sergiDA

Hi all:

I am trying to upgrade my brakes for my 964 c2 1990, I use the vehicle exclusively for track, I don't want to spend a hell of a lot of money and have been offered with a 986 Boxster kit with all the necessary assembly for 1300 $

http://www.ladismantler.com/index.ph...em&inv_id=1446

I will use high temp fluid and good Pagid yellow pads.

Do you think braking will improve? is this a recommendable upgrade?


Thanks for all your support.

Sergi

ilko

I would start by getting 964 C4 (or 964 C2 MY92+) 4 piston rear calipers, along with higher boiling point brake fluid and a nice set of pads. You can get the calipers for around $300 on this side of the pond. They are completely plug & play you don't have to replace the rotors, or anything else. And will definitely notice an improvement.

race911

As Ilko said, the rear caliper upgrade is all you need. Plenty of us race(d) stock class and have to run stock brakes (pads/fluid/air ducting free), and have zero problems with 3200 lb. cars (w/ driver).

sergiDA

Thank you both for the advise, straight and very clear answers.

Can you recommend me a place where i could get them?



Thanks again.

boxsey911

There are a number of 4 pot rear calipers that will fit. I got some off a 928 S4 from ebay. Just needed to refurb them and swap the bleeds and feeds before fitting.

sergiDA

Do the rear 993 calipers work, or they would be too big?


http://cgi.ebay.com/ebaymotors/ws/eB...20887048140112


Thanks

boxsey911

Rear calipers off a 993 C4 will fit as they are essentially the same small body 4 pot caliper with 30/28 pistons. The calipers from the 993 C2 and C2S have 34/30 pistons are normally only used when fitting big reds or big blacks to the front. Unfortunately, that ad gives piston sizes that are different to both of these options so I can't tell if they're the ones you want (i.e. the C4 version).

sergiDA

thanks Steve, this is helping me to narrow the search.

Great

Bill Verburg

If you are retaining your stock 964 front brakes then you want 28/30 rears from a 964/928/968/944 note that some of these are trailing mount so you will need to swap the bleeds and feeds for use on a 964 in the leading mount position

you do not want to use the 993 rears, which are 30/34(the ad is misleading but probably correctly id'd the calipers as 993) unless you are using either big reds or 964RS in front.

the 986 brakes are not an upgrade for you

Oracle

Bill,
If you don't mind me asking why not?
I don't know brakes but the Boxter's look newer,bigger, improved?? What is the logic for "brake upgrade" ? (if it's easy to put in a few words)


Thanks
Gaspar

Bill Verburg

the whole point of a brake upgrade is either greater thermal performance or less often greater brake torque.

the former comes from larger rotors w/ more mass and better internal flow and better mechanical proprerties, the latter form bigger pistons and greater rotor diameter

comparing 964 to 986 you will see that neither condition is bettered in the 986

here's a quick comparison in order from least to most capable in thermal capacity and toque
986
298x24 w/ 36/40
292x20 w/28/30

964 stock
298x28 w/ 36/40
299x24 w/28/30


993
304x32 w/ 36/44
299x24 w/ 30/34


964RS
322x32 w/ 36/44
299x24 w/ 30/34



993RS
322x32 w/ 36/44
322x28 w/ 30/36

there are other differences that are harder to see and evaluate such as the internal rotor struture and materials

boxsey911

To back up Bill's figures I can say that as an owner of both a 964 and 986 boxster that while the boxster stops very well it just doesn't feel like it has the retardation power of the 964's brakes.

sergiDA

My mechanic has traced a pair of 928 s4 rears at 400 € delivered and we have just ordered them.

Since I am changing the worn out rotors and pads, and the whole thing needs to be modified... I will paint all 4 calipers in yellow, remove the dust covers, as advised by someone here ( think Bogadonuts) and install a brake cooling kit in place of the fog lights...

Thanks all once again.

boxsey911

Sergi, one thing we haven't mentioned is that you're advised to swap the brake proportioning valve from the standard 45 bar unit to the later 55 bar unit. Buy it from Porsche for about 50 euros (part no 964 355 305 10). It's very easy to swap.

In case it's of any use here's my write up on fitting 928 S4 rear calipers to my 964:

http://964uk.com/html/How-tos%20-%20Brakes.htm

sergiDA

Great report, I will follow all instructions in detail, the truth is that second hand equipment needs to be refurbished and I will do as well.

By the way where did you find the : "new spring plates and screws. These come as a kit with green Loctite already impregnated on the screws"

i am saving 964uk.com in my favourite pages.

Bye now.
Sergi