Any difference between RSA and "regular" 964 calipers?
 

Hi, bought an SC the PO installed RSA front calipers on. I need to buy new pads. I'm assuming from what I've read there is no difference between stock 964 and the RSA calipers but just wanted to make sure.

http://forums.pelicanparts.com/uploa...1183396089.jpg

They're the same.

In fact they use the same pad as the 930 caliper.

Be advised that the setup you have is not very good for several reasons

dicounting the performance reasons, the caliper is designed for a 28mm rotor, using it on a 24mm rotor can lead to issues w/ the pistons.

He also used carrera rotors and carrera calipers in the rear. I'll do a search on the specific performance reasons you mention. I assume it's been well bashed in the forum. If not, anything you can add would be helpful.

Thanks,

It's just that the stock calipers can easily overheat Carrera rotors, using the 964s which can put more heat into the rotors more quickly make even more of an issue.

Stock '84-89 Carrera rears are a good match but you do not want a p/v w/ them matched to 964 fronts

Thanks. I'm assuming p/v is proportioning valve, not sure if he took care of that, doubt it.

He did add cooling ducts and block off plates to the fronts to help with the cooling issue.

I had the car at the track recently and the brakes felt a bit soft. Just didn't bite very well, didn't seem to get worse during the day. I'm a low intermediate guy at this point, trying to climb my way up the DE ladder :-) safely above all.

I knew the rotors were going to be due to be changed out from the PPI I had, I was planning on going to a PFC 97 pad based on my bit of research of old threads at the same time and of course bleeding the system.

At this point I'll probably take it to the mechanic who built the motor and tranny and is an instructor with our club and ask him what to do.......

Is the p/v a do it yourself install and what part is the right one? Do you go adjustable with this set up?

The soft pedal is another side effect of the 964 calipers, you will want a 930 23.8mm m/c

p/v(proportioning valve) should be eliminated, you could replace it w/ a nice adjustable one but unless you A/X it will be set to off.

The stock p/v is in the front trunk on the line to the rear, follow the brake lines coming off the m/c

Bill,

Thanks for the help. I mis read your earlier post as needing a p/v vs. wanting it gone. I don't AX the car, it's street and DE use at this point.

I'll look through the receipts. I know he did something with the MC but not sure it was anything more than a stock replacement. The car is a euro 83 SC.

Overall I'm gathering you are not a big fan of "upgrading" to 964 calipers. Again, I'll do some reading. I think I have a set of Carrera fronts on the 72 project that's sitting in my garage. Wouldn't be the first parts I stole off of it :-)

Thanks again!

I am a fan of the 964 calipers, but only w/ '78 up 930 rotors, using those calipers w/ Carrera rotors is nonsense.

here is a pic of the 964s I used to have on my own car
front
http://forums.pelicanparts.com/uploa...1183414596.jpg
back
http://forums.pelicanparts.com/uploa...1183414692.jpg

Bill, sorry to bug you again. I wanted to try and summarize my options;

If I stay with the 964 calipers I should remove the p/v if there is one, upgrade to 78+ 930 front rotors and upgrade to a 930 23.8 mm master cylinder. I assume the turbo rotors are a direct swap, just a lot more pricey :-)

I see these two options on pelican for rotors:

930-351-047-00-M136 $417 each (78-80 turbo)

930-351-047-02-M259 $140.24 (81-89 turbo)

Looks like the MC is:

930-355-011-03-M4 $272.25

I'm hoping the rotor option is number 2.

Sounds like I could get a set of Carrera front calipers (which I think I have) and stick with carrera rotos and the rest of the setup currently on the car. I'd get the calipers I have rebuilt.

Am I getting this? Sorry to be a Newbie here, you've been very patient and helpful. Hopefully someone besides me is getting some useful knowledge out of this as well.

Jerry,
For the rotor question, you need the 78-80 floating rotors. You also need the hats and T-Locks for the floating rotors.

The floating rotors/hats are very spendy but worth it if you plan on a lot of track time. I've run 40-50 minute sessions on/off all day at PR and have a hard pedal all day.

Unforunately it's not quite that easy which is why I srted recomending 993 calipers to start w/

964 calipers are axial mount like the A and M that came on your car, this one happens to be a 964 rear modified for mounting on 3" centers on a 911 trailing arm. This will nmeed a '78 -'89 930 rear rotor. This mod is pretty easy.
http://forums.pelicanparts.com/uploa...1183466633.jpg

Unfortunately the 964 front is externlly the same, to use the large 32x304 930 rotors the mounting ears need to be machined off and a radial mount caliper adapter fitted, like this
http://forums.pelicanparts.com/uploa...1183466917.jpg
Then all you need is the 930 m/c

If you leave your brakes as is, yes, remove the m/c and don't let the pads get more than 50% worn.

Don, thanks, I was afraid of that. I'm not prepared to invest in over $1,000 for two front rotors at this point. I'm not doing that much track time, 6-7 DE's a year right now, 20 minute sessions.

I think I'll go see Chris Powell and see what those part numbers are for the calipers on my other car :-)

I have these calipers off of a 72 project car I have which has all sorts of SC and Carrera bits on it. I assumed these were Carrera calipers due to the wire for the pad sensor but wanted to make sure.

It seems from this thread that I'd be better off in the near term to rebuild these if they are the right ones and use them vs. the 964 until I could change out the MC, etc.

Only concern is with Carrera calipers in the rear now, the SC doesn't have a proportioning valve and it sounds like the Carrera's had one installed.

Clear as mud?

http://forums.pelicanparts.com/uploa...1183993889.jpg http://forums.pelicanparts.com/uploa...1183993921.jpg http://forums.pelicanparts.com/uploa...1183993949.jpg http://forums.pelicanparts.com/uploa...1183993977.jpg

If those are 3.2 Carrera front calipers then you are all set. Just use them in the front w/ your existing 3.2 Carrera rotors and leave everything else stock. If they fit over the Carrera rotors on your car now w/ pads installed then yes, they are the correct calipers for your app.

You get all the benefits of the Carrera rotor w/ none of the drawbacks of using an inappropriate caliper w/ it.

Do us all a favor and measure the thickness of the spacer between the 2 Carrera caliper halves. I had it once but can't find it now.

I'd be happy to measure it, what points on the caliper do you want me to use to measure from?

See the big spacer piece that goes right down the middle of the caliper, If you undo the 4 bolts holding the caliper together it will fall into 3 pieces, outer half, spacer, inner half.

Don't take it apart, just measure the thickness of the middle spacer piece,

I see it, I'll do it tonight. I measured the gap between the pads right at 24mm, looks like back in the day this thing had good rotors and pretty new pads.

Too bad it's been sitting, the rotors have a light rust coating on them and I had to hammer off the calipers once they were unbolted.

I may still have the proportioning valve if you end up going this route. I'll dig thru my box.

Sorry for the delay in getting this measurement, the calipers went to the rebuilder and I just got them back and mounted them tonight.

Here is the measurement, looks like .444 inches or roughly 11.3 mm's if I'm reading the caliper correctly.

I put on the calipers and bleed the system tonight, will check everything out tomorrow and put it on the road.

A fellow Pelican is sending me the lines and proportioning valve from an 84 parts cars. For now I have PFC 97's in the fronts and some softer pads in the rears. I'll see how it feels with those and install the other lines when they come in and put the 97's in the rears.

It was a bit of a pain getting the hard lines off my parts car. The 964 calipers had to be installed with several washers at the hard line to soft line connection and the holes were elongated on the calipers to get them to bolt on. I'm glad that stuff is off of there at this point.

http://forums.pelicanparts.com/uploa...1187069906.jpg

Thanks!

Sorry to resurrect a old post, but I have a question for Bill related to using the 964 calipers and want to add to this thread for archiving purposes.

Bill, I have a set of front 964 rotors in my garage and was considering going with the 28mm 86944 turbo rotor route (Since they are much cheaper) with VCI machining plus using Carrera calipers and 24mm rotors in the rear. If I did go with the 930 rotor in front, does the machining of the caliper change or will the same VCI machined caliper work with both the 86 944 turbo rotor and the 930 floating?

Also, why is the 930 floating rotor so expensive? Is there another source to get these, other than Porsche?

VCI's adapter is machined differently for the 944 Turbo rotor. The OE 930 rotor is located differently (has a different offset) than the 944 Turbo rotor. So i'd venture to guess that the caliper adapters Bill used to have for his 964 calipers are dimensioned differently than the VCI adapters.

http://www.vehiclecraft.com/Brakes/vciweb4.htm

I believe VCI does machine calipers for the use of 930-like floaters, but they use the bigger 993/S4 calipers and not the 964 calipers. Reason being, the S4 caliper is originally designed to accept the 32mm thick rotor that is used in this upgrade, vs. the 964 being sized for a 28mm thick rotor. I'm not sure if you're aware of this, but the 86 944T rotor not only requires the calipers to be modified for adapters- you must also use some wheel bearing spacers which are installed onto the strut spindle. These spacers push the rotor another 4mm-5mm (depending on which spacer you request from VCI) away from the a-arm to make the rotor face clear the end of the a-arm. I use the 5mm spacers and still had some rubbing, even after grinding down the a-arm.

There are other sources for the rotors besides the OE floaters. Wilwood, Coleman (VCI uses these -floating or non- and some people have had poor results with them), Brembo racing, AP Racing, Alcon. These need custom sized hats/annulus to mount them to the wheel hub. I used a Wilwood HD 309x32mm rotor with my 993 front brakes. I got the adapters (both the caliper adapters and the rotor hat/adapter) from Dave Walsh at ProBraking.

This doesn't address the most recent question but is an update to what I ended up doing.

The PO for my car had mounted 964 calipers in front, carreras in rear with 24mm rotors all around and no update to the MC. He elongated the mounting holes on the calipers to fit them.

I had a mushy pedal, felt very uncomfortable on the track.

I ended up installing rebuilt carrera calipers and the carrera stock proportioning valve from a friendly Pelican donor. Installed PF97's all around and had much better braking at the track yesterday. I also have cooling ducts in the front.

This seems to be a good compromise for me now. Had good consistent brakes all day yesterday, very predictable.

Could I reuse those 964 calipers later with the elongated holes???

The folks with Carreras that only put the 964 calipers on the front do contend that it works well for them. If I recall correctly, Bill Verburg says this setup with VCI fronts (964 40/36 calipers and '86 951 turbo rotors) and stock Carrera rears, with pressure limiting valve in place and stock master, is more front biased but still can function well.

You can certainly reuse the calipers if they are properly fitted with radial-to-axial adapters. To fit them for adapters, the existing mounting ears with the elongated holes are cut off completely to mill the caliper flat and tap the caliper body to accept the adapter mounting screws.

I wouldn't.

They are a good candidate to be converted to radial mount
like this

http://forums.pelicanparts.com/uploa...1189860272.jpg

Then you can use them w/ 304x32 930 size rotors

Link - text of RSA owner's manual says they're the same as 911 C2:

http://www.rsamerica.net/OEMinfo/Tech%20Service%20Info/index.htm#brakes