Mythbuster: continuing project thread of my 1303 '75

[effvee]

Very nice work Walter. Question, presently I have the 1985 944 rears for both front and rear. Do you feel fix caliper do a better job than floating calipers?

The reason for my question is due to, on my Chevy truck I have floating calipers and the right front wear every time faster and sticks. This is due in large part to the floating caliper design. However, over here fix calipers are hard to find. Unless I want to go to the Porsche junk yard and get rapped by sticker shock



This is the front caliper on the rear, I feel I can't just use four wheel disk brakes from a 944/front engine, and not try and even out the braking. I have a old, I believe a 1970 911 book, in it, they use pretty much the same diameter calipers on front and rear. Leaving the larger caliper on the front, I feel would cause lock up too easy.

[70Turbobug]

Do you feel fix caliper do a better job than floating calipers?

A monoblock or fixed caliper is far better.It has more stability and more clamping pressure and resistance to heat.The resistance to heat without warping is the biggest advantage,because the caliper maintains braking pressure and doesn´t fade as much.

[Wally]

Regarding the 944 MC: I did a lot of hard thinking why the rears gave so little brake force, even with the 23/19 cups.
My conclusion at the moment is that maybe, just maybe, with the brembo alu calipers, the travel is less than on a floating-caliper with a 53mm cup as the older 944's had. That would mean that the fronts already have full contact while the rears have not fully engaged because the rear 19mm cup just isn't pushed any further in the MC...
Its also means that you just can't use the MC cup sizes to 'adjust' your bias! The MC cup sizes are there only to level out the travel of the cups in the MC, so its equels both front and rear to give the same travel/force.
Hope this explaining of mine makes any sense.

A while ago I ordered a 20.6/20.6 MC from Mid america Motorworks and it said you could order even for the superbeetle's inclined flange! For just $39.95! but it was in backorder and would take 4 weeks... Yeah, I thought, so we'll never hear from them again..
Great was my surprise when it turned up at my doorstep exactly 4 weeks later! (today)
Made in China from EMPI in blister packaging! Figured

While the pedals are out to fit a new gaspedal from CB with 'turbo' written on it (that will surely give 20 hp extra!) to replace my worn plastic and too deep lying old pedal, I will install this new MC while I am at it and let you all know what it does on the track next season. Then I can really say that I have tried everything ;-)

[70Turbobug]

Good luck! I´m always very skeptical about Empi parts to put it politely...

[Wally]

Me too, Every Mistake Passes Inspection and all that, but.. there is no alternative for this part, so I kinda have to try it.
And it doesn't look that bad compared to a Varga unit that worked for me in the past as well.
It is heavy tho compared to the alu 944 unit.

And hey, there are only my brakes...what can possibly go wrong? LOL

[oasis]

I hope I'm not intruding on the brake conversation but I am curious about ...

... the holes you drilled in your front spoiler. It is obvious you did it such that the air could travel through the holes as well as the slits in the front apron, but what do you have lurking behind that front apron needing air?

[Wally]

Originally Posted by oasis

... the holes you drilled in your front spoiler. It is obvious you did it such that the air could travel through the holes as well as the slits in the front apron, but what do you have lurking behind that front apron needing air?

Just a relatively small mercedes (Behr) transmission cooler, which I use as an oil cooler.
Amazingly, it seems to be more than enough for this - and former - engine(s)

[Xellex]

that's something I was curious about, too. I've read somewhere in the past (probably on shoptalkforums) about your mercedes oil cooler, and it's obvious it's working good at speed, but is it enough at longer idle times? Actually the question is not aimed specifically at your setup, but all the other radiators w/o electrical fans on them. (and engines that don't have the stock oil cooler on too at the same time, just like yours).

[Wally]

yes, longer idle running is fine because of the porsche fan, original heads. Even with the cast iron cylinders this worked fine, but very long idle time might give elevated oil temps (100-110C) in summer. This is no problem though as head temps are very low at idle as you have no load.

[Steve C]

Hi

Sorry to jump in on your topic Wally.

Om my daily driver/sons 1303, running a mild 1904 Ive fitted a cooler in the nose like Wally has done, Im not running an internal cooler and the car will easily cope with bumper to bumper city traffic without any dramas. I do have a fan on it but it rarely comes on.

Steve

[70Turbobug]

I can also really recommend Mercedes oil coolers.If any of you have the chance of getting one i.e. off of a diesel Mercedes like the older 200D,220D,240D,300D or 300TD buy it.Imho they are one of the best coolers ever built.

[oasis]

Great info. Glad I asked.

[owdlvr]

Regarding the 944 MC: I did a lot of hard thinking why the rears gave so little brake force, even with the 23/19 cups.
My conclusion at the moment is that maybe, just maybe, with the brembo alu calipers, the travel is less than on a floating-caliper with a 53mm cup as the older 944's had. That would mean that the fronts already have full contact while the rears have not fully engaged because the rear 19mm cup just isn't pushed any further in the MC...
Its also means that you just can't use the MC cup sizes to 'adjust' your bias! The MC cup sizes are there only to level out the travel of the cups in the MC, so its equels both front and rear to give the same travel/force.
Hope this explaining of mine makes any sense.

Wally,

Do you have a proportioning valve installed? I've got one on my rally car, for solving different issues, but it strikes me that it would be appropriate for solving your brake issues. Mind you, you're also at a stage where a full dual-master/balancing bar would be appropriate as well!



I put a lever-style prop-valve in the rally car, though you would probably find a rotating knob style (Wilwood) would suit you fine. I suspect you'll balance out the brakes the way you want them and then leave it, as opposed to the rally car which gets changed as the road conditions change. I've done the rotating knob style mounted outside of the passenger compartment in other vehicles, as they aren't adjusted 'once set'. In your case I would think you'd need to install it on your front lines, as opposed to the rear which is typically the case.

-Dave

[Wally]

Hi Dave,

I have exactly that one in your pic
But, its indeed connected to the rear and because the rear still doesn't brake enough, not much use of it. It just look slike it doesnt work in my car at the moment and I think I know wh now (see above).. I don't like installing these on the front as we already run without powerbrakes and it would just be a bandaid imo.

A dual master balancing bar would mean installing a complete pedal assembly and I have never seen one installed in a bug that I like.

It is sooo simple really: I just need to find a set-up that overbrakes the rear a little so I can adjust with the 7-step Tilton... How hard can it be right?...

[Wally]

So today I have engaged into removing some rubber from the rear banana-arms and spring plates so it can be replaced with monoballs, poly-bronze bushings and the occasional black graphite-urethane: