Strut/caliper/rotor question

campbellcj · 09-03-2002, 10:40 PM

My dumba$$ question of the day:

Is it possible to remove or swap the spacer from 911 "A" calipers and use them with a solid 914/4 rotor, drilled to 5-lug?

OR, is there a 3.5" bolt spacing ATE caliper that will work with a 914/4 rotor?

WHY would anyone want to do that, you ask? Give you one guess...

Yep, I am maxed out on class points (POC V5; plenty left in PCA AI), and I can upgrade calipers but no rotor mods. So I could either do the 320 calipers on my 3" struts or use the 3.5" struts (and potentially mondo calipers) somehow with 914/4 rotors. I can move my 914/4 front calipers to the back.

The other factor is, I found the PO's papers on the suspension parts and

the front inserts are P36-0112 HD's -- not -0113 Sports as I had thought/hoped -- and so I may be selling either just the inserts, or possibly both sets of struts I've got (1 914/4, 1 911SC) and going to something else. Whatever I would go to would have 3.5" spacing.

The rears are not a problem; they can be fitted with threaded spring collars, any spring rate I would ever want, and revalved by Bilstein or Smart-Racing as needed. That should do until I can afford (and need) externally adjustable Konis, Ledas or whatever.

Brad Roberts · 09-04-2002, 12:53 AM

Dont make me split a M caliper to check this.

Too late. Your questioned intrigued me. I had never actually tried this. So.. I pulled apart a spare M caliper and tried to bolt it up to a 914 rotor/strut combo.

NO go. Here is why: The 911 caliper has a different offset to be centered on the 911 rotor. The mounting face for the 2 bolts would have to be machined WAY down to get the caliper to center on the solid rotor.

What if we ran the really early 911 5 lug stuff with the solid rotor ? This ran a M type of caliper without spacers, but can be converted to a vented rotor and vented M caliper later.

This is the M without the spacers.

campbellcj · 09-04-2002, 12:57 AM

That's true; an early 911T solid rotor setup might sneak by the classification nazis. But not sure there is much advantage vs just doing the 320 calipers on a drilled 914/4 setup; plus the bimmer calipers would be brand new vs 30 year old rebuilts.

Hell, for now I have no problem trying the stock brakes. The car is not THAT much faster than a stock 2.0; I would probably be fine.

Brad Roberts · 09-04-2002, 01:06 AM

Just get proper cooling to them. That is all they need anyway.

Ask them about the solid rotor 5 lug setup.

The parts places almost give these strut assemblies away.

B

MJHanna · 09-05-2002, 05:32 AM

What kind of pads are you using? If they are not carbon fiber, go get a set. You would be surprised at how much difference they will make on stock brakes. Get some more front calipers to use one the rear; use a brake balancer and I bet you will be more than happy for a long time.

campbellcj · 10:36 AM

Mark - yeah, unlike a lot of guys, I have faith in the stock brakes (when set up right). I am really just planning ahead for when the car (hopefully) gets its steroid infusion to 250-300hp and a lot more tire.

I hate redoing stuff, so I was hoping to come up with a trick setup that would fit my current class and not be too out-gunned later.

With the same brake setup I had on the last car, plus some cooling to the fronts, I'll be fine for now. Not like I need to spend a bunch more money anyway.

MJHanna · 09-05-2002, 10:33 AM

you might want to read this. It puts it in perspective.

http://tech.rennlist.com/911/pdf/Brake_Power_vs_Weight.PDF

Brad Roberts · 09-05-2002, 02:21 PM

Mark,

You say carbon fiber..

Give me a company name that I recognize.

We run Porterfields for the most part currently.

B

MJHanna · 09-05-2002, 02:43 PM

That's one, Performace Friction, Hawk

campbellcj · 09-05-2002, 03:53 PM

Carbon-Kevlar is what you mean, right? (Same difference, carbon based composites).

I think most of the race pads are organic (carbon-based), non-metallic, non-asbestos compounds these days.