Pedal Assemblies

[oasis]

Interesting answer. Thanks.

I, too, shied away from Porsche brakes with all of the talk on master cylinders and proportioning valves. I ordered and should be receiving in the next few days KG-based brakes drilled in a 5x100 pattern for all four corners. I figured in a light car like my 1302, it'll be plenty of stopping power -- although some people profess the too-much-is-never-enough theory -- and without any other issues attached.

Of course, we'll see once everything is installed if my reasoning in reasonable.

[bigwindow]

I have 993TT discs and calipers on my car, with 944MC, but it's still a project car so I have no experience with it yet...

[rip]

Originally Posted by oasis

Interesting answer. Thanks.

I, too, shied away from Porsche brakes with all of the talk on master cylinders and proportioning valves. I ordered and should be receiving in the next few days KG-based brakes drilled in a 5x100 pattern for all four corners. I figured in a light car like my 1302, it'll be plenty of stopping power -- although some people profess the too-much-is-never-enough theory -- and without any other issues attached.

Of course, we'll see once everything is installed if my reasoning in reasonable.

Yea, I'd like to take my car out to the tracks everyonce awhile, not to really compete, but more to drive and have some fun. I'll have a 120Hp type IV motoro done soon and need to stop, plus been looking at rotarys for awhile. And who knows what the future holds.

The main problem I saw with the stockish disc brakes is that they were still single planed rotors, no vents. They will still stop you, but in a daily driving situtation inwhich most new car on the road can out stop you I figured bigger is always better when it comes to brakes.

[rip]

Also can someone tell me why you would have a larger rear mc than the front.

I've been on a few Rx7 forums to see what mc they use for manual brakes. And some have said that they use a

3/4" front mc
1" rear mc

I don't get it. Wouldn't the front brake use more fulid thus need a larger mc?

thanks
rip

[oasis]

Originally Posted by rip

The main problem I saw with the stockish disc brakes is that they were still single planed rotors, no vents. They will still stop you, but in a daily driving situtation inwhich most new car on the road can out stop you I figured bigger is always better when it comes to brakes.

I could have had the brakes cross-drilled and vented. I was told the advantage of that was protection from overheating. Otherwise, more surface area of the brakes not being cross-drilled and vented would offer more braking power in an emergency situation.

My situation will not include so much braking whereas I worry about fade. My mechanic even suggested leaving the rear brakes as drums. (I chose to veto him on that one.)

I do not believe my set-up will have me out-braked by most cars on the road. If you ar right about that, I will be disappointed. I know one thing: when they're installed, I'm going to test them against my 2002 Cabrio, my wife's 2002 Golf, and my dad's 2002 Passat. If my '71 1302 finishes anything less than second place in this four-car test, I will concede you are right with your daily-driving assertion. (I won't test it against my 1993 EuroVan because {a} I'll soon be selling the EuroVan, and {b} it stops better than the heavy Westfalia already.)

Logic tells me my 1302 should darn well match or beat the above competition given the ratio of brake size compared with the ratio of vehicle weights. I realize this logic is dependent on there being a linear relationship between the two factors, and is excluding any other factors.

I'm quite sure there is a geometric relationship between brake size and vehicle weight when it comes to stopping power. There has to be. Otherwise, some figure like 20-inch brakes (try to imagine that one) would theoretically stop the car instantaneously. And if "twenty" was the magic number for zero feet at 60 mph, then 21-inch brakes would produce a negative number.

So being secure a geometric relationship exists, there must be a point of diminishing returns as one deals with the asymptotic tail (for those playing along with a graphing calculator). There may be even a point of negative returns -- where bigger brakes given an otherwise constant situation actually produces worse results. (The provisions and weight of a 20-inch braking system, if even possible, may be just that.)

It is my belief -- and 98% of this belief came from the culling of many opinions here, at other sites and elsewhere plus 2% of my residual knowledge from being an econ/math major -- I should be fine in my daily driving application using TopLine's Karmann Ghia-based brakes and a set of four 205/55-16 tires underneath my 1302.

I'll let everyone know. It would be curious to see what others would produce with their Porsche set-ups even though it would be carried out on a different road surface at different temperatures ... blah, blah, blah.

Now if I drove my 1302 a lot or planned on experiencing track time, maybe going the extra expense and experimentation to find the supreme set-up would be worth it. I may in fact do that on my next Super (a 1303 most likely).

More later ...