I run the same setup and passed KY emissions (when we used to have it).
EM Long Tube Headers
Thread Starter
Intermediate
Joined: May 2007
Posts: 35
Likes: 0
EM Long Tube Headers
Hi, I'm looking at fitting EM LT's on my '94 LT1 and wanted to hear from anyone else who's got them how they get on with emmissions?
As I've heard that with the LT's this deletes the cat's and makes passing emmision tests a problem?
Is this true?
Thanks
Mark
As I've heard that with the LT's this deletes the cat's and makes passing emmision tests a problem?
Is this true?
Thanks
Mark
Drifting
Joined: May 2005
Posts: 1,370
Likes: 1
From: Raleigh NC
I have Exotic Muscle long tubes with Random Technology 3 inch cats that slip fit over the collector and clamped with a band clamp. Then 3 inch exhaust with a x pipe welded to the cats. The only challege I've had is a slight ticking exhaust leak at the cats where the band clamps are. I've learned to live with it and it's become a lot less noticeable with the hotcam installed since the valvetrain is noisier.
Le Mans Master
Joined: Jun 2002
Posts: 6,097
Likes: 2
From: Cincinnati Oh
Race Director
Joined: Jan 2002
Posts: 12,263
Likes: 86
From: O'Fallon Missouri
I picked up my PowerCats from Summitt Racing or Jegs.
Here is a comparable set of cats for an even a better deal than the Dynatechs. If you are going to use the slip-fit method you'll need the 3" version.
http://flowmonster.com/mm5/merchant...._Code=metallic
Here is a comparable set of cats for an even a better deal than the Dynatechs. If you are going to use the slip-fit method you'll need the 3" version.
http://flowmonster.com/mm5/merchant...._Code=metallic
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Le Mans Master
Joined: Aug 2004
Posts: 5,141
Likes: 7
From: Metairie Louisiana
Le Mans Master
Joined: Jan 2002
Posts: 9,036
Likes: 13
From: Edmonton AB
to whatever rubber material is used.
Also keep in mind that heat causes significant growth in the exhaust
system, not just in dia but in length, too. My vote is that anything
that inhibits the freedom of the exhaust to expand when it is hot is
likely to impart stress that may lead to premature cracks.
As for spacing the X-brace. Instead of using flat washers, consider
fabricating shims from sheet or plate stock that closely approximate
the shape of the contact surface of the OEM mounting points. This
increases the clamping area and helps the bolts continue to work in
tension rather than in shear.
.
Le Mans Master
Joined: Aug 2004
Posts: 5,141
Likes: 7
From: Metairie Louisiana
This is not recommended due to the heat that would be radiated
to whatever rubber material is used.
Also keep in mind that heat causes significant growth in the exhaust
system, not just in dia but in length, too. My vote is that anything
that inhibits the freedom of the exhaust to expand when it is hot is
likely to impart stress that may lead to premature cracks.
As for spacing the X-brace. Instead of using flat washers, consider
fabricating shims from sheet or plate stock that closely approximate
the shape of the contact surface of the OEM mounting points. This
increases the clamping area and helps the bolts continue to work in
tension rather than in shear.
.
to whatever rubber material is used.
Also keep in mind that heat causes significant growth in the exhaust
system, not just in dia but in length, too. My vote is that anything
that inhibits the freedom of the exhaust to expand when it is hot is
likely to impart stress that may lead to premature cracks.
As for spacing the X-brace. Instead of using flat washers, consider
fabricating shims from sheet or plate stock that closely approximate
the shape of the contact surface of the OEM mounting points. This
increases the clamping area and helps the bolts continue to work in
tension rather than in shear.
.
Thanks
Le Mans Master
Joined: Jan 2002
Posts: 9,036
Likes: 13
From: Edmonton AB
Under some conditions, the temperature of the exhaust under
the passenger compartment can become hot enough to scorch and
even ignite the tunnel/floor.
My vote is that conventional rubber-like materials are going
to suffer by or beyond temperatures of 300ºF. If there was
some air space between the heat source and the rubber object,
this would help but direct contact would result in short life.
Some silicones have better heat resistance. The popular silicon
oven mitt claims to protect to 500ºF.
However, best results would be realized with the heat-resistant
material sold by companies like Thermo-Tec and DEI. Fiberfax
makes ceramic fiber insulation that is widely used for kilns,
chimneys and various industrial applications.
FWIW, 2-1/2" collectors work well with an R-D brace on an
'89 coupe.
The x-brace is fabricated from steel strip that is formed into
a shape intended to provide a balance of lightness and
longtitudinal stiffness. Take a long narrow strip of cardboard
and check how it flexes, then form it into a shape similar to
the legs of the x-brace. The formed version will be stiffer.
As for hijacking - you are commenting about EM headers on
an LT1, maybe the OP has a convertible, too?
Edit to change spelling to Thermo-Tec from ThermoTech
.
the passenger compartment can become hot enough to scorch and
even ignite the tunnel/floor.
My vote is that conventional rubber-like materials are going
to suffer by or beyond temperatures of 300ºF. If there was
some air space between the heat source and the rubber object,
this would help but direct contact would result in short life.
Some silicones have better heat resistance. The popular silicon
oven mitt claims to protect to 500ºF.
However, best results would be realized with the heat-resistant
material sold by companies like Thermo-Tec and DEI. Fiberfax
makes ceramic fiber insulation that is widely used for kilns,
chimneys and various industrial applications.
FWIW, 2-1/2" collectors work well with an R-D brace on an
'89 coupe.
Originally Posted by rickreeves1
The factory x-brace has a weird grooved shape to it.
a shape intended to provide a balance of lightness and
longtitudinal stiffness. Take a long narrow strip of cardboard
and check how it flexes, then form it into a shape similar to
the legs of the x-brace. The formed version will be stiffer.
As for hijacking - you are commenting about EM headers on
an LT1, maybe the OP has a convertible, too?
Edit to change spelling to Thermo-Tec from ThermoTech
.
Last edited by Slalom4me; Jan 3, 2008 at 08:09 PM.
Melting Slicks
Joined: Nov 2002
Posts: 2,471
Likes: 2
From: 1993 Quasar Blue 'vert Scottsdale AZ
Rick, I have the same problem as you do. I talked to Trevor down at EM, and he said that he justs sticks a prybar between the x-brace and the exhaust and resets it. I'm a little leary because it sounds like a very temporary fix.
