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Posted by: makinson1 Aug 13 2003, 07:58 AM

Are there any other calipers for the 914/4 that have the same bolt patern and backspacing that one should consider as an upgrade like the BMW 320i calipers?

Posted by: Qarl Aug 13 2003, 08:52 AM

Sure there is.. you can use the ones from a BMW 320i.

Wait... you stated the answer in your own question... so what's the question?

There is one from a Volvo as well... they are even bigger than the 320i calipers. I think a 240 Volvo, bu I am not sure what year.

Posted by: Bleyseng Aug 13 2003, 09:12 AM

I have read the ones off a 2002 tii will fit too. Why don't you get a set and let us know how it goes.

Geoff

Posted by: Brad Roberts Aug 14 2003, 02:22 AM

I looked at a 4 piston caliper from a Toyota 4 runner... it might work.

I said this in another thread... be VERY careful putting a bigger brake pad on a 914 stock rotor. The rotor was sourced by Porsche/VW to handle the heat that the stock caliper generates... adding a larger caliper to it is like playing with fire... all your doing is stressing the rotor like it was never meant to be.


Let us know what you find.... I still havent met a 914 I couldnt make stop.


B

Posted by: makinson1 Aug 14 2003, 06:09 AM

Pelican recommends the BMW 320i calipers. Any reason this advice is misguided?

Posted by: tat2dphreak Aug 14 2003, 08:09 AM

I have the 2002 calipers on my now-demoted to parts car.... they work great! however, I recommend the 320i calipers over the 2002s... the 2002 has 2 inlets for brake fluid instead of 1(stock for 914s and 320i) so some creativity("t" fittings from a beetle) was required which allow for more opportunity for air getting in the system... so I wouldn't do it the same way again...

also it can be mentioned... both of my cars are '72... a '73+ will need machining for either caliper to work to the best of my knowledge.

Posted by: Brad Roberts Aug 14 2003, 12:53 PM

Lets put it this way:

Pelican doesnt build cars or work on cars..nor do they race.

I know the BMW calipers work. I also know a lot of people who have removed them after installing them.

I personally am against them. With minor effort the stock system works just fine. Most of them have been severely neglected.

B

Posted by: TonyAKAVW Aug 14 2003, 02:23 PM

I'm curious about the differences between the rotors on the 320i and the 914. I know that the 320i had solid rotors but I can't seem to find out the size difference between a 914 rotor and a 320i rotor. Are there other factors that would dramatically affect its ability to disspate more heat than a 914 rotor? Aside from mass and surface area, what else is there (assuming of course that neither are drilled, slotted, etc.)?

-Tony

Posted by: 1973914 Aug 14 2003, 03:03 PM

Aside from mass and surface area (assuming same metal composition), and no drilling or slotting or cryo-treating, there really are no other factors involved. Not sure anyone has indicated they installed the corresponding rotors along with the calipers on the 914.

Think of it this way:

The rotor and pad make contact, the resulting friction causes the rotor to slow, thus slowing the wheel. At a given friction level, the pad and rotor contact will cease to slow the wheel any further (diminishing returns) without locking them. Heat causes this threshold to extend further along this curve (known generally as Fade), until it ceases to serve as a friction surface at all (known generally as "Oh Sh*&"). The hotter those surfaces get for a given combination of pad and rotor materials, the closer it gets to that "Oh Sh*&" point! With a larger pad and same size rotor, the rotor is going to get hotter, sooner.

Laymans explanation....

Posted by: TonyAKAVW Aug 14 2003, 05:31 PM

Well, I was thinking along the lines of differences in the materials. As far as I know (which isn't very far) brake rotors are made of pretty much the same things, steel, etc. If though, the rotors were made to have significantly different thermal conductivities, then the heat could be transmitted to the wheel or suspension copmonents faster or slower, thus dissipating heat at different rates. I doubt thought that the difference would be large unless you had copper rotors versus steel rotors

So with this out of the way, we might be able to determine whether the 914 rotor could handle a 320i brake pad size by comparing the size and weight of the two rotors. If they are very close, then maybe its not worth worrying about much. If the 320i is considerably larger, lets say more than 10% then maybe there's something to at least think about. ???

-Tony

Posted by: bernbomb914 Aug 14 2003, 09:04 PM

I installed Volvo 4 pot calipers on my car .I used Richard Johnson Tees that allowed me to use the origional brake line for a simple bolt up. with no machining required. just a simple washer to align the caliper on the disk. They work much better than the rebuilt stock calipers that they replaced. This is a dailey driver and I dont race it. heat has not been a problem. they came from a 240 85 model.

Bernie

Posted by: Bleyseng Aug 14 2003, 09:29 PM

I thought the BMW rotors where about the same size. I like the 320i calipers as it helps me stop alittle better with less fading atleast when I autocross. I have not run it on a track yet.
Still gonna install a 911 set up when I get time.

Geoff

Posted by: tat2dphreak Aug 15 2003, 08:13 AM

my car is a street car only, and the BMW brakes have been very sweet to me several times when my little car wasn't seen by some C*ck, in a giant SUV, talking on the cell phone while reading the paper.... THAT is Dallas!

Posted by: seanery Aug 15 2003, 08:16 AM

I know we've talked about this before, but the stock calipers/rotors with a 19mm m/c on my 74 could lock at will. That tells me that I had plenty of stopping power. Am I crazy?

Posted by: Part Pricer Aug 15 2003, 08:31 AM

Yes, you are crazy. But, that has nothing to do with this conversation.

Posted by: jdogg Aug 15 2003, 08:36 AM

[QUOTE]I personally am against them. With minor effort the stock system works just fine. Most of them have been severely neglected

Brad, what minor effort are you referring to? Just a stock rebuild, fresh rotors, ang good pads? Stock 17 mm m/c or 19mm? Any tricks?

Posted by: Part Pricer Aug 15 2003, 08:37 AM

You experience brake fade while autocrossing?? I find it hard to believe that your brakes would get hot enough during a typical AX run where you would experience fade. Please explain.

Posted by: seanery Aug 15 2003, 08:40 AM

Blair is faster than Geoff, right?

Now, we know why!
Geoff uses the brakes. I bet Blair doesn't!!

Posted by: jdogg Aug 15 2003, 08:45 AM

I experienced some fade in the last DE I did at VIR. Actually I don't know if it was so much fade or boiling brake fluid. I had fresh ATE SUper Blue Racing fluid in it, and after bleeding the brakes after the first day, the pedal came back strong until the last seesion o fthe day again. Is this just to be expected? I haven' t measured my rotors to see if maybe it is time to replace them. Would new, thicker rotors disipate the heat more quickly to sloe down the boiling of the brake fluid? Is there no other solution than air ducts? The most frightening turn at VIR is turn 1 at the end of the front straight, 110 mph down to about a 35 mph almost 180....pucker factor is significantly higher in the last session with a soft pedal.......

Posted by: seanery Aug 15 2003, 08:48 AM

Track cars are a different story. Vented rotors will make a big difference, so setup that utilizes vented rotors is desirable for a track used car.

Posted by: jdogg Aug 15 2003, 08:53 AM

How about some sort of universal set-up that helps in both cases. I AX the car mostly, and would like to stay legal in CS and next year CSP classes....Is there a vented rotor available for us without going to the 911 front end? I haven't consulted the rule book, but are 911 struts, spindles, brakes, etc. legal in CSP?

Posted by: seanery Aug 15 2003, 09:01 AM

dunno about the rules.

Brad mentioned something about vented, but gave no details.

Posted by: brant Aug 15 2003, 09:04 AM

JDOGG,

What pads are you running...
race pads are designed to work in a higher temp range and a small part of your problem could be bad pads...

NEXT... make SURE that the rain-splash guards are remove. This allows quite a bit more air, is legal, lightens the car, is relatively easy, and FREE.

Your fluid selection will be fine (IMHO).

I believe that the above items will make a difference. If this is insufficient the next 4 items I would do:
1) use less brake
2) bleed the brakes at noon
3) buy titanium pad backers.. heat shields
4) duct some air onto the leading edge of the rotor.

$.02
brant

Posted by: jdogg Aug 15 2003, 09:41 AM

Brant- currently running PBR Metal Masters front and rear, all purpose type pad. The car sees street, AX, and a few DEs. Next year I do intend to run a race pad for track events, 150 clams per axle for pads was a little strong for this year. Thanks for the advice.


1) Use less brake............Yeah, maybe next year with some more 'sperience!!haha

Posted by: brant Aug 15 2003, 11:05 AM

JDOGG,

people will disagree with this.. but it is my opinion...

for now, buy just the front axle.. and I really preffer the $100 KFP's over the $150 Pagids...

On a heavier car the pagids are better, but on a lighter car (914) I've had very good experiences with the KFP's.

and if you haven't taken the water shields off... do that...

brant

Posted by: jdogg Aug 15 2003, 01:10 PM

Brant - Do the KFPs come in different compounds? Which do you like? Makes sense to me to just do fronts, as most of the braking power comes from there. Are those pads very rotor friendly?

Posted by: brant Aug 15 2003, 03:22 PM

JDOGG,

yeah different compounds...
I always get confused on this one because it used to be the company was cool carbon and they used a different color chart for the same compounds. (When they changed to KFP, they kept the compounds but changed the colors). At the time I was told the compounds were reall the same.

I have found this to be a very rotor friendly pad.
anyways I don't want to confuse you too...
basically I use the GOLD on the fronts.

brant

Posted by: makinson1 Aug 21 2003, 06:52 AM

Interesting page for the Volvo 240 brake pads:

http://www.exford.co.uk/Brakeworld/Buyguide/HTML/BW033.HTM

Posted by: makinson1 Aug 21 2003, 02:03 PM

It looks like the area of the Volvo 240 pads are the same as the sttock 914 pads, 34 sq. Cm.
The BMW 320i are close to 50 sq. Cm. Any comments?