It should be no different, the track width hasnt changed on mine with the same brakes.
Do you have the Sigma rotors as well? cause some people just use the 120y rotors.
In order to use the sigma ge rotors you must have the centres opened up 2 or 3mm to
match the 1200 centre hole. Someone else has done a sylvia front rotors with mazda
rx7 s5 4 spot calipers however the owner knew nothing about it as he didnt do the conv.

You've gotta do all things in proportion, have a look at the size of all the front end steering and suspension components and you really don't want to go too crazy in the brake and therefore wheel department. The sigma disks should pull it up well, mine work fine. people still use front drums for track use with great success. your front track is exactly the same. i can't see the r31 maddat setup being any real benefit over what you have. its still a single piston caliper and solid disk that is pulling up all of 700kg's.

Wurzel, if you have a twin res master, take out the little nugget at the base of the m'c which is made to hold pressure for the drums. its under the big nuts at the base of the MC

Gav you must remember a Sigma GE weighs about 1200kg and your new engine conversion is
perhaps 30kg lighter so Im thinking on the weigh bridge you are under 675kg even with
the iron carrier h165 (if thats what you have?).
Thats more than halve a ton difference. Step back a tad and look how far youve come
and get some 14s for starters just to see how you like your ride with 165/55/14 or
175/50/14 also found some wheels you might like from SAfrica.
You can always have more than one set depending on your mood :)

Well i'm pretty keen to see what else maddat can come up with. That front end kit sounds pretty enticing, poly bushes would be awesome.

Thanks for that info guys.

Gav, its a 7/8 MC

I really have no problems with pulling up, its just the intermittent cacophony coming from both front and rear (at different times!) and lack of handbrake that gets me, but I'm beginning to suspect they are 2 (or 4) separate issues.

All good points and my main question was answered. My car does pull up well at the moment. Just thinking what it would be like with more horse power. How can I tell the difference between sigma and 120y disc?

I have been after one of neil's kits for a while. I think he is having trouble getting the hubs laser cut. Does neil's kit affect track?

D
Those wheels would be fine but remember, I need something like a 0 to +15 for the front and +38 or +40 for the rear. Finding a matching set in both is the hard part. I still have a few options to chase up but relax. It will be tatseful. I promise I wont put 20"s on.

Wurzel
Take your car to a brake and clutch place (a helpful one) and get them to match the master to brakes. Once you take that valve out you should be able adjust your handbrake up more. Disc handbrakes were never very good.

My kit doesn't affect track
I built it that way for a reason

And if Dundee ever gets the sample hub off Ben he can get them quoted and we can move forward on making some more kits

As for the need for a sample hub. I have 2 complete setups in storage.
So I can help out in that dept if need be.

mmn, this progress sounds good.