REMOVE CAT or High flow CAT?
Thread Starter
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Member
Joined: May 2009
Posts: 83
From: Oversea
REMOVE CAT or High flow CAT?
if i want to concentrate on 0-30 mph Low end power,
should i totally remove the CAT for better accuration or
change to High flow CAT?
Some ppl said this or that is better.
L15A with turbo 0.5bar only
Auto gear.
should i totally remove the CAT for better accuration or
change to High flow CAT?
Some ppl said this or that is better.
L15A with turbo 0.5bar only
Auto gear.
Member
Joined: Sep 2008
Posts: 622
From: Québec city
Backpressure will kill HP/Torque!! What you need is the BIGGEST pipe that will let the exhaust FLOW enough at HIGH RPM's without being a RESTRICTION, yet, being SMALL enough so that it still have GOOD exhaust gases VELOCITY!! 60mm will be too much for a 1.5l Fit that revs at 7K RPM!
-Too BIG = Flow at High RPM's but low Exhaust gases Velocity at low RPM's = Less scavenging effect = Loss of Low End Torque!
-Too Small = High exhaust velocity at Low RPM's = Good Low End Torque but Little flow at Upper Revs = Loss of Top End power!!
Personately, 50mm pipe with 1 or 2 good quality perforated core Resonators (Maybe 3 if you delete the Cat!), a good straight thru Muffler and a Header with a Merged collector! Forget about the Louvered cores resonators and mufflers that adds turbulence and restriction to the exhaust stream...
Marko!
-Too BIG = Flow at High RPM's but low Exhaust gases Velocity at low RPM's = Less scavenging effect = Loss of Low End Torque!
-Too Small = High exhaust velocity at Low RPM's = Good Low End Torque but Little flow at Upper Revs = Loss of Top End power!!
Personately, 50mm pipe with 1 or 2 good quality perforated core Resonators (Maybe 3 if you delete the Cat!), a good straight thru Muffler and a Header with a Merged collector! Forget about the Louvered cores resonators and mufflers that adds turbulence and restriction to the exhaust stream...
Marko!
Last edited by DOHCtor; Aug 29, 2009 at 03:35 AM.
Thread Starter
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Member
Joined: May 2009
Posts: 83
From: Oversea
Thank you.
I think i have to put back my CAT. I felt no power during 800 RPM to 2500 RPM. at high speed, I feel nothing change.
Normally i don't race and mostly travel to work only.
So , conclusion, remove CAT is not the way for city drive.
it will slow u down ALOT ALOT ALOT.......
I think i have to put back my CAT. I felt no power during 800 RPM to 2500 RPM. at high speed, I feel nothing change.
Normally i don't race and mostly travel to work only.
So , conclusion, remove CAT is not the way for city drive.
it will slow u down ALOT ALOT ALOT.......
Thread Starter
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Member
Joined: May 2009
Posts: 83
From: Oversea
Problem again.
After installed back stock CAT, i improve back my Low torque and lost alot of my torque and higher RPM.
1) should I change to high flow Cat? what will happen? lost abit torque at low RPM and gain abit at high? ( half half gain)
2) install Control value before CAT, when higher RPM, the control v/v will auto open
3) install Control value after CAT, so that still have abit of back pressure.
After installed back stock CAT, i improve back my Low torque and lost alot of my torque and higher RPM.
1) should I change to high flow Cat? what will happen? lost abit torque at low RPM and gain abit at high? ( half half gain)
2) install Control value before CAT, when higher RPM, the control v/v will auto open
3) install Control value after CAT, so that still have abit of back pressure.
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