My first question is, does compression effect your emissions? I am pretty sure it does but im just asking to set a base for my next question

If i changed my pistons to run around 11.5:1 (CA shitty gas) and i came time to do smog check could i put 2 or even 3 oem head gaskets on to lower my compression enough to pass smog? this may seem like a bad idea to most but for the simple intent of going down the street and back would it cause a problem? and better yet would it work?

 

it would be easier for you to add cats as opposed to change head gaskets.

 

hey guys more people please chime in

 

Yes, as mentioned in previous posts, people with CTR pistons and such will have a harder time passing smog because of increased emissions.

 

That is the way to go.

 

get your ecu tuned...make sure your cat is working and you should pass regardless of compression ratio.

tuning for power is totally different than tuning for emissions though.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by TypeRPaul &raquo;</TD></TR><TR><TD CLASS="quote">My first question is, does compression effect your emissions? </TD></TR></TABLE>

Higher compression = higher NOX during loaded mode testing.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by visi0n &raquo;</TD></TR><TR><TD CLASS="quote">get your ecu tuned...make sure your cat is working and you should pass regardless of compression ratio.
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Compression does affect NOx emissions. I find that anything over 12.5:1 CR will be very hard to pass and require major tweaking to the ign, cam timing and fuel maps. A functional (and preferably piping hot during E-test) catalyic converter is a must.