5 stud conversion.

[johnkennedy]

is there any 5 lug rotors available for 914s with out changing to 911 stuff?

[Zeke]

The main reason to change rotors in the front is to get the vented rotors. Otherwise just use adaptors. If looking to use 7 inch wheels, you probably will have to find some FWD deep backset wheels you like. If you want Fuchs, you might be able to drill your hubs and rotors like you do the rears (well the hubs anyway on the rears and I really don't know that you can drill the fronts, just a thought), but that's more work than changing the struts and using 911 parts. 911 M front calipers and the struts for the M's are dirt cheap. The struts for the S or A caliper can be more expensive, however there are other caliper options like BMW and SKline is using Volvo's, I think. Don't go too early on the 911 stuff, though, they had a solid rotor like the 914.

[skline]

There are a lot of people who drilled their front rotors for the five lug and then drilled out the rear hubs and installed the 914-6 rear rotors to go the cheaper 5 lug route. There is a guy on the for sale board selling a front assembly for a 71 911T and those had the vented rotors. He is asking $250.00 for it which is cheap but it wont be available till the first of the year. I am running the vented rotors and a 911 front end with the Volvo 24o calipers. They make them for the vented and unvented rotors. They are a 4 piston caliper and are twice the size pads as the 911/914. Should be maximum stopping power. But to answer your question, yes you can drill your front rotors and your rear hubs and use the 6 rear rotor to do the conversion.

[Joe Bob]

914/6 rotors are usuable....but you have to drill the rear hubs, install new bearings, the fronts need pressed in studs and a spacer to keep from bottoming out the new alloy nuts you just bought.

Do it the right way....get an SC front end. The rears are not as critical.

[SteveStromberg]

914-6 rear rotor are about 7mm larger in diameter. Steve

[Joe Bob]

Well yeah.....you hog out the caliper....

[Dave at Pelican Parts]

Originally posted by skline
... Volvo 24o calipers. They make them for the vented and unvented rotors. They are a 4 piston caliper and are twice the size pads as the 911/914. Should be maximum stopping power.

Not really. The 240 calipers will not, in general, improve stopping distances over a well-working stock caliper. If you can lock up the wheel, that's all the braking you can do at that point in time. (Rather, if you get the wheel to just before locking up.)

The 240 calipers will drastically change the brake balance of the car, and cover up a lot more of the rotor giving you slightly worse heat dissipation. On the up-side, they have more mass so they can hold more heat before they start fading, and the larger pad should last longer.

--DD

[skline]

Dave, are you trying to burst my bubble?
I have high hopes for this setup. I wont get to drive it till maybe next summer but I thought I had it all planned out. Now you are putting questions in my head.

[Zeke]

Well, yeh, the whole thing is a trade off as far as any size caliper is concerned. But with a huge caliper, less pedal pressure is needed. However, no matter how you approach it, inertia is changed to heat. The same amount of heat will be generated no matter what the setup is. It's just how that heat is disipated.

Now to what DD says, it probably is a bad idea to have such a big caliper on the front and a little caliper with a solid rotor on the back. My approach on my race car was if I went up a step in the front, I would go up a step in the rear. So, I took a proven combination from a 911. S's or A's in the front on vented rotors and M's on the rear on vented rotors. I removed the proportioning valve and can/will install an adjustable one to fine tune the balance if needed.

Once the dissipation is fairly balanced, so you are not over heating one axle while the other barely warms up, the aspect of which axle will lock up first has to be addressed. In my mind, that will be in close balance as well and will differ from car to car due to springs, etc. and preferrence if using in competition. You need to take these things in baby steps.

[TyFenn]

Depends on what kind of driving you want to do - heard that one before? The drilled rotors appears to alright for the street but, in my past exp. reading this board, it's not recommended for the track or auto-x for various safety reasons. This can be done kinda' inexpensively (in relation to the 911 switch). But you know, you get what you pay for and everything has its pros and cons.

I've got the drilled rotors - never been used - want to send me some fuchs and I'll check it out or you -hahhaaa.

Also, not mentioned...yet, is the BMW 320i brake conversion. I did that too. I don't drive on the track (yet) nor do I auto-x - just street and these have been fine for me.

Some things to consider...hope it helps

[SteveStromberg]

I recommend 911 Slotted rotors over Drilled although the "drilled "are actually cast in holes. Steve

[cruiksdr]

As long as we're on the subject... I've just completed the five lug conversion on my car. I went with 911T front end and rears Ms front and back and vented rotors front and back. I adapted the 911 hand brake (ala Wilco). I'm still working on getting the system bled, so I haven't gotten to feel the difference in handling.

Anyway, I notice that there appears to be very little difference in the size of the rotors or the brakes. The M pads are very slightly larger (perhaps 5%?) and the pistons appear a bit larger. My question is this; How much difference in braking performance can I realistically expect with the 911 M's over the stock 914s? Part of what I was after was the five lug (I installed 15X7 cookie cutters, and love the look), but I was also after improved braking performance. My car only has a 2.2 six, so the SC set-up would have been overkill. But have a really gained anything here?

I think this is relevant to JFKs dilemma.

[Zeke]

Originally posted by cruiksdr
But have a really gained anything here?

The pedal may feel the same and the car may stop in the same distance, but you will be able to stop more times before fade sets in.

I'm curious, did you have any caliper/rotor clearance issues when transfering the rear 911 setup to the 914?

[cruiksdr]

Yes, the rear 911 calipers did not center correctly on the rotors initially. I used some 1/16th" spacers, and that took care of the problem. It all went together pretty easily. Even the 911 hand brake was a piece of cake!

[Dave at Pelican Parts]

If you keep the rear proportioning valve, don't expect much of an improvement in stopping distances. With the larger brakes up front (larger pistons, e.g.) you can add more rear brake bias and make the rear wheels do more work. This will decrease your stopping distance, but you have to be careful to keep your rear brakes from locking before the fronts do.

An aftermarket adjustable proportioning valve is one way to do this. Some people say that just a T is good enough; I would suggest being more careful.

--DD

--DD

[cruiksdr]

I actually have the T but have never installed it. What is the problem with getting rid of a PV all together and just using the T?

Your advice is always good, so I trust it, but I'm just not sure why to avoid the T.

[Zeke]

With the T, you have no control over brake bias. It is what it is. With the PV, you have no control over brake bias, it is what it is. They will be different. Listen to DD.

[Joe Bob]

Do some time on a skid pad....

An adjustable bias is cheap insurance and allows you to adjust things.....a tee gives you what it gives you....

[Dave at Pelican Parts]

Since sliding friction is less than starting friction, tires that are sliding have less grip than those that are still turning and gripping the pavement. So a wheel that is "locked up" has less grip than one that is still turning.

If you lock up the rear brakes before the front ones, the car will want to try to swap ends. That's not a problem under many circumstances (e.g., you have the car pointed straight or you have lots of runoff room or whatever). But all it takes is one time where the car spins uncontrollably in freeway traffic to make you very unhappy.

The conclusion--you want the front brakes to lock up before the rears. Heading downhill on dry pavement is the most severe test, and some stock street cars will actually lock the rears slightly before the fronts if the hill is steep enough. When you start messing with the brake system, you have to realize what you're doing and be able to deal with the consequences.

--DD

[Vaughan Williams]

I also have a set of front struts with Bilstein Inserts. These are the 914-6 typr, M caliper spacing, with hubs and new ball joints, I'll sell for $250