S3 - How do I locate the hidden front exhaust bracket bolt hole.

[virden]

! have 1996 S3 X/F and tiring of the unceasing blowing of the middle primary exhaust gasket have decided to experiment with a front bracket to support the 4:1 system.  How far from the rear bracket bolt hole is the hidden front one?

[Jonathan Kay]

With a magnet IIRC... 

Jonathan

[SM25T]

Normally about 800-805mm from the centre of the rear mount hole. Drill a small hole to see which way to enlarge it.

[revilla]

As Jonathan says, we recently did this with a small strong magnet and it was ridiculously easy. Took all the guesswork out of it. See this thread, comment #26 onwards.

[Mankee]

A 96 chassis may or may not have the threaded bush in the chassis tube. Mine didn't. Used small, strong magnet, tape measure, drilled a pilot hole, opened it up, rooted around and... the bugger wasn't in there! Arch made me a bush to sit in the chassis tube and the silencer front bracket is nut and bolted through into the cabin. Not ideal if you are into cosmetics, but works perfect for me, as a Powerspeed system is awesome but quite heavy.

[Terry Field]

I have never had that problem in 16 years, and I only have the rear support. Have you checked if the inlet manifold is flat, and have you tried copper exhaust gaskets (which I think you can still get)?

Terry

[virden]

Mankee, thanks for the info.

Terryfield,this has been going on for years, it is a 4:1 system, and always no. 2/3 that blows. I have had the surface trued, twice, checked the head, tried Burton, etc. etc gaskets, double and single, tried  FF racing gaskets, made up copper  ones of varying thickness, tried fitting the primaries first, then the collector all gto no avail, so this time I shall try a front bracket. 

[Terry Field]

Sounds like you have tried all the obvious things. I'll be interested to see how you get on. 

Thinking slightly out of the box (and probably not an issue of you have had the problem for years), but is  there any excessive engine movement, mounts etc, that could be causing the problem?

Cheers

Terry

 

[simonpa]

I agree that you cold probably do with the extra bracket - but have you replaced the engine mounting rubbers?  There should be no discernable movement of the engine when you try and rock it..

 

[virden]

The mounts are fine, just 20K miles on the clock, the engine is rock solid.  I took the car to a chap who builds racing exhausts for modern and vintage cars and he thought the problem may lie with a misalignment of one of the primaries, two which leak at their union with the collector.