I recently removed my 99 civic SI CAT and made a test pipe for my electron blue hatch...for some reason the vtec doesn't sound as loud...? or the "switch" is queiter now... Is it because of the change in speed of the exhaust movement..? flowing faster= quiter note... JUST a question

 

when using a test pipe, your exhaust will be notably louder...

 

exhaust louder may mean you are not hearing you intake when vtec crosses over

 

Who cares. Maybe now you actually have a more linear power band.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by dpw41285 &raquo;</TD></TR><TR><TD CLASS="quote">exhaust louder may mean you are not hearing you intake when vtec crosses over</TD></TR></TABLE>

This is what I'm thinking...

Installing a test pipe really shouldn't affect your VTEC at all. You probably just can't hear the VTEC engage as well.

I can still hear my VTEC and I have a test pipe.

 

on my friends' cars, the vtec switchover is alot more prominent with the testpipe than without it. sounds like a sudden "snap" when vtec hits

 

who cares, noise does not = power.

ask any turbo guy

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by accurate &raquo;</TD></TR><TR><TD CLASS="quote">on my friends' cars, the vtec switchover is alot more prominent with the testpipe than without it. sounds like a sudden "snap" when vtec hits</TD></TR></TABLE>

yeah maybe something in the vtec system is acting up but it seems that the crossover was the louder and i heard the sudden snap. The car does "seem" to have a wider power band now as opposed to the functioning cat(99 civic SI)...I know that things like the oil press can affect the vtec function since it's pressure activated or pressure "applied"....so lets see if we can work out this bug and still make the power!

I need a dyno

 

Ok well i found my problem... I retarded the intake cam 1 degrees to compensate for the milling of the head and the decked block...I also advanced the exhaust cam gear 1 degrees to hopefully give it some overlap but i obiviously have no idea what i am doing so i but it back 1 or 2 degrees on the intake cam and 0 on the exhaust gear....I guess since the swithc over wasn't equal the resonance had changed...and it seemed to lack power but make it later in the process....either way I set it back and it seems stronger.... I NEED A DYNO before I blow **** up

Any one have a base line setup I can run...or just a common knowledge of cam timing to machined heads? i.e retard both gears 1-3 degrees for a stock NA motor with a milled head? etc.. Thanks