Hi, I've read many threads on rear brake conversions. I just happen to have a pair of vented rear rotors off a 71 that are in excellent shape. I also have relatively new 914 rear rotors that I can have drilled. I've read where people have had spacers made so they can use their existing rears with vented rotors. Does anybody make these or have some? Or do I need to just find a place that can do them one-off? Or, I may just drill out my existing rotors for 5-lug. Just looking for easy options!

Thanks in advance,

Jim

a '71 -what- ?

might want to do a search... they're out there. I don't remember who it was but they were going to make a batch soon. Pricey IMHO.

I'd just drill the rotors you have to 5-lug, especially if you're using the stock caliper.

Next step would be to get 914-6 rotors and look into the grinding required for the caliper. The six rotor is slightly larger than the four. (grind the caliper once, grind the rotors everytime you get a new set...).

I'm not sure what you are asking for. There may be two kinds of spacers involved. There is the spacer ( about 1/8" thick ) that goes behind the rotor to position it properly inside the caliper. Then there are the spacers for the calipers that widen them to accept the vented rotors. There are two kinds of those as well; spacers for the 914/4 caliper (custom made) and the 914/6 caliper (from the 911 wide rear calipers). I guess I'll have to take a photo of all the parts so that everyone can see what is used where.

I just sold a set of spacers for the 914/4 rear caliper; they are off to Germany as I write. I have three sets left.

For all, sorry I was not more descriptive.

I have:
1. vented rotors off of a 71 911
2. 914-6 stub axles
3. 911 hubs
4. 914-4 rear calipers

What I was asking about was the spacers required to widen my stock 914-4 calipers to be able to use the 911 vented rotor.

Davep,

Are the spaces you have for widening the 914-4 stock calipers? If so, could you pm me how much you want and how difficult it is to install them?

Anybody else have some insights?

Jim

I know you need both the spacers between the caliper for the vented rotor and spacers between the caliper and the trailing arm.
I just used two washers behind each bolt for the trailing arm.
I was also told you need to turn down the outer diameter of the 911 rotor to fit a 914.

Steve

Some have reported this getting the caliper too close to the control arm but that must be a six caliper. The other method is to have a spacer made for the hub that fits under the rotor.

Okay, these are some of the parts:

911 / 914-6 hub spacer between hub and rotor


914-6 caliper spacers 914-4 caliper spacers

notice the differences in thickness and bolt spacing

I just did a little checking. The rotor diameters are different, so some turning of the rotors will be needed.
914/4 rear 282 mm
914/6 rear 286 mm
911 vented 290 mm
I have used the 914/6 rotor with 914/4 calipers without problem.
I have used the 911 vented rotor with 914/6 calipers.
The 911 vented rotor will not fit in the 914/4 caliper without some machining. There is not enough material in the 914/4 caliper to consider grinding it to fit. Allow enough clearance for the rotor to grow when it is hot. I would be inclined to reduce the diameter to 282 mm. Excess diameter does nothing for you. The pads do not work out there, it is extra unsprung weight, and a greater flywheel effect.

Dave,
I just got a 911 hub and rear axle set up as pictured and have rear vented 911 rotors. Besides machining the rotor diameter to 282mm, what else would I need to run stock 914 rear calipers? I'm considering 911 rear calipers with the Renegade hand brake.

Whoever did my rear suspension (bought it used), Put a spacer in the calipers, I think its a fine way of doing it, just make sure that you get new bolts that match the new length.

Dont know what spacer they used, so I cant really help you. lol

Andrew

http://www.914world.com/bbs2/index.php?act...&hl=spacer&st=0

Check the pics (1st and second page).