VCI 964 brake upgrade

[Todd Simpson]

I installed this kit a few weeks ago and thought I'd share details.

This is the kit sold here.

http://www.vehiclecraft.com/Brakes/VCI911_2_964.htm

Ship VCI your 964 calipers and you get the below shipped back. All 4 calipers need to be machined to mount to an early 911.



Front rotors are from an '86 944 turbo, 28mm thick. You can see it's bigger than a 24mm Carrera rotor, but also the "offset" of the rotor is different, requiring the wheels bearings to be spaced out 4mm with a spacer.



Here is the VCI spacer installed behind the original spacer, with the other side spacers for reference. For some reason, my car did not have the original spacers at all, the wheel bearings were installed all the way up the spindle. No wonder my Carrera calipers needed to be shimmed on the spindle to center over the rotor.



AJ-USA cooling kit backing plates had to be replaced as well with 930 items. Notice the SC/Carrera plates left a gap, the new 930's do not.



23mm master cylinder compared to the original. Pushrod is different, one feedline needs to be moved and hard lines need to be bent, not the difference in the outputs. Brake switch gets tossed.



Fully installed front and rear.





Lots of clearance with a 7x16 fuch. They also easily clear 17" Lindseys which use a 16x6 center. Clearance in 951 8's and 930 9's is ridiculous, probably an inch or more.



I tried to get the pad overhang in this shot. I may open the throats down the road and try to use 930 rotors so I'm using all the pad. F-R bias is 1.71 and this overhang means even more front bias.



I've only done two track days since the install and I'm still getting used to the modulation. I like the completeness of the kit, you need pads and figure out a few details otherwise it's all there.

Bang for the buck is low, this is a lotta dough, and you still are a good distance away from 930 rotors in terms if thermal capacity. That's not a concern from me as I never faded my old Carrera/SC brakes. 2200 lb. car.

One last thing, I "warped the rotors" in my first session...what was really happening was pad deposition, made worse by poor braking technique. Once I got on the brakes hard and for short periods of time, that went away.

[threegunner]

Todd,
I've been waiting to hear about this particular kit. Thanks for the report. Excellent pics and comments.

[89911]

Originally posted by Todsimpson

One last thing, I "warped the rotors" in my first session...what was really happening was pad deposition, made worse by poor braking technique. Once I got on the brakes hard and for short periods of time, that went away.

Been there. I warped a set of front rotors the first weekend out that were part of the VCI package for 930 upgrades. They turned out to be Coleman rotors that had very little mass compared to equivalent sized Brembos that I later switched to. I've use those for 2 years with no issues since. Be prepared for more of the same if your using the same rotors as replacement.

[jpahemi]

The pad over hang and 4 mm spacer kept me from going for this kit.
j.p.

[ovilla]

Just curious. Can you mount 15X6 fuchs on the front? I know everyone uses 16" wheels but I love my 15's on my 914. Thanks

[Jeff Alton]

The warping todd describes is actually pad material being deposted on the rotor. His "proper technique" wiped that clean and everything returned to normal. This is fairly common not just with this particular application.

Jeff

[911-32]

I have the same kit installed in the front. You don't need to do the rear kit if you just use Carrera rear rotors/calipers and remove the proportioning valve, thereby getting rid of the pad overhang problem and virtually halving the cost. Doing it without the rear kit gives you a set-up very close to the early 964s with the 2-piston rear calipers only with slightly more front bias.

You can also do this with a standard 3.2 master cylinder rather than upgrading to 23mm - if you start with a 3.2 of course. So the cost of the 964 front kit on a 3.2 becomes even lower compared to 930 brakes. Cost-benefit then starts to make some sense. Replacement rotors are also cheap compared to 930.

Three comments on driving impressions. First, it is ever so slightly too front biased - as you would expect. On cold tyres (or cr@p old tyres) it is easier (not easy per se, just easier) to lock the fronts - so the bias isn't perfect. Once everything heats up, its pretty damn good though. Secondly, it is a fraction more difficult to modulate near to lock-up. Maybe the bigger master cylinder would help - you always have that option. I am going to try different pads. My first set of Pagid Blues are holding up remarkably well. Three track days and they have only worn by 1-2mm. I have never thought the Blue compound was very communicative anyway but it works street and track and is relatively rotor friendly. Thirdly, the thermal reserves seem more than adequate. I had to run last week without any ducts after the hoses started to fall apart. Seemed to be no problem at all, although it was pretty cold. My car is a still fairly heavy G50 Carrera weighing 1200kg with half a tank of gas. As it is only getting lighter, it works for me.

Richard

[89911]

Originally posted by catca
The warping todd describes is actually pad material being deposted on the rotor. His "proper technique" wiped that clean and everything returned to normal. This is fairly common not just with this particular application.

Jeff

Granted, this is true. When I pulled mine off the car and turned them, they looked like a vinyl record left out in the sun. I like mostly what VCI does but would stay away from there rotors regardless.

[Todd Simpson]

The rotors in this kit are Zimmerman 944 turbo rotors, not the Colemans.

[Bill Verburg]

Chris Streit has been using that setup for a couple of years now, he likes it. The only problems( I have heard of so far) were over-cooling the brakes on a couple of the longer tracks that don't stress them much, solution, block off some of the cooling duct area.

While you can use the 20.64 power brake m/c from an SC or Carrera the 23.8 gives a much, much better feel, the 20.64 is border line w/ Carrera rears and over the edge into dangerously inadequate w/ the 964 rears.

[Jeff Alton]

89911, I agree about Coleman rotors. I have heard stories about them not even being true when new! IF there is another option, I would say get it, like you did. VCI seems to like them, but then they also are trying to sell them so......

Jeff

[cstreit]

The overhang and spacer are no biggie. I've used them for 3 seasons now and find that the bias is fine. The spacer doesn't appear to stress the bearings at all as I thought they might... While I go through a set of rear bearings every season, the fronts have remained perfect for 3 now...

I too experienced the pad deposition issue (and also thought it was warping initially) but solved this by getting away from overpriced PAGID's and moving to Performance Friction pads...