Monday, April 02, 2012

Brake dancing

I have a number of brake set ups on/for my TR7s and always seem to be in tranisition to where I want to end up - two steps forward and one step back, or is it the other way round?

Well, with no driving to be done for 50 weeks now seemed a good time to make some more moves.

Here's the standard disc set up on UNJ which doesn't look too bad until you see the comparison with --
the uprated BMW/Volvo combo I have on BRP
Apart from the surface rust of course, the major differences are the much bigger dimensions of both the vented disc and the 4 pot calipers giving much improved fade resistance.

I had hoped originally that this set up would be fine for historic rallying but it was not to be. "Proper Group 4" brakes were necessary and so these were purchased and the necessary machining done etc. I have never actually fitted them though due to the interruption to my rallying plans but they are going on to BRP at some point as I still aim to compete in stage rallying co-driving in the car.

My plan now though, was to fit the BMW/Volvo combo to UNJ and so uprate that car's brakes from standard and ideally fit the Group 4 brakes to BRP. If I actually did the last bit though they would then be on a car that is unlikely to turn a wheel in anger for maybe 2 or 3 years which wouldn't do them any good.

So, still going down this route I removed the offside brakes from UNJ and BRP and whilst I was at it put all three set ups next to each other as a comparison - see below
I then trial fitted the Group 4 brakes on BRP and they do look the business

It was good to make sure all the bolt holes lined up - that was quite a relief! As I said though, it wasn't my intention to leave the Group 4 brakes on so I packed the disc and caliper away into their packaging and back into storage for the day when they finally do get fitted.

What was actually accomplished was the offside BMW/Volvo combo removed from BRP and fitted to UNJ and the standard set up fitted temporarialy to BRP so that it can still roll (but not brake!).

Alot of work but as always, getting closer to the end result.

The nearside will be the next job.

1 comment:

dursley92-cars said...

Those look like the original AP 4pot that we used to call the "forest" spec and were used on loads of rally cars in the 70's and 80's.
I ran them on my Sunbeam and there were excellent. Interesting they are still available new.