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914World.com _ 914World Garage _ Improving stock brakes

Posted by: Jaiden Feb 17 2006, 12:28 PM

During my front end build I had planned on swapping out the brakes to a 911 set up, but other problems have been found that eat into the budget.

So the vented diskes are out... For now....

I'm swapping out the MC with a 19mm unit since it's a nasty stocker that has internal leaks. What else can I do to improve the stock brakes?
Braided flex lines? Super blue fluid? What else?

The stock rotors are still in spec but I'm not sure they could take a cut and the pads look to have a lot of meat left but I am unaware of the material.

I'm getting new bearings as well!

Let me know things to better my car's braking

Posted by: ChrisReale Feb 17 2006, 12:36 PM

If everything is within specs and in working order, stock brakes on a stock car work great. But, if you so desire, the hubs that Mueller designed allow you to retain 4 lug wheels with the added benefit of 911 brakes and rotors. I would suggest just going through the system and replacing lines, pads and maybe the rotors, and new fluid and you will have more than enough braking power

Posted by: JOHNMAN Feb 17 2006, 12:49 PM

QUOTE
What else can I do to improve the stock brakes?
Braided flex lines? Super blue fluid? What else?

Why the braided fles lines?

Over the years there has been debate about those not matching the internal diameter of the stock rubber lines. The braided lines having a larger inside diameter causing a more spongy pedal.

Super blue is ok. Keep it fresh by flushing periodically.

The biggest improvement to be made to stock brakes is to make sure that the pads do not hang up in the calipers, and that all the pistons work freely (sometimes this takes rebuilding the calipers).

Once the calipers are known to work correctly and not stick or bind, the second largest improvement would be pad compound. Select the one that is right for your driving habits. Racing pads are not good for the street as they wouldn't be in the correct heat range, just like street pads won't work for racing.

After you have calipers that work and pads that work, the next largest improvement is proper bleeding of the brakes to make sure there is no air or moisture trapped in the fluid. Moisture will boil causing bubbles. Bubbles (air) will compress, giving a squishy pedal.

I hope my $0.02 helps.

Stock brakes can be made to work well.

Just my opinion.

Posted by: trekkor Feb 17 2006, 12:51 PM

Properly maintained stock brakes are very good.

Add high quality pads ( I use race pads ) and you will really notice the difference.

Making sure your quality fluid is fresh and the system is bled properly may be the most important of all.

I like the SS braided lines

KT

Posted by: Mueller Feb 17 2006, 12:53 PM

just install new rubber lines....who knows the last time the lines on your car has been replaced....

good quality brake pads, not the $15 set sold at Autozone

have someone stomp on your brake pedal and see if the mastercylinder is moving...if so, install a brace (sold by Travis in the Resource section)

Posted by: Dave Bell Feb 17 2006, 01:01 PM

Replace stock proportioning valve with a T-line or aftermarket in cabin adustable prop valve.

Put a firm back up structure behind the master cylinder to prevent flexing... firmer feel. Grassroots motorsports did a 914 article 2-3 years back on that topic others may have proposed similar things.

I know I have seen cross-drilled rotors for the stock 914 brakes, perhaps slotted also... some cooling help perhaps... better at keeping the pads clean than solid.

- Dave

Posted by: Van914 Feb 17 2006, 01:06 PM

Stock Brakes work great for a stock motor or even a small 6, when you take the time to set them up.

19MM Master cyl
Working Calipers
Good rotors
For the track good pads
T in place of the prop.-valve
#1 in my book proper venting clearance on the rear.
( be sure you hold the rotor on with the lugs and some washers when you set)

van914

Posted by: brant Feb 17 2006, 01:13 PM

pads... pads... make sure everything is good like calipers... and then pads. .... pads.... pads...

did I mention the pads?

freshen everything and then try a set of portefield street pads.

brant

Posted by: tat2dphreak Feb 17 2006, 01:15 PM

get good pads, porterfield r4S is good.
19mm M/C if you like harder feel
good fluid and flush good...
braided lines don't really add anything, why pay more for them?

get Eric to rebuild calipers, so they work like new... and stock brakes are fine...

if you must, you could go 320i BMW brakes... but i don't think it helps much... the real issue is needing vented rotors... use Mueller's alloy hubs, I think Eric may have some of the calipers you'd need...

Posted by: Eric_Shea Feb 17 2006, 04:06 PM

QUOTE
Replace stock proportioning valve with a T-line or aftermarket in cabin adustable prop valve.
Not! That's 'Bad' advice for stock brakes.

You've got a lot of good advice here... work your way out from where your dogs hit the pedals:

*Pedal Assembly in good working order, not binding.
*Master cylinder in good working order, not leaking.
*Hard lines, no leaks. (they rarely fail)
*Rubber lines... when in doubt, replace. They're only about $50.00 for a full set. The rears are a P-A-I-N to get at.
*Calipers not binding or sticking. Check rubber dust boots for cracks or holes that can let water in. Rebuild them if you have any problems. Old fluid and water/rust cause a grunge buildup on the upper end of the piston past the seal, this can cause problems.
*Pads, organic (not metallic). Porterfields as recommended here are some of the best.
*Fluid, change it! New fuild can keep the components in great shape. I've torn apart hundreds of calipers and fluid 'really' makes a BIG difference.
*Seat belts. Make sure you've got them on because, as Gint likes to say, 'Stock brakes can throw you through the windshield.'

Posted by: sk8kat1 Feb 17 2006, 04:29 PM

my car came from the PO w/ the bmw upgrade and the 19mm MC and stainless lines... they lock up nicely

Posted by: stock93 Feb 17 2006, 06:33 PM

Johnman,
The inner diameter of the brake line being larger with braided line shouldn't have anything to do with spongy feel. Basic hydraulics dictates that pressure is distributed equally in all directions regardless of size. The only ways you will change feel is having air in the system, having lines that are flexing, or changing the master cylinder piston to caliper piston ratio.

John

Posted by: Sideways Feb 17 2006, 07:22 PM

Don't forget the final part of the equation......Good quality tires.

Great brakes, stock or otherwise are no good if your contact patch with the road is sub-standard.

Posted by: Jaiden Feb 19 2006, 08:44 PM

Thanks guys for all the advice!!

I'm just about ready to start cleaning up the parts before I reasemble and I will definity take my time inspecting the calipers.