If anyone else has this problem try sourcing early 911 rear pads from 1965-1968. Alfa 105/115 rear pads are the same as well. You will have to drill out one of the pin holes in the pad but, you'd probably have to do that anyway with these pads.

Well i have portofield orange pads in the rear, but i got hawk pads first for the BMW fronts.i had the most trouble trying to find HAWKS for the rear. I didnt know i couldnt find them for the back and this is the first time i heard of the portofields.....Oh well guess i will switch to portofields in the front when i wear them out....

Yup... looks like the early 911 ones are hard to find as well.

After conferring with Eric on this, I wanted to post my experience with the brake T here for posterity. My car was set up with 911 M calipers up front, stockers in the back, and a brake T in place of the prop valve because that was what I heard was the way to do it....same place Eric heard it from no doubt. I had 235 up front and 255 on the rear. On April 27, 08 my rear breaks locked up as I was coming out of a turn and, as confirmed by Eric, majorly contributed to my wrecking the car and injuring one of our members and my friend Chris. The rear definitely broke loose on me because I was breaking coming out of the turn. I had thought that odd, but after reading this thread and talking with Eric it makes more sense how things happened and I will never use a brake T again.

If you don't mind... I'm going to try to find the PM I sent back to you. I think it has a lot of relevant info.

Thanks for posting. As stated earlier in this thread. "Real things can go wrong real fast". A little wet weather, a twisty and a locking rear caliper... you know the rest of the story.

Abso-friggen-lutely.

We all use to spout the wisdom regarding the T on 911 calipers etc. That T fitting story has been prolific on 914 sites for years. For me it initially made a "lot" of sense as your standard 911 weighs in at roughly the same poundage and has no valve BUT; it all hit me when I began to understand the actual dynamics of the valve AND the dynamics of a mid-engine car in a spin:

1. The car - As we know, they are "very" controllable to that breaking point but, once they go beyond they can spin violently with little or no recovery method. Like a top with the weight in the center. The 944/968 design is better with the weight at the ends.

...it is all concentrated in the middle. Like the 944, 968 or 928, this makes for a well-balanced, neutral handling car. However, as opposed to the others, it has a very low polar moment of inertia, which has two significant effects on its handling. It tends to be susceptible to crosswinds, and on slippery surfaces it rotates extremely quickly. - Vic Elford - High Performance Porsche Hand Book - Page 55.

2. The valve - As you know now (me too over the last couple of years) the valve operates as a T basically passing fluid until it should shut itself down. So... the valve doesn't, in any way, inhibit your rear caliper activity as I once thought.

If you were on a wet road with a twisty and you came up on it fast... you went into heavy braking (normal) but your rears decided to lock? Perfect storm and you know what could be the rest of the story.

I never heard of Porterfields identified by colors. All I know is R4 Race pad R4S Steet/ AX pad.

I was reading about Carbo Tech the other day. Large selection. Might be worth a set of new pads to try them out. By other racing buddies love them on everything from 2800 pound 400 HP race cars to cute little Miatas.

Eric, thanks for posting this--it's important . . .

It's easy to forget that the 914's quick "turn-in" also means it can spin in a heart-beat. Its relatively low moment if inertia also makes it easy to over-correct and start a spin in the opposite direction (BTDT )

Basically, the moment of inertia of an object describes how easy it is to change its angular motion about its axis of rotation. Even if a 924/944 had exactly the same mass as a 914, it would require more effort to change the 924/944's angular motion because its mass is distributed further from its axis of rotation. That also means that a 75/76 914 with the big/heavy bumpers has a slightly higher moment of inertia than an earlier car.

Food for thought I guess

Thanks again--and sorry for the hi-jack.