New exhaust installed, but car feels restricted...

[Gerard <gerard@poboxes.com>]

Hi!

Over the weekend my 200t decided to split open its exhaust system.
I think the split has been there for the past few months, but on the
weekend it just snapped open. I looked at the pipes today and found that
at the 2 bolted joints along the piping cracks had formed. The rear
joint had a crack along the welding point. The middle joint, the
2nd pipe along the exhaust system, had almost split off all the way
around about 2 inches before the joint. A failed rubber hanger had
probably caused the final twist to split the pipe. When giving enough
gas from launch the exhaust would vibrate enough to hit body work
and gearbox. Anyway, I installed a stainless steel system with
2 generic free-flow airboxes. Car sounds deeper than it used to. The
thing now is that it feels quite restricted. The piping is 57mm all
the way through and is 1 long pipe (apart from the 2 boxes) as I had
the joint removed and put in piping instead. Would 2 small splits in
the exhaust pipe make so much difference that the car would seem to
be "tight" and restrictive? I had to battle to find someone who would
do 57mm tubing. About 2 weeks ago I had the rear box done as it used
to have a small useless and incorrect diameter. Would the splits in
the exhaust make so much difference to gas flow that the car would
rev better and pull better during the day than it does now with the
sealed exhaust system in place? Perhaps I should try a hard run at
night to see for any difference. But don't really want to do that
as my engine light comes on every now and again and when I pull the
codes it says 2142 (bad knock sensor or sensor wiring). I took the
car in to the Audi agent$$$$$ and booked it in for next week, the guy
who tested it had the light come on for him 3 times in a time span of
1 minute!

So, would it be better to actually fit a larger bore exhaust system in
place of the stock sized system? How much difference would a 63mm
(2.5in) exhaust system make from a 57mm (2.25in) system on the '90 200t?
Would a leaky exhaust system make a very HUGE difference in engine
character from a system that was "perfect"?

G.
-- 
"a thousand miles from here, there is another person smiling"
1990 Turbo (200t, MAC13A ECU, 1.4-1.6 bar, FWD auto)
name   : gerard van vught
tel    : +27-21-696 0331 (h) / 082 923 9609 (cell)
url    : http://homepages.acenet.co.za/gerard/
e-mail : gerard@poboxes.com  / han.solo@galaxycorp.com