[Es2] [s-cars] RS Tuning tube header cracks at second track event

Trevor Frank tfrank at symyx.com
Mon Aug 8 20:02:42 EDT 2005

Ya..so I just got done building another header for a guy with a 1.8t
motor in a formula atlantic.  He had a steel header that blew holes
everywhere, I replaced it with a custom 321 peice, nice 4 into one
collector etc.  But I didn't do a great job of holding down the waste
gate, the turbo held on just fine, but we kept on ripping the waste gate
off of the thing right at the top of the weld on the merger.  So I made
a big brace a lot like what lehman did, from the turbo flange to the
wastegate flange.  still it ripped it off.   My final conclustion, is
that the turbo is frist held by all of the pipes and welded onto a nice
big merger with lot's of weld area and in the right orientation.  The
wastegate is welded at 90 deg to the merger, in kina a weak and high
temperature spot.  with the waste gate mounted a few inches above it and
a lot of moment on that arm really.  as well since the tube is so short
from the merger to the waste gate the stress that is built in from the
waste gate's weight is almost directly placed on the weak point above
that weld and onto the collector.  I suspect that if you put a bent
section of tube to connect to the waste gate you might be ok, or even
lengthened it and then held the wastegate fairly ridgedly.  We didn't
see this problem in practice, almost always in the race where 3g in a
turn is probably the lower end on this car.  I suspect that Elijah was
pushing his car a bit around the track maybe even some banking and that
10 pounds turned into 30 with a moment arm and at temperatures that
really did some damage.  We had a flex cupling right after the wastegate
and it was a tial so lighter and shorter than what we have on our cars,
and still.   The solution was what I like to think of a the bigger
hammer, Javad had initially requested this but in my infinite wisdom I
kinda shot it down, thick wall 316 weld ells and then I used his planer
merger design and put some serious gussets from the merger to the
The update is with the steel header basically the same design as the 316
he would have holes after practice and meterial failures everywhere.
With 321 thin wall, everything held accept for the waste gate tube,
witch again I think I just made to stiff, to much tranfer of the stress
and strain.  With the 316 in a similar design and thickness of the
steel, no material failures and no "ripping" of the wastegate tube off
the header. 
Just a few words from my lesson learned in the last few months.  Oh and
he finnally won and finished a race!

	-----Original Message-----
	From: djdawson2 at aol.com [mailto:djdawson2 at aol.com] 
	Sent: Monday, August 08, 2005 2:52 PM
	To: Trevor Frank; elijahallen92 at aol.com;
s-car-list at audifans.com; es2 at audifans.com
	Subject: Re: [s-cars] RS Tuning tube header cracks at second
track event
	I'd buy in to the weight arguement, IF the crack had occured on
one of the main tubes.  But on the WG pipe?  The only weight there
should be the WG itself.
	Not to beat a dead horse, but these headers should hold up.  I
now have 22k miles on mine... much of which I would never consider to be
"normal" use.  My use has included numerous extended WOT throttle runs
that have produced 1500+ degree (F) EGTs... repeated dyno tests... and
many use situations that have resulted in the entire header glowing red,
as well as the turbine housing and the first 8-10 inches of the DP.  My
header has no additional bracing or supports to reduce stress on the
	If Elijah's WG pipe has failed, I'd have to guess that he's
missing a flexible pipe between the WG and the main DP body... in which
case, this type of failure should be expected.
	-----Original Message-----
	From: Trevor Frank <tfrank at symyx.com>
	To: djdawson2 at aol.com; elijahallen92 at aol.com;
s-car-list at audifans.com; es2 at audifans.com
	Sent: Mon, 8 Aug 2005 14:25:13 -0700
	Subject: RE: [s-cars] RS Tuning tube header cracks at second
track event
	Even with something flexable the weight it'self in a turn is
	-----Original Message-----
	From: s-car-list-bounces at audifans.com
	[mailto:s-car-list-bounces at audifans.com
<mailto:s-car-list-bounces%40audifans.com> ] On Behalf Of
djdawson2 at aol.com <mailto:djdawson2%40aol.com> 
	Sent: Monday, August 08, 2005 2:22 PM
	To: elijahallen92 at aol.com <mailto:elijahallen92%40aol.com> ;
s-car-list at audifans.com <mailto:s-car-list%40audifans.com> ;
es2 at audifans.com <mailto:es2%40audifans.com> 
	Subject: Re: [s-cars] RS Tuning tube header cracks at second
track event
	Do you have a flexible section of pipe between your WG and your
	downpipe?  If not, that is why it failed.  Otherwise, I think
you are
	having excessive EGTs.  It is pretty odd that it cracked on the
WG pipe.
	Good luck, Dave
	-----Original Message-----
	From: elijahallen92 at aol.com <mailto:elijahallen92%40aol.com> 
	To: s-car-list at audifans.com <mailto:s-car-list%40audifans.com> ;
es2 at audifans.com <mailto:es2%40audifans.com> 
	Sent: Mon, 08 Aug 2005 10:15:46 -0400
	Subject: [s-cars] RS Tuning tube header cracks at second track
	Hey guys, just got back from a 3 day event at Waterford Hills.
The car
	ran good
	most of the time but I did have a few issues. The first one was
that the
	subframe bolts would not stay tight and when I went to re-torque
them I
	torqued one and it broke off up in the frame. Luckily there was
	there that had an engine blow and was being trailored home so I
was able
	to get
	a bolt from him to continue the event. I got a bolt extractor
	drilled and
	extracted the bolt only having to miss one  rungroup. I put a
bunch of
	tight one them and they seemed to hold. The other problem I was
	was after
	about 15 minutes on the track the car would dial boost back from
	24-26psi down
	to 10-12psi. I never figured out why it was doing this but all I
	think is
	the EGT's were just getting to hot. My oil and coolant temps
were fine
	although I don't have an intake air temp sensor the tube coming
out of
	the cold
	side of the intercooler stayed fairly cool. On the last
	  day I felt like I had a boost leak and could hear a hissing
sound so I
	of to check and noticed a nice size crack in the tube header on
the tube
	goes to the WG. This car has only been to two track events so
I'm not
	excited about the build quality of these headers. Hope the
	running them
	do some major looking over and maybe some more structural welds
like HAP
	I'll be having mine welded for now but am going to have a better
	made soon.
	Any feedback on the boost backoff is greatly appreciated.
	S-CAR-List mailing list
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