Joe Rose

A friend of mine who has owned several street 914's--and has also raced one--suggests one of the best improvements anyone can make to his/her 914 brake system is to replace the brake pressure regulator valve with the simple "T" connector used to join the lines to the rear brakes on an old VW Beetle. Anyone here ever hear of this or do this? I'm tempted to try it, but I don't really want the rear brakes locking up on me with every hard stop. My 914 is strictly for street use.

DERSIX

Joe,
I would use an adjustible regulator ( Kelsey-Hayes ) rather than just installing a "T"
Pete

art

Do your rear brakes lock up? I've never been able to lock front or rear with my -6 brakes. I now have larger front calipers and still can't.
Art

Joe Rose

Say, folks, let me make myself clear as to why I started this thread. No, I presently cannot get my rear brakes to lock up. Then again, even with new pads and everything working well at all four corners, my '75 hardly stops much better than my '73 VW Thing. For those of you who have driven a stock Thing with drum brakes all around, you know what I mean. My friend suggested the "T" as an improvement in stopping power. He also suggested that I change to a 19mm master cylinder. I thought I'd make the "cheaper" improvement first if the general consensus was that a "T" rather than the stock regulator would produce the desired effect without an undesired one.

Rouser

For a stock, daily-driven car, leave the rear p-valve installed; no major braking improvement will be noticed, but you might induce rear lock-up in a panic stop.

The 19mm MC is considered an upgrade over the original 17mm unit, but it should also include a thorough inspection of the braking system, and replacement of worn/brittle flex lines.

Trust me

Try new brake lines. I had ones before were so clogged that nothing worked well. After line replacement, all was good. Oh, the rears are a pain in the a$$.

Troy

Joe Rose

Thanks, folks, I appreciate your input. And for respondent "Trust Me", I know exactly what you mean about those rear lines. I replaced one the other day and used some words I didn't know were in my vocabulary. I have the other new rear line on my workbench and will install it the next time I feel I need to punish myself. Thanks again for all your help.

philinjax

If you haven't upgraded your brakes, there is no need to go to a 19 mm master cylinder. It won't give you any additional braking power, all it does is shorten you pedal stroke and require a little more force to get the same braking power as you have with the 17 mm mc.

philinjax

Joe Rose

Hmmm..again I learn something here I didn't know before. What, then, are the specific upgrades I can make to my daily driver 914 that will improve its braking power?

Trust me

911 front end and "big red" brakes. Also 911 rear end hubs. The 911 parts you can get for a pretty good price. The "Big Red" brakes......well, cha-ching $$$$$$.

art

There are BMW 320i front calipers that will fit on a 914. I know there have been write-ups on this, so search around. This brings you up to what a stock -6 would have, which in my opinion is still weak.

I got a second set of struts and modded them to take rx-7 turbo front 4 piston aluminum calipers ($30.00 ea at the junkyard). It works pretty well, but still not phenomenal. I think the piston area was 12% more that the stock. I still use the 17mm m/c for lower leg effort.



Art

Chris Campbell

Good pads and good fluid are essential. One high-quality street pad is the Porterfield R4S. ATE Super Blue fluid is fine for most applications and not terribly expensive.

I would echo the advice of NOT removing the proportioning valve unless you have upgraded the brakes. This is however a worthwhile mod if you have larger front calipers, in which case you can utilize a bit more pressure to the rears than allowed by the stock valve.

I currently have a 911SC (A-caliper and vented rotor) front setup and stock 914-4 front calipers with 914-6 rotors on the rear. SS lines, 19mm M/C, VW "tee". Pagid Black pads up front and Orange in the back. (This is a track car.) WAY more braking power than I need on our local tracks or on the most challenging local canyon/mountain roads...zero fade, zero drama.

art

Are the porterfields carbon pads? I tried performance friction pads in the -6 calipers and they were useless unless very hot.

It took a 100-20 hard stop to get them hot enough to work, and that was supposedly the street compound!

Art

Chris Campbell

I actually have never used the R4S street pads myself; the R4 full-race pads however are carbon-based but still worked OK before fully hot in my experience. A bit grabby and noisy, but -very- functional. These kinds of pads have like 3X the cF of the original organic pads.

FWIW the Pagid carbon race pads on my current car also work plenty fine when cold, and actually are less noisy and dusty than the Porterfields...but cost about 40% more.