Having a lower CR in a boosted motor....

My stock block GSR was 10:1. I am OBD2 and need to have my computer scanned every other year. There is NO way around CT emissions testing now. So that you get an idea as to how stiff the program is now they scan the eyeball of the qualified tech that is doing the test....

My question is will I be able to pass emissions, with NO CEL, with a lower CR.... say 9.0:1. I would be converting everything back to stock including injectors, header, exhaust, ECU ect....

My best guess says that I would fail because of the stock ECU and timing issues. Generally with 1 CR point there can be a 5-7deg timing difference.

Please give me some insight on this.

 

I want to use CP pistons as well. I don't want to use anything else!

Do you think I would pass with a CP 9.8:1?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tepid1 &raquo;</TD></TR><TR><TD CLASS="quote">

My best guess says that I would fail because of the stock ECU and timing issues. Generally with 1 CR point there can be a 5-7deg timing difference.

Please give me some insight on this.

</TD></TR></TABLE>

Where are you getting the 5-7* number? I'd say it's more like 1-2*. You should be able to pass. Are you OBDII or OBDI? Check out my thread on how to pass emissions and if you are close adjusting the timing at the dizzy could knock you to the good range.

 

I got that from this thread http://forums.evans-tuning.com...=1612....

Unless I am not understanding it correctly....