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  • SN95 4.6L Mustang Tech

Compression and emissions

  • Thread starter Thread starter johnnyvista
  • Start date Start date Feb 11, 2004
J

johnnyvista

New Member
Jan 15, 2004
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Feb 11, 2004
#1
  • Feb 11, 2004
  • #1
How much will raising the compression in my engine affect CA emissions? If I run an 11:1 compression ratio with a stage 1 cam, will i be able to pass a sniffer?
 

Beau

Founding Member
Jan 29, 2000
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San Diego
Feb 11, 2004
#2
  • Feb 11, 2004
  • #2
isn't 11:1 pretty high compression?

i think with stage 1 cams you'll be fine. i am planning on doing VT Engines stage 1 cams this summer and i think i'll pass emissions without any problem.
 
J

johnnyvista

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Jan 15, 2004
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Feb 11, 2004
#3
  • Feb 11, 2004
  • #3
on the stroker kit i'm going with, i have the option of running 9.5:1, which is basically stock, or 11:1. i'll get a lot more HP out of the higher compression but i want to make sure my car'll pass next year first.
 

mrvax

Stay thirsty my friends
Founding Member
Nov 29, 1999
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SN Moderator: Orlando, Fl.
Feb 11, 2004
#4
  • Feb 11, 2004
  • #4
The increased compression should help emissions if anything. Cams that have a lot of duration would tend to hurt, and lift wouldn't bother emissions at all.
 

KJ Hoppus

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Mar 18, 2003
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Elk Grove CA
Feb 11, 2004
#5
  • Feb 11, 2004
  • #5
i would agree with mrvax...subscribing
 

trinity_gt

10 Year Member
Jan 31, 2003
3,125
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Canada
Feb 11, 2004
#6
  • Feb 11, 2004
  • #6
Increased compression may lead to higher NOx emissions levels due to higher peak combustion temps. Check the overlap on the cams...too much may increase HC emissions. If your idle is lumpy due to the cams it's possible the overlap might cause an HC fail. Alot depends on the tune and the condition and temp of the cats during the test.
 
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