Eric,
thanks for all this info. for once it seams i made the right decision, that is to NOT change my calipers, but stay with the stock ones. I did not know as i was thinking about this last week ,and i was strongly considering: the Brembo alloy front caliper "upgrade" and 914-6 rears, that not only would it be so much more $$, it would not have been the best decision considering my choice of conversion-(914 rotors drilled to the 5 lug spec). Now if i had sourced 911 hubs etc, then of course 911 rotors and matching calipers would be the way to go. So- glad i asked the question before just blindly jumping in and going the other way.
-btw the rest of my order arrived yesterday!! Going to have fun this weekend -
except i think i just realized that although i just put my tranny back in and replaced all my CV gaskets, i guess i will have to replace these again?(its been less than 1500 miles)
Phil
QUOTE(Eric_Shea @ Sep 10 2013, 02:08 PM)
Some Further Edification:
There's a couple ways to go to get a 5x130 rotor on the back of a 914 and, there are a lot of fit issues with each. The choice is usually predicated upon price and caliper selection.
If you are using stock 914-4 calipers with modified 914-4 hubs the choice should be a 914-4 rear rotor drilled to the 5x130 specs. with care given when indexing to retain the 2 chamfered mounting holes. The reasons being:
1. Your 914 hubs have these mounting holes machined into them and hopefully, they were also indexed to retain them. On our "group buy" the hubs and 914 rear rotors were both indexed to match and the mounting holes were retained.
2. You're going to have to machine either rotor so you might as well machine the less expensive 914-4 rotor to 5x130 vs. machining the expensive 914-6 rotor to the proper diameter
If you are using 911 rear hubs (as the 914-6 did) and stock 914-4 calipers, then you should probably get the 914-6 rotors and have them machine the diameter to match the 914-4 diameter. This involves shaving 2mm off the edge or 4mm off the total diameter. Because:
1. You will not have to machine two new rotor mounting screws into your 911/914-6 hubs.
2. You will not have to machine the rotor to 5x130. With both of those bits of machining needed, it would probably be a wash in price for the 914-4 rotor and the 914-6 rotor with minimal machining needed.
Obviously, 914-6 calipers and 914-6 rotors will mate right up. 914-6 rotors and 911 rear calipers will also mate up.
Here's another element of surprise:
If you want to move to a vented rear rotor (911 is about the only one available), then you will need to:
1. Take 4mm off the diameter if you are using a spaced 914-4 caliper "and" put 4.5 to 5mm spacers under the rotor hat or under the caliper mounting ears.
2. Check for fit with a 914-6 caliper and 911 rear "and" put 4.5 to 5mm spacers under the rotor hat or under the caliper mounting ears. Some brands of 911 rear rotors (Brembo Sports) seem to fit in this application whereas Zimmermann and Sebro appear to need the diameter trimmed.
If you go to a vented rotor you have the choice of either special ordering the factory GT rear rotors (still available and around $250.00 each last we checked) or simply spacing out the 911 rear rotor 1/2 the distance of the 10mm caliper spacer.
In Phil and Chris's case, the group buy used 914 hubs and 914 rotors so everything is a straight forward bolt on application.