Brakes, tell me something Options

[slivel]

QUOTE (Brad Roberts @ May 2 2005, 10:43 PM)

QUOTE Just curious, did Chris' race car run a tee? He does have a tee in place. He *talked* about a running a bias valve, because he felt something weird with the car in ONE corner of the track. You dont drive around the course adjusting the brake bias for evey corner so it doesnt really make sense to have great braking for 14 corners out of 15. My all time favorite: Carrera fronts on the rear.. turbo 944's up front. From there I go into full blown custom braking setups with Colemans or something. B

Brad,

How do you fit Carrera fronts on the rear? Isn't the bolt spacing 3.5 on the Carrera calipers and 3 on the rear suspension?

Steve

[eeyore]

Personal experience at DE:

Stock -4 brake system. New ATE Super Blue. $30 brake pads from Pelican. No front valence. I noticed a little fade at the beginning of the day, but it never got worse. Somewhere in the second session I stopped paying attention and just braked my little heart out for the rest of the day.

[Brad Roberts]

Correct on the bolt spacing. Cut the stock ears off and weld on a new flat plate with the proper spacing and location. Not easy

The other combo that works well: M calipers on the rear and 944 Turbo fronts.


B

[slivel]

Thanks, Brad
I was hoping that someone made an adapter that would simplify the job - but no suck luck.

Steve

[TimT]

Like everyone has mentioned, get some air to the front brakes!

Bleed fluid before every event

I like Hawk Blue pads, but have had great results with Porterfields.

The brakes on my 914 are a bastard setup,

Wilwood Superlites w/944T rotors up front
Carrera calipers with carrera discs in the rear
19mm m/c

We found the Ate Blue/Gold is nothing more than high quality street fluid. At CMP and Roebling Road we had major fluid boiling problems on the 935 clone, and switched to the expensive Castrol SRF fluid, and have had no more fluid problems.

Another fluid that I like and use in my 914 is Castrol syntheic brake fluid, Its cheaper than the Ate fluids, and has higher boiling points. The Ford fluid is also a good bang for the buck fluid

[nine14cats]

You've seen us run auto-x's with the old 628. We also ran that car HARD (2 drivers) at DE's and Time Trials. We never had brake fade....

Fronts: 911T vented discs and calipers
Rears: 944 S vented discs and calipers

You lose the parking brake.

Fluid: ATE Superblue

Pads: Porterfield R4's (race compound, not street)

Adjustable Brake Prop: Yes (I ran it wide open most of the time but at Sears Point I would dial in more bias. It would feel better under hard braking).

I like the air venting to the front brakes. We put in vents and never had a fade issue.

The Porterfields worked fine for Auto-x or track. The car was dedicated to racing. Not street legal.

Here are some pics of our vents.....

Bill P.

[nine14cats]

pic 2

[nine14cats]

pic 3

[Mueller]

QUOTE

You've seen us run auto-x's with the old 628. We also ran that car HARD (2 drivers) at DE's and Time Trials. We never had brake fade.... Fronts: 911T vented discs and calipers

which for you 4 luggers out there, the billet hubs run the same vented discs and calipers....and they work !!!!!

[Dave_Darling]

I would recommend the Porterfield street compound brake pads, not the Porterfield race compound. The race ones, while being fantastic at "working" temperatures, are rather sub-par when dead-cold. That's the first corner on the track (no BFD), or pretty much every single corner you take on the street (very BFD!).

ATE Super Blue, ATE Gold, Ford Heavy Duty are all very good street brake fluids.

Motul is probably better, Vegas Racer's experience notwithstanding. I know more people who have had fewer problems with the Motul than with the ATE fluids.

The SRF is "the shit", to appropriate B's expression. Amazing stuff--and so is the cost!!

If you still had a -4, I would suggest an adjustable proportioning valve over a tee. Not sure in your case, because you have significant extra weight in the rear of the car (six-cylinder motor) which gives the rear wheels better grip and lets you send more pressure to them...

--DD

[ArtechnikA]

QUOTE (Dave_Darling @ May 3 2005, 01:19 PM)

I would recommend the Porterfield street compound brake pads, not the Porterfield race compound.... Motul is probably better, Vegas Racer's experience notwithstanding. I know more people who have had fewer problems with the Motul than with the ATE fluids. If you still had a -4, I would suggest an adjustable proportioning valve over a tee.

i just came from the Porterfield site and after i *eventually* found the car model in question (hint - they only have a few years listed for any given model...) i discovered that they actually have 4 compounds. we can eliminate the Race and Endurance Race compounds, but in addition to their street compound they have what they call a "Vintage Race" compound that sounds like it'd be pretty decent for AX and DE. i'm thinking very seriously about giving that a try at the 911's first big track day, which may be Watkin's Glen this October. i'll probably have sets of Race and Street available - just in case...

one of the aspects of the very high dry boiling temp fluids is that they are even more hygroscopic than street fluids - so it REALLY needs to be kept fresh. as in change right before a track event, rather than right after. Earl's also has a pair of very high boiling point )wet and dry) fluids, but since i don't have as convenient sources for those, i don't plan to try them any time soon.

i DO like the Valvoline SynPower fluid.

on proportioners, i almost think our cars have it backward... especially if we can learn to avoid panic braking and carrying Way Too Much stuff in the front and nothing in the back, the balance seems to be pretty good - at least that was my experience with the S calipers front and stock, widened calipers back, on my /6. if they're well-balanced with the tee, for adjustment, we'd want to be able to limit braking to the *front* for cases like rain, where there is less weight transfer.

in theory, you could mount a pressure-relief valve type proportioner anywhere in the front system but i'm really leery of that.

ideally, we'd run dual MC brake systems with a balance bar; they're expensive tho...

[Series9]

QUOTE (Brad Roberts @ May 2 2005, 10:26 PM)

Save your money. The other way to control bias: Run sticky pads up front and run Pep Boys crap in the rear.. or vice versa depending on what you want. B

That's how I'm handling bias with a 'T'. Everything is working great so far.

[Brad Roberts]

QUOTE

in theory, you could mount a pressure-relief valve type proportioner anywhere in the front system but i'm really leery of that.

I actually tested that. Late model Corvettes (92-98) had a "buffer" in place right after the MC. I put one on a 914 in the front... AWESOME. It did exactly what I wanted. I could nail the brakes as hard as I wanted and it would "bleed" pressure to the front calipers slowly (I say slowly.. I mean fractions of second worht of soft delay) Barely noticable, but it kep the tires moving instead of imediately locking them up.


B

[jgiroux67]

QUOTE (Eric_Shea @ May 2 2005, 10:24 PM)

M-Calipers - -4 Rears - T-fitting M-Calipers - -6 Rears - P-Valve A or S-Calipers - -6 Rears - T-Fitting A or S-Calipers - M Rears - T-Fitting A or S-Calipers - Carrera Rears - P-Valve 930 Calipers - Carrera Rears - T-Fitting

What about A calipers in front and stock 4's in the rear?

I just put in a T but will that be enough to get atleast some power to the rears or should I use realy good pads in the rear and just decent one in the front?

[Trekkor]

Here's what I'm going to do: (IMG:http://www.914world.com/bbs2/html/emoticons/rolleyes.gif)

Install tee, install Porterfield race pads front and rear,
and change the fluid. (IMG:http://www.914world.com/bbs2/html/emoticons/dry.gif)

I'll see how that works and duct cooling air if *needed*.

BTW, are people leaving their dust shields on?


KT

[Andyrew]

You can use the dust shields as a place to force the air into.... IE make an opening in them on the back and bolt the air hose to it...

Theres a kit for it for the 911's I think on PP's....

[ArtechnikA]

QUOTE (trekkor @ May 4 2005, 01:53 AM)

...are people leaving their dust shields on?

i leave the dust shields on the workbench until i can put them in a big box with all the other dust shields.

on the front, i do re-install the 3 M6 bolts to keep crud and corrosion out and to fill the holes.

on a vented-disk car, cooling air is directed to the eye of the disk; that's what the kits that look like dust shields do (they don't shroud the disk tho...)

solid disk cars are harder tho - you can't just direct cooling air to one side or you'll wind up with a giant Belleville washer. you need to find a way to get air to both sides.

[Brett W]

(IMG:http://www.914world.com/bbs2/html/emoticons/agree.gif) You beat me to it. Yes you have to make a splitter that cools both sides of teh rotor to keep warpage to a minimum.

[KenH]

ATE Blue fluid or eqiuv.

Porterfields are hard to "bed-in". If they are not bedded-in properly thet may never be right.

I use PAGID "Orange". Simple to "bed-in". They work good "cold" or "hot". ie A/X - track.

Never a problem braking from 100mph to a sharp 90 turn.

Ken 180