VCI Wheel Bearing Spacer Specs

[Jaybird12]

When using an 86' 944 turbo front rotor on a 911 VCI uses a wheel bearing spacer. Does anyone know the specs (dimensions) of these spacers? I'm trying to upgrade my front calipers with some small Brembos from a 964.

[911pcars]

I recall VCI spacers are about 0.040" thick. The spacer ID is slightly undersize to install with heat onto the steering knuckle spindle. I'd suggest a trial fit to confirm the spacer thickness needed to center the rotor to the caliper.

Sherwood

[Jaybird12]

OK. That's a starting point. The only pieces of the system I've assembled so far are the calipers. Need to track down some rotors next.

[911pcars]

Originally Posted by Jaybird12

OK. That's a starting point. The only pieces of the system I've assembled so far are the calipers. Need to track down some rotors next.

Going to use the matching 28mm '86 Turbo rotor?

Sherwood

[KTL]

Originally Posted by 911pcars

I recall VCI spacers are about 0.040" thick. The spacer ID is slightly undersize to install with heat onto the steering knuckle spindle. I'd suggest a trial fit to confirm the spacer thickness needed to center the rotor to the caliper.

Sherwood

Agreed. I've used this brake kit and found that the spindle spacer was sized to accommodate the most clearance from the brake rotor to the ball joint area on the A-arm. Meaning, the spacers do not do a great job of centering the rotor within the caliper.

Also agree with Sherwood that the spacers are a slight press fit so you have to heat up the spacer to install/remove them. Note that the spacer goes BEHIND the spindle collar. I've seen some people put this spacer INSIDE the wheel bearing hub between the grease seal and the bearing

I have some of these spacers at home I can measure. I recall VCI offers them in various thicknesses. 3, 4, 5 mm thicknesses if I remember? I think I have the 4mm size and a friend is using the 5mm I gave to him with the calipers.

All told it's not a perfect fit brake upsize. But it's a very nice job by VCI and works very well. We've been using it in our circle of race & track cars for about 10 yrs. and it's a solid upgrade to the front brakes on an SC or Carrera. We've found that the rear brakes are OK to remain stock (Carrera w/out pressure limiting valve installed is slightly better than stock SC) instead of using the VCI modified rear Brembos. There's really nothing to be gained by using those rear Brembos on a stock Carrera rotor, aside from the larger pad being a better heat insulator, so just stick with the stock SC or Carrera calipers and rotor. Plus the use of the stock rear brakes affords you the use of the stock master cylinder. No need to use the 930 master cylinder if you've already got the stock 20.64mm SC/Carrera master. Pedal effort and travel are OK with the SC/Carrera master

[Jaybird12]

I do plan on sourcing the 86' turbo rotors from a 944. Am I to understand that 86' is the only suitable year? Kevin; that's fantastic info. Thanks. My situation is this. 1975 911S Targa. Front struts are only 3" spacing so I need to upgrade to the 3-1/2" spacing. My rear calipers are stock. M type (or is that just the front?) Either way, I need to figure out if they will work with the new set up in the front without causing an unbalanced issue.

[911pcars]

Originally Posted by Jaybird12

I do plan on sourcing the 86' turbo rotors from a 944. Am I to understand that 86' is the only suitable year? Kevin; that's fantastic info. Thanks. My situation is this. 1975 911S Targa. Front struts are only 3" spacing so I need to upgrade to the 3-1/2" spacing. My rear calipers are stock. M type (or is that just the front?) Either way, I need to figure out if they will work with the new set up in the front without causing an unbalanced issue.

Here's a couple of threads on the subject:
951 caliper piston size
Help! Brake upgrade on a Carrera with some issues - Brembo from a 944 turbo

S

[Jaybird12]

Excellent. Thanks again. Not sure if my stock, albeit brand new, 19mm master cylinder will be up to the challenge when all is said and done.

[KTL]

Yep the '86 944T is the only rotor that works. This is a one-model-year-only rotor for that car. No other Porsche car uses this rotor that i'm aware of.

Here's some good info C2 front caliper on a SC/Carrera? Do a search with my username and "VCI" and you'll find i've commented on these brakes a number of times. I think its the best bang for your buck in terms of a medium sized brake upgrade.

Got tied up at home last night and didn't get a chance to go thru the parts bins to find those spacers. Will try again tonight