adjustable WG cap mod, & other incremental increases

[Ken Keith]

On 14 Jun 2001, at 23:11, Gerard wrote:
>
> The main crack is all the way around, actually right where Audi seem to
> have put the join on the 2-piece EMs. The 2-piece is also not the
> be-all-and-end-all of preventing cracked manifolds. I sent my 1-piece in
> for welding as it had a hairline crack on the front piece near the join
> between the two halves and also had a crack on the vanes of the
> collector on the turbo end. This seemed to extend all the way through
> the metal.

The above story must be about a 2-piece, right Gerard?
 
> The odd thing is that I have another 2-piece EM and the thing has the
> same cracks in the very same locations. I suspect the other one arriving
> in the next week or so will have the same cracks.

I wonder if the cracking is caused by a temperature change upon 
cooldown, warmup, or physical stress?  All of the above, I would 
imagine.
 
> > Maybe the warpage I've always seen referred to was the Dialynx
> > unit.
> 
> I recall someone saying these warp, but don't crack. Much heavier than
> stock and apparently a real pain to install. The 2-piece is alot beefier
> than the 1-piece and I think the Dialynx is even thicker. I've never
> seen a Dialynx, just going on what I recall from list traffic.

I've seen pictures.  I think maybe at the TAP website.  I'd like to 
see a group effort put forth to get some type of turbo header, or 
tubular manifold.  Apparently only certain materials can be used for 
turbo manifolds tho', also due to cracking problems.
 
> I haven't even got a clue what iconel is. High nickel content cast iron?

I would imagine.  It's what give the RS2 manfolds their light grey 
instead of black color, as far as I know.  To my knowledge, the 
Dianlynx manifolds don't look the same color as the RS2 ones.  
Anyone?

And another question.  Would this cracking potential be any worse 
if I lived in a hot area like AZ?  Or are the temperatures or factors 
that cause cracking problems for everyone?

OK, more questions.  Would ceramic coating help the situation?

Thanks,

Ken