also use 17-inch rims btw.

Basically, if you go with the Brembo you WILL have an imbalance of front being too grippy SO you WILL need a more aggressive (grippy) rear pad. If you wait for the Gyro solution for front and rear you will lose the emergency brake function.

Hope this helps.

 

Sure, just change to a grippier set of pads with your otherwise stock setup. Lowest cost solution to getting greater stopping power with the stock brake hardware. You might want to consider EBC Greenstuff (can get those at TireRack) or Ferodo DS2500's. Personally, though, I was very happy with Porterfield R4S pads on all four corners before I went with the Brembo GT big front kit. Your stock dealer-supplied semi-metallic brakes probably have a friction number of between 3.0 and 3.5. I now have R4S pads on the front (the Brembo GT kit uses Ferrari 360-shaped pads), and Greenstuffs on the rears to get nearer to the stock front/rear bias. Note that higher friction numbers aren't always better for a primarily street-driven car.

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

 

Presumably your brake lines aren't the original 28 year old ones. But you might try steel braid lines in place of some of the older rubber lines to get a more responsive brake "feel".

 

Youre mixing everything together and it doesn't belong together.

First of all, the brakes don't stop the car, the tires do; therefore, if you want to reduce stopping distances, get better tires.

The brakes, again, don't stop the car; they're a heatsink - they convert kinetic enrgy into thermal energy (heat) - so, to speak of 'braking performance' is really to speak of 'braking consistency.'

To answer your question, new disks, provided their either of larger diameter or thicker, will aid in increasing the braking systems consistency and aversion to fade but they will not reduce stopping distances.

 

Good post. But I would urge EVERYONE NOT to use EBC pads on anything they value - they're notoriosly hard on rotors and they crumble when used in a track car/race car - they're junk. And, to boot, damp pieces of wood provide better pedal feel.

 

This depends entirely on the compound you select and the pads you choose. A pad like the CobaltFriction Spec VR, while having a very high mu (0.65) is actually very gentle on rotors because of its compound composition. I know, because I've had about 3 sets of these pads.
Other pads, like, say, HAWK blues or EBCs will abosloutly eat your rotors, while a pad like the Carbotech Panther XP10 and Ferodo DS2500 are middle of the road - however, both the Ferodo and Panther have greater initial bite than the Cobalt -while all have similar mu values - but the Cobalt has, to me, a flatter torque curve and therefore provides excellent modulatioin, even on dual or even single piston calipers.

 

This depends entirely on how the brake system is desingned and whether or not it's designed with an OEM prop valvle or not. You can design calipers with piston bores that will compliment the OEM prop valve (Stoptech does an excellent job at this), while other you may need a new prop valve, booster, and possibly a master cyl.

MY question to you is: What do you want out of the brakes, the car and what is your intended use? That's the paramount question. Also, what tires are you using/will you be using?
Rule of thumb is: If you can currently lock your brakes at will, you brakes are generating sufficent braking torque; the questions then become: 1, can they do this repeatedly w/out fade, and 2, can they do this safely and provide amble feedback?

 

Interesting comment and opinion, but there are MANY folks here at FChat who use or have used EBC Greenstuff pads and are quite pleased with them, including for light track. Obviously, how hard they are on rotors also depends on the compound you use, as is true with any pad brand. The new EBC "Yellow" compound has a .46 friction coefficient (the same as the Greenstuff compound) and looks to be a potentially better choice and with specific claims of being "rotor friendly" for street and track.

 

Greg--several things to consider--
larger rotors will have the geatest effect
keeping the proper bias front/back is VERY important.

I designed my own system ( engineer here) putting 12.2" rotors in front, 12.0" rotors in back and 4 piston calipers ( with different piston sizes- to match force bias) all around. I now have exactly 2x the brakes as befor.. On track days I am outbraking all but the stradalles---the whole thing was about 3000 ( for all 4 corners)

 

PS--I use HAWK pads--they are awsome

 

Pad choice is clearly personal preference and experience. When I was asking for suggestions from Eric at Girodisc, HE specifically suggested NOT using Hawk pads if you ever take your car on the track!

 

Mike--interesting that he did not like HAWK pads--They have a really broad variety of pads-- I have run the HPS series now for 4 events and they were strong and still 2/3's left. I just got a set of HP+ pads to try. Can't wait to see what they are like because the regular HPS units are unbelievable on the track.

about 1/2 of the current Rolex and Grand-Am teams are runing them--but those are the serious race compounds.....

http://www.hawkperformance.com/product_features.cfm

 

FINALLY a voice of reason. Stopping distances with bigger brakes will deteriorate less in hard uses stated, but you WILL NOT STOP ANY QUICKER than with stock working brakes.

As stated, that depends on tires and the weight of your car. New brakes look better and may require less effort, and may be better in hard use, but will not improve the stopping distance in normal use.

Ken