honger

hey guess i sorta have my mods in right now but not planning to tune it till spring time..anyways here goes.. i have a cai/header/exhaust setup and i would wanna run vafc to tune it. heres the catch..i have a 2.5" collector header with a test pipe (note: i have a b16a2 engine so 2.5" wouldnt fit unless i have a test pipe) BUT i have a 3" apexi bpipe and axle back. i know its only .5 of a mm difference but will this .5 of a mm hurt me while im tuning? im really worried that the .5mm will let "too much air out" causing me to lose power....just wondering what u ppl have to say..thanks.

dantastic

a 3" b-pipe is already too large for that mild of a setup. you can buy a 2.5" cat instead of running a 2.5" test pipe for your JDM style header. btw 0.5" = 12mm.

i bet you'll gain ALOT of low end torque by going with a 2.25" mandrel bent cat-back or any off the shelf bolt on exhaust. i had a 2.5" custom cat back with no resonators. then i went to a brospeed 2.25" catback and driveability was 10x better going to the smaller exhaust. i had a b16a with i/h/e also.

rodrez.

What car? What Apex exhaust kit is this? I don't remember them offering a 3inch cat back.

honger

btw its not jdm header.. its a mugen 4-2-1 header...
i have a canadian version 00 si (so sir here in canada) wtih apexi n1... the n1 3" piping was only offered for turbos..reg n1 comes in 2.5 i believe

rodrez.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by honger &raquo;</TD></TR><TR><TD CLASS="quote"> wtih apexi n1... the n1 3" piping was only offered for turbos..reg n1 comes in 2.5 i believe</TD></TR></TABLE>

I see. I've only seen 60mm piping (outer diameter, not inner) cat backs for Honda's offered by Apexi. I didn't even know they offered a turbo set up.

Exhaust velocity does have a bearing on how much power/torque you'll make. Personally, I prefer a 2.5in exhaust front to back for a 1.8 or larger Vtec motor. For a B16, with basic bolt ons, I think 3inch is overkill. You'd be better off with a 2.25-2.5. If you want to keep that header, 2.5 would be ideal.

Hatchamaback

3in isnt overkill unless your boosted. But true true N/a exhaust velocity isnt compromised by your 2.5 exhaust. It would be best to hit up 2.5 all the way through.

rodrez.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by conFusedEG &raquo;</TD></TR><TR><TD CLASS="quote">3in isnt overkill unless your boosted. But true true N/a exhaust velocity isnt compromised by your 2.5 exhaust. It would be best to hit up 2.5 all the way through.</TD></TR></TABLE>

Really? You think that 3in is overkill on a boosted application? When I used to race a turbo SOHC CRX, the jump from 2.5 to a full 3in exhaust set up actually helped out quite a bit. The car made more power in the midrange, and of course the top end.

honger

well my friend said put donuts or some **** in it or iono ..but yea lets hope this **** works *cross figure*