[Steve C]

Hi

I will spill my guts here, I'm trying not say too much on my local sites, you never know who is looking.

I recently got my STI powered bug on the road, had it all checked off by an approved engineer, passed by another examiner, paid all my fees etc.

Then I took the car home and pulled the car apart to finish some wiring issues and just a general tidy up, a week later I was told to bring the car in for a more thorough examination, a random check on the approved engineers is what they said was the issue.

They have a few issues with my car, they reckon that my stock 19 mm master cylinder can not properly cope with my upgraded brakes, I'm running 996 rears on the front and Boxster rears on the rear, both these callipers use 30 & 26 mm pistons.

These are the figures that I gave to my engineer to show that my master cylinder is suitable for the task.

One calliper has a piston area of 2x 30 pistons = 1413.71669411541
And 2x 28 pistons = 1231.5043202072
Total piston area for one Porsche calliper = 2645.22101432261

A stock VW Beetle calliper has 2 x 40 mm pistons, total piston area for one calliper = 2513.27412287183

Incidentally a Type 3 VW uses the same size master cylinder, its callipers use 42 mm pistons. Total area = 2770.8847204662

Another issue is my wheel base is too long by 30 mm, the 944 alloy trailing arms must have done this.

I was trying to find the stroke of a 1303 master cylinder to give the engineer more ammo, I'm pretty sure it would be the same on all disc brake VWs.

I'm using a Volvo 240 master cylinder reservoir, does anybody know the volume of one of these? another thing that worried them if my reservoir was big enough.

There are other issues but will I keep quiet about those for now, one is hilarious.

Steve