which high flow cat is best
#1
08-26-2007, 06:11 PM
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which high flow cat is best
hey guys just want to know which hi flow cats work best with the ram1500, im getting a flowmaster super 44 muffler with duals put on in a week or so just thought i might take the opertunity to put a new cat on,and oh yeah what do ya think, side sweep or straight out the back on the pipes.thanxs for the input!
#2
08-26-2007, 06:16 PM
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08-26-2007, 09:30 PM
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08-27-2007, 12:19 AM
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#5
08-27-2007, 08:02 AM
RE: which high flow cat is best
It is hard to find reliable flow data on catalytic converters
but this month's (Sept 2007) Hot Rod magazine
has an article by Marlan Davis
where he dyno tests some Dynatech catalytic converters
as part of a build up on a GM 6.0 V8 truck engine
from that did very well.
In a prior article form Sept of year 2000
Hot Rod magazine has an article about the Houston Texas
branch of the School of Automotive Machinists (SAM) student project of mods to a drag racing '99 Camaro with a LS1 engine.
Inside the article is a small table where S.A.M. students flow tested some
catalytic converters looking for a less restrictive one. It is rare to see an
independent test of cats, especially at the standard flow bench pressure of
1.5 Mercury (20.4 inches of water).
Most times the cat manufacturers like to list the cfm @ 24 or 28 inches of
water. This gives a higher number and sounds better for 'hype' advertising.
The highest flowing cat listed was out of a '98 Chevy Tahoe Vortec 350 V8 with 459 cfm at 1.5 inches of Hg pressure.
The lowest flowing was out of a Dodge Viper 273 cfm @ 1.5"Hg
{but doesn't a Viper has two of these catalytic converters ?}.
The '99 Camaro factory cat was 304 cfm at 1.5"Hg.
In between were aftermarket cats from Car Sounds, Random Technologies, MAC and
Dynomax. Part numbers are listed along with cfm's but none were all that good. I didn't have pen or paper to write the numbers down. Maybe someone who gets Hot Rod magazine can post them?
What does the factory catalytic converter on a Dodge Ram flow ?
I don't know, I haven't read of a flow test.
But on the Dakota list there have been dyno reports that the factory cat
causes a restriction of 1 psi at max horsepower. This was equal to a 6 Hp
loss.
Bolstering these dyno tests, the Dodge Ram Field Service Manual chapter on
diagnostics says that a good, unclogged factory Ram truck cat should have less than 2 psi backpressure at full throttle.
but this month's (Sept 2007) Hot Rod magazine
has an article by Marlan Davis
where he dyno tests some Dynatech catalytic converters
as part of a build up on a GM 6.0 V8 truck engine
from that did very well.
In a prior article form Sept of year 2000
Hot Rod magazine has an article about the Houston Texas
branch of the School of Automotive Machinists (SAM) student project of mods to a drag racing '99 Camaro with a LS1 engine.
Inside the article is a small table where S.A.M. students flow tested some
catalytic converters looking for a less restrictive one. It is rare to see an
independent test of cats, especially at the standard flow bench pressure of
1.5 Mercury (20.4 inches of water).
Most times the cat manufacturers like to list the cfm @ 24 or 28 inches of
water. This gives a higher number and sounds better for 'hype' advertising.
The highest flowing cat listed was out of a '98 Chevy Tahoe Vortec 350 V8 with 459 cfm at 1.5 inches of Hg pressure.
The lowest flowing was out of a Dodge Viper 273 cfm @ 1.5"Hg
{but doesn't a Viper has two of these catalytic converters ?}.
The '99 Camaro factory cat was 304 cfm at 1.5"Hg.
In between were aftermarket cats from Car Sounds, Random Technologies, MAC and
Dynomax. Part numbers are listed along with cfm's but none were all that good. I didn't have pen or paper to write the numbers down. Maybe someone who gets Hot Rod magazine can post them?
What does the factory catalytic converter on a Dodge Ram flow ?
I don't know, I haven't read of a flow test.
But on the Dakota list there have been dyno reports that the factory cat
causes a restriction of 1 psi at max horsepower. This was equal to a 6 Hp
loss.
Bolstering these dyno tests, the Dodge Ram Field Service Manual chapter on
diagnostics says that a good, unclogged factory Ram truck cat should have less than 2 psi backpressure at full throttle.
#6
08-28-2007, 01:35 PM
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