So I'm browsing around on EBAY today and run across a turbo caliper from '78. Is there any big downside to using a set of them on my conversion car? Obviously, I've got to find a set first...

Here's a link to the auction so you can see what caliper I'm talking about.

Later,
Kevin

only downside is cost...I think all 4 calipers will run you about $1500 min.........but they will fit under 15" rims

the conversion gets brought up a lot - you could probably even do a search about it. I have them on my V8 car - you need 911 struts with the correct bolt spacing on the front calipers and the correct rotor and hat. The struts you just have to be sure you get the right set. The rotors and hats are available from VCI

http://vehiclecraft.com/Brakes/930_upgrade.htm

or you can use stock early stuff (either 77-78 or it's 78-79, you'd have to verify) but the stock stuff ain't cheap.

The rears require the caliper mounting be remachined. VCI does this and includes the spacers and such - then they bolt right up and use a turbo rear rotor.

I got all my floating rotors/hats/machining from VCI. I bought the calipers used and have RSR front struts fyi. Supposedly the VCI rotors wear faster than stock, but I can't verify that personally as I have limited use thus far. They work awesome though! And are about the only good upgrade caliper that still fits under 15s.

as mueller said... they arent cheap!

and i think boxsters fit under 15's

mounting turbo calipers isn't the problem (they bolt right up to a 3.5" strut)
the trouble is in the rotors

the 930 had spacers incorporated into the wheelhub so the rotor has a different offset than a narrow bodied 911

so if you mount the turbo rotor to a narrowbody wheelhub, it won't fit inside the caliper

and if you use 930 wheel hubs, the wheels are not gonna fit inside your fenders (unless you have flares)

so to use the turbo calipers on a narrow bodied car, you'll need custom rotors (or custom hats with floating rotors)
those are expensive and since rotors are a service item, that's not such a good idea (IMO)

also, do you really need calipers that big?
how big are your tires?
if the calipers are too big, all you gonna do is lock up your brakes

I don't know about your car, but you could be better of with SC or Carrera 3.2 calipers/rotors
the 3.2 has the same caliper (padsize) as the SC, but it's spaced a little wider to fit over thicker rotors

if those are not big enuf, you could use the 3.2 rotors with 944 turbo calipers (which only need a very small modification to mount to a 911 3.5" strut)

lots and lots and lots cheaper (both on initial purchase and later when you need to replace your rotors) and probably more than enuf braking capacity

whats a floating rotor?

oh... the 944 turbo calipers won't fit in 15" wheels (you need 16")
if you want to use 15" wheels, check on Boxster calipers (about the same size as the 944T calipers and also use a 3.2 rotor IIRC)
you need special mounting brackets for those
check with Rich Johnson (see the "resources" forum) for those

seperate rotor and hat
the rotor is bolted to the hat (you buy the hat only once)

check the VCI site, mentioned above

I love my 930 brakes. My only concern is when it is time to buy new rotors. Cha-Ching$$$ To get the most out of them you should use an agressive pad and they are not rotor friendly. DLee

oh got it....

slick.

yes and no... you can have non-floating with a rotor and hat (NASCAR setups for instance like Wilwood).

Floating is best described on the VCI site - but the short story is that the rotor is on "T" instead of hard bolted to the hat. The rotor can move back and forth on the T so that when you go through a corner, the rotor doesn't distort with the hat and hub. Keeps the rotor and pads parallel more or less.

They make a small rattling noise when you drive them, which is the rumor why Porsche went solid later - customers kept complaining that the car made noise while they drove it and wanted it fixed and couldn't understand why it couldn't be fixed. That is the rumor at least...

edit = a link
http://vehiclecraft.com/Brakes/rot_ques.htm

We simply bought a complete 930 front suspension and bolted it up to the front of our flared track car. We then got rid of all our front wheel spacers. 930 front ends are 2" wider than 911 front ends. 1" per side.

You will need a bigger master cylinder with 4 piston calipers. A 23mm works well.

For the street, I can't imagine NEEDING that much braking, but on the track with 2 drivers, we need all the cooling we can get.


Good luck Kevin.

I gotta go bolt my 3.2 in my car at last.....

Is the rotor supposed to have some play in it. I noticed mine wiggles a bit but I figure thats how it is supposed to be.

Since when they wear out they just need the disc and not the hat I would think the price wouldn't be that bad

Any play you feel in a stock 914 setup is bearing play. There should be a minimal amount of play (can't describe, something you have to feel "right" at some point to know in the future). As races/bearings wear, you get more play until you sieze up and launch a wheel

Did that once on my old Mustang by over-tightening the bearing set I replaced First time I ever did a set of bearings, and clearly didn't know what "feels right" was. Had a friend show me what "right" was the 2nd time around. Tore the rotor up pretty bad and the caliper is the only thing that kept the front tire on the car when it went...

err... you're right
you've got 2 piece rotors (still a seperate rotor and hat, but they're bolted together rigidly)
a floating rotor is "loosley" bolted to the hat (special mounting system, check the VCI site) that allows the rotor to expand (in diameter) when heating up
they can be noisy or have a "shudder" when cold
from what I know, that's primarily used to prevent warping

or your rotors can be loose with the attachment hardware about to fall out.......not a good thing.....

so they are supposed to be able to float or not

All the bolts were in and it was loose all around evenly. I better make sure with Dave

do you have 930 brakes?

Holy mackarel!

I guess I had "forgotten" about these brake calipers and when I ran across them again today I un-forgot them.

If you can look at that VCI webpage and not want those calipers you oughta sell your Porsche(s) (even the NARPs!) and buy a Prius.

I've actually got a set of S2 calipers sitting in the garage now waiting for that phase of the project (6 mos out). This car will have 17" as the primary wheel at that point. I don't see any reason to worry abou the 16" wheel minimum given that. I've been finding that the leading edge of high performance tires is quickly leaving everything below 17" behind anyway.

But back to brakes, simply put, I like the looks of the 930 calipers. It's not really a matter of necessity now is it? It sounds like quite a commitment in making the switch to those calipers though; much more than any other common conversion.

I'm gonna put the 930 calipers on my "watch list." If I find a used set I might just snap 'em up. I've 6 mos before I pull the trigger on this anyway.

Later,
Kevin

Try to buy a 930 complete front suspension and bolt it right in. You'll have everything you need including the aluminum crossmember and the torsion bars...it all bolts right in.

Bill

Please allow me to give you a little primer on putting 930 brakes on a 914.


I found an orphaned set of rear 930 brakes @ Hershey a few years back,and thought WTH I'll give it a shot.

Bought'em for 400.00 for the pair,then needed new rotors,200.00 more.then had to get the cal's machined to fit the trailing arms.100.00 more.
Total,700.00 just for the rears.

Fast forward to 2006.Now I go to Hershey looking for fronts to match the rear.I place adds on PP's classified WTB a set of 930 front's.I get several e-mails from many 911 people willing to sell,but almost all have only a complete set to sell

Finally get an e-mail from a guy parting out a '78 930.He's willing to sell me the front calipers,930 hubs,Spacer,& rotors.Cost,1800.00 delivered.I take it.

Parts have been stripped clean & bead blasted and are now at my powder coater for some paint.
Now,for the fun when they get back.

2 new floating rotors,600.00,rebuild kits for both calipers,200.00.new wheel brg's 60.00, and a must have 23mm naster cylinder.200.00
that's 1100.00 I planned on after the cal's come back from the pc.

The going rate for a properly done 930 setup on either a 914 or a 911 is 4-5 thousand dollars. and it ain't gonna get any cheaper.
It's a lotta bling,but damn it sure is a helluva braking sytem.
One note,with the fronts.The '80 up 930's used a fixed rotor,those are relatively cheap.about 200.00 a pair but you MUST have the matching 930 hubs also cause of the offset.The early floating setup is essentially the race setup to have,the fixed rotor setup is quieter for the street.

Ron

The part that concerns me the most is the rotors. I hate to have $$$$ tied up in disposable parts. Although I guess if I were to extrapolate from the other car which is getting 20k on rotors I might say that is five years on the 914 which maybe isn't such a big deal then.

Later,
Kevin

small side note, I ran 944 turbo's with 15 in rims. Most of the time I ran small spacers to push the track out a bit (15mm) per side on a flared car. I don't remember and interferance to the wheel.

I beg to differ sir I have 944 turbo (later style) calipers on my 944 with 15" phone dials and they clear just fine. HOWEVER I tried a set of 7" Fuch's and barely had enough room to slide a piece of paper inbetween the wheel and the caliper. 15's will fit just depends on the offset.

Or you could run 4 piston Wilwood Forged Superlights. Pick your piston sizes. Put a small spacer (washer) between it and the mounts on a stock late 911 front end. You have 4cm^2 less pad area than a 930 caliper (4%), calipers that are only $130 each, the ability to completely rebuild them, including pistons for ~$45, and ANY brake pad compound you want for under $100. Lots of room under a 15x6 Fuch.

Jeroen has it right on the floating rotors. They're supposed to be "loose", in that the friction surface of the rotor is not supposed to be firmly attached to the "hat". The rotor shouldn't rotate much with respect to the hat, but they may rattle around a bit. The rotors float so that they can expand as they heat up, and don't distort since the mounting points have some give in them.

This also somewhat isolates the rotor and hat thermally, so the hat (which is often made of Al, where the rotor is made of iron) won't conduct rotor heat into the hub, thus making life easier for the wheel bearings.

Actually Jack Olsen (bird board guy for those that don't know him) has a rather nice 911 (in the Pelican Parts ads now in Excellence) with 930 brakes on it. He tracks the crap out of it (I guess at least a once a month average) and I know from personally being in the car he is not easy on the brakes - he has something like 6 or 7 yrs on his stock rotors!! So if I have any wear issues with the VCIs, I will spend the $350 and get the stock rotors.

So he drives the car to and from the track and beats hell out of it at least 12 track days a year and has at least 6yrs on a set of rotors. And his car is at least 200-300lbs heavier than an average 914, so I wouldn't worry about the cost of the rotors!

I have $3K in my setup btw and bought the calipers "used, but never actually used" (think new in box) for $1400 a few years back, so I have a reasonable deal on them. $3500 for a solid braking setup on a Porsche isn't unreasonable, sadly enough.

It would be nice to adapt a Wilwood setup to the car cost-wise, but the rears might not be easy to convert I would guess. Just have to get a turbo rotor and try it...

I'm glad you said that...now the mob will be at your door. I was thinking that it didn't seem so bad. Which just goes to show you how mad all this stuff really is.

All things considered the VCI kit looks like a pretty decent deal if you don't want to mess around and just do it.

Later,
Kevin

VCI uses or used Coleman rotors. You can source the rotors direct from Coleman, and skip the middle man mark-up.

930 brakes are just awesome, using the VCI components, that Doug sells seperately will result in great brakes.

Wilwoods can be set up a few ways, they fit over stock SC or Carrera, these work ok, but are at the thermal max, to work properly you should get a hat and proper rotor.

You can also add big reds ..cost will be $4k from Racetech..

How do you figure the Wilwoods are at the thermal max? The calipers can take the heat probably better than 930 units and I would think the rotors have enough venting to be more than acceptable.

Remember, depending on how you figure the 930 brakes to be amazing, you can get the same thing much cheaper. You can get Wilwoods with more pad area that are more resistant to heat.

For rears, you could just add a tab to make the bolt spacing 3.5 inches. The calipers would fit up with just a small spacer.

Matt

I bet there are all kinds of brakes options that yield similar or even superior performance when compared to 930 brakes. But compare...the...looks. The 930 caliper looks period appropriate unlike the modern monoblock calipers. At a price, I'd do the S2 brakes no question. Price not a factor: 930 brakes.

Check 'em out...
The 930 and big red are from VCI. The Wilwood is from the Wilwood catalog.

Later,
Kevin

ummmmm big reds... That sure looks nice. i really want a set of monoblocks. What kind of money are we talking for that route?
Eric

just saying Wilwood brakes is kinda being "generic", there are some Wilwood calipers that might melt after a good track run and others that'll darn near stop a 747 while landing....

what Tim was referring to was that to maximize the brakes, a new rotor and hat design would be better than just throwing the Wilwood superlights on and keeping the stock one-piece rotor/hat

from what I've read on the Pelican site and other sites, many of the more popular used Wilwood rotors do not last as long as the Brembo rotors.....but at only $39 a pop, who cares (that is what my Wilwood 12"x.810" vented rotors cost)

thats easy, its not the caliper that is being overly taxed... its the rotors. Putting a nice big caliper, with 4 pistons, larger pad area, and more aggresive pads on a stockish rotor taxes the thermal reserves of the brake rotor..

The rotor is what gets rid of all (most) the energy (heat) that you generate from decelerating a car

a really nice brake system for 914s that is cost effective, but unfortunately doesnt have much bling, is a take off set from a carrera. Can be had for cheap, rotors are cheap, and makes a matched system.

I have the boxster 4piston calipers with 15's in my sixer

The boxster calipers are much cheaper and more
effective.

Wilco

It's Aaron's fault!!!!


I had them on my 3.2 and I have a set for my 914 too
I never tried them with 15" wheels though
Aaron recently posted they wouldn't fit (and I was stoopid enuf to trust/believe him )

Hi Aaron

This brings up an interesting point that I've never been able to resolve. People will argue that if you are stopping a certain weight car in a set distance, regardless of brake size, it generates the same amount of heat. I'm not an engineer (shadetree doesn't count ), but that sounds resonable to me.

If that is the case, then the size of the caliper, number of pistons, etc. deosn't really matter. That said, as long as the rotor can handle the thermal loads, the caliper isn't that important.

In my mind, the biggest problem 90% of people have is lack of airflow. Heck, I got stock brakes to work on my car with ~175 horse out of a 2270. At places like Watkins Glen, Pocono, Limerock and Sebring they weren't a problem. At NHIS, I could overheat them in about 15 minutes, but NHIS is one of the hardest tracks on brakes in the country.

Matt

Yeah I wopuld pretty much agree you are generating the same amount of heat. It's the rotors ability to shed the heat.

Friction of the tires to the road stops the car. Brakes convert your momentum into heat. Or something liek that

I'm not a thermal engineer, but I play one on television.

What is heat?

I have had great success running the 944 Turbo calipers F+R with 84+up Carrera rotors on a 914. They fit under the 15inch Fuchs and provide more than enough stopping power for all the track cars/street cars I have ran them on.

I have done the complete 930 setup on a V8 conversion car. All it does it lock up the 205/45/16's on 16x6 Fuchs. WAY overkill.. but the COOL factor is way UP.


B

here a pic lifted from Bill V on pelican, it shows in extreme, what happens when you overstress a stock sized rotor.

Is it hard to control the locking with that size master and did you use a 23mm?

I put 83 fronts on my car with stock rears and stock m/c. Car stops really well for me and I like the softer pedal.

Altough my ego wanted monster colorful calipers with logos, I forced myself to listen to the experts and get what was right for me. I guess my favorite question is are your current brakes working?

FWIW I have noting against Wilwood calipers. Wilwood makes some great components.

I have Wilwood superlites on my 914, but with hats and 11.75X1.25in rotors front, and carrera calipers/rotors rear.

The 944 turbo calipers can bring much joy also.. ie on my 911 I have 951 front and 965 rear calipers.. I use 944T rotors up front and 930 turbo rotors rear.

Part of the cool factor with 930 brakes is really that they are 917 calipers

I ran the 944T fronts on my 2400# 3.2 carrera and they worked very well
No more fading on the track
So they'll be more than plenty for my 914 (weight goal 1750#)


Do the rears bolt on to the 914 rear trailing arm
Or do they need spacers/shims/adapters/machining?


Did you machine your hubs? or what did you do to fit them?